JP6667925B2 - Electric valve control device and electric valve device provided with the same - Google Patents

Description

  The present invention relates to a motor-operated valve control device for controlling a valve opening of a motor-operated valve and a motor-operated valve device including the same.

  Conventionally, in refrigeration cycle systems used for air conditioners, refrigeration / refrigeration showcases, etc., the flow rate of the circulating refrigerant is adjusted for the purpose of stabilizing the cooling capacity and operating efficiently with a constant degree of superheat. However, in order to perform the adjustment at that time with high accuracy, an electric expansion valve that operates a valve element by a stepping motor and an electric valve as a flow control valve are widely used. Also, there are motor-operated valves such as a shut-off valve that uses a stepping motor to open and close the flow path of the refrigerant to flow or shut off the refrigerant, and a three-way valve (flow path switching valve) that switches the direction in which the refrigerant flows (for example, And Patent Document 1).

  However, in the case of a motor-operated valve or the like using the above-described stepping motor, the opening is generally controlled using open-loop control that does not feed back the absolute opening (actual opening). When the power supply is stopped, the valve body does not return to the initial position and stops at the position at the time of power cutoff. Therefore, there is a problem that the position (absolute opening) where the valve element is stopped cannot be accurately grasped when the power is turned on next time.

  Therefore, in controlling an electric valve or the like using the above-described stepping motor, initialization (also referred to as origin position finding, base position finding, or initialization) is usually performed when power is turned on, and the valve body is controlled. The control of the opening is started after the positioning is performed (for example, see Patent Document 2). Here, the initialization means the number of pulses exceeding the full stroke from the fully open position to the fully closed position or from the fully closed position to the fully open position, more specifically, for example, the rotor of the stepping motor surely collides with a detent called a stopper. This is a process for sufficiently rotating the stepping motor in the valve closing direction or the valve opening direction by the number of pulses for stopping the rotation, thereby determining the initial position of the 0 pulse or the maximum pulse of the motor-operated valve.

JP 2000-356278 A Japanese Patent No. 4032993

  The stepping motor of the motor-operated valve normally rotates in synchronization with the input pulse. However, the stepping motor may not be synchronized with the input pulse due to various factors such as an overload and a rapid change in speed (this phenomenon may occur). Out-of-sync or out of sync) As described above, in the conventional motor-operated valve driven by open-loop control that does not feed back the absolute opening (actual opening), when the step-out occurs, until the next initialization is performed (for example, Until the power is turned on, the step-out state is maintained, and there is a concern that the control accuracy of the valve opening during that time may be reduced.

  In the past, it was necessary to make a decision to perform initialization on the master ECU side, which is the control device of the system.However, this decision was difficult, and initialization was performed more than necessary, shortening the life of the motor-operated valve. However, there is a possibility that the valve opening cannot be controlled normally without performing the necessary initialization.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a motor-operated valve control apparatus and a motor-operated valve control apparatus capable of reliably preventing a decrease in control accuracy of a valve opening due to step-out. To provide a motor-operated valve device.

  In order to solve the above problems, an electric valve control device according to the present invention is an electric valve control device for controlling a valve opening of an electric valve, the current valve opening of the electric valve and the electric valve control device. A flag indicating that the initialization request signal is output to the outside when a step-out that is different from the valve opening stored in the memory is detected, the nonvolatile storage unit is provided, and the initialization request signal is output to the outside. Is stored in the storage unit, and the flag is cleared from the storage unit after the initialization is performed.

  In another preferred aspect, when the initialization request flag is stored at the time of startup, the initialization request signal is output to the outside.

  In another preferred aspect, when the initialization request flag is not stored at the time of startup, the initialization request signal is not output to the outside.

  In another preferred aspect, a transmission / reception unit that transmits / receives signals to / from the outside, a calculation unit that calculates a control signal of a valve opening degree of the motor-operated valve according to a signal received from the outside by the transmission / reception unit, A motor drive unit that operates a motor of the electric valve in accordance with a control signal of a valve opening degree of the electric valve; and a step-out detection unit that detects step-out of the electric valve.

  In another preferred aspect, the out-of-step detection unit is provided in the motor drive unit.

  In another preferred aspect, the out-of-step detection unit is provided in the arithmetic unit, and the out-of-step detection unit includes a rotation angle detected by a rotation angle detection unit attached to a motor of the electric valve; The step-out of the electric valve is detected based on the rotation angle stored in the electric valve control device.

  In another preferred embodiment, LIN communication, CAN communication, or FlexRay communication is used for communication for controlling the opening degree of the electric valve.

  Further, the electric valve device according to the present invention is characterized in that the electric valve control device and the electric valve are integrally assembled.

  According to the present invention, when an out-of-step is detected, an initialization request signal is output to the outside, so that initialization is performed every time an out-of-step is detected. It can be reliably prevented.

  Also, a flag indicating that the initialization request signal has been output to the outside is stored in the non-volatile storage unit, and after the initialization is performed, the flag is cleared from the non-volatile storage unit, so that the initialization request signal is output. After the flag is stored in the non-volatile storage unit, before the initialization is actually executed or when the power is turned off during the initialization, the fact that the initialization has not been completed is stored in the non-volatile storage unit. Therefore, the initialization request signal can be output to the outside if the flag of the nonvolatile storage unit is not cleared at the next start-up (for example, at the time of turning on the power or returning from the sleep mode), As a result, the initialization can be executed with certainty, and this also reduces the control accuracy of the valve opening due to step-out. It is possible to really prevent. In addition, since the initialization request signal is not output to the outside when the flag is cleared at the time of startup, there is no possibility that the life of the motor-operated valve is shortened by performing unnecessary initialization.

1 is a system block diagram of a first embodiment of a motor-operated valve control device according to the present invention and a motor-operated valve device including the same. 4 is a flowchart showing a processing flow of step-out detection by the motor-operated valve control device shown in FIG. 1. 3 is a flowchart showing a processing flow of initialization by the motor-operated valve control device shown in FIG. 1. FIG. 4 is a system block diagram of a second embodiment of a motor-operated valve control device according to the present invention and a motor-operated valve device including the same. 5 is a flowchart showing a processing flow of step-out detection by the motor-operated valve control device shown in FIG. 4.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(1st Embodiment)
[Electric Valve Control Apparatus and Configuration of Electric Valve Apparatus Provided Therewith]
FIG. 1 is a system block diagram of a first embodiment of a motor-operated valve control device and a motor-operated valve device including the same according to the present invention. In the following description, a case where the motor-operated valve control device according to the present invention is applied to an expansion valve of a refrigeration cycle system used for a car air conditioner will be described as an example.

  The motor-operated valve device 12 of the illustrated embodiment is a device in which the motor-operated valve 9 and the motor-operated valve control device 11 are connected by a lead wire or the like, and are not integrally located but separated from each other. An expansion valve 5 having a valve element (not shown) for controlling the flow rate of a fluid (refrigerant) and a stepping motor 8 for driving the valve element of the expansion valve 5. The rotation of the stepping motor 8 causes the expansion valve 5 to rotate. The valve opening of the (electrically operated valve 9) is adjusted. In place of the expansion valve 5, the shut-off valve opens and closes the flow path of the refrigerant to flow or shut off the refrigerant, a three-way valve (flow path switching valve) for switching the direction of flow of the refrigerant, or other than an application as an expansion valve. May be used.

  Although illustration is omitted, for example, in a refrigeration cycle system used for a car air conditioner, a compressor, a condenser, (the expansion valve 5 of) the motor-operated valve 9, and an evaporator are sequentially connected via piping. The flow rate of the refrigerant flowing through the piping is controlled by adjusting the valve opening of (the expansion valve 5 of) the electric valve 9.

  A battery power supply (+ Vb, GND) of the vehicle is connected to the motor-operated valve control device 11, and a LIN bus (or CAN bus or FlexRay bus) 14, which is an in-vehicle LAN used for communication in the vehicle, is connected. It is connected. The motor-operated valve control device 11 operates as a slave node, and transmits a LIN communication signal (a CAN communication signal in the case of a CAN bus, a LIN communication signal transmitted from an air conditioner ECU 16 of a master node which is a control device of a system connected to the same LIN bus 14. A command such as the pulse number of the stepping motor 8 and a signal of an initialization operation instruction is received by a FlexRay communication signal in the case of a FlexRay bus, and the opening (valve opening) of the electric valve 9 (expansion valve 5) is controlled.

  The communication method between the air conditioner ECU 16 and the motor-operated valve control device 11 is the input / output to / from the serial interface as described above (LIN communication, CAN communication, FlexRay communication, or the like: “hereinafter, LIN communication, etc.”). ), I / O port input / output (ON-OFF signal, etc.) by digital signal, wireless (Wi-Fi (registered trademark), Bluetooth (registered trademark), etc.) input / output, etc. Alternatively, the present invention is not limited to the LIN communication described above. In FIG. 1, since LIN communication, which is an in-vehicle LAN normally used in a car air conditioner or the like, is applied, transmission and reception of an initialization request signal, an initialization instruction signal, and the like, which will be described later, used for control of the motor-operated valve control device 11 are performed by LIN communication. It is performed by communication. The use of the existing in-vehicle LAN such as LIN communication eliminates the need to attach a new transmission / reception signal line.

  The motor-operated valve control device 11 is mainly provided from a regulator 11a for generating a power supply + Vc (for example, + 5Vdc) used in an internal circuit of the motor-operated valve control device 11 from a battery power supply + Vb (for example, + 12Vdc), and from the air conditioner ECU 16 through the LIN bus A ROM for storing a program for controlling the rotation of the stepping motor 8 based on the transmitted LIN communication signal, a CPU for executing the program stored in the ROM and performing arithmetic processing, and a program for executing initialization operation status and communication data. RAM that temporarily stores data required for execution, I / O circuits that input and output to and from peripheral circuits, timers that measure the time of interrupt processing, etc., A / D converters that convert analog signals to digital values, etc. A microcomputer 11b as an arithmetic unit having a microcomputer, and is connected between the LIN bus 14 and the microcomputer 11b. The LIN transceiver 11c serves as a transmission / reception unit that converts the voltage into a circuit voltage level inside the microcomputer 11 and enables LIN communication with the microcomputer 11b, and controls the rotation of the stepping motor 8 of the motor-operated valve 9 based on a control signal from the microcomputer 11b. A stepping motor driver 11d as a motor drive unit and data connected to the microcomputer 11b and stored in the RAM data of the microcomputer 11b that need to be retained even when the battery power is turned off or shifted to the sleep mode (for example, an initialization request described later). EEPROM 11e, which is a non-volatile memory as a storage unit for storing a flag or the like, is mounted on, for example, a board (not shown). It should be noted that an IC in which two or more of the regulator 11a, the LIN transceiver 11c, the stepping motor driver 11d, the EEPROM 11e, and the microcomputer 11b are integrally formed may be used. In this case, the size of the device can be further reduced.

  The specific configuration of the motor-operated valve control device 11 is not limited to the above-described configuration, and the present invention can be implemented as long as the invention can be implemented (that is, the valve opening control and the initialization control of the motor-operated valve 9 can be performed). Any configuration may be used.

  The air conditioner ECU 16 needs to determine, for example, 0 pulses as the initial position of the motor-operated valve 9 when the battery power is turned on to the motor-operated valve control device 11. A command for executing the initialization operation (initialization instruction signal) is transmitted to the motor-operated valve control device 11 via the LIN bus 14 as a LIN communication signal. Here, the maximum pulse number refers to the stepping motor 8 during the movement from the lower limit position of the valve element (the limit position at which the valve element can move downward) to the upper limit position (the limit position at which the valve element can move upward). The number of pulses to be applied, or the number of pulses applied to the stepping motor 8 while moving from the upper limit position to the lower limit position of the valve body. For example, the lower limit position of the valve body is a fully closed position, an upper limit position. Is the fully open position. The current position of the valve body is the number of pulses applied (increased or decreased) in the valve opening or valve closing direction to move the valve body between the fully closed position and the fully open position, with the lower limit position of the valve body as 0 pulse. It is. Of course, the number of pulses applied with the upper limit position of the valve element set as 0 pulse may be counted.

  The motor-operated valve control device 11 that has received the LIN communication signal does not know the current position (the number of pulses) of the stepping motor 8 when the battery power is turned on, so the maximum number of pulses that the motor-operated valve 9 can control (for example, 500 pulses) In addition, the initialization (the initialization operation of the electric valve 9) in which the stepping motor 8 is rotated in the valve closing direction by a pulse number (for example, 700 pulses or more) obtained by adding a pulse number sufficient for the rotor to reliably collide with the stopper (rotation stop). ) (Set the initial position of 0 pulse). Note that, instead of the initialization for rotating the stepping motor 8 in the valve closing direction, an initialization for rotating the stepping motor 8 in the valve opening direction may be performed.

  The microcomputer 11b of the motor-operated valve control device 11 normally opens the motor-operated valve 9 (expansion valve 5) based on a control signal transmitted from the air conditioner ECU 16 via the LIN bus 14 which is a signal transmission / reception line. In addition to controlling the degree, step-out is detected (also referred to as stall detection) in which the current valve opening and the valve opening managed by the microcomputer 11b in the RAM are different. The microcomputer 11b executes an initialization every time the step-out is detected. An initialization request flag for that is prepared in advance, and the state of the initialization request flag is stored in the EEPROM 11e (to be described later in detail). Statement).

  In this example, a function (step-out detection unit) for detecting the step-out is provided in the stepping motor driver 11d. The detection function of the stepping motor driver 11d is, for example, when the rotation angle of the stepping motor 8 is controlled, the stepping motor driver 11d monitors the applied voltage and the fluctuation range, and when the applied current value exceeds a predetermined threshold value. This is a function to determine that the step-out occurs.

  When the microcomputer 11b receives a power-off signal or a sleep mode transition signal from the air conditioner ECU 16, the microcomputer 11b stops the operation of the operating electric valve 9 (expansion valve 5), for example, and stops the operation of the electric valve control device 11 Power off or transition to sleep mode.

  Here, the sleep mode is a mode in which power is turned on, but power is saved by limiting or partially stopping the function of the microcomputer 11b. At this time, the state shifts to a state where the storage of the RAM for temporarily storing the valve opening information is not held. For example, during a period in which data transmission and reception are not performed, the mode shifts to the sleep mode, and when data transmission is detected, the mode is returned from the sleep mode, whereby power saving can be achieved.

  The microcomputer 11b restarts the control of the motor-operated valve 9 (valve opening control) when the power is turned on again via the air conditioner ECU 16 or the sleep mode is restored.

[Detection of step-out of motorized valve by motorized valve control device and initialization]
Next, a processing flow of step-out detection and initialization by (the microcomputer 11b of) the motor-operated valve control device 11 will be described with reference to FIGS. This process is executed at regular intervals, for example.

  As shown in FIG. 2, the microcomputer 11b checks the signal at the time of step-out (that is, whether or not the step-out occurs) outputted by the detection function of the stepping motor driver 11d at regular time intervals. (Step S21).

  When detecting the out-of-step signal (Step S21: Yes), the microcomputer 11b transmits an initialization request signal to the air conditioner ECU 16 via the LIN bus 14 (Step S22). Further, the microcomputer 11b sets (sets to 1) the initialization request flag prepared in advance and stores it in the EEPROM 11e (step S23).

  In performing the initialization, as shown in FIG. 3, the microcomputer 11b determines at regular time intervals whether or not there is an initialization instruction signal (via the LIN bus 14) from the air conditioner ECU 16 that has received the initialization request signal. (Step S31).

  When there is an initialization instruction signal (Step S31: Yes), the microcomputer 11b performs initialization (for example, a process of rotating the stepping motor 8 in the valve closing direction by the maximum number of pulses or more (for example, 700 pulses or more)) (Step S31). S32).

  Next, the microcomputer 11b determines whether or not the initialization request flag stored in the EEPROM 11e is 1 (Step S33).

  If the initialization request flag stored in the EEPROM 11e is 1 (step S33: Yes) (that is, if the initialization is performed when the out-of-step signal is detected), the microcomputer 11b clears the initialization request flag ( 0) and store it in the EEPROM 11e (step S34). In this control, in the storage area of the EEPROM 11e in which the initialization request flag is set, the state in which the initialization request flag is set is identified as 1 and the state in which the initialization request flag is cleared is identified as 0.

  On the other hand, if the initialization request flag stored in the EEPROM 11e is not 1 (step S33: No) (for example, when the power is turned on during normal use or when returning from the sleep mode, the initialization is performed by the initialization instruction from the air conditioner ECU 16). Is performed), the process goes through step S34, and the process ends.

  When the step-out detection and the initialization are completed, the motor-operated valve 9 is in a normal operation state, and the valve opening control of the motor-operated valve 9 is started according to an instruction from the air conditioner ECU 16.

  In the above control, the state where the initialization request flag is stored is 1 and the state where the initialization request flag is cleared is 0 in the storage area of the EEPROM 11e. However, it is possible to identify whether or not the initialization request flag is stored. If so, it goes without saying that the signal to be specifically assigned is arbitrary. For example, the state in which the initialization request flag is stored may be 0, the state in which the initialization request flag has been cleared may be 1, or another number. Further, a flag indicating a state in which the initialization request flag is stored and a flag indicating a state in which the initialization request flag is not stored (that is, a state in which the flag is cleared) may be provided as different configurations.

[Operation and Effect of Electric Valve Control Apparatus and Electric Valve Apparatus Provided Therewith]
As described above, the motor-operated valve control device 11 of the present embodiment outputs an initialization request signal to the outside (the air conditioner ECU 16 which is a control device of the system) when a step-out is detected. Since the initialization is performed, it is possible to reliably prevent a decrease in the control accuracy of the valve opening due to step-out.

  In addition, an initialization request flag indicating that the initialization request signal has been output to the outside is stored in an EEPROM (non-volatile storage unit) 11e, and after the initialization is performed, the initialization request flag is cleared from the EEPROM 11e. Is output and the initialization request flag is stored in the EEPROM 11e (set to 1), and before the initialization is actually executed or during the initialization, if the power is suddenly cut off due to, for example, a short circuit or disconnection of a lead wire, Since the fact that the initialization has not been completed is stored in the EEPROM 11e, the initialization request flag of the EEPROM 11e is set to 1 at the next startup (for example, at the time of turning on the power or returning from the sleep mode). , From microcomputer 11b Can output a request signal to the outside, thereby, possible to reliably perform the initialization, this also makes it possible to reliably prevent a reduction in control accuracy of the valve opening by the step-out.

  In addition, when the initialization request flag is not set at the time of startup, the initialization request signal is not output to the outside, so that there is no possibility that the life of the motor-operated valve 9 is shortened by performing unnecessary initialization.

(2nd Embodiment)
FIG. 4 is a system block diagram of a second embodiment of a motor-operated valve control device and a motor-operated valve device including the same according to the present invention. The configurations of the motor-operated valve control device of the second embodiment and the motor-operated valve device having the same are substantially the same as the structures of the motor-operated valve control device 11 of the first embodiment and the motor-operated valve device 12 having the same. The only difference from the first embodiment is the configuration and processing for detecting step-out. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Hereinafter, the differences will be described.

  That is, in the present embodiment, as shown in FIG. 4, the stepping motor 8 of the motor-operated valve 9 is provided with a rotation angle sensor 20 composed of a magnetic sensor as a rotation angle detection unit. 11b detects out-of-step of the electric valve 9 using the rotation angle detected by the rotation angle sensor 20.

  FIG. 5 is a flowchart showing a processing flow of step-out detection by (the microcomputer 11b of) the motor-operated valve control device 11 shown in FIG.

  As shown in FIG. 5, the microcomputer 11b acquires the actually measured value of the valve opening of the electric valve 9 (expansion valve 5) by the rotation angle sensor 20 (Step S51).

  Next, the microcomputer 11b calculates the valve opening degree (theoretical value) of the motor-operated valve 9 (expansion valve 5) in accordance with the control signal transmitted from the air conditioner ECU 16 and stores it in the RAM and the actual measurement value acquired in step S51. Is determined (step S52), and it is determined whether the difference is equal to or greater than a preset threshold (step S53).

  If the difference is equal to or greater than the threshold (step S53: Yes), the microcomputer 11b determines that the step-out has occurred, and transmits an initialization request signal to the air conditioner ECU 16 via the LIN bus 14 (step S54). Further, the microcomputer 11b sets (sets to 1) the initialization request flag prepared in advance and stores it in the EEPROM 11e (step S55).

  On the other hand, if the difference is smaller than the threshold value (step S53: No), the microcomputer 11b determines that there is no step-out, skips steps S54 and S55, and ends the processing.

  The initialization in this case can be performed according to the same flow as in the first embodiment.

  As described above, the motor-operated valve control device 11 of the second embodiment also outputs an initialization request signal to the outside (the air-conditioning ECU 16 which is a control device of the system) when a step-out is detected. In addition to obtaining the same operation and effect as described above, the use of the rotation angle sensor 20 can increase the detection accuracy of step-out.

  In the above embodiment, the case where the motor-operated valve control device 11 and the motor-operated valve device 12 are applied to the expansion valve 5 (motor-operated valve 9) of the refrigeration cycle system used for a car air conditioner has been described. The electric valve control according to the present invention is not limited to an electric valve provided with an inlet and an outlet for a fluid, a valve body for controlling the flow rate of the fluid flowing out from the outlet, and a motor for driving the valve body. Needless to say, the device 11 and the motor-operated valve device 12 can be applied. Further, for example, the present invention may be applied to a flow path switching valve such as a motor-operated shut-off valve that opens and closes a flow path of a refrigerant to flow or shut off a refrigerant, a three-way valve or a four-way valve that switches a flowing direction of the refrigerant. Is natural.

  In each of the above-described embodiments, regarding the initialization, the stepping motor 8 is rotated in the valve closing direction or the valve opening direction by the number of pulses exceeding the full stroke from the fully open position to the fully closed position or from the fully closed position to the fully open position. Although described as a process (initialization) to be performed, it is a matter of course that the present invention is not limited to this. For example, the number of pulses to be rotated in the valve closing direction or the valve opening direction at the time of initialization is a predetermined number sufficient for the rotor to reliably collide with the stopper to the number of pulses detected by the rotation angle sensor 20 when step-out is detected. The number of pulses obtained by adding the number of pulses (for example, 200 pulses), or the number of pulses obtained by adding the predetermined number of pulses to the number of pulses managed in the RAM by the microcomputer 11b when a step-out is detected may be used.

5 Expansion valve 8 Stepping motor 9 Electric valve 11 Electric valve control device 11a Regulator 11b Microcomputer (arithmetic unit)
11c LIN transceiver (transmitter / receiver)
11d Stepping motor driver (motor drive unit)
11e EEPROM (non-volatile storage unit)
12 Motorized valve unit 14 LIN bus 16 Air conditioner ECU
20 Rotation angle sensor (Rotation angle detection unit)

Claims (8)

An electric valve control device for controlling a valve opening of an electric valve,
When detecting a step-out difference between the current valve opening of the motor-operated valve and the valve opening stored in the motor-operated valve control device, outputs an initialization request signal to the outside,
A nonvolatile storage unit,
A motor-operated valve control device, wherein a flag indicating that the initialization request signal has been output to the outside is stored in the storage unit, and the flag is cleared from the storage unit after initialization is performed.   2. The motor-operated valve control device according to claim 1, wherein when the initialization request flag is stored at the time of startup, the initialization request signal is output to the outside.   3. The motor-operated valve control device according to claim 1, wherein the initialization request signal is not output to the outside when the initialization request flag is not stored at the time of startup.   A transmission / reception unit that transmits / receives signals to / from the outside, a calculation unit that calculates a control signal of a valve opening degree of the motor-operated valve in accordance with a signal received from the outside by the transmission / reception unit, and a valve opening of the motor-operated valve from the calculation unit 4. A motor drive unit for operating a motor of the motor-operated valve in accordance with a control signal of a degree, and a step-out detecting unit for detecting a step-out of the motor-operated valve. The motor-operated valve control device according to the above section.   The motor-operated valve control device according to claim 4, wherein the step-out detection unit is provided in the motor drive unit. The step-out detection unit is provided in the calculation unit,
The step-out detection unit is configured to perform step-out of the electric valve based on a rotation angle detected by a rotation angle detection unit attached to a motor of the electric valve and a rotation angle stored in the electric valve control device. The motor-operated valve control device according to claim 4, wherein   The electric valve control device according to any one of claims 1 to 6, wherein LIN communication, CAN communication, or FlexRay communication is used for communication for controlling the valve opening of the electric valve.   A motor-operated valve device, wherein the motor-operated valve control device according to any one of claims 1 to 7 and the motor-operated valve are integrally assembled.

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