JP2017198273A - Lock detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lock detecting device capable of simplifying a wiring structure for detecting a lock state of rotary equipment.SOLUTION: A lock detecting device 10 detects a lock state of a compressor to which power is transmitted from an engine through an electromagnetic clutch 3. The lock detecting device 10 includes a rotation detecting section 11, and a determining section 13. The rotation detecting section 11 detects a rotation state of the compressor, and outputs a signal in accordance with the detected rotation state of the compressor. The determining section 13 determines whether the compressor is in the lock state or not based on only the output signal of the rotation detecting section 11, and cuts off supply of electricity to the electromagnetic clutch 3 when it is determined that the compressor is in the lock state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lock detection device that detects a locked state of a rotating device.

  One of the rotating devices is a compressor of a vehicle air conditioner. This compressor operates by obtaining a driving force from a traveling engine via a belt. In such a compressor, the transmission of power from the traveling engine to the compressor and the cutoff thereof are controlled by switching the electromagnetic clutch on and off.

  The electromagnetic clutch generally includes a pulley, an electromagnetic coil, and an armature. The pulley rotates based on torque transmitted from the traveling engine through the belt. The electromagnetic coil generates an electromagnetic force for connecting the pulley and the armature by energization. The armature is connected to the rotating shaft of the compressor via a hub. When the pulley and the armature are connected by electromagnetic force, that is, when the electromagnetic clutch is turned on, the pulley torque is transmitted to the rotating shaft of the compressor via the armature and the hub, and the compressor is driven. Further, when the energization to the electromagnetic coil is interrupted, the connection between the pulley and the armature based on the electromagnetic force is released, that is, the electromagnetic clutch is turned off, and the compressor is stopped.

  In such a compressor, the movable part may be in a so-called locked state in which the movable part is seized and fixed to the fixed part for some reason. When the compressor is locked, the armature and the pulley connected to the rotation shaft of the compressor do not rotate, and the belt may slip with respect to the pulley, and as a result, the belt may break.

  Conventionally, there is a lock detection system as a system for avoiding such belt breakage. The lock detection system includes a lock sensor. The lock sensor outputs a predetermined signal when the rotation shaft of the compressor is rotating. Based on the output signal of the lock sensor, the lock detection system determines whether or not the rotation shaft of the compressor is rotating at a normal rotation speed corresponding to the rotation speed of the engine. The lock detection system protects the belt by turning off the electromagnetic clutch when it is detected that the rotation shaft of the compressor is not normally rotated based on the output signal of the lock sensor.

JP-A-8-326670

  By the way, an engine is generally equipped with an engine speed sensor that outputs a signal corresponding to the engine speed, and a control device that detects the engine speed based on the output signal of the engine speed sensor. Yes. Therefore, when a system that uses the rotational speed of the engine is configured as in the lock detection system described above, the engine rotational speed detected by the control device through each sensor after the output signal of the lock sensor is taken into the control device. Whether or not the electromagnetic clutch is in the locked state may be determined based on the rotation speed of the rotation shaft of the compressor.

  However, in such a system, wiring connecting the control device and the engine rotation speed sensor is essential. This complicates the routing of wiring and causes cost deterioration.

  Such a problem is not limited to a lock detection system that detects the lock state of the compressor, but is a problem common to a lock detection system that detects the lock state of a required rotating device.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a lock detection device capable of simplifying a wiring structure for detecting a locked state of a rotating device.

  The lock detection device (10) that solves the above problem detects the locked state of the rotating device (4) to which power is transmitted from the prime mover (2) via the electromagnetic clutch (3). The lock detection device includes a rotation detection unit (11) and a determination unit (13). The rotation detection unit detects a rotation state of the rotating device and outputs a signal corresponding to the detected rotation state of the rotating device. The determination unit determines whether or not the rotating device is in a locked state based only on the output signal of the rotation detection unit. When it is determined that the rotating device is in a locked state, the electromagnetic clutch is de-energized. .

  If the determination unit determines the locked state of the rotating device based on only the output signal of the rotation detection unit as in this configuration, it is not necessary to use the rotational speed of the prime mover for detecting the locked state. Therefore, unlike the conventional lock detection system, it is not necessary to capture the output signal of the rotation detection unit in the control device that detects the rotation speed of the prime mover. Therefore, according to the said structure, the routing of the wiring which connects the control apparatus which detects the rotational speed of a motor | power_engine, and a rotation detection part becomes unnecessary. Thereby, since it becomes possible to arrange | position a rotation detection part and a determination part closely, the wiring structure for detecting the locked state of a rotation apparatus can be simplified.

  In addition, the code | symbol in the bracket | parenthesis as described in the said means and a claim is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  ADVANTAGE OF THE INVENTION According to this invention, the lock | rock detection apparatus which can simplify the wiring structure for detecting the locked state of rotary equipment can be provided.

It is a block diagram which shows schematic structure of a power transmission device provided with the lock | rock detection apparatus of this embodiment. It is a block diagram which shows schematic structure of the lock | rock detection apparatus of this embodiment. It is a flowchart which shows the procedure of the process performed by the lock | rock detection apparatus of this embodiment.

  Hereinafter, an embodiment of the lock detection device will be described. First, an outline of a power transmission device equipped with the lock detection device of the present embodiment will be described.

  As shown in FIG. 1, the power transmission device 1 of the present embodiment transmits a power of an engine 2 used as a driving source for traveling of a vehicle to a compressor 4 via an electromagnetic clutch 3, thereby 4 is a device for actuating 4.

  The compressor 4 is used in a refrigeration cycle apparatus for a vehicle air conditioner. The vehicle air conditioner is a device that adjusts the temperature in the passenger compartment by adjusting the temperature of the blown air that is blown into the passenger compartment, which is the air conditioning target space. The refrigeration cycle device functions as a device for cooling the blown air in the vehicle air conditioner. The refrigeration cycle apparatus includes a compressor 4, a radiator, an expansion valve, and an evaporator. The refrigerant circulates through these elements. The compressor 4 is a part that compresses the refrigerant discharged from the evaporator.

The electromagnetic clutch 3 includes a pulley 30, an armature 31, and an electromagnetic coil 32.
The pulley 30 is connected to the engine-side pulley 20 via a V belt 33. The engine-side pulley 20 is connected to the drive shaft 21 of the engine 2 and rotates based on the power of the engine 2. That is, when torque is applied to the engine-side pulley 20 based on driving of the engine 2, the torque is transmitted to the pulley 30 via the V-belt, and the pulley 30 rotates.

  The armature 31 is connected to the rotary shaft 40 of the compressor 4. The armature 31 is made of a magnetic material.

  The electromagnetic coil 32 couples the armature 31 and the pulley 30 by generating an electromagnetic force that attracts the armature 31 to the pulley 30 based on energization. Further, when the energization to the electromagnetic coil 32 is interrupted, the electromagnetic force generated from the electromagnetic coil 32 disappears, and the armature 31 is pulled away from the pulley 30 by the elastic force applied from an elastic member (not shown). That is, the connection between the armature 31 and the pulley 30 is released.

  When the pulley 30 and the armature 31 are connected by energizing the electromagnetic coil 32, the power of the engine 2 is transmitted in the order of the engine side pulley 20, the V belt 33, the pulley 30, the armature 31, and the rotary shaft 40 of the compressor 4. Then, the compressor 4 is driven. When the connection between the pulley 30 and the armature 31 is released by cutting off the energization of the electromagnetic coil 32, the power of the engine 2 is transmitted in the order of the engine side pulley 20, the V belt 33, and the pulley 30. Is idle. That is, transmission of power from the engine 2 to the compressor 4 is interrupted, and the compressor 4 stops.

  Hereinafter, for convenience, the state in which the pulley 30 and the armature 31 are connected in the electromagnetic clutch 3 is referred to as an ON state of the electromagnetic clutch 3. In addition, a state where the connection between the pulley 30 and the armature 31 in the electromagnetic clutch 3 is released is referred to as an off state of the electromagnetic clutch 3.

  The energization of the electromagnetic clutch 3, more specifically the energization of the electromagnetic coil 32, is controlled by the control device 5. The control device 5 is mainly composed of a microcomputer having a CPU, a memory and the like. The control device 5 switches the electromagnetic clutch 3 between the on state and the off state based on a command transmitted from the air conditioning ECU that generally controls the vehicle air conditioner.

  Specifically, the electromagnetic clutch 3 is energized from the vehicle power source 6 via the power supply line 7. The vehicle power supply 6 is, for example, a battery mounted on the vehicle. The power supply line 7 is provided with a relay 8. The relay 8 includes a relay switch 80 and a relay coil 81. The relay switch 80 is provided on the feeder line 7. The relay coil 81 is connected in parallel to the relay switch 80.

  The control device 5 includes a switching element 50 and a control unit 51. The switching element 50 is provided on the ground line of the relay coil 81. The switching element 50 is composed of, for example, a bipolar transistor. The control unit 51 turns on the switching element 50 when the electromagnetic clutch 3 is turned on based on a command from the air conditioning ECU. Thereby, since a current flows through the relay coil 81, the relay switch 80 is turned on. Therefore, the electromagnetic clutch 3 is energized from the vehicle power source 6 through the power supply line 7, and the electromagnetic clutch is turned on. The control unit 51 turns off the switching element 50 when the electromagnetic clutch 3 is turned on based on a command from the air conditioning ECU. As a result, no current flows through the relay coil 81, so that the relay switch 80 is turned off. Therefore, the power supply from the vehicle power source 6 to the electromagnetic clutch 3 is cut off, and the electromagnetic clutch 3 is turned off.

  The lock detection device 10 is fixedly provided in the casing 41 of the compressor 4. The lock detection device 10 is a device that detects the locked state of the compressor 4.

  As shown in FIG. 2, the lock detection device 10 includes a rotation detection unit 11, a switching element 12, and a determination unit 13.

  The rotation detector 11 detects the rotation state of the rotation shaft 40 of the compressor 4 and outputs a signal corresponding to the detected rotation state. Specifically, the rotation detection unit 11 outputs a pulsed voltage signal having a frequency corresponding to the rotation speed of the rotation shaft 40 of the compressor 4. The rotation detection unit 11 is always energized from the power supply line 7 of the electromagnetic clutch 3. Thereby, the operation power supply of the rotation detection part 11 is ensured.

  The rotation detection unit 11 is configured to output a logic high level voltage signal when the detected object approaches, and to output a logic low level voltage signal when the detected object separates. The detection target of the rotation detection unit 11 is provided integrally with the rotation shaft 40 of the compressor 4. The detected body is configured to periodically approach and separate from the rotation detection unit 11 when rotating integrally with the rotation shaft 40. As such a detected object, for example, a counterweight provided integrally with the rotary shaft 40 of the compressor 4 can be used. When the detection target periodically repeats approaching and separating from the rotation detection unit 11, a logic high level voltage signal and a logic low level voltage signal are alternately output from the rotation detection unit 11. That is, a pulse voltage signal is output from the rotation detector 11. Thus, the rotation detection unit 11 outputs a pulsed voltage signal when the rotation shaft 40 of the compressor 4 rotates. Moreover, when the rotational speed of the rotating shaft 40 of the compressor 4 changes, the period in which the detection target approaches and separates from the rotation detection unit 11 also changes. Therefore, the period of the pulsed voltage signal output from the rotation detector 11 changes according to the rotational speed of the rotary shaft 40 of the compressor 4. As such a rotation detection unit 11, a magnetic sensor or the like that can magnetically detect the approach and separation of the detected part made of a magnetic material can be used.

  The switching element 12 is configured by, for example, an FET (Field Effect Transistor). The switching element 12 is provided on the power supply line 7 of the electromagnetic clutch 3. That is, when the switching element 12 is turned on, energization from the vehicle power source 6 to the electromagnetic clutch 3 is performed. Further, when the switching element 12 is turned off, the energization from the vehicle power source 6 to the electromagnetic clutch 3 is interrupted. The switching of the switching element 12 is controlled by the determination unit 13.

  The determination unit 13 includes a counter 130 and the like. The determination unit 13 captures the output signal of the rotation detection unit 11. The determination unit 13 is always energized from the power supply line 7 of the electromagnetic clutch 3. Thereby, the operating power supply of the determination part 13 is ensured. The determination unit 13 basically turns on the switching element 12. Further, the determination unit 13 detects the rotation speed Nc of the rotating shaft 40 of the compressor 4 based on the output signal of the rotation detection unit 11, and the compressor 4 is in the locked state based on the detected rotation speed Nc. It is determined whether or not. When it is determined that the compressor 4 is in the locked state, the determining unit 13 forcibly turns off the electromagnetic clutch 3 by switching the switching element 12 from the on state to the off state.

  Next, with reference to FIG. 3, the procedure of the process performed by the determination part 13 is demonstrated concretely. In addition, the determination part 13 repeatedly performs the process shown by FIG. 3 with a predetermined period during the period when the electromagnetic clutch 3 is an ON state. In addition, when the determination part 13 starts the process shown by FIG. 3, the switching element 12 is an ON state, ie, the electromagnetic clutch 3 is an ON state.

  As FIG. 3 shows, the determination part 13 detects the rotational speed Nc of the rotating shaft 40 of the compressor 4 first as step S10. The determination unit 13 calculates the rotation speed Nc of the rotation shaft 40 from the pulse period of the output signal of the rotation detection unit 11.

  The determination unit 13 determines whether or not the rotation speed Nc is less than a predetermined rotation speed Nth as step S11 following step S10. The predetermined rotation speed Nth is obtained in advance by experiments or the like so that it can be determined whether or not the compressor 4 is in the locked state. The predetermined rotational speed Nth is set to a value smaller than the rotational speed of the rotating shaft 40 of the compressor 4 when the engine 2 is in an idle operation and the electromagnetic clutch 3 is in an on state, for example. The The predetermined rotation speed Nth is set to “300 [rpm]”, for example. When the rotational speed Nc is equal to or higher than the predetermined rotational speed Nth, that is, when a negative determination is made in step S11, the determination unit 13 determines that the compressor 4 is not in the locked state, and returns to step S10.

  When the rotational speed Nc is less than the predetermined rotational speed Nth, that is, when an affirmative determination is made in step S11, the determination unit 13 determines that the compressor 4 is in the locked state, and executes step S12. That is, the determination unit 13 uses the counter 130 to measure the elapsed time T from when it is determined that the compressor 4 is in the locked state. Moreover, the determination part 13 determines whether measurement time T became larger than predetermined time Tth as step S13 following step S12. The predetermined time Tth is set to “3 seconds”, for example.

  When the rotational speed Nc becomes equal to or higher than the predetermined rotational speed Nth before the measurement time T becomes longer than the predetermined time Tth, the determination unit 13 makes a negative determination in step S13. In other words, the determination unit 13 makes a negative determination in step S13 when the compressor 4 is unlocked before the measurement time T becomes longer than the predetermined time Tth. If the determination unit 13 makes a negative determination in step S13, the determination unit 13 returns to step S10.

  When the measurement time T becomes longer than the predetermined time Tth because the state where the rotation speed Nc is lower than the predetermined rotation speed Nth is maintained longer than the predetermined time Tth, the determination unit 13 determines in step S13. Make an affirmative decision. In other words, the determination unit 13 makes an affirmative determination in step S13 when the predetermined time Tth has elapsed while the locked state of the compressor 4 is maintained. In this case, the determination unit 13 cuts off the energization of the electromagnetic clutch 3 by turning off the switching element 12 as step S14.

  According to the lock detection device 10 of the present embodiment described above, the operations and effects shown in the following (1) to (7) can be obtained.

  (1) In the lock detection device 10 of the present embodiment, since the determination unit 13 determines the locked state of the compressor 4 based only on the signal output from the rotation detection unit 11, the rotation of the engine 2 is used to detect the lock state There is no need to use speed. Therefore, unlike the conventional lock detection system, it is not necessary to capture the output signal of the rotation detector 11 in the control device that detects the rotation speed of the engine. Therefore, if the lock detection apparatus 10 of this embodiment is used, the wiring which connects the control apparatus which detects the rotational speed of an engine, and the rotation detection part 11 becomes unnecessary. Thereby, since it becomes possible to arrange | position the rotation detection part 11 and the determination part 13 closely, the wiring structure for detecting the locked state of the compressor 4 can be simplified.

  (2) The lock detection device 10 includes a switching element 12 disposed on the power supply line 7 of the electromagnetic clutch 3. The switching element 12 interrupts energization of the electromagnetic clutch 3 based on switching from the on state to the off state. The determination unit 13 cuts off the energization of the electromagnetic clutch 3 by turning off the switching element 12. Thereby, since energization of the electromagnetic clutch 3 can be easily interrupted, the electromagnetic clutch 3 can be forcibly turned off more accurately.

  (3) The output signal of the rotation detector 11 is a pulsed voltage signal having a frequency corresponding to the rotational speed of the rotary shaft 40 of the compressor 4. Thereby, based on the output signal of the rotation detection part 11, the rotational speed Nc of the rotating shaft 40 of the compressor 4 can be detected easily.

  (4) The determination unit 13 detects the rotation speed Nc of the rotation shaft 40 of the compressor 4 based on the output signal of the rotation detection unit 11, and the detected rotation speed Nc is less than the predetermined rotation speed Nth. Based on the above, it is determined that the compressor 4 is in the locked state. Thereby, the locked state of the compressor 4 can be determined easily.

  (5) The predetermined rotational speed Nth is set to a value smaller than the rotational speed of the compressor 4 when the engine 2 is idling. Thereby, when the compressor 4 becomes a locked state, the state can be detected more accurately.

  (6) After the rotational speed Nc of the rotating shaft 40 of the compressor 4 becomes less than the predetermined rotational speed Nth, the determination unit 13 continues the state for a predetermined time Tth, so that the compressor 4 is in the locked state. Judge that there is. Thereby, it becomes possible to determine more accurately whether or not the compressor 4 is in the locked state.

  (7) The lock detection device 10 is fixed to the casing 41 of the compressor 4. Thereby, since the wiring which connects the lock | rock detection apparatus 10 and the compressor 4 can be shortened, the wiring structure for detecting the locked state of the compressor 4 can further be simplified.

In addition, the said embodiment can also be implemented with the following forms.
The switching element 12 and the determination unit 13 of the lock detection device 10 may be provided separately from the compressor 4.

  Each value of the predetermined rotation speed Nth and the predetermined time Tth can be arbitrarily changed.

  The configuration of the rotation detection unit 11 can be changed as appropriate as long as the rotation state of the rotation shaft 40 of the compressor 4 can be detected.

  The device whose lock state is detected by the lock detection device 10 is not limited to the compressor 4, and an appropriate rotating device can be used. At this time, a device for transmitting power to the rotating device is not limited to the engine 2, and any prime mover can be used.

  The switching element 12 is not limited to the FET, and may be configured by an arbitrary switching element such as a bipolar transistor.

  The means and / or function provided by the determination unit 13 can be provided by software stored in a substantial storage device and a computer that executes the software, only software, only hardware, or a combination thereof. For example, when the determination unit 13 is provided by an electronic circuit which is hardware, it can be provided by a digital circuit including a large number of logic circuits or an analog circuit.

  -This invention is not limited to said specific example. That is, the above-described specific examples that are appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. For example, the elements included in each of the specific examples described above, their arrangement, conditions, and the like are not limited to those illustrated, and can be changed as appropriate. Moreover, each element with which embodiment mentioned above is provided can be combined as long as it is technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

2: Engine (motor)
3: Electromagnetic clutch 4: Compressor (rotary equipment)
10: Lock detection device 11: Rotation detection unit 12: Switching element 13: Determination unit 41: Housing

Claims (7)

A lock detection device (10) for detecting a locked state of a rotating device (4) to which power is transmitted from a prime mover (2) via an electromagnetic clutch (3),
A rotation detector (11) for detecting a rotation state of the rotating device and outputting a signal corresponding to the detected rotation state of the rotating device;
Based on only the output signal of the rotation detector, it is determined whether or not the rotating device is in a locked state, and when it is determined that the rotating device is in a locked state, the energization of the electromagnetic clutch is cut off. A determination unit (13);
A lock detection device comprising: A switching element (12) disposed on a power supply line connecting the power source of the electromagnetic clutch and the electromagnetic clutch, and configured to cut off the energization of the electromagnetic clutch based on switching from an on state to an off state;
The lock detection device according to claim 1, wherein the determination unit cuts off the energization of the electromagnetic clutch by turning off the switching element. The lock detection device according to claim 1, wherein the output signal of the rotation detection unit is a pulsed voltage signal having a frequency corresponding to a rotation speed of the rotating device. The determination unit detects a rotation speed of the rotating device based on an output signal of the rotation detection unit, and the rotation based on the detected rotation speed of the rotating device being less than a predetermined rotation speed. The lock detection device according to claim 1, wherein the device is determined to be in a locked state. The lock detection device according to claim 4, wherein the predetermined rotation speed is set to a value smaller than a rotation speed of the rotating device when the prime mover performs an idle operation. The determination unit determines that the rotating device is in a locked state based on the fact that the state continues for a predetermined time after the rotating speed of the rotating device becomes less than a predetermined rotating speed. 5. The lock detection device according to 5. The lock detection device according to any one of claims 1 to 6, wherein the determination unit and the rotation detection unit are fixed to a casing (41) of the rotating device.

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