Construction machinery control system

Abstract

To provide a control system capable of avoiding a situation where a construction machine unexpectedly moves even when an opening / closing body opening and closing an opening of a cabin is opened.SOLUTION: A first signal transmission antenna 11 provided inside a cabin 5 of a hydraulic shovel 10 transmits a first signal X1. A portable key 50 transmits a second signal X2 when receiving the first signal X1. An electric power switch 9 is provided inside the cabin 5. A main controller 20 puts an engine 35 in a start operable state when determining that the portable key 50 is compatible with the hydraulic shovel 10 based on the second signal X2. A key detection range changing portion 21 controls the first signal transmission antenna 11 so as to transmit the first signal X1 in a first key detection range R1 when a getting-on / off door 7 is in a closed state, and so as to transmit the first signal X1 in a second key detection range R2 that is narrower than the first key detection range R1 when the getting-on / off door 7 is in an opened state.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a control system for a construction machine that determines whether a drive source of the construction machine is in an operable state by transmitting and receiving signals with a portable key that can be carried by an operator.

Background Art

[0002] Conventionally, when it is determined that a portable key for an operator that can transmit and receive signals to and from a construction machine corresponds to the construction machine, there is a known technique of making the drive source of the construction machine operable by a power switch provided inside the cabin. For example, in the control system for a construction machine disclosed in Patent Document 1, a transmission antenna capable of transmitting a first signal is disposed inside the cabin, and when a portable key carried by an operator of the construction machine receives the first signal transmitted from the transmission antenna, the portable key transmits a second signal that is an authentication signal. When the controller of the construction machine receives the second signal transmitted from the portable key, it determines whether the portable key carried by the operator corresponds to the construction machine based on the second signal. When it is determined that the portable key corresponds to the construction machine, the drive source of the construction machine is made operable by a power switch provided inside the cabin.

[0003] In the case of the control system as described above, in order for an operator located inside the cabin to start the drive source of the construction machine, it is necessary for the portable key located inside the cabin and the controller to transmit and receive the first and second signals. Therefore, the transmission range of the first signal by the transmission antenna is generally set to cover the entire area inside the cabin.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in the case of a control system such as Patent Document 1, when the boarding door provided in the cabin for opening and closing the boarding and alighting opening is opened, the inside and the outside of the cabin communicate with each other through the boarding and alighting opening. Therefore, the first signal transmitted from the transmission antenna leaks out of the boarding and alighting opening to the outside of the cabin. Then, even when the portable key is located outside the cabin, transmission and reception of the first and second signals are established between the portable key and the controller of the construction machine. That is, the reception antenna provided inside the cabin receives the authentication signal transmitted by the portable key located outside the cabin, and the drive source of the construction machine can be brought into an operable state by the power switch provided inside the cabin. For example, if the power switch is operated by another operator who does not have a portable key, the drive source may start and the construction machine may move unexpectedly, which may pose a safety problem. The same can be said when opening and closing an opening / closing body such as a window provided in the cabin other than the boarding door.

[0006] The present invention has been made in view of such a point, and an object thereof is to provide a control system capable of avoiding a situation in which a construction machine moves unexpectedly even when an opening / closing body that opens and closes an opening of a cabin is in an open state.

Means for Solving the Problems

[0007] In order to achieve the above object, the present invention is characterized in that a range for detecting a portable key on the cabin side is changed according to the open / closed state of an opening / closing body of the cabin.

[0008] Specifically, targeting a control system for a construction machine including a portable key configured to be portable by an occupant and transmitting an authentication signal, and control means for making the drive source of the construction machine operable by a power switch provided inside the cabin when it is determined that the portable key corresponds to the construction machine based on the authentication signal received within a predetermined key detection range, the following solution means is taken.

[0009] That is, in the first invention, the cabin has an opening / closing body that opens and closes an opening communicating with the inside thereof, and opening / closing detection means capable of detecting the opening / closing state of the opening / closing body. The control means is connected to the opening / closing detection means, and when the opening / closing detection means detects that the opening / closing body is in the closed state, it sets a first key detection range including the inside of the cabin, while when the opening / closing detection means detects that the opening / closing body is in the open state, it is characterized by including a key detection range changing unit that sets a second key detection range narrower than the first key detection range including the inside of the cabin.

[0010] In the second invention, in the first invention, signal transmission means capable of transmitting a first signal is disposed inside the cabin of the construction machine, the portable key is configured to transmit a second signal, which is the authentication signal, when receiving the first signal, and the key detection range changing unit, when the opening / closing detection means detects that the opening / closing body is in the closed state, transmits the first signal within the first key detection range, while when the opening / closing detection means detects that the opening / closing body is in the open state, controls the signal transmission means to transmit the first signal within the second key detection range.

[0011] In the third invention, in the second invention, the signal transmission means includes a first antenna unit capable of transmitting the first signal, and a second antenna unit disposed at a position separated from the opening / closing body more than the first antenna unit and capable of transmitting the first signal. The key detection range changing unit, when the opening / closing detection means detects that the opening / closing body is in the closed state, causes the first signal to be transmitted from both the first antenna unit and the second antenna unit to set the first key detection range, while when the opening / closing detection means detects that the opening / closing body is in the open state, causes only the second antenna unit to transmit the first signal to set the second key detection range.

[0012] In the fourth invention, in the second invention, the key detection range changing unit is characterized by switching between the first key detection range and the second key detection range by changing the output intensity of the first signal.

[0013] In the fifth invention, in the fourth invention, the opening / closing detection means is configured to be able to detect the degree of opening of the opening / closing body, and when the degree of opening of the opening / closing body detected by the opening / closing detection means is large, the key detection range changing unit changes the second key detection range to be narrower than when it is not so.

[0014] In the sixth invention, in any one of the second to fifth inventions, the boundary line of the second key detection range is set to be located inside the cabin.

[0015] In the seventh invention, in any one of the second to sixth inventions, when the drive source is started in a state where the transmission of the first signal is within the second key detection range, the key detection range changing unit changes the transmission of the first signal from the second key detection range to the first key detection range.

Advantages of the Invention

[0016] In the first invention, when the opening / closing body is in the closed state, a key detection range is set inside the cabin, so that the authentication operation can be surely performed between the portable key located inside the cabin and the control means of the construction machine. On the other hand, when the opening / closing body is in the open state, since the key detection range is narrower than when the opening / closing body is in the closed state, if the portable key is located outside the cabin, it becomes difficult for the authentication signal to be transmitted and received between the portable key and the control means of the construction machine. For example, it is possible to prevent another operator without a portable key from entering the inside of the cabin and operating the power switch to start the drive source of the construction machine.

[0017] In the second invention, when the opening / closing body is in the closed state, the entire cabin surrounds the signal transmitting means, making it difficult for the first signal to be transmitted outside the cabin and making it difficult for transmission and reception of the first and second signals to be established between the portable key located outside the cabin and the control means of the construction machine. On the other hand, when the opening / closing body is in the open state, the transmission range of the first signal becomes narrower than when the opening / closing body is in the closed state, and it becomes difficult for the first signal to leak out from the opening of the cabin to the outside of the cabin. Therefore, even if the portable key is located outside the cabin, it becomes difficult for transmission and reception of the first and second signals to be established between the portable key and the control means of the construction machine. Thus, when the portable key is located outside the cabin, regardless of the open / closed state of the boarding door, it becomes difficult for transmission and reception of the first and second signals to be established between the portable key and the control means of the construction machine. Therefore, for example, it is possible to prevent another operator without the portable key from entering the cabin and operating the power switch to start the drive source of the construction machine.

[0018] In the third invention, when the opening / closing body is in the closed state, the first signal is transmitted from both the first antenna portion and the second antenna portion, so that the first signal spreads over the entire area inside the cabin, and the portable key located inside the cabin can surely transmit and receive the first and second signals with the control means of the construction machine. Also, when the opening / closing body is in the open state, since the first signal is no longer transmitted from the first antenna portion disposed near the opening / closing body, it is possible to surely prevent the first signal from leaking out from the opening of the cabin.

[0019] In the fourth invention, since the transmission range of the first signal can be changed to a desired range, the key detection range of the first signal can be adjusted to an arbitrary range so that the first signal does not leak out of the cabin when the opening / closing body is in the open state.

[0020] In the fifth invention, when the opening / closing body is in the open state and the degree of opening of the opening / closing body is relatively small, the range in which the first signal is transmitted does not become so narrow. Therefore, even when the portable key is located relatively far from the signal transmission means inside the cabin, the first signal can be received. Thus, it is possible to avoid a situation where the drive source of the construction machine cannot be started even though the portable key is inside the cabin. Also, when the opening / closing body is in the open state and the degree of opening of the opening / closing body is relatively large and there is a high possibility that the first signal leaks out from the opening, the transmission range of the first signal becomes narrower. Therefore, it is possible to surely prevent the first signal from leaking out from the opening of the cabin.

[0021] In the sixth invention, when the opening / closing body is in the open state, the first signal does not reach the opening of the cabin. Therefore, it is possible to surely avoid the first signal from leaking outside the cabin through the opening when the opening / closing body is in the open state.

[0022] In the seventh invention, when the drive source of the construction machine is started in a state where the first signal is being transmitted within the second key detection range, the transmission range of the first signal is returned to the first key detection range. Thus, for example, when starting the drive source, the portable key was placed within the second key detection range, but after once stopping the drive source and then operating the power switch to try to restart the drive source with the position of the portable key moved from the original position to a position outside the second key detection range, a situation where the portable key cannot receive the first signal and the drive source of the construction machine cannot be started can be avoided.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiments is merely illustrative in nature.

[0025] FIG. 1 shows a hydraulic excavator 10 (construction machine) equipped with a control system 1 according to an embodiment of the present invention. The hydraulic excavator 10 is mainly for excavation work, and includes a crawler-type lower traveling body 2 and an upper revolving body 3 attached above the lower traveling body 2 via a slewing mechanism. The upper revolving body 3 is rotatable around a slewing axis extending in the vertical direction. Note that the crawler 2a of the lower traveling body 2 is driven by the hydraulic pressure of a hydraulic pump driven by an engine 35 (see FIG. 3).

[0026] On one side in the width direction of the upper revolving body 3, an excavation attachment 4 is provided. The excavation attachment 4 includes a boom 4a, an arm 4b, and a bucket 4c in order from the proximal end side, and is driven by the hydraulic pressure of a hydraulic pump driven by an engine 35 (see FIG. 3).

[0027] On the other side in the width direction of the upper revolving body 3, a box-shaped cabin 5 for protecting the operator (crew) of the hydraulic excavator 10 is provided, and the cabin 5 includes a cabin body 6 forming the skeleton of the cabin 5.

[0028] On approximately the front half of the other side surface of the cabin body 6 in the width direction, as shown in FIG. 2, an entrance / exit 6a (opening) in the shape of a rectangular frame is provided.

[0029] An entrance / exit door 7 in the shape of a rectangular plate extending in the vertical direction is attached to the entrance / exit 6a so as to be openable and closable.

[0030] At approximately the center inside the cabin 5, a driver's seat 8 on which the operator of the hydraulic excavator 10 can sit is provided, and the operator sitting on the driver's seat 8 can operate the hydraulic excavator 10 using respective levers and the like.

[0031] On one side in the width direction of the driver's seat 8 inside the cabin 5, a power switch 9 that can be pushed down by the operator sitting on the driver's seat 8 is arranged, and by pushing down the power switch 9, the start and stop of the engine 35 are switched.

[0032] A main controller 20 is arranged behind the driver's seat 8 inside the cabin 5, while a first signal transmission antenna 11 and a second signal reception antenna 12 connected to the main controller 20 are arranged at the lower front part in front of the driver's seat 8 inside the cabin 5.

[0033] Next, the control system 1 according to the embodiment of the present invention will be described with reference to FIG. 3.

[0034] The control system 1 is composed of a first signal transmission antenna 11, a second signal reception antenna 12, a door open / close sensor 13, a power switch sensor 14, a main controller 20, an engine controller 30, an engine 35 (starter motor 31, fuel injection valve 32), and a portable key 50 that can be taken out from the hydraulic excavator 10, and the first signal X1 and the second signal X2 are transmitted and received between the main controller 20 and the portable key 50.

[0035] Here, the first signal X1 is an LF (Low Frequency) signal in the band of about 125 kHz, and is configured to request the transmission of the second signal X2 to the portable key 50. Also, the second signal X2 (authentication signal) is an RF (Radio Frequency) signal in the band of about 312 MHz, and includes an authentication ID code set for each portable key 50.

[0036] The first signal transmission antenna 11 is configured to be communicable with the main controller 20, and is adapted to transmit the first signal X1 based on a command from the main controller 20.

[0037] The second signal reception antenna 12 is configured to be communicable with the main controller 20, and when the second signal X2 is received, is adapted to transmit the second signal X2 to the main controller 20.

[0038] The door opening / closing sensor 13 is capable of detecting the degree of opening / closing (open / closed state) of the boarding door 7 attached to the cabin 5, and is configured to transmit the detected value to the main controller 20.

[0039] The power switch sensor 14 is capable of detecting the operating state of the power switch 9, and is configured to transmit the detected value to the main controller 20.

[0040] The main controller 20 includes a key detection range changing unit 21, an authentication unit 22, and a startup control unit 23, and is adapted to execute the processing in each unit by a processor (not shown).

[0041] The key detection range changing unit 21 is adapted to change the output intensity of the first signal X1 transmitted from the first signal transmission antenna 11, whereby the transmission range (key detection range) of the first signal X1 is changed.

[0042] The authentication unit 22 compares the authentication ID code included in the second signal X2 received from the portable key 50 with a preset normal ID code, and determines whether the portable key 50 corresponds to the hydraulic excavator 10.

[0043] When the power switch 9 is pressed while the first signal X1 and the second signal X2 are being transmitted and received between the hydraulic excavator 10 and the portable key 50, the start control unit 23 issues a start command to the engine controller 30.

[0044] The engine controller 30 is configured to be communicable with the main controller 20, and controls the starter motor 31 and the fuel injection valve 32 based on the commands of the main controller 20.

[0045] The starter motor 31 starts the engine 35 based on a drive command from the engine controller 30.

[0046] The fuel injection valve 32 can supply fuel (e.g., light oil) into the cylinders of the engine 35, and injects the fuel injection amount based on the command of the engine controller 30 into the cylinders of the engine 35.

[0047] The portable key 50 includes a first signal receiving antenna 51, a second signal transmitting antenna 52, and a portable key controller 55.

[0048] The first signal receiving antenna 51 is configured to receive the first signal X1 transmitted from the first signal transmitting antenna 11 of the hydraulic excavator 10, and transmit the first signal X1 to the portable key controller 55 when the first signal X1 is received.

[0049] The second signal transmitting antenna 52 transmits the second signal X2 based on the command of the portable key controller 55.

[0050] The portable key controller 55 includes a portable key control unit 56, and the portable key control unit 56 is configured to execute the following-described processes by a processor (not shown).

[0051] Next, each process executed in the control system 1 will be described. Each of these processes is configured to be executed at a predetermined period (for example, every 0.1 seconds).

[0052] First, the process of the key detection range changing unit 21 in the main controller 20 will be described with reference to FIG. 4.

[0053] In step S1, the sensor value of the door opening / closing sensor 13, that is, information regarding the degree of opening / closing of the boarding / alighting door 7, is acquired, and the process proceeds to step S2.

[0054] In step S2, based on the information acquired in step S1, it is determined whether the boarding / alighting door 7 is closed.

[0055] If the determination in step S2 is Yes, that is, if it is determined that the boarding / alighting door 7 is in a closed state, the process proceeds to step S3 where the transmission range of the first signal X1 is set to the first key detection range R1, and then the process proceeds to step S5. The first key detection range R1 in the present embodiment is set to a range such that the first signal X1 covers the entire area inside the cabin 5. For example, the first signal X1 transmitted from the first signal transmission antenna 11 hits the inner surface of the closed boarding / alighting door 7, that is, the surface on the side of the driver's seat 8, and is reflected inside the cabin 5.

[0056] On the other hand, if the determination in step S2 is No, that is, if it is determined that the boarding / alighting door 7 is in an open state, the process proceeds to step S4 where the transmission range of the first signal X1 is set to the second key detection range R2, and then the process proceeds to step S5. The second key detection range R2 in the present embodiment is set to a range narrower than the first key detection range R1, and is set so that even if the boarding / alighting door 7 of the cabin 5 is open, the first signal X1 does not leak out of the cabin 5 from the boarding / alighting opening 6a.

[0057] In step S5, after giving an operation command to the first signal transmission antenna 11 so that the first signal X1 reaches each transmission range set in step S3 or step S4, the process proceeds to END and the process ends. The first signal transmission antenna 11 that has received the operation command transmits the first signal X1 within the set key detection range. In step S4, when the second key detection range R2 is set, the output intensity of the first signal X1 is set to be lower than when the first key detection range R1 is set.

[0058] Next, the process of the portable key control unit 56 in the portable key controller 55 will be described with reference to FIG. 5.

[0059] In step S11, it is determined whether the first signal X1 is received by the first signal reception antenna 51.

[0060] If the determination in step S11 is Yes, that is, if it is determined that the first signal X1 has been received, the process proceeds to step S12, where an operation command is given to the second signal transmission antenna 52 to transmit the second signal X2, and then the process proceeds to END and the process ends. At this time, the second signal transmission antenna 52 that has received the operation command transmits the second signal X2.

[0061] On the other hand, if the determination in step S11 is No, that is, if it is determined that the first signal X1 has not been received, the process proceeds to END and the process ends.

[0062] Next, the process of the authentication unit 22 in the main controller 20 will be described with reference to FIG. 6.

[0063] In step S21, it is determined whether the second signal X2 is received by the second signal reception antenna 12.

[0064] If the determination in step S21 is No, that is, if it is determined that the second signal X2 has not been received, the process proceeds to END and the process ends.

[0065] On the other hand, if the determination in step S21 is Yes, that is, if it is determined that the second signal X2 is received, the process proceeds to step S22. After executing the authentication process of the portable key 50 based on the received second signal X2, the process proceeds to step S23. That is, in step S22, the comparison processing result between the authentication ID code included in the received second signal X2 and the preset regular ID code is output.

[0066] Then, in step S23, based on the comparison processing result in step S22, it is determined whether the portable key 50 is a regular one. That is, when the authentication ID code included in the second signal X2 matches the regular ID code, it is determined that the portable key 50 corresponds to the hydraulic excavator 10. On the other hand, when the authentication ID code included in the second signal X2 does not match the regular ID code, it is determined that the portable key 50 does not correspond to the hydraulic excavator 10. If it is determined that the portable key 50 is not a regular one, the process proceeds to step S25.

[0067] If the determination in step S23 is Yes, that is, if it is determined that the portable key 50 is a regular one, the process proceeds to step S24. After setting the engine 35 to an operable state for starting, the process proceeds to the end and the process ends. Note that the operable state for starting is a state in which the engine 35 can be started by operating the power switch 9 when the engine 35 is in a stopped state.

[0068] On the other hand, if the determination in step S23 is No, that is, if it is determined that the portable key 50 is not regular, the process proceeds to step S25. After setting the engine 35 to a non - operable state for starting, the process proceeds to the end and ends. Note that the non - operable state for starting is a state in which the stopped engine 35 cannot be started even if the power switch 9 is operated.

[0069] Next, the processing of the start control unit 23 in the main controller 20 will be described with reference to FIG. 7. Note that the processing of the start control unit 23 is configured to be executed in the stopped state of the engine 35.

[0070] In step S31, the sensor value of the power switch sensor 14, that is, information regarding the operation state of the power switch 9 (whether it is pressed or not) is acquired, and the process proceeds to step S32.

[0071] In step S32, it is determined whether the power switch 9 has been operated based on the information acquired in step S31. If the determination in step S32 is No, that is, if it is determined that the power switch 9 is not pressed, the process proceeds to End and the process ends.

[0072] On the other hand, if the determination in step S32 is Yes, that is, if it is determined that the power switch 9 has been pressed, the process proceeds to step S33 and it is determined whether the engine 35 has been set to the start - operable state by step S24.

[0073] If the determination in step S33 is Yes, that is, if the engine 35 has been set to the start - operable state, the process proceeds to step S34.

[0074] In step S34, since the determination in step S32 is Yes (it is determined that the power switch 9 is pressed) and the determination in step S33 is Yes (it is determined that the portable key 50 corresponds to the hydraulic excavator 10), after issuing a start command for the engine 35 to the engine controller 30, the process ends. When the engine controller 30 receives the start command, it issues an operation command to the starter motor 31 and the fuel injection valve 32 to start the engine 35. When the engine 35 starts, the hydraulic pump is driven in conjunction with the start of the engine 35, so that each hydraulic actuator for driving the crawler 2a, the attachment 4, etc. in the hydraulic excavator 10 becomes operable by each lever etc. provided inside the cabin 5.

[0075] On the other hand, if the determination in step S33 is No, that is, if the engine 35 has been set to the non - start - operable state, the process proceeds to step S35.

[0076] In step S35, since the determination in step S32 is Yes (determination that the power switch 9 is pressed), and the determination in step S33 is No (determination that the portable key 50 does not correspond to the hydraulic excavator 10), the engine 35 is not started, and the process proceeds to the end to terminate the process.

[0077] Next, with reference to FIG. 8, the operation and effect of the key detection range changing unit 21 of the control system 1 will be described.

[0078] In FIG. 8(a), since the boarding / alighting door 7 is closed, the first signal X1 transmitted from the first signal transmission antenna 11 is reflected by the inner surface of the boarding / alighting door 7 and does not leak outside the cabin 5. Therefore, when the boarding / alighting door 7 is in the closed state, the transmission range of the first signal X1 is the first key detection range R1 that extends over the entire area inside the cabin 5.

[0079] However, as shown in FIG. 8(b), when the boarding / alighting door 7 is opened, the first signal X1 transmitted from the first signal transmission antenna 11 leaks outside the cabin 5 through the boarding / alighting opening 6a. Therefore, even when the portable key 50 is located outside the cabin 5, if the portable key 50 receives the first signal X1, it will transmit the second signal X2, so there is a risk that the engine 35 may be started by another operator or the like who does not have the portable key 50.

[0080] On the other hand, according to the present embodiment, as shown in FIG. 8(c), when the boarding / alighting door 7 is in the opened state, the transmission range of the first signal X1 is changed to the second key detection range R2 that is narrower than the first key detection range R1. That is, the boundary line of the second key detection range R2 is located inside the cabin 5, so it is possible to suppress the first signal X1 from leaking outside the cabin 5 through the boarding / alighting opening 6a.

[0081] Therefore, according to the present embodiment, when the boarding and alighting door 7 is in the closed state, the entire cabin 5 comes to surround the first signal transmission antenna 11, so it becomes difficult for the first signal X1 to be transmitted to the outside of the cabin 5, and it becomes difficult for the transmission and reception of the first signal X1 and the second signal X2 to be established between the portable key 50 located outside the cabin 5 and the main controller 20 of the hydraulic excavator 10. On the other hand, when the boarding and alighting door 7 is in the open state, the transmission range of the first signal X1 becomes narrower than when the boarding and alighting door 7 is in the closed state, and it becomes difficult for the first signal X1 to leak out from the boarding and alighting opening 6a of the cabin 5 to the outside of the cabin 5. Therefore, even if the portable key 50 is located outside the cabin 5, it becomes difficult for the transmission and reception of the first signal X1 and the second signal X2 to be established between the portable key 50 and the main controller 20 of the hydraulic excavator 10. In this way, when the portable key 50 is located outside the cabin 5, regardless of the open / closed state of the boarding and alighting door 7, it becomes difficult for the transmission and reception of the first signal X1 and the second signal X2 to be established between the portable key 50 and the main controller 20 of the hydraulic excavator 10. Therefore, for example, it is possible to prevent another operator without the portable key 50 from entering the inside of the cabin 5 and operating the power switch 9 to start the engine 35 of the hydraulic excavator 10.

[0082] In addition, since the key detection range changing unit 21 changes the output intensity of the first signal X1, the transmission range of the first signal X1 can be changed to a desired range. Therefore, when the boarding and alighting door 7 is in the open state, the key detection range of the first signal X1 can be adjusted to an arbitrary range so that the first signal X1 does not leak out to the outside of the cabin 5.

[0083] In addition, since the boundary line of the second key detection range R2 is set to be located inside the cabin 5, when the boarding and alighting door 7 is in the open state, the first signal X1 does not reach the boarding and alighting opening 6a of the cabin 5. Therefore, it is possible to surely avoid the first signal X1 from leaking out to the outside of the cabin 5 through the boarding and alighting opening 6a when the boarding and alighting door 7 is in the open state.

[0084] In this embodiment, one first signal transmission antenna 11 is disposed inside the cabin 5. However, as shown in FIG. 9(a), as signal transmission means capable of transmitting the first signal X1, a first antenna 25a (first antenna unit) disposed between the entrance / exit door 7 and the driver's seat 8, and a second antenna 25b (second antenna unit) disposed on the side of the driver's seat 8 opposite to the entrance / exit door 7, that is, at a position separated from the entrance / exit door 7 farther than the first antenna 25a may be provided. Then, when the door opening / closing sensor 13 detects that the entrance / exit door 7 is in the closed state, as shown in FIG. 9(a), the key detection range changing unit 21 causes the first signal X1 to be transmitted from both the first antenna 25a and the second antenna 25b to set the first key detection range R1. On the other hand, when the door opening / closing sensor 13 detects that the entrance / exit door 7 is in the open state, as shown in FIG. 9(c), the key detection range changing unit 21 may cause only the second antenna 25b to transmit the first signal X1 to set the second key detection range R2. By doing so, when the entrance / exit door 7 is in the closed state, the first signal X1 is transmitted from both the first antenna 25a and the second antenna 25b, so that the first signal X1 spreads over the entire area inside the cabin 5, and the portable key 50 located inside the cabin 5 can surely transmit and receive the first signal X1 and the second signal X2 with the main controller 20 of the hydraulic excavator 10. Further, when the entrance / exit door 7 is in the open state, since the first signal X1 is not transmitted from the first antenna 25a disposed near the entrance / exit door 7, as shown in FIG. 9(b), it is possible to surely prevent the first signal X1 from leaking out from the entrance / exit opening 6a of the cabin 5.

[0085] In addition, in this embodiment, the key detection range changing unit 21 sets the transmission range of the first signal X1 based on the open / closed state of the boarding door 7. However, when the degree of opening of the boarding door 7 detected by the door open / close sensor 13 is large, the second key detection range R2 may be changed to be narrower than when it is not. By doing so, when the boarding door 7 is in the open state, when the degree of opening of the boarding door 7 is relatively small, the transmission range of the first signal X1 does not become so narrow, so that even when the portable key 50 is located relatively far from the first signal transmission antenna 11 inside the cabin 5, the first signal X1 can be received. Therefore, it is possible to avoid a situation where the engine 35 of the hydraulic excavator 10 cannot be started even though the portable key 50 is inside the cabin 5. Also, when the boarding door 7 is in the open state and the degree of opening of the boarding door 7 is relatively large and there is a high possibility that the first signal X1 leaks out from the boarding opening 6a of the cabin 5 to the outside, the transmission range of the first signal X1 becomes narrower, so that it is possible to surely prevent the first signal X1 from leaking out from the boarding opening 6a of the cabin 5.

[0086] In addition, in this embodiment, the key detection range changing unit 21 sets the transmission range of the first signal X1 based on the open / closed state of the boarding door 7. However, when the engine 35 is started in a state where the first signal X1 is within the second key detection range R2, the transmission of the first signal X1 may be changed from the second key detection range R2 to the first key detection range R1. By doing so, when the engine 35 of the hydraulic excavator 10 is started in a state where the first signal X1 is transmitted within the second key detection range R2, the transmission range of the first signal X1 is returned to the first key detection range R1. Therefore, for example, when starting the engine 35, the portable key 50 was placed within the second key detection range R2, but after once stopping the engine 35, when the power switch 9 is operated to start the engine 35 again with the position of the portable key 50 moved from the original position to a position outside the second key detection range R2, it is possible to avoid a situation where the portable key 50 cannot receive the first signal X1 and the engine 35 of the hydraulic excavator 10 cannot be started.

[0087] Also, in the present embodiment, the key detection range changing unit 21 sets the transmission range of the first signal X1 based on the open / closed state of the boarding door 7. However, when the boarding door 7 is changed from the open state to the closed state, or when the key of the boarding door 7 is changed from the unlocked state to the locked state, the transmission of the first signal X1 may be changed from the second key detection range R2 to the first key detection range R1.

[0088] Also, the control system 1 of the present embodiment changes the transmission range of the first signal X1 when the boarding door 7 opens and closes. However, when a window that is attached to the window frame of the cabin body 6 so as to be openable and closable opens and closes, the transmission range of the first signal X1 may be changed. That is, the window of the cabin 5 includes a film in which a metal layer is laminated, and when the passenger opens and closes the window, the key detection range changing unit 21 may change the transmission range of the first signal X1.

[0089] In addition, in the present embodiment, the key detection range changing unit 21 sets the transmission range of the first signal X1 transmitted by the first signal transmission antenna 11 based on the open / closed state of the entrance / exit door 7. However, the present invention is not limited to this. For example, based on the open / closed state of the entrance / exit door 7, the reception range of the second signal reception antenna 12 may be set. Specifically, when the entrance / exit door 7 is in the closed state, the reception range of the second signal X2 is set to the first reception range (the first key detection range), while when the entrance / exit door 7 is in the open state, the reception range of the second signal X2 may be set to a second reception range (the second key detection range) that is narrower than the first reception range. Then, when the entrance / exit door 7 is in the closed state, since the first reception range (the first key detection range) is set inside the cabin 5, the authentication operation can be surely performed between the portable key 50 located inside the cabin 5 and the main controller 20 of the hydraulic excavator 10. On the other hand, when the entrance / exit door 7 is in the open state, since the range for receiving (detecting) the second signal X2 becomes narrower than when the entrance / exit door 7 is in the closed state, if the portable key 50 is located outside the cabin 5, it becomes difficult for transmission and reception of the first signal X1 and the second signal X2 to be established between the portable key 50 and the main controller 20 of the hydraulic excavator 10. For example, it is possible to prevent another operator who does not have the portable key 50 from entering the cabin 5 and operating the power switch 9 to start the engine 35 of the hydraulic excavator 10.

[0090] In addition, in the present embodiment, the portable key 50 transmits the second signal X2 as an authentication signal when receiving the first signal X1. However, even if the portable key 50 does not receive the first signal X1, it may be configured to transmit the second signal X2.

[0091] In addition, in the present embodiment, an example in which the engine 35 is mounted as a drive source has been described. However, instead of the engine, an electric motor may be a drive source, or a hybrid drive source in which both an electric motor and an engine are mounted may be used.

[0092] In addition, the control system 1 of the present embodiment has been described by taking the example of being applied to the hydraulic excavator 10, but it may be applied to construction machines other than the hydraulic excavator 10.

Industrial Applicability

[0093] The present invention is suitable for a control system of a construction machine that determines whether a drive source of the construction machine is in an operable state by transmitting and receiving signals with a portable key that can be carried by an operator.

Explanation of Signs

[0094] 1 Control system 5 Cabin 6a Entrance / exit (opening) 7 Entrance / exit door (opening / closing body) 9 Power switch 10 Hydraulic excavator (construction machine) 11 First signal transmission antenna (signal transmission means) 13 Door opening / closing sensor (opening / closing detection means) 20 Main controller (control means) 21 Key detection range change unit 25a First antenna (first antenna unit) 25b Second antenna (second antenna unit) 35 Engine (drive source) R1 First key detection range R2 Second key detection range X1 First signal X2 Second signal

Claims

1. A control system for a construction machine, comprising: a portable key configured to be carried by an operator and transmit an authentication signal; and control means for activating the drive source of the construction machine to an operable state by a power switch provided inside the cab when it is determined that the portable key corresponds to the construction machine based on the authentication signal received within a predetermined key detection range. The cab has an opening / closing body for opening and closing an opening communicating therewith inside, and opening / closing detection means capable of detecting the opening / closing state of the opening / closing body. The control means is connected to the opening / closing detection means, and when the opening / closing detection means detects that the opening / closing body is in the closed state, it sets a first key detection range including the inside of the cab, while when the opening / closing detection means detects that the opening / closing body is in the open state, it sets a second key detection range narrower than the first key detection range including the inside of the cab. A control system for a construction machine, characterized by comprising a key detection range changing unit.

2. In the control system for a construction machine according to Claim 1, Signal transmission means capable of transmitting a first signal is disposed inside the cab of the construction machine. The portable key is configured to transmit a second signal, which is the authentication signal, when it receives the first signal. The key detection range changing unit controls the signal transmission means to transmit the first signal within the first key detection range when the opening / closing detection means detects that the opening / closing body is in the closed state, and to transmit the first signal within the second key detection range when the opening / closing detection means detects that the opening / closing body is in the open state. A control system for a construction machine, characterized by this.

3. In the control system for a construction machine according to Claim 2, The signal transmission means includes a first antenna unit capable of transmitting the first signal, and a second antenna unit disposed at a position separated from the opening / closing body more than the first antenna unit and capable of transmitting the first signal. The key detection range changing unit causes both the first antenna unit and the second antenna unit to transmit the first signal to set the first key detection range when the opening / closing detection means detects that the opening / closing body is in the closed state, and causes only the second antenna unit to transmit the first signal to set the second key detection range when the opening / closing detection means detects that the opening / closing body is in the open state. A control system for a construction machine, characterized by this.

4. In the control system for a construction machine according to Claim 2, The control system for a construction machine, wherein the key detection range changing unit switches between the first key detection range and the second key detection range by changing the output intensity of the first signal.

5. In the control system for a construction machine according to claim 4, the opening / closing detection means is configured to be able to detect the degree of opening of the opening / closing body, the key detection range changing unit is characterized in that when the degree of opening of the opening / closing body detected by the opening / closing detection means is large, the second key detection range is changed to be narrower than when it is not. The control system for a construction machine.

6. In the control system for a construction machine according to any one of claims 2 to 5, the boundary line of the second key detection range is set to be located inside the cabin. The control system for a construction machine is characterized by this.

7. In the control system for a construction machine according to any one of claims 2 to 6, the key detection range changing unit is characterized in that when the drive source is started in a state where the transmission of the first signal is within the second key detection range, the transmission of the first signal is changed from the second key detection range to the first key detection range. The control system for a construction machine.

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