Work machine

Abstract

The invention provides a work machine with improved convenience. An air compressor (10) is provided with a tank section (20), a compression section (40), and a control section (100). The tank part (20) stores compressed air. The compression unit (40) delivers compressed air to the tank unit (20). The control unit (100) includes a pressure sensor (108) that detects the pressure inside the tank unit (20). The control unit (100) is capable of executing a compression unit diagnostic control for diagnosing whether or not maintenance of the compression unit (40) is necessary on the basis of the driving time of the compression unit (40) and the pressure of the tank unit (20), and a tank unit diagnostic control for diagnosing whether or not maintenance of the compression unit (40) is necessary. The tank diagnosis control diagnoses whether or not maintenance of the tank (20) is necessary on the basis of the elapsed time from the point in time at which driving of the compression unit (40) is stopped and the amount of pressure reduction of the tank (20).

Description

Technical Field

[0001] This invention relates to a work machine. Background Technology

[0002] The air compressor described in Patent Document 1 includes an air tank for storing compressed air, a compression section for compressing air and supplying it to the air tank, a detection section for detecting current and voltage, and a control section.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2018 / 198672 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] An air compressor, as an example of a work machine, has a compression section for compressing air and a tank section for storing the air compressed by the compression section. If the components constituting the compression section are worn, the pressure in the tank section may be difficult to rise even with continuous operation of the compression section. Therefore, it is necessary to diagnose the wear condition of the components constituting the compression section.

[0008] However, when diagnosing the operating status of an air compressor, the reason why the pressure in the tank is difficult to rise is not limited to wear of the components that make up the compression section, so diagnosing only the compression section is insufficient.

[0009] The purpose of this invention is to provide an operating machine that improves convenience.

[0010] Solution for solving the problem

[0011] One embodiment of the work machine includes: a tank for storing compressed air; a compressor for driving and delivering compressed air to the tank; and a control unit including a pressure detection unit for detecting the pressure inside the tank. The control unit is capable of performing diagnostic control of the compressor and diagnostic control of the tank. The diagnostic control of the compressor is for diagnosing whether maintenance of the compressor is required, and the diagnostic control of the tank is for diagnosing whether maintenance of the tank is required.

[0012] One embodiment of the work machine includes: a tank for storing compressed air; a compressor for driving and supplying compressed air to the tank; and a control unit including a pressure detection unit for detecting the pressure inside the tank. The control unit is capable of performing tank diagnostic control, which involves driving the compressor and stopping the driving of the compressor when the pressure in the tank exceeds a predetermined stop threshold, and diagnosing whether the tank needs maintenance based on the elapsed time since the time the compressor was stopped and the amount of pressure reduction in the tank.

[0013] Invention Effects

[0014] According to the present invention, the convenience of the work machine can be improved. Attached Figure Description

[0015] Figure 1 This is a perspective view showing the appearance of the air compressor according to this embodiment.

[0016] Figure 2 This is a cross-sectional view showing the internal structure of the air compressor in this embodiment.

[0017] Figure 3 This is a front view of the internal structure of the air compressor in this embodiment, viewed from the front.

[0018] Figure 4 This is a longitudinal sectional view of the internal structure of the air compressor of this embodiment, viewed from the rear.

[0019] Figure 5 This is a block diagram showing the connection status of various parts in the air compressor of this embodiment.

[0020] Figure 6 This is an explanatory diagram showing the information displayed on the touch panel of the air compressor in this embodiment.

[0021] Figure 7 This is a graph showing the relationship between elapsed time and tank pressure under tank diagnostic control of the air compressor in this embodiment.

[0022] Figure 8 This is a list of examples of messages related to the pressurization time, air leakage, and cumulative operating time set for the air compressor of this embodiment.

[0023] Figure 9 This is a flowchart illustrating the processes performed before the diagnostics of the air compressor in this embodiment begin.

[0024] Figure 10 This is a flowchart illustrating the various processes involved in diagnosing the compression section of the air compressor in this embodiment.

[0025] Figure 11 This is a flowchart illustrating the various processes involved in diagnosing the compression section of the air compressor in this embodiment.

[0026] Figure 12 This is a flowchart illustrating the various processes involved in the tank diagnostics (air leak diagnostics) of the air compressor in this embodiment.

[0027] Figure 13 This is a graph showing the relationship between elapsed time and tank pressure under tank diagnostic control of the air compressor in this embodiment.

[0028] Figure 14 These are graphs showing the relationship between the elapsed time of the air compressor in this embodiment and the tank pressure, as well as graphs showing the relationship between the elapsed time and the power supply voltage.

[0029] Figure 15 This is a table of standard boost time determined by a combination of average voltage and cumulative operating time in the air compressor of this embodiment.

[0030] Figure 16 This is a graph showing the relationship between elapsed time and tank pressure under air leak diagnosis of the air compressor in this embodiment.

[0031] Figure 17 This is a schematic diagram showing the machine diagnostic system of the air compressor included in this embodiment. Detailed Implementation

[0032] Hereinafter, an embodiment of the work machine of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in all the drawings referred to for the purpose of explaining the embodiment, the same or substantially the same symbols are used for the same structures and elements. In addition, structures and elements that have been described once will generally not be described again.

[0033] [Overview of air compressors]

[0034] exist Figure 1 As an example of a working machine, an air compressor 10 is shown. The air compressor 10 is capable of supplying compressed air to air-operated working machines such as nail hammers. The air compressor 10 has a main frame 12, a tank section 20, a compression section 40, and a control section 100. Figure 5 ).

[0035] <Main Framework>

[0036] The main frame 12 includes a pair of handles 16. An operation panel 14 is provided on the main frame 12. The operation panel 14 includes a touch panel 121 capable of displaying information such as the remaining capacity of the battery pack 52 (described later) and the internal pressure (MPa) of the tank 20. Figure 6 Multiple feet 18 are provided on the lower surface of the main frame 12. The main frame 12 supports the tank section 20, the compression section 40, and the control section 100. Figure 5 The operator can lift the air compressor 10 by grasping a pair of handles 16, which allows the compressor to be moved to any set surface M.

[0037] <Definition of direction>

[0038] The air compressor 10 is upright on the mounting surface M along the vertical direction, which is one example of the vertical direction. Regarding the horizontal direction, which is orthogonal to the vertical direction, the mutually orthogonal directions are defined as the front-back direction and the left-right direction. That is, the vertical direction, the left-right direction, and the front-back direction are all orthogonal. Here, the operation panel 14 is located at the upper part of the center of the front end of the air compressor 10. Furthermore, the definitions of the vertical direction, the front-back direction, and the left-right direction are merely for ease of explanation.

[0039] <jar section>

[0040] like Figure 2 As shown, the tank section 20 includes a first air tank 22, a second air tank 32, a third air tank 34, and a fourth air tank 36. The first air tank 22, the second air tank 32, the third air tank 34, and the fourth air tank 36 respectively store compressed air A. The first air tank 22, the second air tank 32, the third air tank 34, and the fourth air tank 36 are respectively positioned relative to the mounting surface M (… Figure 1 It extends vertically. As a result, the installation area of ​​the air compressor 10 is smaller than the installation area of ​​a structure in which multiple air tanks extend horizontally.

[0041] The first air tank 22 and the second air tank 32 are arranged in a left-right direction. The third air tank 34 and the fourth air tank 36 are arranged in a left-right direction. The first air tank 22 and the third air tank 34 are arranged in a front-back direction. The second air tank 32 and the fourth air tank 36 are arranged in a front-back direction.

[0042] Furthermore, the first air tank 22, the second air tank 32, the third air tank 34, and the fourth air tank 36 have the same structure, except for their arrangement in the air compressor 10. Therefore, in describing the structure of the tank section 20, the first air tank 22 will be described, and the specific descriptions of the second air tank 32, the third air tank 34, and the fourth air tank 36 will be omitted.

[0043] <<The First Air Tank>>

[0044] like Figure 1 As shown, the first air canister 22 is a longitudinally elongated canister extending in the vertical direction. The first air canister 22 includes a cylindrical portion 23, a lower cover portion 27, and an upper cover portion 28.

[0045] The cylindrical section 23 is constructed from a cylindrical steel plate. The cylindrical section 23 has a central axis running vertically. Both ends of the cylindrical section 23 in the vertical direction are closed by a lower cover 27 and an upper cover 28. A waste liquid pipe 25 is connected to the cylindrical section 23 for discharging waste liquid (water) stored inside the first air tank 22. Figure 2 ) and the compression section 40 described later.

[0046] The lower cover 27 and the upper cover 28 are welded to the cylindrical portion 23. That is, the interior of the first air tank 22 is sealed. Therefore, the first air tank 22 can store compressed air A ( Figure 2 ).

[0047] <Compression Section>

[0048] like Figure 2 As shown, the compression unit 40 is surrounded by the tank section 20. The compression unit 40 draws in air at atmospheric pressure, which exists outside the air compressor 10. The compression unit 40 generates compressed air A by compressing the drawn-in air. Then, the compression unit 40 delivers the compressed air A to each air tank in the tank section 20. The compressed air A delivered from the compression unit 40 flows into the first air tank 22, the second air tank 32, the third air tank 34, and the fourth air tank 36. In other words, the tank section 20 stores the compressed air A delivered from the compression unit 40. Furthermore, air is an example of a gas.

[0049] The compression unit 40 can be powered by the battery pack 52 ( Figure 1 The battery pack 52 is a rechargeable secondary battery. Specifically, the battery pack 52 can be powered by a power plug 54 connected to a commercial power source. Figure 1 The device is charged by the power supply of the control panel 14. Figure 1 The compression unit 40 can switch its operating state at will.

[0050] As an example, the compression unit 40 has a structure that compresses air at atmospheric pressure to high pressure in two stages. The compression unit 40 has a first compression unit 42 that compresses air taken in from the outside and a second compression unit 44 that further compresses the air compressed by the first compression unit 42. The first compression unit 42 and the second compression unit 44 are arranged opposite each other in the left-right direction.

[0051] An eccentric shaft 48, which is rotatably disposed between the first compression section 42 and the second compression section 44, is rotated by a motor 46.

[0052] The first compression unit 42 includes a cylindrical cylinder 43A, a cylindrical piston 43B housed in the cylinder 43A, and a piston ring 43C disposed on the outer periphery of the piston 43B. The piston ring 43C slides relative to the inner circumferential surface of the cylinder 43A as the piston 43B reciprocates. In the first compression unit 42, the piston 43B operates within the cylinder 43A as the eccentric shaft 48 rotates, thereby generating compressed air A.

[0053] The second compression unit 44 includes a cylindrical cylinder 45A, a cylindrical piston 45B housed within the cylinder 45A, and piston rings 45C disposed on the outer periphery of the piston 45B. The piston rings 45C slide relative to the inner circumferential surface of the cylinder 45A as the piston 45B reciprocates. In the second compression unit 44, the piston 45B operates within the cylinder 45A as the eccentric shaft 48 rotates, thereby generating compressed air A. Furthermore, the piston rings 43C and 45C are made of rubber. Therefore, they are susceptible to wear due to the movement of the pistons 43B and 45B.

[0054] Compressed air A generated by the first compression unit 42 and the second compression unit 44 flows into the first air tank 22, and then into the second air tank 32, the third air tank 34, and the fourth air tank 36. The first air tank 22, the second air tank 32, the third air tank 34, and the fourth air tank 36 are interconnected. That is, the internal pressure from the first air tank 22 to the fourth air tank 36 is maintained at the same level.

[0055] The eccentric shaft 48 is rotated by the motor 46. The motor 46 is a brushless motor. The motor 46 is positioned on the axis of the eccentric shaft 48 between the first compression section 42 and the second compression section 44. The motor 46 is powered by either the battery pack 52 or the power plug 54. Figure 1 The motor 46 rotates by a power supply from the drive circuit 116. Figure 5 Rotate in the predetermined direction and at the predetermined speed.

[0056] Additionally, the compression unit 40 includes a cooling fan 56 that rotates via a motor 46. The cooling fan 56 is designed to cool the first compression unit 42, the second compression unit 44, and the battery pack 52, which become hotter with prolonged operation. Figure 1 ) and drive circuit 116 ( Figure 5 It has cooling functions such as cooling.

[0057] like Figure 1 As shown, as an example, the air compressor 10 is provided with four connectors 64. These four connectors 64 can be used to connect pneumatic tools such as nail machines that operate powered by compressed air A. A pressure reducing valve 62 is provided on the upper side of each connector 64 of the air compressor 10.

[0058] like Figure 3 As shown, the pressure reducing valve 62 is provided with a dial 63, a first flow path 65, and a second flow path 67. The dial 63 is rotated by the operator. The first flow path 65 is located upstream of the pressure reducing valve 62 in the direction of airflow. The second flow path 67 is located downstream of the pressure reducing valve 62 in the direction of airflow.

[0059] In the pressure reducing valve 62, the operator rotates the dial 63 to adjust (reduce) the pressure of the compressed air A output from the connector 64. This allows the pneumatic tool connected to the connector 64 to operate at the appropriate air pressure, matching its specifications.

[0060] A pair of connecting portions 58 are provided on the lower side of the connector 64 of the air compressor 10. Other air compressors can be connected to the connecting portions 58. For example, when other air compressors 10 are connected to each connecting portion 58, the overall capacity of compressed air A can be increased to three times.

[0061] <Piping>

[0062] like Figure 2 As shown, as an example, the first air tank 22, the second air tank 32, the third air tank 34, and the fourth air tank 36 are interconnected by a metal (aluminum) piping section 72. Specifically, the piping section 72 includes a first pipe 73, a second pipe 74, a third pipe 75, a fourth pipe 76, and a fifth pipe 77. Alternatively, the first pipe 73, the second pipe 74, the third pipe 75, the fourth pipe 76, and the fifth pipe 77 may be made of resin.

[0063] like Figure 4 As shown, the first flow path section 65 and the second air tank 32 are connected by a pipe 82. The second flow path section 67 and the connector 64 are connected by a pipe 83. The first air tank 22 and the connecting part 58 are connected by a pipe 84. Pressure sensors 108, described later, are provided in the first flow path section 65 and the second flow path section 67.

[0064] <Discharge Section>

[0065] like Figure 3 As shown, the air compressor 10 has a discharge section 92. The discharge section 92 discharges waste liquid stored in the tank section 20 to the outside. Specifically, the discharge section 92 has an open valve 94, a discharge pipe 96, and a waste liquid stopcock 98.

[0066] <<Open Valve>>

[0067] An open valve 94 is provided in the tank section 20. A discharge pipe 96 extends from the open valve 94 to the outside of the air compressor 10. A waste liquid stopcock 98 is provided in the open valve 94. As an example, the open valve 94 is provided in the second air tank 32. The open valve 94 has a flow path (not shown). The opening and closing of the flow path of the open valve 94 is controlled by opening and closing the waste liquid stopcock 98.

[0068] When the waste liquid stopcock 98 is opened, the release valve 94 is open, and the compressed air A inside the tank 20 is discharged from the release valve 94 to the outside of the air compressor 10 through the discharge pipe 96. When the waste liquid stopcock 98 is closed, the release valve 94 is closed, and the compressed air A inside the tank 20 remains inside the tank 20. In this way, the release valve 94 can release the compressed air A inside the tank 20.

[0069] <Structure of Control Systems>

[0070] like Figure 5 As shown, in addition to the structure already described, the air compressor 10 also includes a control unit 100, a power control unit 112, an operation circuit 114, a drive circuit 116, a rotation detection circuit 118, a notification unit 120, an AC power supply unit 126, and a DC power supply unit 128.

[0071] AC power section 126 is for connecting power plug 54 ( Figure 1 The external power supply unit 128 includes a battery pack 52. Figure 1 The power control unit 112 controls the power supply to supply power to each part of the air compressor 10 from at least one of the AC power supply unit 126 and the DC power supply unit 128.

[0072] The operation circuit 114 is located on the operation panel 14 ( Figure 1 When operated by an operator, an operation signal is output to the control unit 100. By operating the control panel 14, the operator switches the operating mode related to the power supply of the air compressor 10. The operating modes include a first operating mode using the AC power supply unit 126, a second operating mode using the DC power supply unit 128, and a third operating mode that switches between the AC power supply unit 126 and the DC power supply unit 128.

[0073] The drive circuit 116 is controlled by the control unit 100, thereby controlling the power supply to the motor 46. That is, the drive circuit 116 drives and stops the motor 46. The rotation detection circuit 118 detects the rotational speed of the motor 46 based on the number of rotational position detections counted per unit time. The detection result of the rotation detection circuit 118 is output to the control unit 100 as a detection signal.

[0074] <Control Department>

[0075] Figure 5The control unit 100 shown functions as a computer. The control unit 100 includes a CPU (Central Processing Unit) 102, a storage unit 104, a memory 106, a pressure sensor 108, and a timer 109. The control unit 100 can control the operation of various parts of the air compressor 10. The storage unit 104 or the memory 106 stores various data, including the program executed by the CPU 102. A portion of the storage unit 104 can be used to execute the program. The program is used to cause the CPU 102 to execute the steps described later. The pressure sensor 108 detects pressure in the tank 20 (… Figure 2 An example of a pressure detection unit within the pressure sensor.

[0076] <<Pressure Sensor>>

[0077] like Figure 4 As shown, the pressure sensor 108 includes a first pressure sensor 108A disposed in the first flow path section 65 and a second pressure sensor 108B disposed in the second flow path section 67. The first pressure sensor 108A detects the pressure of the compressed air A before the pressure reducing valve 62 reduces the pressure, i.e., the pressure of the tank section 20. The second pressure sensor 108B detects the pressure of the compressed air A after the pressure reducing valve 62 reduces the pressure.

[0078] The pressure information detected by the first pressure sensor 108A and the pressure information detected by the second pressure sensor 108B are stored in the storage unit 104. Figure 5 In this embodiment, during the diagnosis of the operating state of the tank 20, the pressure information (pressure value) of the first pressure sensor 108A is used as the pressure information of the pressure sensor 108.

[0079] <Notification Department>

[0080] like Figure 6 As shown, the notification unit 120 is configured to receive data from the control unit 100 (described later). Figure 5 The notification unit 120 sends a signal and notifies the diagnostic results. As an example, the notification unit 120 is located on the operation panel 14. Figure 1 The touch panel 121 is configured as follows. As an example, the touch panel 121 has a button display section 122, a mode display section 123 and a status display section 124.

[0081] The button display section 122 displays a start button for initiating the compressor unit diagnosis and tank unit diagnosis, which will be described later. Furthermore, during the preparation phase before the diagnosis begins, the start button is displayed in reverse, making it impossible to operate. The mode display section 123 displays messages indicating self-diagnosis mode, the operating mode of the air compressor 10, etc. The status display section 124 displays messages such as the results of each diagnosis, errors, and the status during diagnosis.

[0082] <Controls of the air compressor>

[0083] Figure 5 The control unit 100 shown can perform start judgment control, compression section diagnostic control, and tank section diagnostic control. The start judgment control determines whether diagnostics can begin, and the compression section diagnostic control is used to diagnose piston rings 43C and 45C. Figure 2 The aforementioned tank diagnostic control is used to diagnose whether there is wear or not, and to detect any air leaks. Furthermore, the control unit 100 is capable of performing normal drive control.

[0084] <<Start Control Assessment>>

[0085] like Figure 7 As shown, in the control unit 100 ( Figure 5 In the process, a starting threshold Ps (MPa) is set for the pressure of the tank section 20. Then, before executing the compression section diagnostic control described later, the control unit 100 performs a judgment on whether the compression section 40 can be driven. Figure 5 The control unit 100 determines whether the compression unit 40 can be started if the pressure in the tank 20 is below the start threshold Ps. In other words, the control unit 100 determines that the various diagnostic controls can be started.

[0086] On the other hand, if the pressure in tank 20 is higher than the start threshold Ps, the control unit 100 determines that the drive of the compression unit 40 cannot be started. In other words, the control unit 100 determines that diagnostic control cannot be started. Furthermore, if the pressure in tank 20 is higher than the start threshold Ps, the operator will turn the waste liquid stopcock 98 (… Figure 1 The canister 20 is opened, thereby reducing the pressure in the canister 20. Therefore, diagnosis can begin as long as the pressure in the canister 20 is below the initial threshold Ps.

[0087] <<Compression Section Diagnosis and Control>>

[0088] The compression unit diagnostic control is a control unit 100 that diagnoses whether the compression unit 40 needs maintenance based on the drive time (s) of the compression unit 40 and the pressure (MPa) of the tank 20.

[0089] After the control unit 100 starts judging and controls, if it determines that it can start the diagnosis, it will start the operation circuit 114 ( Figure 5 Upon receiving an instruction from the pressure unit for diagnosis, the compression unit 40 is driven. Then, the control unit 100 diagnoses whether the compression unit 40 needs maintenance based on whether the pressure of the tank 20 has reached a predetermined pressure within a predetermined elapsed time ΔT (s).

[0090] Specifically, if the pressure in tank 20 reaches a predetermined pressure within a predetermined elapsed time ΔT (s), the control unit 100 diagnoses that maintenance of the compression unit 40 is not required. If the pressure in tank 20 does not reach the predetermined pressure within a predetermined elapsed time ΔT (s), the control unit 100 diagnoses that maintenance of the compression unit 40 is required. Furthermore, in this embodiment, the control unit 100 notifies the notification unit 120 (… Figure 5 The results of the pressure department diagnostic control are notified, but regardless of the results of the pressure department diagnostic control, the tank department diagnostic control is then executed.

[0091] <<Tank Diagnosis and Control>>

[0092] The tank section diagnostic control is a control unit 100 that diagnoses whether the tank section 20 needs maintenance based on the elapsed time (s) since the start of the operation of the compressor 40 and the amount of pressure drop (MPa) in the tank section 20.

[0093] Figure 7 The graph GA represents the relationship between elapsed time and pressure in tank 20 during tank diagnostic control. Tank diagnostic control is executed after the start judgment control and compression section diagnostic control.

[0094] The control unit 100 drives the compression unit 40 in the tank section diagnostic control. The control unit 100 in the tank section 20 ( Figure 5 If the pressure of the compressor 40 exceeds a predetermined stop threshold Pt (MPa) within a predetermined elapsed time ΔT (s), the compressor 40 is stopped. Then, the control unit 100 diagnoses whether the tank 20 needs maintenance (air leak) based on the elapsed time ΔT1 since the compressor 40 was stopped and the pressure drop ΔP of the tank 20.

[0095] <<Typical Drive Control>>

[0096] In addition, the control unit 100 performs normal drive control of the air compressor 10. Normal drive control means that the control unit 100 controls the drive of the compressor 40 to keep the pressure of the tank 20 within the normal pressure range NP, with the restart threshold Pr (MPa) as the lower limit and the stop threshold Pt as the upper limit. The restart threshold Pr is the lower limit value of the pressure of the tank 20 when the compressor 40 needs to be restarted. The stop threshold Pt is the upper limit value of the pressure of the tank 20 when the operation of the compressor 40 needs to be stopped. That is, in normal drive control, the control unit 100 starts the drive of the compressor 40 when the pressure of the tank 20 is lower than the restart threshold Pr, and stops the drive of the compressor 40 when the pressure of the tank 20 exceeds the restart threshold Pr. Here, the aforementioned start threshold Ps is smaller than the restart threshold Pr. However, even if the pressure of the tank section 20 is lower than the restart threshold Pr and the control unit 100 starts driving the compression unit 40, the pressure of the tank section 20 is still lower than the restart threshold Pr when the pneumatic tool consumes more compressed air A than the compression unit 40 generates more compressed air A.

[0097] <Notification of Diagnosis Results>

[0098] Figure 5 Based on the aforementioned compressor section diagnostic control and tank section diagnostic control, the control unit 100 shown sends a signal indicating either a diagnostic result showing that the compressor section 40 is in a maintenance-required state or a diagnostic result showing that the tank section 20 is in a maintenance-required state. As an example, the destination of this signal is the notification unit 120.

[0099] In the compression section diagnostic control, when the driving time of the compression section 40 until the pressure of the tank section 20 reaches the diagnostic pressure threshold is longer than the driving time threshold, and the pressure reduction of the tank section 20 at the time of the elapsed time under the tank section diagnostic control is greater than or equal to the reduction amount threshold, the control section 100 causes the notification section 120 to notify the tank section 20 that it is in a maintenance-required state.

[0100] Furthermore, in the compression unit diagnostic control, if the driving time of the compression unit 40 until the pressure of the tank 20 reaches the diagnostic pressure threshold is longer than the driving time threshold, and the pressure drop of the tank 20 when the elapsed time is the elapsed time threshold is smaller than the drop amount threshold, the control unit 100 causes the notification unit 120 to notify the compression unit 40 that it is in a maintenance-required state.

[0101] <<Example of notification of diagnostic results>>

[0102] exist Figure 8 As an example of a diagnostic result notification, a list of multiple messages displayed on the notification unit 120 is shown. This list, as an example, is stored in the memory 106.

[0103] in addition, Figure 8 The parameters shown are those that appear in the diagnostic process described later. The measured pressurization time is set as T, the preset standard pressurization time is set as Ts, and the pressurization reference time when waste liquid accumulates in tank 20 is set as Td. Furthermore, the cumulative operating time of air compressor 10 is set as Ta. "Air leakage" refers to the presence or absence of air leakage within the compression section 40. As an example, t1, t2, and t3 refer to the time points (boundary values) at which the cumulative operating time Ta is divided into four time domains.

[0104] For example, when the pressurization time T is longer than the standard pressurization time Ts and the tank diagnostic control diagnoses "no air leakage", piston rings 43C and 45C ( Figure 2 The possibility of wear is high. Therefore, a message recommending the replacement of piston rings 43C and 45C is displayed on the notification unit 120. On the other hand, if an air leak is diagnosed, a message recommending an air leak inspection of piping, etc., is displayed on the notification unit 120.

[0105] When the pressurization time T is shorter than the standard pressurization time Ts, and the tank diagnostic control indicates "no air leak," there are no abnormalities in the wear of piston rings 43C and 45C or in terms of air leaks. However, if the cumulative operating time Ta is longer, a message recommending an inspection is displayed on the notification unit 120. On the other hand, if an "air leak" is diagnosed, although there is no problem with the wear of piston rings 43C and 45C, a message recommending an air leak inspection of piping, etc., is displayed on the notification unit 120.

[0106] When the pressurization time T is shorter than the pressurization reference time Td, and the tank diagnostic control indicates "no air leak," there are no abnormalities in the wear and air leak of piston rings 43C and 45C. However, a message recommending waste liquid confirmation (waste liquid discharge) is displayed on notification unit 120. On the other hand, if an air leak is diagnosed, an air leak check of piping, etc., is recommended, and a message recommending waste liquid confirmation is displayed on notification unit 120. Other conditions and display content are as follows: Figure 8 As shown.

[0107] [The function of this implementation method]

[0108] Next, the function of the air compressor 10 will be explained. Additionally, for the symbols used in the various components of the air compressor 10, please refer to... Figures 1 to 6 Some drawing numbers are omitted.

[0109] <Diagnosis and Treatment>

[0110] Figure 9 , Figure 10 , Figure 11 as well as Figure 12Each of the processes shown is performed in the following manner: In the control unit 100, the CPU 102 reads the diagnostic processing program from the storage unit 104 or the memory 106, expands it in the storage unit 104 and executes it.

[0111] In step S10, the control unit 100 determines whether the motor 46 is stopped. If the motor 46 is stopped (S10: Yes), proceed to step S12. If the motor 46 is running (S10: No), proceed to step S14.

[0112] In step S12, the control unit 100 determines whether the internal pressure of the tank 20 is below 0.05 MPa based on the pressure information detected by the pressure sensor 108. If the internal pressure of the tank 20 is below 0.05 MPa, the process proceeds to step S16. If the internal pressure of the tank 20 is above 0.05 MPa, the process proceeds to step S18.

[0113] In step S14, the control unit 100 requests the motor 46 to stop. Then, it proceeds to step S30.

[0114] In step S16, the control unit 100 uses a temperature sensor to determine whether the temperature of the motor 46, etc., is below 70 (°C). If the temperature is below 70 (°C) (S16: Yes), proceed to step S20. If the temperature is above 70 (°C) (S16: No), proceed to step S22.

[0115] In step S18, the control unit 100 displays on the touch panel 121 that the tank 20 is in a high-pressure state and requests the use of the waste liquid valve 98 to vent the gas. Then, it proceeds to step S30.

[0116] In step S20, the control unit 100 determines whether the power supply voltage is 85 (V) or below based on information from the power supply control unit 112. If the power supply voltage is 85 (V) or below (S20: Yes), proceed to step S24. If the power supply voltage is above 85 (V) (S20: No), proceed to step S26.

[0117] In step S22, the control unit 100 displays on the touch panel 121 that the temperature of the motor 46, etc., is in a high-temperature state and requests standby time for natural air cooling. Then, it proceeds to step S30.

[0118] In step S24, the control unit 100 can operate the start button (diagnostic start button) of the touch panel 121. Specifically, the reversed display of "diagnostic start" is set to a colored display, allowing operation of the diagnostic start button. Then, proceed to step S28.

[0119] In step S26, the control unit 100 causes the touch panel 121 to display a low voltage state and requests confirmation of the battery pack 52's installation status and the power plug 54's connection status. Then, it proceeds to step S30.

[0120] In step S28, the control unit 100 determines whether the diagnostic start button has been operated. If the diagnostic start button has been operated (S28: Yes), proceed to step S32. If the diagnostic start button has not been operated (S28: No), proceed to step S10.

[0121] In step S30, the control unit 100 keeps the diagnostic start button on the touch panel 121 in a reversed display state, making it inoperable. Then, it proceeds to step S10.

[0122] In step S32, the control unit 100 starts the motor 46. Then, it proceeds to step S34.

[0123] In step S34, the control unit 100 prepares for the timer 109 to start counting the boost. Furthermore, the boost time (count value) of the timer 109 is set to Te. That is, in step S34, Te is set to 0. Then, the process proceeds to step S36.

[0124] In step S36, the control unit 100 obtains the tank pressure P (MPa) of the tank section 20 based on the output of the pressure sensor 108. Then, it proceeds to step S38.

[0125] In step S38, the control unit 100 starts the counting (Te) of the timer 109. Then, it moves to step S40.

[0126] In step S40, the control unit 100 causes the touch panel 121 to illuminate the diagnostic start button. For example, the start button is illuminated in green. Then, the process proceeds to step S42.

[0127] In step S42, the control unit 100 causes the touch panel 121 to display a diagnostic message. The control unit 100 also causes the touch panel 121 to display a message to prevent air from being expelled. Then, the process proceeds to step S44.

[0128] In step S44, the control unit 100 determines whether the internal pressure of the tank 20 is 2 (MPa) or higher based on the output of the pressure sensor 108. If the pressure is 2 (MPa) or higher (S44: Yes), proceed to step S46. If the pressure is lower than 2 (MPa) (S44: No), proceed to step S48.

[0129] In step S46, the control unit 100 determines whether the internal pressure of the tank 20 is 4.4 MPa or higher based on the output of the pressure sensor 108. If the pressure is 4.4 MPa or higher (S46: Yes), proceed to step S50. If the pressure is lower than 4.4 MPa (S46: No), proceed to step S52.

[0130] In step S48, the control unit 100 determines whether the count (Te) of the timer 109 is shorter than the first boost reference time T1 (s) up to 2.0 (MPa). If the count is greater than or equal to the first boost reference time T1 (S48: No), proceed to step S58. If the count is shorter than the first boost reference time T1 (S48: Yes), proceed to step S42.

[0131] In step S50, the control unit 100 stops the rotation of the motor 46. Then, the process moves to step S54.

[0132] In step S52, the control unit 100 determines whether the count (Te) of the timer 109 is shorter than the second boost reference time T2 (s) up to 4.4 (MPa). If the count is shorter than the second boost reference time T2 (S52: Yes), proceed to step S46. If the count is greater than or equal to the second boost reference time T2 (S52: No), proceed to step S58.

[0133] In step S54, the control unit 100 displays "Diagnosing" on the start button of the touch panel 121. For example, the start button is illuminated in blue. Then, the process proceeds to step S56.

[0134] In step S56, the control unit 100 stops the timer 109. Then, the process proceeds to step S60.

[0135] In step S58, the control unit 100 causes the touch panel 121 to display "Entering air leak diagnosis". At this time, a message is displayed indicating that the pressure rise time is slower than the reference time. Furthermore, tank diagnostic control is performed during the air leak diagnosis. Then, the process proceeds to step S82.

[0136] In step S60, the control unit 100 acquires the boost time T from step S58 as data. Then, it proceeds to step S62.

[0137] In step S62, the control unit 100 obtains the cumulative operating time Ta (s) of the air compressor 10. Then, it proceeds to step S64.

[0138] In step S64, the control unit 100 obtains the average voltage Va (V) of the air compressor 10 during operation. Then, it proceeds to step S66.

[0139] In step S66, the control unit 100 obtains the standard boost time Ts(s) from the storage unit 104. The standard boost time Ts is a preset time corresponding to the length of the cumulative operating time Ta. Then, the process proceeds to step S68.

[0140] In step S68, the control unit 100 determines whether the boost time T obtained in step S60 is shorter than the standard boost time Ts obtained in step S66. If the boost time T is shorter than the standard boost time Ts (S68: Yes), proceed to step S70. If the boost time T is greater than or equal to the standard boost time Ts (S68: No), proceed to step S78.

[0141] In step S70, the control unit 100 obtains the pressure rise reference time Td (s) when waste liquid accumulates in the tank 20 from the storage unit 104. Further, the control unit 100 determines whether the pressure rise time T is shorter than the pressure rise reference time Td. If the pressure rise time T is shorter than the pressure rise reference time Td (S70: Yes), proceed to step S72. If the pressure rise time T is greater than or equal to the pressure rise reference time Td (S70: No), proceed to step S76.

[0142] In step S72, the control unit 100 displays a message urging confirmation on the touch panel 121 to check whether waste liquid has accumulated in the tank 20. At this time, a message indicating premature pressurization and OK / NG buttons are also displayed. Then, the process proceeds to step S74.

[0143] In step S74, the control unit 100 determines whether waste liquid has accumulated in the tank 20 based on the operator's button operation. Specifically, if the OK button is operated (S74: Yes), the control unit 100 determines that no waste liquid has accumulated and proceeds to step S80. On the other hand, if the NG button is operated (S74: No), it proceeds to step S72. In addition, when moving from step S74 to step S72, a message instructing the waste liquid to be discharged can be displayed.

[0144] In step S76, the control unit 100 causes the touch panel 121 to display a message indicating that the boost is OK. Then, the process proceeds to step S80.

[0145] In step S78, the control unit 100 causes the touch panel 121 to display a message indicating boost NG. Then, the process proceeds to step S80.

[0146] In step S80, the control unit 100 causes the touch panel 121 to display "Entering air leak diagnosis". At this time, a message is displayed indicating that the pressure rise time is shorter than the reference time. Then, the process proceeds to step S82.

[0147] In step S82, the control unit 100 prepares for the start of the counting of the timer 109. Furthermore, the time of the timer 109 in the air leak diagnosis is set to Tc (s). That is, in step S82, Tc is set to 0. Then, the process proceeds to step S84.

[0148] In step S84, the control unit 100 starts the timer 109 to count Tc. Then, it moves to step S86.

[0149] In step S86, the control unit 100 displays the start button on the touch panel 121 as "Diagnosing". For example, the start button is illuminated in purple. Then, the process proceeds to step S88.

[0150] In step S88, the control unit 100 causes the touch panel 121 to display a message "Air leak confirmed". Then, it proceeds to step S90.

[0151] In step S90, the control unit 100 determines whether Tc has elapsed for more than 120 seconds. If Tc has elapsed for more than 120 seconds (S90: Yes), the process moves to step S92. If Tc is less than 120 seconds (S90: No), step S90 is repeated.

[0152] In step S92, the control unit 100 obtains the pressure P1 (Tc corresponds to 120) inside the tank 20 via the pressure sensor 108. Then, it proceeds to step S94.

[0153] In step S94, the control unit 100 obtains the pressure PX inside the tank 20 via the pressure sensor 108. Then, it proceeds to step S96.

[0154] In step S96, the control unit 100 determines whether the pressure (P1-PX) is lower than the reference pressure Pa (MPa) for air leakage detection. If the pressure (P1-PX) is lower than the reference pressure Pa (S96: Yes), the process proceeds to step S98. If the pressure (P1-PX) is higher than the reference pressure Pa (S96: No), the process proceeds to step S102.

[0155] In step S98, the control unit 100 determines whether the time Tc for obtaining the pressure PX is 420 (s) or more. If the time Tc is shorter than 420 (s) (S98: Yes), the process moves to step S100. If the time Tc is 420 (s) or more (S98: No), the process moves to step S96.

[0156] In step S100, the control unit 100 causes the touch panel 121 to display the diagnostic result "No air leak". Then, the program ends.

[0157] In step S102, the control unit 100 causes the touch panel 121 to display the diagnostic result "Air leak". Then, the program ends.

[0158] <Diagnostic Case>

[0159] Figure 13 The diagram shows graphs G1, G2, G3, and G4 illustrating the relationship between elapsed time and pressure in tank 20. Furthermore, the first pressurization reference time T1 corresponds to the upper limit time used to determine whether there are any abnormalities when pressurizing to 2 MPa. The second pressurization reference time T2 refers to the upper limit time used to determine whether there are any abnormalities when pressurizing to 4.4 MPa. Td is the pressurization reference time when waste liquid accumulates in tank 20. Ts is the standard pressurization time.

[0160] In the case of curve G1, the first pressure rise reference time T1 elapsed before the pressure in tank 20 reached 2 MPa, therefore motor 46 stopped. In this case, since the pressure rise was low relative to the elapsed time (slow pressure rise), if the pressure rise were to continue as before, an extra elapsed time would be required. Therefore, the diagnosis for compression unit 40 is NG.

[0161] In the case of curve G2, although the pressure in tank 20 reached 2 MPa within the first pressure boosting reference time T1, the second pressure boosting reference time T2 passed before the pressure in tank 20 reached 4.4 MPa, so the motor 46 stopped. In this case, the pressure rise was low relative to the elapsed time (slow pressure boost), so the diagnosis of the compression unit 40 was NG.

[0162] In the case of curve G3, the pressure in tank 20 reached 2 MPa within the first pressurization reference time T1, and the pressure in tank 20 reached 4.4 MPa within the second pressurization reference time T2 (within the standard pressurization time Ts). Therefore, the diagnosis of compression unit 40 is OK.

[0163] In the case of curve G4, the pressure in tank 20 reaches 4.4 MPa before the first pressurization reference time Td, which is earlier than the first pressurization reference time T1. This state indicates that the pressure in tank 20 is rising too quickly, and there is a possibility that the volume of tank 20 has decreased. In other words, there is a possibility that the rapid pressure rise is due to a large amount of waste liquid accumulating in tank 20. Therefore, it is also possible that the touch panel 121 ( Figure 5 This indicates a warning that waste liquid has accumulated inside the tank 20.

[0164] Figure 14 The graph G5 shows the pressure in tank 20 reaching 4.4 MPa at time T4, and the graph G6 shows the change in power supply voltage up to time T4.

[0165] As shown in graph G6, when the power supply voltage drops during the operation of air compressor 10 (i.e., within time T3 (< T4), the time required for pressurization of tank 20 is longer compared to the case where the power supply voltage does not drop. Here, the power supply voltage per unit time is defined as the average voltage Va. Furthermore, a table is pre-set with standard pressurization times Ts corresponding to multiple average voltages Va. Then, the standard pressurization time Ts is determined by combining it with the measured average voltage Va. Figure 13 Even when the power supply voltage drops, it can still perform various diagnostics appropriately.

[0166] Figure 15 The diagram shows nine standard boost times Ts (Ts1 to Ts9) when the average voltage Va (V) is divided into three stages and the cumulative operating time Ta (s) of the air compressor 10 is divided into three stages. Thus, it is preferable to change the standard boost time Ts according to the cumulative operating time Ta of the air compressor 10 and the average voltage Va during operation.

[0167] As an example, when the cumulative operating time Ta is greater than or equal to Ta1 and less than Ta2, and the average voltage Va is greater than or equal to Va1 and less than Va2, the standard boost time Ts is set to Ts5. If the elapsed time required for boosting is faster than Ts5, the diagnosis is "no abnormality". If the elapsed time is greater than or equal to Ts5, the diagnosis is "abnormality" and "inspection required".

[0168] Figure 16 The graphs G7 and G8 show the relationship between time (count value Tc) and pressure in tank 20 in the case of diagnosing an air leak. Furthermore, regarding time Tc, any time between 120s and 420s is defined as TX(s). The reference time for diagnosing air leaks is 420s. The pressure in tank 20 at the start of diagnosis (Tc is 0) is set to 4.4MPa, and the pressure in tank 20 at Tc is set to P1.

[0169] In curve G7, the pressure of tank 20 when Tc is TX is set as PX1. In curve G8, the pressure of tank 20 when Tc is 420s is set as PX2. Pressures PX1 and PX2 are examples of pressure PX. Pressure range AP refers to the range of pressures that serve as the reference for air leak diagnosis corresponding to time TX.

[0170] Immediately after motor 46 stops, the air temperature inside tank 20 is high. As the air temperature decreases, the pressure inside tank 20 also decreases. Therefore, the pressure P1 (MPa) inside tank 20 120 seconds after motor 46 stops is obtained for air leak diagnosis. Furthermore, as an example, the pressure range AP is set from pressure PX1 to pressure P1.

[0171] In the case of curve G7, the pressure of tank 20 falls below pressure range AP within the reference time of 420s, therefore the control unit 100 diagnoses "air leak". In the case of curve G8, the pressure of tank 20 is within pressure range AP within the reference time of 420s, therefore the control unit 100 diagnoses "no air leak".

[0172] <Summary of Functions>

[0173] As explained above, in the compressor unit diagnosis of the air compressor 10, the need for maintenance of the compressor unit 40 is determined based on the operating time of the compressor unit 40 and the pressure of the tank 20. If the pressure of the tank 20 does not rise to the predetermined pressure even after prolonged operation of the compressor unit 40, maintenance of the compressor unit 40 is diagnosed as necessary. However, if the pressure of the tank 20 does not rise to the predetermined pressure even after prolonged operation of the compressor unit 40, the cause may not necessarily be the compressor unit 40. For example, if there is an air leak in the tank 20, it may be difficult to raise the pressure of the tank 20 to the predetermined pressure even after prolonged operation of the compressor unit 40.

[0174] Here, in the tank section diagnostic control of the air compressor 10, based on the elapsed time since the start of the compressor unit 40 and the amount of pressure drop in the tank section 20, it is determined whether the tank section 20 needs maintenance. That is, it is determined whether there is an air leak in the tank section 20. Thus, if the pressure does not rise to the predetermined pressure during the compressor unit diagnostic, it can be known that the main cause lies in the tank section 20, rather than the compressor unit 40.

[0175] In this way, tank diagnostic control is also performed in conjunction with the compressor unit diagnostic control, so that not only the presence or absence of malfunctions in the air compressor 10 can be detected, but the cause of the malfunction can also be distinguished (the location of the malfunction can be specified), thereby improving the convenience of the air compressor 10.

[0176] In the air compressor 10, before performing compression section diagnostic control, it is determined whether the compressor 40 can be driven. Furthermore, the compressor 40 can only be driven if the pressure in the tank 20 is below the start threshold Ps. This ensures that the initial pressure of the tank 20 at the start of compression section diagnostic control is always below the start threshold Ps, thus enabling appropriate compression section diagnostics. Additionally, by ensuring that the initial pressure at the start of compression section diagnostics is consistent, conditions such as temperature at the end of compression section diagnostics are also consistent, thus enabling appropriate tank section diagnostic control as well.

[0177] In the air compressor 10, the starting threshold Ps of the tank 20 pressure is set to a value smaller than the restart threshold Pr within the normal pressure range NP, thereby avoiding unnecessary increase of the tank 20 pressure at the start of diagnostics. This prevents unnecessary operation of the compressor 40.

[0178] In the air compressor 10, by opening the open valve 94, the compressed air A remaining inside the tank 20 can be released, so that the starting threshold of the pressure of the tank 20 can be set to a value close to 0 (zero) for diagnosis.

[0179] In the air compressor 10, the control unit 100 sends a signal that selectively displays either the diagnostic results of the compressor unit 40 or the diagnostic results of the tank unit 20. Thus, if the signal is received within the air compressor 10, the diagnostic results can be displayed on the air compressor 10; if the signal is received on an external device outside the air compressor 10, the diagnostic results can be displayed on that external device, thereby improving the convenience of the work machine.

[0180] If both the compressor section 40 and the tank section 20 require maintenance, it indicates that an air leak has occurred at least in the tank section 20. Therefore, the diagnosis of the tank section 20 is considered correct.

[0181] On the other hand, air leakage at the tank section 20 is highly likely to have an impact, as it is a major reason why the pressure rise in the compression section 40 takes a long time. Therefore, if the tank section 20 is maintained, it is possible to eliminate the need for maintenance of the compression section 40. Based on these reasons, if both the compression section 40 and the tank section 20 are diagnosed as requiring maintenance, it is sufficient to notify the tank section 20 that it requires maintenance.

[0182] Then, if the diagnosis result of the compressor unit 40 indicates that maintenance is required, but the diagnosis result of the tank unit 20 does not indicate that maintenance is required, since there is no air leakage at the tank unit 20, the diagnosis result of the compressor unit 40 is considered correct. In this case, it is sufficient to notify the compressor unit 40 that maintenance is required. In this way, the air compressor 10 can appropriately notify both the diagnosis results of the compressor unit 40 and the tank unit 20.

[0183] In the air compressor 10, if the pressure in the tank 20 does not exceed a predetermined stop threshold within a predetermined time, it can be diagnosed that the compressor unit needs maintenance.

[0184] In tank section diagnostic control, based on the elapsed time since the start of the stop compressor 40 and the pressure drop in tank section 20, it is determined whether tank section 20 requires maintenance. That is, it diagnoses whether there is an air leak in tank section 20. Therefore, if the pressure does not exceed the predetermined stop threshold Pt, the primary cause lies in tank section 20, not compressor 40. In this way, tank section diagnostic control can be performed simultaneously with the diagnosis of compressor 40.

[0185] Furthermore, by performing start control, the pressure in the tank 20 at the start of diagnosis can be ensured to be the same level each time, thus enabling high-precision detection of the pressure rise. This improves the convenience of the air compressor 10. However, although some errors may occur, the control unit 100 can perform tank diagnostic control even without start control.

[0186] [Modifications of this embodiment]

[0187] This embodiment is not limited to the above-described embodiment, and various modifications can be made without departing from its spirit. Hereinafter, variations of this embodiment will be described.

[0188] The number of air tanks in the air compressor 10, which serves as the tank section 20, is not limited to four; it can also be one, two, three, or five or more. The compression section 40 is not limited to compression in two stages; it can also compress in one stage or three or more stages.

[0189] In the air compressor 10, the start-up determination of whether the compressor 40 can be driven can be skipped before the compressor unit diagnostic control is executed. The start-up threshold Ps can also be equal to the restart threshold Pr.

[0190] The release of compressed air A inside the tank 20 is not limited to being done through the open valve 94, but can also be done through the connector 64, etc.

[0191] The destination of the diagnostic result signal is not limited to the notification unit 120 (touch panel 121), but can also be the portable terminal 132 described later. Figure 17 ).

[0192] Notifications of diagnostic results from Notification Department 120 are not limited to message displays; they can also be delivered via sound. Alternatively, notifications can be sent based on whether the indicator light on the target item is lit.

[0193] [Other variations]

[0194] Figure 17 A machine diagnostic system 130 is shown. As an example, the machine diagnostic system 130 includes a portable terminal 132 and an air compressor 10 capable of wireless communication with the portable terminal 132. A wireless communication unit 134 is provided in the air compressor 10. The wireless communication unit 134 communicates with the portable terminal 132 via short-range wireless communication such as Bluetooth (registered trademark).

[0195] Portable terminal 132 is an example of an external device, such as a smartphone or tablet. As an example, portable terminal 132 has a touch panel 121. Portable terminal 132 can send control unit 100 data to wireless communication unit 134. Figure 5 It can receive and display diagnostic results information by sending a diagnostic control action start signal.

[0196] The control unit 100 is capable of performing the aforementioned compressor section diagnostic control and tank section diagnostic control. Furthermore, the control unit 100 can send information about each diagnostic result to the portable terminal 132. Thus, various diagnostics of the air compressor 10 can also be performed through communication with external devices of the air compressor 10. Additionally, in the compressor section diagnostic control, the control unit 100 can use information such as sound and vibration generated in the compressor section 40 due to wear of piston rings 43C and 45C, instead of using the drive time of the compressor section 40 and the pressure of the tank section 20. Similarly, in the tank section diagnostic control, the control unit 100 can use information such as sound and vibration generated in the tank section 20 due to air leakage, instead of using the elapsed time since the start of the compressor section 40's operation and the pressure drop in the tank section 20.

[0197] <Postscript>

[0198] A diagnostic system for a work machine includes a portable terminal and a work machine capable of wirelessly communicating with the portable terminal. The work machine includes: a tank for storing compressed air; a compressor for driving and delivering compressed air to the tank; a control unit including a pressure detection unit for detecting the pressure inside the tank; and a wireless communication unit capable of wirelessly communicating with the portable terminal. The portable terminal is capable of sending an operation start signal for diagnostic control of the control unit to the wireless communication unit and receiving and displaying diagnostic results. The control unit is capable of performing diagnostic control of the compressor and diagnostic control of the tank. The diagnostic control of the compressor diagnoses whether maintenance of the compressor is required based on the driving time of the compressor and the pressure in the tank. The diagnostic control of the tank diagnoses whether maintenance of the tank is required based on the elapsed time since the stopping of the driving of the compressor and the pressure drop in the tank.

[0199] Symbol Explanation

[0200] 10—Air compressor, 12—Main frame, 14—Control panel, 16—Handle, 18—Foot, 20—Tank section, 22—First air tank, 23—Cylindrical section, 25—Waste liquid piping, 27—Lower cover, 28—Upper cover, 32—Second air tank, 34—Third air tank, 36—Fourth air tank, 40—Compression section, 42—First compression section, 43A—Cylinder, 43B—Piston, 43C—Piston ring, 44—Second compression section, 45A—Cylinder, 45B—Piston, 45C—Piston ring, 46—Motor, 48—Eccentric shaft, 52—Electric Pool assembly, 54—Power plug, 56—Cooling fan, 58—Connector, 62—Pressure reducing valve, 63—Dial, 64—Connector, 65—First flow path section, 67—Second flow path section, 72—Piping section, 73—First piping, 74—Second piping, 75—Third piping, 76—Fourth piping, 77—Fifth piping, 82—Piping, 83—Piping, 84—Piping, 92—Drain section, 94—Open valve, 96—Drain pipe, 98—Waste liquid stopcock, 100—Control section, 102—CPU, 104—Storage section, 106—Memory, 108—Pressure reducing valve Force sensor, 108A—First pressure sensor, 108B—Second pressure sensor, 109—Timer, 112—Power control unit, 114—Operating circuit, 116—Drive circuit, 118—Rotation detection circuit, 120—Notification unit, 121—Touch panel, 122—Button display unit, 123—Mode display unit, 124—Status display unit, 126—AC power supply unit, 128—DC power supply unit, 130—Worker diagnostic system, 132—Portable terminal, 134—Wireless communication unit, A—Compressed air, AP—Pressure range, M—Settings NP—Normal pressure range, P—Tank pressure, P1—Pressure, Pa—Reference pressure, Pr—Restart threshold, Ps—Start threshold, Pt—Stop threshold, PX—Pressure, PX1—Pressure, PX2—Pressure, T—Pressure boosting time, T1—First pressure boosting reference time, T2—Second pressure boosting reference time, T3—Time, T4—Time, Ta—Cumulative operating time, Tc—Time, Td—Pressure boosting reference time, Ts—Standard pressure boosting time, TX—Time, Va—Average voltage, ΔP—Pressure reduction, ΔT—Elapsed time, ΔT1—Elapsed time.

Claims

1. A work machine characterized by comprising: having: a tank portion that stores compressed air; a compression portion that sends out compressed air to the tank portion; and a control portion that includes a pressure detection portion that detects the pressure in the tank portion, the control portion is capable of performing compression portion diagnosis control and tank portion diagnosis control, the compression portion diagnosis control diagnoses whether the compression portion needs maintenance, the tank portion diagnosis control diagnoses whether the tank portion needs maintenance.

2. The work machine according to claim 1, characterized in that: the control portion performs the compression portion diagnosis control based on the drive time of the compression portion and the pressure of the tank portion.

3. The work machine according to claim 1, characterized in that: the control portion performs the tank portion diagnosis control based on the elapsed time from the point in time at which the drive of the compression portion was stopped and the amount of decrease in the pressure of the tank portion.

4. The work machine according to claim 2 or 3, characterized in that: the control portion is capable of performing a startability determination that determines whether the compression portion can be driven, before performing the compression portion diagnosis control, in the startability determination, the control portion determines that the drive of the compression portion can be started when the pressure of the tank portion is below a start threshold value, and determines that the drive of the compression portion cannot be started when the pressure of the tank portion is higher than the start threshold value.

5. The work machine according to claim 4, characterized in that: the control portion performs normal drive control that starts the drive of the compression portion when the pressure of the tank portion is below a restart threshold value, and stops the drive of the compression portion when the pressure of the tank portion exceeds a stop threshold value, the start threshold value is smaller than the restart threshold value.

6. The work machine according to claim 5, characterized in that: the tank portion is provided with an opening valve that can release the compressed air inside the tank portion.

7. The work machine according to claim 1, characterized in that: the control portion sends a signal that displays either one of a diagnosis result that the compression portion is in a state in which maintenance is needed and a diagnosis result that the tank portion is in a state in which maintenance is needed, based on the compression portion diagnosis control and the tank portion diagnosis control.

8. The work machine according to claim 7, characterized in that: there is a notification portion that can receive the signal and notify the diagnosis result, in the compression portion diagnosis control, the drive time of the compression portion until the pressure of the tank portion reaches a diagnosis pressure threshold value is longer than a drive time threshold value, and in the tank portion diagnosis control, when the elapsed time from the point in time at which the drive of the compression portion was stopped is the elapsed time threshold value, the amount of decrease in the pressure of the tank portion is above a decrease amount threshold value, the control portion causes the notification portion to display that the tank portion is in a state in which maintenance is needed, In the above-mentioned compression unit diagnostic control, if the driving time of the compression unit until the pressure of the tank reaches the diagnostic pressure threshold is longer than the driving time threshold, and in the above-mentioned tank unit diagnostic control, if the pressure drop of the tank when the elapsed time is the elapsed time threshold is smaller than the pressure drop threshold, the control unit causes the notification unit to display that the compression unit is in a maintenance-required state.

9. A work machine characterized by comprising: have: The tank section stores compressed air; The compression unit is driven to supply compressed air to the aforementioned tank; and The control unit includes a pressure detection unit that detects the pressure inside the aforementioned tank. The aforementioned control unit is capable of performing tank diagnostic control, in which the compression unit is driven, and when the pressure of the tank exceeds a predetermined stop threshold, the driving of the compression unit is stopped, and the tank is diagnosed as needing maintenance based on the elapsed time since the time the compression unit was stopped and the amount of pressure reduction in the tank.

10. The work machine according to claim 9, characterized in that, Regarding the aforementioned control unit, The system is capable of performing start control, in which the drive of the compression unit is enabled when the pressure in the tank is below a start threshold, and disabled when the pressure in the tank is above the start threshold. After the compressor is started by the start control described above, when the pressure in the tank exceeds the predetermined stop threshold within a predetermined time, the compressor is stopped, and the tank diagnostic control can be performed.

Images