Compressor and control method for a compressor

Abstract

The present application provides a compressor and a control method of the compressor, which further improves the operation reliability in a high ambient temperature environment, and controls the operation of a motor (104) based on either of a normal operation mode and a thermal safety mode, wherein in the thermal safety mode, a set pressure of the motor (104) corresponding to the pressure in a container (107) storing compressed air is gradually reduced in either case where the ambient temperature exceeds a first temperature threshold and where the difference between the ambient temperature and the temperature of the discharge portion region exceeds a HS mode temperature difference threshold (T DTH ).

Description

Technical Field

[0001] This invention relates to compressors and compressor control methods. Background Technology

[0002] A gas compressor is known to generate compressed gas that is used as a power source or air source for machine tools, presses, blowers, etc. in a production line.

[0003] In addition, there are encapsulated gas compressors, which have a compressor body and an electric motor that drives the compressor body, and integrate the control circuit, operation panel and other components into the encapsulation, thereby saving space.

[0004] In these gas compressors, the reliability and durability of the gas compressor decrease due to the rise in the ambient temperature. Therefore, one solution to ensure a continuous supply of compressed gas is to reduce the load on the gas compressor.

[0005] The background technology of this invention is described in Patent Document 1.

[0006] Patent document 1 describes a compressor control method in which, when the sensor detection values ​​of any one of the discharge air temperature, differential pressure, coil temperature, and current reach a preset upper limit value, the speed of the drive motor is set to a low speed or the compression pressure is set to a low pressure, thereby preventing emergency stop and ensuring continuous operation.

[0007] Patent document 1 describes an operating method for a screw compressor, which inputs the compressed air temperature detected by an air temperature detection sensor, the first pressure and the second pressure detected by a first pressure and a second pressure detection sensor, the coil temperature detected by a coil temperature detection sensor, and the current of the drive motor detected by a current detection sensor to the controller, calculates the pressure difference between the first pressure and the second pressure, and switches to a reduced operating load mode by using the controller to reduce the operating load of the screw compressor when any of the compressed air temperature, pressure difference, coil temperature, and current reaches a predetermined upper limit value.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2003-3981 Summary of the Invention

[0011] The technical problem that the invention aims to solve

[0012] However, compared to when Patent Document 1 was filed, it requires further improvements in reliability so that it can work without problems even in higher temperature environments.

[0013] This invention provides a compressor and a compressor control method, which further improves the operational reliability in environments with high ambient temperatures.

[0014] Technical solutions to the problem

[0015] The present invention includes multiple solutions to the above-mentioned problems. One example is characterized by comprising: an electric motor; a compressor body driven by the electric motor, having a compressor mechanism capable of discharging compressed air; an ambient temperature sensor for measuring the ambient temperature of the compressor; a discharge temperature sensor for measuring the temperature of the discharge area where the compressed air is discharged; and a control unit for controlling the operation of the electric motor based on the pressure within the container storing the compressed air and a set pressure. The control unit controls the operation of the electric motor based on either a normal operating mode or a thermal safety mode, wherein, in the thermal safety mode, the set pressure is gradually reduced in either the case where the ambient temperature exceeds a first temperature threshold or the case where the difference between the ambient temperature and the temperature of the discharge area exceeds a second temperature threshold.

[0016] Invention Effects

[0017] According to the present invention, operational reliability in environments with high ambient temperatures can be further improved. Other technical problems, features, and effects will become clear in the following description of the embodiments. Attached Figure Description

[0018] Figure 1 This is a perspective view showing the appearance of the compressor in Embodiment 1 of the present invention.

[0019] Figure 2 This is a perspective view showing the internal structure of the compressor in Embodiment 1 of the present invention.

[0020] Figure 3 This is a diagram illustrating the conceptual structure of the compressor applied in Embodiment 1 of the present invention.

[0021] Figure 4 This diagram illustrates the functional modules of the control circuit board of the compressor in Embodiment 1 of the present invention.

[0022] Figure 5 This is a diagram showing the outline of the operation of the thermal safety mode installed in the compressor according to Embodiment 1 of the present invention.

[0023] Figure 6 This is a diagram showing the operating state flow of the compressor in Embodiment 1 of the present invention.

[0024] Figure 7This is a perspective view showing the internal structure of the compressor in Embodiment 3 of the present invention.

[0025] Figure 8 This is a diagram illustrating an example of a second temperature threshold corresponding to the lower limit setting pressure of each unit in a compressor according to Embodiment 3 of the present invention. Detailed Implementation

[0026] The following description uses accompanying drawings to illustrate embodiments of the compressor and compressor control method of the present invention. Furthermore, in the drawings used in this specification, the same or corresponding components are labeled with the same or similar reference numerals, and repeated descriptions of these components are sometimes omitted.

[0027] In the following embodiments 1 to 6, an encapsulated compressor is described as an example, in which a compression chamber is formed between a fixed scroll member and a rotating scroll member, and air is compressed by rotational motion. However, the compressor of the present invention is not limited to the encapsulated type. Similarly, it is not limited to scroll compressors, but can also be applied to other reciprocating compressors, screw compressors, turbo compressors, etc. In addition, the working fluid is not limited to air, and can also be other gases.

[0028] <Implementation Method 1>

[0029] In Embodiment 1 of the compressor and compressor control method of the present invention, using Figures 1 to 6 Please provide an explanation.

[0030] First, use Figures 1 to 3 Describe the overall structure of the compressor. Figure 1 This is a perspective view showing the appearance of the compressor 100 in Embodiment 1. Figure 2 This is a perspective view showing the internal structure of the compressor 100 in Embodiment 1. Figure 3 This is a diagram showing the overall conceptual structure of the compressor in Implementation Method 1.

[0031] Figure 1 and Figure 2 The compressor 100 shown is a single-stage compressor having one compressor body 103 and one electric motor 104. The front panel, which forms part of its housing, can be detached from the housing outside the front panel by means of a retaining mechanism such as bolts. In addition, an operation section 117 for the user to operate the compressor 100 is provided on one side of the front surface.

[0032] like Figure 3As shown, the compressor 100 includes a filter 102, a compressor body 103, a motor 104, a check valve 105, an aftercooler 106, a container 107, a dryer 108, a switch 110, a control circuit board 111 that controls the operation of the motor 104 based on the pressure in the container 107 storing compressed air and a set pressure, a pressure sensor 112, a magnetic switch 113, a main body temperature sensor 114, an ambient temperature sensor 115, etc.

[0033] In compressor 100, such as Figure 3 As shown, air 101 supplied from outside the compressor 100 to the inside passes through filter 102 and is supplied to the compressor body 103.

[0034] A drive belt is installed between the electric motor 104 and the compressor body 103 to transmit the power of the electric motor 104 to the compressor body 103, thereby driving the compressor body 103. The compressed air in the compressor body 103 passes through the check valve 105, the aftercooler 106 and is temporarily stored in the container 107. It then passes through the dryer 108 and is supplied to the outside as compressed air 109.

[0035] The compressor 100 is operated by the switch 110 of the operation unit 117 to start / stop the compressor as a whole, and the operation of each component of the compressor is controlled by the control circuit board 111.

[0036] In addition, based on the pressure inside the container 107 detected by the pressure sensor 112, the control circuit board 111 sends a command to the magnetic switch 113, thereby controlling the intermittent operation of the compressor body 103.

[0037] Furthermore, in the compressor 100 of this embodiment, a main body temperature sensor 114 is provided to measure the side temperature of the compressor main body 103 as the temperature of the discharge section area where compressed air is discharged, and a peripheral temperature sensor 115 is provided to measure the air temperature near the intake port 118 as the peripheral temperature of the compressor 100.

[0038] Based on this, the control is configured to issue an alarm / abnormality when the ambient temperature of the compressor 100, as measured by the ambient temperature sensor 115, is outside the specified range of the compressor 100, and to issue an alarm / abnormality to prevent malfunction of the compressor body 103 when the temperature difference between the ambient temperature and the temperature of the compressor body 103, as measured by the body temperature sensor 114, exceeds a specified threshold.

[0039] Because the temperature of the air discharged from the compressor body 103 is about 200°C, the temperature measured by the body temperature sensor 114 is about 100°C when the compressor 100 is running. On the other hand, because the ambient temperature sensor 115 is located near the air intake 118 of the housing, the temperature measured by the ambient temperature sensor 115 is the temperature of the place where the compressor 100 is running, such as room temperature (e.g., in the range of 0°C to 40°C).

[0040] In addition, the discharge temperature measured by the main body temperature sensor 114 is not limited to the side temperature of the compressor body 103, but can also be measured by measuring the temperature of the structure from the compressor body 103 to the aftercooler 106, or the temperature of the compressed air itself in between.

[0041] Similarly, the ambient temperature measured by the ambient temperature sensor 115 is not limited to the air temperature near the intake port 118. It can also be measured by directly measuring the temperature outside the housing near the intake port 118 or by measuring the temperature of the atmosphere inside the housing outside the intake port 118.

[0042] Figure 4 This is a functional block diagram showing the control circuit board 111 in Embodiment 1. Figure 5 This is a diagram showing the operational overview of the thermal safety mode (sometimes referred to as "HS mode") equipped in the compressor of Embodiment 1.

[0043] like Figure 4 As shown, the control circuit board 111 includes a pressure control unit 201, an ambient temperature judgment unit 202, a pressure setting judgment unit 203, a pressure setting change unit 204, a temperature difference judgment unit 205, and a recording unit 206 as its functional structure.

[0044] The pressure control unit 201 processes the sensor inputs from the pressure sensor 112, the main body temperature sensor 114, and the ambient temperature sensor 115, and issues opening and closing commands to the magnetic switch 113.

[0045] The pressure control unit 201, based on the ambient temperature and pressure setting determined by the ambient temperature judgment unit 202 and the pressure setting judgment unit 203, and mainly based on the pressure setting changed by the pressure setting change unit 204, uses the temperature difference judgment unit 205 to determine the difference between the ambient temperature and the temperature of the discharge section area, i.e., the compressor body 103, and executes the pressure control. Figure 6 The operating status flow of compressor 100 is shown.

[0046] Specifically, the pressure control unit 201 of the control circuit board 111 controls the operation of the motor 104 based on either the normal operating mode or the thermal safety mode. In the thermal safety mode, the operation is controlled when the ambient temperature exceeds a first temperature threshold and when the difference between the ambient temperature and the temperature of the discharge area exceeds the temperature difference threshold T used in the HS mode. DTH In any of the following situations, gradually reduce the set pressure.

[0047] Here, either the operation stop pressure (upper limit pressure) which serves as the reference for stopping when the pressure of container 107 reaches a certain specified pressure, or the operation recovery pressure (lower limit pressure) which serves as the reference for restarting when the pressure of container 107 reaches a certain specified pressure, can be used as the set pressure to be changed. In this embodiment, the case of changing only the lower limit pressure is described as an example.

[0048] The normal operating mode is when the ambient temperature exceeds the first temperature threshold and the difference between the ambient temperature and the temperature in the discharge area exceeds the normal mode temperature difference threshold T. DT In any of the following situations, a warning is issued indicating an abnormal shutdown due to high temperature, and the operation of the motor 104 is stopped, thereby stopping the operation of the compressor body 103.

[0049] On the other hand, the thermal safety mode is activated when the ambient temperature exceeds the first temperature threshold and the difference between the ambient temperature and the temperature of the discharge area exceeds the temperature difference threshold T used in the HS mode. DTH In any of the following situations, a warning is issued indicating an abnormal shutdown due to high temperature, and the operation of the motor 104 is stopped, thereby stopping the operation of the compressor body 103, which is common to the normal operating mode.

[0050] The difference between thermal safety mode and normal operation mode is that when the ambient temperature exceeds the temperature difference threshold T in HS mode... DTH In this case, the set pressure (in this embodiment, the lower limit pressure) is reduced by a predetermined value, thereby delaying the recovery of the motor 104's operation and making it difficult for the temperature of the compressor body 103 to rise. Furthermore, once the ambient temperature no longer exceeds the temperature threshold, the set pressure is restored to its original value.

[0051] In addition, since there is a necessary air pressure in the user equipment connected downstream of the compressor 100, it is preferable to set a lower limit for the setting change value of the lower limit pressure in order to prevent it from falling below the necessary pressure.

[0052] The HS mode uses a temperature difference threshold T corresponding to the set pressure. DTH For example, as described later. Figure 8 (Embodiment 3) As shown, the data is recorded as table data in the recording section 206 within the control circuit board 111.

[0053] As a thermal safety mode, for example Figure 5 As shown, there are two modes: a first thermal safety mode that can be set to reduce the set pressure and change the temperature threshold when the ambient temperature is above 45°C but below 47°C, and a second thermal safety mode that reduces the pressure and changes the temperature threshold when the ambient temperature is above 47°C but below 50°C, and immediately stops operation when the ambient temperature is determined to be above 50°C.

[0054] Furthermore, in the thermal safety mode of this embodiment, when the control circuit board 111 drives the compressor body 103 in thermal safety mode, it simultaneously reduces the temperature difference threshold T for HS mode according to the set pressure, while reducing the control pressure. DTH This is because the temperature of the compressor body 103 is difficult to rise in thermal safety mode, making it difficult to detect whether a high-temperature load has been applied to the compressor. Therefore, in cases of high external temperatures, to avoid operating under undesirable conditions and to improve fault detection accuracy, the temperature difference threshold T used in HS mode is lowered. DTH The structure.

[0055] The user can freely select between the normal operating mode and the thermal safety mode using the operation unit 117, and the user's selection is saved in the recording unit 206 of the control circuit board 111.

[0056] Next, use Figure 6 The control flow of the compressor 100 in this embodiment is explained. Figure 6 This is a conceptual diagram illustrating the operation flow of the compressor in Implementation Method 1. Figure 6 In this process, the main body of each step is the various parts within the control circuit board 111, but the following description is based on the control circuit board 111.

[0057] like Figure 6 As shown, firstly, after the control circuit board 111 starts the process (S301) and begins the operation of the compressor 100 (S302), it determines whether the thermal safety mode is valid (S303). If it is valid, the process proceeds to step S308. Conversely, if it is not valid, the process proceeds to step S304, switching to normal mode control.

[0058] In normal mode control, the control circuit board 111 determines the temperature difference T between the ambient temperature measured by the ambient temperature sensor 115 and the temperature of the discharge area measured by the main body temperature sensor 114. D Is it greater than the normal mode temperature difference threshold T? DT (S305).

[0059] In step S305, the temperature difference T between the ambient temperature and the discharge area temperature is determined. D Temperature difference threshold T greater than normal mode DT When the compressor body malfunctions, the control circuit board 111 attaches a compressor body malfunction flag (S331) and issues an alarm / malfunction, then terminates the process (S307).

[0060] In contrast, the temperature difference T is determined. D In the normal mode, the temperature difference threshold T is used. DT At this time, the control circuit board 111 cycles through the normal control mode (S306).

[0061] If the determination of the validity of the thermal safety mode is valid (S303), the control circuit board 111 switches to thermal safety mode control (S308).

[0062] In thermal safety mode control, firstly, the control circuit board 111 determines whether the ambient temperature AT is above 45°C (S309).

[0063] If the ambient temperature AT is determined to be less than 45°C, the process proceeds to step S310, where the control circuit board 111 determines whether the thermal safety mode is invalid (S310). If the thermal safety mode is determined to be invalid, the control circuit board 111 switches to normal mode control (S304), and if it is determined to be valid, the thermal safety mode control cycle continues (S311).

[0064] In contrast, if the ambient temperature AT is determined to be above 45°C in step S309, the process proceeds to step S312, where the control circuit board 111 continues to determine whether the ambient temperature AT is above 47°C (S312). If the ambient temperature AT is determined to be above 45°C but below 47°C, the process proceeds to step S313, where the control circuit board 111 determines whether the lower limit pressure setting value Pu is below 0.55 MPa (S313).

[0065] When the control circuit board 111 determines that the set value Pu of the lower limit pressure is less than 0.55MPa, it keeps the set value Pu unchanged and advances the process to step S315A. When it determines that the set value Pu is above 0.55MPa, it sets the lower limit pressure to 0.55MPa (S314) and advances the process to step S315A.

[0066] Therefore, it is preferable to set a minimum reference value for the lower limit pressure of the set pressure in thermal safety mode. In addition, it is preferable to keep the set value of the control circuit board 111 unchanged when the lower limit pressure is below the set value in thermal safety mode, and change it only when the lower limit pressure exceeds the set value.

[0067] Then, the control circuit board 111 sets the value corresponding to the lower limit pressure, i.e., the temperature difference threshold T for HS mode.DTH (S315A), switch to the first thermal safety mode control (S316).

[0068] In the first thermal safety mode control, the control circuit board 111 determines the temperature difference T between the ambient temperature measured by the ambient temperature sensor 115 and the temperature of the discharge section area measured by the main body temperature sensor 114. D Is it greater than the temperature difference threshold T in HS mode? DTH (S317).

[0069] In step S317, the temperature difference T between the ambient temperature and the discharge area temperature is determined. D Temperature difference threshold T greater than HS mode DTH When the compressor body malfunctions, the control circuit board 111 is marked with an abnormality flag (S331), and the process ends (S307).

[0070] In contrast, the temperature difference T is determined. D In HS mode, the temperature difference threshold T is used. DTH Next, the control circuit board 111 again determines whether the ambient temperature AT is less than 45°C (S318). If it determines that the temperature is less than 45°C, the process proceeds to step S333A, where the lower limit pressure setting value Pu is changed to the user-set pressure, and the HS mode is changed to use the temperature difference threshold T. DTH Increase to the normal mode using the temperature difference threshold T DT (S333A), then the process proceeds to step S310.

[0071] In this way, after the preferred control circuit board 111 changes the set pressure according to the ambient temperature, it also uses the temperature difference threshold T to adjust the set pressure and HS mode according to the subsequent ambient temperature. DTH Increase to the normal mode using the temperature difference threshold T DT .

[0072] In contrast, if it is determined that the temperature is above 45°C, the process proceeds to step S319. The control circuit board 111 determines whether the ambient temperature AT is below 47°C (S319). If it is determined that the temperature is below 47°C, the process proceeds to step S310A. The control circuit board 111 determines whether the thermal safety mode is invalid (S310A).

[0073] If the condition is deemed invalid, the process proceeds to step S333B, where the control circuit board 111 changes the lower limit pressure setting value Pu to the user-defined pressure and switches the HS mode to the temperature difference threshold T. DTH Increase to the normal mode using the temperature difference threshold T DT (S333B), then the process proceeds to step S304 and transfers to normal mode control (S304). In contrast, if the determination in step S310A is valid, the first thermal safety control cycle continues (S321).

[0074] In contrast, in step S319, if it is determined that the temperature is above 47°C, the process proceeds to step S320. The control circuit board 111 determines whether the ambient temperature AT is higher than 50°C (S320). If it is determined that the ambient temperature is higher than 50°C, an ambient temperature abnormality flag is added (S332) and an alarm / abnormality is issued, and then the operation ends (S307).

[0075] In contrast, if it is determined that the temperature is below 50°C, the first thermal safety mode will not continue to cycle. Instead, the process will return to step S309 and proceed to the process that sets which thermal mode to use.

[0076] If the ambient temperature AT is determined to be above 47°C in step S312, the process proceeds to step S322. The control circuit board 111 determines whether the ambient temperature AT is above 50°C (S322). If the ambient temperature is above 50°C, an ambient temperature abnormality flag is added (S332), and the operation ends (S307).

[0077] In contrast, if the ambient temperature AT (above 47°C) is less than 50°C, the process proceeds to step S323, and the control circuit board 111 determines whether the set value of the lower limit pressure Pu is below 0.45MPa (S323).

[0078] When the control circuit board 111 determines that the set value Pu of the lower limit pressure is less than 0.45MPa, it keeps the set value Pu unchanged and advances the process to step S315B. When it determines that the set value Pu is above 0.45MPa, it sets the lower limit pressure to 0.45MPa (S324) and advances the process to step S315B.

[0079] Then, the control circuit board 111 sets the value corresponding to the lower limit pressure, i.e., the temperature difference threshold T for HS mode. DTH (S315B), switch to the second thermal safety mode control (S325).

[0080] Additionally, the temperature difference threshold T set in step S315A for the HS mode DTH The temperature difference threshold T for the HS mode set in step S315B. DTH As mentioned above, these are threshold values ​​corresponding to the lower limit pressure. If the lower limit pressure is the same set value, the values ​​will be the same; if the lower limit pressure is different set values, the values ​​will be different.

[0081] In the second thermal safety mode control, the control circuit board 111 determines the temperature difference T between the ambient temperature measured by the ambient temperature sensor 115 and the temperature of the discharge section area measured by the main body temperature sensor 114. D Is it greater than the temperature difference threshold T in HS mode? DTH (S326).

[0082] In step S326, the temperature difference T between the ambient temperature and the discharge area temperature is determined. D Temperature difference threshold T greater than HS mode DTH When the compressor body malfunctions, the control circuit board 111 is marked with an abnormality flag (S331), and the process ends (S307).

[0083] In contrast, the temperature difference T is determined. D In HS mode, the temperature difference threshold T is used. DTH Next, the control circuit board 111 again determines whether the ambient temperature AT is less than 45°C (S327). If it determines that the temperature is less than 45°C, the process proceeds to step S333A, where the lower limit pressure setting value Pu is changed to the user-set pressure, and the HS mode is changed to use the temperature difference threshold T. DTH Increase to the normal mode using the temperature difference threshold T DT (S333A), then the process proceeds to step S310.

[0084] In contrast, if it is determined that the temperature is above 45°C, the process proceeds to step S328. The control circuit board 111 determines whether the ambient temperature AT is below 47°C (S328). If it is determined that the temperature is below 47°C, the second thermal safety mode is not allowed to continue cycling. Instead, the process returns to step S309 and proceeds to the process that cycles with which thermal mode.

[0085] In contrast, in step S328, if it is determined that the temperature is above 47°C, the process proceeds to step S329. The control circuit board 111 determines whether the ambient temperature AT is higher than 50°C (S329). If it is determined that the ambient temperature is higher than 50°C, an ambient temperature abnormality flag is added (S332), and the operation ends (S307).

[0086] In contrast, in step S329, if it is determined that the temperature is below 50°C, the process is advanced to step S310B, and the control circuit board 111 determines whether the thermal safety mode is invalid (S310B).

[0087] If the condition is deemed invalid, the process proceeds to step S333B. The control circuit board 111 changes the lower limit pressure setting value Pu to the user-set pressure and uses the temperature difference threshold T in the HS mode. DTH Increase to the normal mode using the temperature difference threshold T DT (S333B), then the process proceeds to step S304 and transfers to normal mode control (S304). In contrast, if it is determined to be valid in step S310B, the second thermal safety mode control cycle continues (S330).

[0088] Next, the effects of this embodiment will be explained.

[0089] The compressor 100 of Embodiment 1 of the present invention includes: an electric motor 104; a compressor body 103 driven by the electric motor 104, which has a compressor mechanism capable of discharging compressed air; an ambient temperature sensor 115 for measuring the ambient temperature of the compressor 100; a body temperature sensor 114 for measuring the temperature of the discharge section area where the compressed air is discharged; and a control circuit board 111 for controlling the operation of the electric motor 104 based on the pressure in the container 107 storing compressed air and a set pressure. The control circuit board 111 controls the operation of the electric motor 104 based on either a normal operating mode or a thermal safety mode. In the thermal safety mode, the operation is controlled when the ambient temperature exceeds a first temperature threshold and when the difference between the ambient temperature and the temperature of the discharge section area exceeds the temperature difference threshold T used in HS mode. DTH In any of the following situations, gradually reduce the set pressure.

[0090] In recent years, summer maximum temperatures have risen significantly, and users have demanded compressors that can operate continuously even under high temperatures. To address this, a thermal safety mode that lowers the set pressure is used when high temperatures occur. This reduces the heat generated by the compressor as the set pressure decreases, thus slowing the temperature rise and allowing for continued operation. This further improves the reliability of operation in high ambient temperature environments.

[0091] In addition, when the compressor body 103 is driven in thermal safety mode, the control circuit board 111 lowers the temperature difference threshold T for HS mode accordingly with the set pressure. DTH The above-mentioned thermal safety mode suppresses heat generation during operation. Therefore, there are situations where the compressor should stop due to abnormal high temperature in normal operation mode, but can continue to operate in thermal safety mode. Thus, in the control that detects compressor losses by calculating the difference between the exhaust air temperature and the ambient temperature, the threshold for detecting losses is changed accordingly with the compressor's set pressure value when the set pressure is reduced. This makes it easier to stop when the pressure is reduced, and more appropriate protection of the compressor at high temperatures can be provided. Compared with existing compressors, it can also ensure higher reliability in high ambient temperature environments.

[0092] Furthermore, after the control circuit board 111 changes the set pressure in accordance with the ambient temperature, it also adjusts the set pressure and HS mode according to the temperature difference threshold T in accordance with the subsequent ambient temperature. DTH Increase to the normal mode using the temperature difference threshold T DT This allows the system to return from a state of suppressed operation where it no longer needs to operate in thermal safety mode to a normal state, thus enabling stable operation.

[0093] In addition, by setting a minimum reference value for the lower limit pressure of the set pressure in the thermal safety mode, it is possible to ensure the necessary minimum pressure, avoid the interruption of compressed air supply as much as possible, and avoid situations where the compressed air user's machinery stops operating.

[0094] Furthermore, the control circuit board 111 keeps the set pressure (upper limit pressure or lower limit pressure) unchanged when it is below the set value in the thermal safety mode, and changes it when it exceeds the set value, thereby enabling operation corresponding to the user setting.

[0095] <Implementation Method 2>

[0096] The compressor and compressor control method of Embodiment 2 of the present invention will be described.

[0097] In the compressor 100 of the above embodiment 1, in the thermal safety mode, which gradually reduces the set pressure for the operation of the specified motor 104 corresponding to the pressure inside the container 107 storing compressed air, only the lower limit pressure, which is the reference for restarting when the pressure of the container 107 falls below a certain specified pressure, is changed. However, the compressor of this embodiment is in the form of changing the upper limit pressure, which is the reference for stopping when the pressure of the container 107 falls above a certain specified pressure, at the same time as the lower limit pressure.

[0098] Furthermore, when both the upper and lower pressure limits are changed, they do not need to be changed simultaneously. Alternatively, it is also possible to change only the upper pressure limit without changing the lower pressure limit.

[0099] Other structures and operations are substantially the same as those of the compressor and compressor control method in Embodiment 1 described above, and their details are omitted.

[0100] In the compressor and compressor control method of Embodiment 2 of the present invention, the same effects as those of the compressor and compressor control method of Embodiment 1 described above can also be obtained.

[0101] In addition, by changing the upper pressure limit, the compressor can be protected more reliably at high temperatures.

[0102] <Implementation Method 3>

[0103] use Figure 7 and Figure 8 The compressor and compressor control method of Embodiment 3 of the present invention are described. Figure 7 This is a perspective view showing the internal structure of the compressor in embodiment 3. Figure 8 This is a diagram illustrating an example of a second temperature threshold corresponding to the lower limit setting pressure of each unit in the compressor of Embodiment 3.

[0104] Figure 7The compressor 100A shown in this embodiment has multiple compressor bodies 103A, 103B, and 103C. In such a compressor 100A, the control circuit board 111A independently manages the temperature difference threshold T for HS mode for each compressor body 103A, 103B, and 103C. DTH .

[0105] Specifically, a main body temperature sensor 114A is independently installed in the compressor body 103A, a main body temperature sensor 114B is installed in the compressor body 103B, and a main body temperature sensor 114C is installed in the compressor body 103C. Therefore, the temperature difference threshold T in HS mode is managed independently accordingly. DTH .

[0106] like Figure 8 As shown, the temperature difference threshold T in HS mode is changed accordingly to the lower limit set pressure. DTH In the compressor body 103C located at the lowest point in the vertical direction, the HS mode is used with a temperature difference threshold T under all lower limit set pressures. DTH Set to 10°C lower than the compressor body 103B located vertically above it at the center, and use the temperature difference threshold T in HS mode at all lower limit set pressures. DTH It is set to be 5°C lower than the compressor body 103A located at the top in the vertical direction.

[0107] Other structures and operations are substantially the same as those of the compressor and compressor control method in Embodiment 1 or Embodiment 2 described above, and their details are omitted.

[0108] Furthermore, the compressor 100A of this embodiment can be applied not only to the form of compressor 100 of embodiment 1 where only the lower limit pressure is changed, but also to the form of embodiment 2 where both the upper limit pressure and the lower limit pressure are changed, and further, it can also be applied to the form where only the upper limit pressure is changed.

[0109] In the compressor and compressor control method of Embodiment 3 of the present invention, it is also possible to obtain substantially the same effects as the compressor and compressor control method of Embodiment 1 or Embodiment 2 described above.

[0110] In addition, when there are multiple compressor bodies 103A, 103B, and 103C, the control circuit board 111A independently manages the temperature difference threshold T for HS mode for each compressor body 103A, 103B, and 103C. DTH This also enables the handling of situations where cooling efficiency varies depending on the configuration location when there are multiple compressor units.

[0111] <Implementation Method 4>

[0112] The compressor and compressor control method of Embodiment 4 of the present invention will be described.

[0113] The compressor in this embodiment does not, like the compressor 100 in Embodiment 1, use the temperature difference threshold T in the recording section 206 within the control circuit board 111 to display the HS mode in accordance with the set pressure. DTH Instead of recording data in a table, the temperature difference threshold T in the HS mode corresponding to the set pressure is recorded in the recording section 206. DTH The form of a function with variables.

[0114] Other structures and operations are substantially the same as those of the compressor and compressor control method in any of the above embodiments 1 to 3, and their details are omitted.

[0115] Furthermore, the use of a function in this embodiment is effective in various configurations, including Embodiment 2 (which changes both the lower and upper pressure limits), Embodiment 3 (which only changes the upper pressure limit), and Embodiment 3 (a multi-stage compressor 100A). In particular, when used in Embodiment 3, a multi-stage compressor 100A, different functions can be set for each compressor body 103A, 103B, and 103C. Alternatively, it can be modified so that one stage is a table and another stage is a function. Furthermore, in Embodiment 3, a multi-stage compressor 100A where the upper pressure limit is also changed as described in Embodiment 2, different functions can be set for each compressor body 103A, 103B, and 103C. Alternatively, it can be modified so that one stage is a table and another stage is a function.

[0116] In the compressor and compressor control method of Embodiment 4 of the present invention, it is also possible to obtain substantially the same effect as the compressor and compressor control method of any of Embodiments 1 to 3 described above.

[0117] <Implementation Method 5>

[0118] The compressor and compressor control method of Embodiment 5 of the present invention will be described.

[0119] In this embodiment, the compressor is not one of those in embodiments 1 to 4, so that when the compressor body 103 is driven in thermal safety mode, the temperature difference threshold T for HS mode is reduced accordingly with the set pressure (lower limit pressure). DTH Instead, when the compressor body 103 is driven in thermal safety mode, the temperature difference threshold T for HS mode is set by referring to the average of the lower limit pressure and the upper limit pressure or other pressure values ​​such as the average pressure during compressor operation as the set pressure. DTH The form. Furthermore, the temperature difference threshold T of the HS mode can be reduced accordingly, based on the average pressure within container 107 over a certain period in the past. DTHIts form.

[0120] Other structures and operations are substantially the same as those of the compressors and compressor control methods in embodiments 1 to 4 described above, and their details are omitted.

[0121] Alternatively, it can be used together with the compressor of any of Embodiments 1 to 4.

[0122] In the compressor and compressor control method of Embodiment 5 of the present invention, it is also possible to obtain substantially the same effects as the compressor and compressor control methods of Embodiments 1 to 4 described above.

[0123] <Implementation Method 6>

[0124] The compressor and compressor control method of Embodiment 6 of the present invention will be described.

[0125] The compressor in this embodiment is a compressor of any of embodiments 1 to 5 in which operation control is performed by an inverter instead of the magnetic switch 113. In this embodiment, regarding reducing the temperature difference threshold T for HS mode... DTH The reference settings can not only refer to the set pressure, but also to the relationship between the set pressure and the rotation speed.

[0126] Other structures and operations are substantially the same as those of the compressor and compressor control method in any of the above embodiments 1 to 5, and their details are omitted.

[0127] In the compressor and compressor control method of Embodiment 6 of the present invention, it is also possible to obtain substantially the same effects as the compressor and compressor control method of any of Embodiments 1 to 5 described above.

[0128] <Other>

[0129] The above embodiments are merely specific examples that help to understand the concept of the present invention and are not intended to limit the scope of the present invention. Various constituent elements can be added, deleted, or modified within the scope of the present invention without departing from its spirit.

[0130] For example, the various functional units described in the above embodiments can also be implemented using circuits. A circuit can be a dedicated circuit that performs a specific function, or it can be a general-purpose circuit such as a processor.

[0131] Furthermore, at least some of the processes described in the above embodiments can also be implemented using a general-purpose computer as the basic hardware. The program implementing the above processes can be provided stored on a computer-readable recording medium. The program is stored on the recording medium as an installable or executable file. The recording medium can be a disk, optical disk (CD-ROM, CD-R, DVD, etc.), magneto-optical disk (MO, etc.), semiconductor memory, etc. The recording medium can be any recording medium capable of storing programs and readable by a computer. Alternatively, the program implementing the above processes can be stored on a computer (server) connected to a network such as the Internet and downloaded to a computer (client) via the network.

[0132] Explanation of reference numerals in the attached figures

[0133] 100, 100A... compressor

[0134] 101...Air

[0135] 102, 102A, 102B, 102C... Filters

[0136] 103, 103A, 103B, 103C... Compressor body

[0137] 104, 104A, 104B, 104C... Electric motors

[0138] 105, 105A, 105B, 105C... Check valve

[0139] 106, 106A, 106B, 106C, 106D... aftercoolers

[0140] 107……Container

[0141] 108...dryer

[0142] 109... Compressed air

[0143] 110... switch

[0144] 111, 111A... Control circuit board (control unit)

[0145] 112……Pressure sensor

[0146] 113, 113A, 113B, 113C... Magnetic switches

[0147] 114, 114A, 114B, 114C... Main body temperature sensor (exhaust temperature sensor)

[0148] 115... Ambient temperature sensor

[0149] 117... Operations Department

[0150] 118...Intake port

[0151] 201... Pressure Control Department

[0152] 202……Surrounding Temperature Judgment Department

[0153] 203... Pressure Setting Judgment Department

[0154] 204……Pressure Setting Change Section

[0155] 205……Temperature Difference Judgment Department

[0156] 206...Records Department

[0157] AT...Around temperature

[0158] T DT ...The normal mode uses a temperature difference threshold

[0159] T DTH ...HS mode uses temperature difference threshold (second temperature threshold).

Claims

1. A compressor, characterized in that, include: Electric motor; The compressor body driven by the electric motor has a compressor mechanism capable of discharging compressed air; An ambient temperature sensor that measures the ambient temperature around the compressor; A discharge temperature sensor that measures the temperature of the discharge section area from which the compressed air is discharged; and The control unit controls the operation of the electric motor based on the pressure inside the container storing the compressed air and the set pressure. The control unit controls the operation of the motor based on either a normal operating mode or a thermal safety mode. In the thermal safety mode, the set pressure is gradually reduced in either the case where the ambient temperature exceeds a first temperature threshold or the case where the difference between the ambient temperature and the temperature of the discharge section exceeds a second temperature threshold.

2. The compressor as described in claim 1, characterized in that: When the control unit drives the compressor body in the thermal safety mode, it lowers the second temperature threshold in accordance with the set pressure.

3. The compressor as described in claim 2, characterized in that: After the control unit changes the set pressure in accordance with the ambient temperature, it also increases the set pressure and the second temperature threshold in accordance with the subsequent ambient temperature.

4. The compressor as described in claim 1, characterized in that: A minimum reference value is set for the lower limit pressure of the set pressure in the thermal safety mode.

5. The compressor as described in claim 1, characterized in that: The control unit keeps the set pressure unchanged when it is below the set value in the thermal safety mode, and changes it when it exceeds the set value.

6. The compressor as described in claim 1, characterized in that: In the case of having multiple compressor bodies, the control unit manages the second temperature threshold independently for each compressor body.

7. A method for controlling a compressor, wherein the compressor comprises: Electric motor; The compressor body driven by the electric motor has a compressor mechanism capable of discharging compressed air; An ambient temperature sensor that measures the ambient temperature around the compressor; and A discharge temperature sensor that measures the temperature of the discharge area of ​​the compressed air. The compressor control method is characterized by: The operation of the motor is controlled based on either the normal operating mode or the thermal safety mode. In the thermal safety mode, the set pressure is gradually reduced in either the case where the ambient temperature exceeds a first temperature threshold or the case where the difference between the ambient temperature and the temperature of the discharge section exceeds a second temperature threshold.

8. The compressor control method as described in claim 7, characterized in that: When the compressor body is driven in the thermal safety mode, the second temperature threshold is reduced accordingly to the set pressure.

9. The compressor control method as described in claim 8, characterized in that: After the set pressure is changed in accordance with the ambient temperature, the set pressure and the second temperature threshold are also increased in accordance with the subsequent ambient temperature.

10. The compressor control method as described in claim 7, characterized in that: A minimum reference value is set for the lower limit pressure of the set pressure in the thermal safety mode.

11. The compressor control method as described in claim 7, characterized in that: If the set pressure is below the set value in the thermal safety mode, the set value remains unchanged; if it exceeds the set value, it is changed.

12. The compressor control method as described in claim 7, characterized in that: In the case of having multiple compressor bodies, the second temperature threshold is managed independently for each compressor body.

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