JP2007165406A - Apparatus and method for defrosting electromagnetic relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent problems such as poor contact between contacts of a movable terminal and a fixed terminal due to frosting inside an electromagnetic relay case without causing problems such as enlargement of a system, an increase in cost, and an increase in energy loss which might be caused in preventing the relay from frosting. <P>SOLUTION: A control unit 20 determines whether the inside of the case 15 of the electromagnetic relay 10 is frosted, and repeatedly applies and stops voltage to an excitation coil 11 of the relay 10 when the frosting is determined to take place. The movable unit 15 is repeatedly moved in the direction of coming closer to/farther away from the fixed terminal 16, thereby causing vibration in the case 15 or at a spot where the frosting occurs inside the case 15 to defrost. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a freeze release device for releasing freezing when the inside of a casing of an electromagnetic relay that is connected between an electrical load and a power source and switches on / off of power supply to the electrical load occurs. It relates to a method for releasing freeze.

  In the electromagnetic relay, switching is performed by moving the movable terminal toward and away from the fixed terminal by the electromagnetic induction action of the exciting coil. Such an electromagnetic relay is connected between, for example, an electric load of a vehicle and a power supply, and is used as a switch for switching between supply and interruption of the power supply to the electric load.

  By the way, in recent years, the mounting of new electrical systems such as an electric sliding door and an electric four-wheel drive device has been actively promoted in vehicles, and the number of electrical components mounted on the vehicle is increasing. Along with this, the location of electromagnetic relays in vehicles has also changed, and not only places where temperature and humidity changes are relatively gradual, such as in the passenger compartment, but temperature changes and humidity changes such as under the floor are relatively large. There is also a need to place electromagnetic relays in place.

  For this reason, especially in electromagnetic relays mounted on vehicles, there is a high possibility of freezing inside the housing in an environment where the outside air temperature is low, such as early morning, and this freezing causes contact between the movable terminal and the fixed terminal. Since the function as a switch cannot be exhibited if the contact between them is hindered, some countermeasure is required.

  As a measure for preventing freezing of an electromagnetic relay mounted on a vehicle, generally, a heating device such as a heater is installed in the vehicle to maintain the environmental temperature high. However, the method of preventing the electromagnetic relay from freezing by maintaining a high environmental temperature using such a heating device has a problem that the installation of the heating device increases the system size and the cost.

  As a technique for preventing freezing without causing problems due to the installation of the heating device as described above, for example, the technique described in Patent Document 1 may be applied to an electromagnetic relay. In the electromagnetic lock device that switches between locking and unlocking by moving a movable member by electromagnetic induction action of the excitation coil, the technique described in Patent Document 1 divides the excitation coil into a first coil and a second coil. The exciting coil is heated without moving the movable member by applying voltages with the same magnetomotive force to the first coil and the second coil in opposite directions, and the ambient temperature is kept high by the heat of the exciting coil. This is to prevent freezing.

If the method described in Patent Document 1 is applied to an electromagnetic relay, the electromagnetic relay itself can prevent freezing without installing a heating device such as a heater. Problems such as cost and cost increase can be avoided.
Japanese Patent No. 3362305

  However, in the method described in Patent Document 1, since the environmental temperature is kept high by heat accompanying energization of the excitation coil to prevent freezing, the excitation coil is used to keep the environmental temperature high. However, there is a problem that energy loss is large.

  The present invention was devised in view of the above-described conventional circumstances, and causes problems such as an increase in system size, an increase in cost, and an increase in energy loss, which are a concern when trying to prevent freezing. An object of the present invention is to provide a freeze release device and a freeze release method that can effectively prevent problems such as poor contact between the contact points of the movable terminal and the fixed terminal due to freezing inside the casing of the electromagnetic relay. .

  In order to achieve the above object, the present invention determines whether or not freezing has occurred inside the casing of the electromagnetic relay, and when it is determined that freezing has occurred, the freezing of the casing or inside the casing has occurred. A vibration was generated at the location, and the freezing of the inside of the housing was quickly released by this vibration in a short time.

  According to the present invention, when freezing occurs inside the casing of the electromagnetic relay, the freezing is released quickly in a short time due to the vibration of the freezing location inside the casing or inside the casing. It is possible to effectively prevent problems such as poor contact between the contacts. Further, according to the present invention, it is not necessary to install a heating device separately or to generate heat by energizing the exciting coil for a long time, so that problems such as an increase in system size, an increase in cost, and an increase in energy loss can be effectively avoided. can do.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

[Electromagnetic relay]
First, the configuration and basic operation of an electromagnetic relay to which the present invention is applied will be described with reference to FIGS. For example, in an electric four-wheel drive system mounted on a vehicle, the electromagnetic relay 10 is connected between a power source 1 for the vehicle and an electric load 2 such as a drive motor, and a power source for the electric load 2 such as a drive motor. It is used as a switch for switching between supply and cutoff.

  As shown in FIG. 1, the electromagnetic relay 10 includes an exciting coil 11 wound around a bobbin, a yoke 12 that covers the outer periphery of the exciting coil 11 and forms a magnetic circuit when the exciting coil 11 is energized, and an exciting coil. 11, the iron core 13 inserted through the inside of the yoke 12 so as to pass through the winding center, the movable terminal 15 fixed to the iron core 13 via the insulating member 14, and the movable terminal 15 so as to face each other. A pair of fixed terminals 16 are provided.

  Each of these members in the electromagnetic relay 10 is housed inside the housing 17, and only a part of the fixed terminal 16 is exposed to the outside of the housing 17. A portion of the pair of fixed terminals 16 exposed to the outside of the casing 17 is electrically connected to the power source 1 through a power line such as a copper wire, and the other casing of the pair of fixed terminals 16 is connected. A portion exposed to the outside of the body 17 is electrically connected to an electric load 2 such as a drive motor via a power line such as a copper wire.

  In the electromagnetic relay 10 configured as described above, when the excitation coil 11 is not energized, the iron core 13 is biased in the direction of arrow A in FIG. 1 by a force such as a spring (not shown), and as shown in FIG. The movable terminal 15 fixed to 13 is separated from the fixed terminal 16. As a result, the contact 15a provided on the movable terminal 15 and the contact 16a provided on the fixed terminal 16 are brought into a non-contact state, and as a result, the power source 1 and the electric load 2 are electrically disconnected. The power supply to the electric load 2 is cut off.

  On the other hand, when the excitation coil 11 is energized, a magnetic circuit is formed between the yoke 12 and the iron core 13 by the magnetic field generated by the electromagnetic induction action of the excitation coil 11, and the iron core 13 is moved against the biasing force of the spring. The power to make it work. Then, as the iron core 13 moves in the direction of arrow B in FIG. 2, the movable terminal 15 fixed to the iron core 13 is brought into a state close to the fixed terminal 16 as shown in FIG. 2. Thereby, the contact 15a provided on the movable terminal 15 and the contact 16a provided on the fixed terminal 16 are brought into contact with each other. As a result, the power source 1 and the electric load 2 are electrically connected, Power is supplied to the electric load 2. Note that the amount of movement of the iron core 13 when the exciting coil 11 is energized is regulated by, for example, the stopper 13 a provided on the iron core 13 coming into contact with the inner peripheral surface of the yoke 12.

  As described above, in the electromagnetic relay 10, the energization of the exciting coil 11 is controlled, so that the movable terminal 15 moves in the direction of approaching and separating from the fixed terminal 16, and the power source for the electric load 2 such as a drive motor is supplied. Switch between supply and shutoff. Such an electromagnetic relay 10 is also considered to be disposed in a place where a temperature change and a humidity change are relatively large, for example, under the floor of a vehicle, due to requirements on the in-vehicle layout, and is movable by freezing in a low temperature environment. In order to prevent a contact failure between the contact 15a of the terminal 15 and the contact 16a of the fixed terminal 16, it is required to take some measures. That is, when the electromagnetic relay 10 is disposed under the floor of the vehicle, for example, in an environment where the outside air temperature is extremely low, such as in a cold region or early morning, moisture in the air adheres to the inside of the housing 17 and freezes. Freezing may occur. In particular, since a part of the fixed terminal 16 is exposed to the outside of the housing 17 and exposed to the outside air, there is a high possibility of freezing when the outside air temperature becomes extremely low, and the fixed terminal 16 is frozen to cover the contact 16a of the fixed terminal 16. When the layer is formed, a contact failure occurs between the exciting coil 11 and the contact 15a of the movable terminal 15 when the energizing coil 11 is energized, and the function as a switch cannot be properly exhibited.

  The present invention has been proposed as one of the effective measures for preventing the contact failure between the movable terminal 15 and the fixed terminal 16 due to freezing inside the casing 17 of the electromagnetic relay 10 as described above. When it is determined whether or not the inside of the casing 17 of the electromagnetic relay 10 has been frozen, and it is determined that the freezing has occurred, vibration is generated at the freezing occurrence location inside the casing 17 or the casing 17. The main feature is that the internal freezing of the housing 17 is quickly released in a short time by this vibration. The electromagnetic relay to which the present invention is applied is not particularly limited to the electromagnetic relay 10 having the above-described configuration. The present invention is such that the movable terminal is moved closer to and away from the fixed terminal by the electromagnetic induction action of the exciting coil. The present invention is widely applicable to electromagnetic relays that perform switching by moving in the direction in which they move.

  Hereinafter, first to fourth embodiments will be described as specific examples of the freeze release apparatus according to the present invention.

[First embodiment]
FIG. 3 is a configuration diagram for explaining the freeze release apparatus of the first embodiment. The freeze release device of this example is realized as a function of the control unit 20 that controls the operation of the electromagnetic relay 10, and repeatedly moves the movable terminal 15 of the electromagnetic relay 10 in the direction of approaching and separating from the fixed terminal 16. By moving, the housing 17 or a portion where freezing occurs inside the housing 17 is vibrated to release the freezing inside the housing 17.

  The control unit 20 switches between power supply and shut-off for the electric load 2 such as a drive motor by controlling energization to the excitation coil 11 as described above, for example, according to an external on / off command, for example. Take control. In this example, the control unit 20 is provided with a function as the frozen state determination means 21 and a function as the vibration generation means 22 in addition to the normal control functions as described above.

  The frozen state determination means 21 determines whether or not freezing has occurred inside the casing 17 of the electromagnetic relay 10. Specifically, the control unit 20 has a circuit voltage on the power source 1 side to which one of the pair of fixed terminals 16 of the electromagnetic relay 10 is connected and an electric power to which the other of the pair of fixed terminals 16 is connected. The circuit voltage on the load 2 side is input. Further, for example, a detection value of a temperature sensor 31 installed in the vicinity of the casing 17 of the electromagnetic relay 10 and the fixed terminal 16 exposed to the outside thereof is input to the control unit 20. Then, the frozen state determination means 21 of the control unit 20 energizes the exciting coil 11 to move the movable terminal 15 in the direction approaching the fixed terminal 16, and thereby contacts 15 a of the movable terminal 15 and contacts 16 a of the fixed terminal 16. The circuit voltage on the power source 1 side and the circuit voltage on the electric load 2 side when the operation is made to contact are compared, and depending on whether or not the difference is equal to or less than a predetermined threshold value, the movable terminal 15 and the fixed terminal 16 is determined. Then, a potential difference exceeding the threshold value is generated, the electrical continuity between the movable terminal 15 and the fixed terminal 16 is determined to be defective, and the inside of the casing 17 of the electromagnetic relay 10 is frozen based on the detection value of the temperature sensor 31. In the case where it is estimated that the temperature state is reached, it is determined that the inside of the casing 17 of the electromagnetic relay 10 is frozen.

  The vibration generation means 22 generates vibration at the vibration generation location in the casing 17 or the casing 17 when the frozen state determination means 21 determines that the inside of the casing 17 of the electromagnetic relay 10 is frozen. Is. Specifically, the vibration generating means 22 repeatedly applies and stops the voltage to the exciting coil 11 of the electromagnetic relay 10 and repeatedly moves the movable terminal 15 in the direction of approaching and separating from the fixed terminal 16. Vibration is generated at the freezing occurrence location in the housing 17 or the housing 17.

  In this example, assuming that the fixed terminal 16 is likely to be frozen particularly in a low temperature environment, in order to effectively remove the icing layer adhering to the contact 16a surface of the fixed terminal 16, Try to generate large vibrations. In order to realize this, the vibration generating means 22 fixes the frequency when moving the movable terminal 15 in the direction of approaching and separating from the fixed terminal 16, that is, the repetition frequency of applying and stopping the voltage to the exciting coil 11. The resonance frequency of the terminal 16 is set, and the fixed terminal 16 is caused to vibrate at the resonance frequency. As a result, a vibration with a large amplitude is generated in the fixed terminal 16, and the effect of freezing release is increased.

  The resonance frequency of the fixed terminal 16 of the electromagnetic relay 10 may be calculated in advance from the structure and material of the fixed terminal 16 or may be obtained by actually manufacturing a part and conducting an experiment or the like in advance. May be. Further, in the process of repeatedly applying and stopping the voltage to the exciting coil 11, the vibration amplitude of the fixed terminal 16 may be measured and control may be performed to adjust the frequency so that the amplitude becomes large. In addition, even if the repetition frequency of applying and stopping the voltage to the exciting coil 11 does not completely match the resonance frequency of the fixed terminal 16, the effect of the fixed terminal 16 and the ease of control are taken into consideration. A frequency close to the resonance frequency may be selected.

  FIG. 4 shows a series of steps executed by the control unit 20 in order to release the freezing of the inside of the casing 17 of the electromagnetic relay 10 in the freeze releasing device of the present example realized as one function of the control unit 20 as described above. It is a flowchart which shows the flow of a process of. The processing flow shown in FIG. 4 is started, for example, when the ignition switch of the vehicle is switched from OFF to ON, or when the electric four-wheel drive system using the electromagnetic relay 10 is activated.

  When the processing flow of FIG. 4 is started, the control unit 20 first initializes the value of the number n of repetitions of voltage application and stop to the exciting coil 11 of the electromagnetic relay 10 to 0 in step S101. Next, in step S <b> 102, the control unit 20 applies a predetermined voltage to the excitation coil 11 of the electromagnetic relay 10, and moves the movable terminal 15 in a direction close to the fixed terminal 16. Then, the control unit 20 makes the movable terminal 15 close to the fixed terminal 16 and the circuit voltage Vs on the power source 1 side connected to one of the pair of fixed terminals 16 of the electromagnetic relay 10 in step S103. The circuit voltage Vl on the electric load 2 side connected to the other of the pair of fixed terminals 16 is measured, and in step S104, the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is measured. That is, it is confirmed whether or not the potential difference between one and the other of the pair of fixed terminals 16 of the electromagnetic relay 10 is equal to or less than a predetermined threshold value V0. The threshold value V0 includes the electrical resistance value of the fixed terminal 16, the electrical resistance value of the movable terminal 15, the contact resistance between the contact 16a of the fixed terminal 16 and the contact 15a of the movable terminal 15, and each. Considering the change of the resistance value due to temperature, etc., the optimum value is set in advance.

  If the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is not more than the threshold value V0 in this step S104, the electrical conduction state between the movable terminal 15 and the fixed terminal 16 is good. Therefore, the control unit 20 determines that freezing has not occurred in the housing 17, and ends the processing flow shown in FIG. On the other hand, if the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side exceeds the threshold value V0 in step S104, the process proceeds to step S105.

  Next, in step S105, the control unit 20 stops applying voltage to the exciting coil 11 of the electromagnetic relay 10, and in step S106, the temperature detection value detected by the temperature sensor 31 is a predetermined threshold T. It is determined whether it is below ℃. Here, the threshold value T ° C. is the distance from the freezing point of a liquid such as water or the position where the temperature sensor 31 is installed to the expected freezing point (in this example, the vicinity of the contact 16a of the fixed terminal 16 inside the housing 17). In consideration of the specific heat of the material of the fixed terminal 16 where freezing is expected, the optimum value is set in advance.

  If the detected value of the temperature sensor 31 exceeds the threshold value T ° C in this step S106, it is between the movable terminal 15 and the fixed terminal 16 even though the inside of the casing 17 of the electromagnetic relay 10 is not in a temperature state leading to freezing. Therefore, the control unit 20 determines that a failure has occurred in the electromagnetic relay 10 due to some factor other than freezing inside the housing 17. Then, for example, processing such as notifying the vehicle occupant to that effect by displaying a warning light or the like is performed, and the processing flow shown in FIG.

  On the other hand, if the detected value of the temperature sensor 31 is equal to or lower than the threshold T ° C. in step S106, the control unit 20 increments the value of the number n of repetitions of voltage application and stop to the exciting coil 11 in the next step S107. Then, in step S108, the control unit 20 determines whether or not the value of the number of repetitions n of applying and stopping the voltage to the exciting coil 11 has reached a predetermined value N, and applying and stopping the voltage to the exciting coil 11. If the value of the number of repetitions n has not reached the specified value N, the process returns to step S102 to resume the application of voltage to the exciting coil 11, and the subsequent processing is repeated.

  Here, in this example, the frequency at which the control unit 20 repeats applying and stopping the voltage to the exciting coil 11 is set to a member that is expected to generate freezing inside the housing 17, specifically, In this example, the resonance frequency f0 of the fixed terminal 16 is set. As a result, with the movement of the movable terminal 15 due to the electromagnetic induction action of the exciting coil 11, vibration with a frequency matching the resonance frequency f0 of the fixed terminal 16 is generated, and the fixed terminal 16 vibrates with a large amplitude. . When the icing layer on the surface of the contact 16a is removed by the vibration of the fixed terminal 16, the electrical continuity between the movable terminal 15 and the fixed terminal 16 becomes good, so that the control unit 20 performs step S104. Then, it is confirmed that the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is equal to or less than the threshold value V0, and the processing flow shown in FIG.

  On the other hand, if the electrical continuity between the movable terminal 15 and the fixed terminal 16 is not recovered even if the voltage application to the exciting coil 11 is repeatedly applied and stopped until the value of the number of repetitions n reaches the specified value N. The control unit 20 shifts the process to step S109, determines that a failure has occurred in the electromagnetic relay 10 due to some factor other than freezing inside the housing 17, and for example, displays the warning light on the vehicle. Processing such as notifying the passenger to that effect is performed, and the processing flow shown in FIG. 4 ends.

  As described above in detail with a specific example, according to the freeze release apparatus of the first embodiment of the present invention, the control unit 20 that controls the operation of the electromagnetic relay 10 includes the housing of the electromagnetic relay 10. 17, specifically, whether or not the freezing has occurred in the vicinity of the contact 16 a of the fixed terminal 16, and when the freezing has occurred, the voltage application to the exciting coil 11 is repeatedly applied and stopped, By repeatedly moving the movable terminal 15 in the direction of approaching and separating from the fixed terminal 16, the frozen fixed terminal 16 is vibrated to release the freezing. It is possible to effectively prevent a problem such as a contact failure between the contact points of the movable terminal 15 and the fixed terminal 16 of the electromagnetic relay 10 as a factor.

  In particular, in the freeze release apparatus of this example, the freeze is released by mechanically vibrating the fixed terminal 16 or the like that is the place where the freeze has occurred. Compared with the case of releasing, it is possible to quickly release the freeze in a short time.

  Further, in the freeze release device of this example, the fixed terminal 16 or the like where the freeze occurs is caused to vibrate at a frequency that matches the resonance frequency of the self, so that the fixed terminal 16 or the like is vibrated with a large amplitude. And freezing can be released efficiently.

  Further, in the freeze release device of this example, the freeze is released by the operation of the electromagnetic relay 10 itself. For example, there is no need to separately install a dedicated heating device or the like for releasing the freeze. Problems such as an increase in the size of the system and an increase in cost, which are a concern when a heating device or the like is separately installed, can be effectively avoided.

  Further, in the freeze release device of this example, the electromagnetic relay 10 is energized only when it is determined that freezing has occurred in the housing 17 of the electromagnetic relay 10, and the fixed terminal 16 or the like where the freezing occurs is mechanically vibrated. Since the freezing is released by the operation, for example, in order to prevent the freezing itself, the energy loss can be greatly reduced as compared with the case where the exciting coil is energized for a long time to generate heat. .

  In the above description, the control unit 20 repeatedly applies and stops the voltage to the exciting coil 11, and repeatedly moves the movable terminal 15 in the direction of approaching and separating from the fixed terminal 16. The vibration of the frequency matching the resonance frequency of the freezing occurrence location is generated, but the vibration of the frequency matching the resonance frequency of the casing 17 of the electromagnetic relay 10 is generated to make the casing 17 with a large amplitude. Even if it is made to vibrate, it is effective in releasing freezing inside the housing 17.

[Second Embodiment]
Next, a freeze release apparatus according to a second embodiment of the present invention will be described. The freeze release device of this example is realized as one function of the control unit 20 that controls the operation of the electromagnetic relay 10 as in the first embodiment described above. The movable terminal 15 of the electromagnetic relay 10 is fixed to the fixed terminal 16. The fixed terminal 16 or the like where the freezing occurs is vibrated by repeatedly moving it in the direction of approaching and separating, thereby releasing the freezing.

  However, in the freeze release device of this example, the excitation coil 11 of the electromagnetic relay 10 is used when the vibration generating means 22 of the control unit 20 performs a process of releasing the freeze by vibrating the fixed terminal 16 or the like where the freeze is generated. Is set to a voltage higher than the voltage value applied to the exciting coil 11 during normal switching operation. Further, in the freeze release device of this example, when the vibration generating means 22 of the control unit 20 performs a process of releasing the freeze by vibrating the fixed terminal 16 or the like where the freeze is generated, the voltage is applied to the excitation coil 11. Is set to be longer than the time to stop the voltage application.

  FIG. 5 is a flowchart showing a flow of a series of processes executed by the control unit 20 in order to release the freezing inside the casing 17 of the electromagnetic relay 10 in the freeze releasing device of this example. The processing flow shown in FIG. 5 is started, for example, when the ignition switch of the vehicle is switched from OFF to ON, or when the electric four-wheel drive system using the electromagnetic relay 10 is activated.

  When the processing flow of FIG. 5 is started, the control unit 20 first initializes the value n of the number of repetitions of applying and stopping the voltage to the excitation coil 11 of the electromagnetic relay 10 to 0 in step S201. 11 is set to a value Va equivalent to the voltage applied during normal switching operation.

  Next, in step S202, the control unit 20 applies the voltage Va set in step S201 to the exciting coil 11 of the electromagnetic relay 10 to move the movable terminal 15 in a direction close to the fixed terminal 16. Then, counting of the voltage application time T1 is started by a built-in timer or the like. In step S203, the control unit 20 sets the circuit voltage Vs on the power source 1 side connected to one of the pair of fixed terminals 16 of the electromagnetic relay 10 in a state where the movable terminal 15 is brought close to the fixed terminal 16. Then, the circuit voltage Vl on the electric load 2 side connected to the other of the pair of fixed terminals 16 is measured, and in step S204, the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is measured. That is, it is confirmed whether or not the potential difference between one and the other of the pair of fixed terminals 16 of the electromagnetic relay 10 is equal to or less than a predetermined threshold value V0.

  If the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is less than or equal to the threshold value V0 in step S204, the electrical continuity between the movable terminal 15 and the fixed terminal 16 is good. Therefore, the control unit 20 determines that freezing has not occurred in the housing 17, and ends the processing flow shown in FIG. On the other hand, if the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side exceeds the threshold value V0 in step S204, the process proceeds to step S205.

  Next, in step S205, the control unit 20 waits until the voltage application time T1 reaches a predetermined time Tm set in advance, and resets the timer when the voltage application time T1 reaches the predetermined time Tm, and then proceeds to step S206. move on. In step S206, the control unit 20 stops applying voltage to the exciting coil 11 of the electromagnetic relay 10 and starts counting the voltage application stop time T2. In step S207, the temperature detected by the temperature sensor 31 is started. It is determined whether or not the detected value is equal to or lower than a predetermined threshold value T ° C.

  If the detected value of the temperature sensor 31 exceeds the threshold value T ° C in this step S207, it is between the movable terminal 15 and the fixed terminal 16 even though the inside of the casing 17 of the electromagnetic relay 10 is not in a temperature state leading to freezing. Therefore, the control unit 20 determines that a failure has occurred in the electromagnetic relay 10 due to some factor other than freezing inside the housing 17. Then, for example, processing such as notifying the vehicle occupant to that effect by displaying a warning light or the like is performed, and the processing flow shown in FIG.

  On the other hand, if the detected value of the temperature sensor 31 is less than or equal to the threshold T ° C in step S207, the control unit 20 increments the value of the number n of repetitions of voltage application and stop to the exciting coil 11 in the next step S208. Then, in step S209, the control unit 20 determines whether or not the value of the number of repetitions n of applying and stopping the voltage to the exciting coil 11 has reached a predetermined value N, and applying and stopping the voltage to the exciting coil 11. If the value of the number of repetitions n has not reached the specified value N, the process proceeds to step S211.

  Next, in step S211, the control unit 20 waits until the voltage application stop time T2 reaches a preset time Tn, and resets the timer when the voltage application stop time T2 reaches the predetermined time Tn. The process proceeds to S212. The predetermined time Tn used for the determination in step S211 and the predetermined time Tm used for the determination in step S206 described above are set so as to satisfy the relationship of Tn <Tm. That is, in this example, the voltage application time T1 for the exciting coil 11 is set to be longer than the voltage application stop time T2.

  Next, in step S212, the control unit 20 switches the value of the applied voltage V to the exciting coil 11 from a value Va equivalent to the applied voltage at the time of normal switching operation to Vu larger than Va. Returning to S202, the application of voltage to the exciting coil 11 is restarted, and the subsequent processing is repeated.

  Here, in this example, the frequency at which the control unit 20 repeats applying and stopping the voltage to the exciting coil 11 is set to a member that is expected to generate freezing inside the housing 17, specifically, In this example, the resonance frequency f0 of the fixed terminal 16 is set. As a result, with the movement of the movable terminal 15 due to the electromagnetic induction action of the exciting coil 11, vibration with a frequency matching the resonance frequency f0 of the fixed terminal 16 is generated, and the fixed terminal 16 vibrates with a large amplitude. . When the frozen layer or the like on the surface of the contact 16a is removed by the vibration of the fixed terminal 16, the electrical continuity between the movable terminal 15 and the fixed terminal 16 becomes good. Therefore, the control unit 20 performs step S204. Then, it is confirmed that the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is equal to or less than the threshold value V0, and the processing flow shown in FIG.

  On the other hand, if the electrical continuity between the movable terminal 15 and the fixed terminal 16 is not recovered even after the voltage application and stop to the exciting coil 11 are repeated until the number of repetitions n reaches the specified value N, the control is performed. The unit 20 shifts the process to step S210, determines that a failure has occurred in the electromagnetic relay 10 due to some factor other than freezing inside the housing 17, and for example, displays a warning light to the vehicle occupant. Processing such as notification to that effect is performed, and the processing flow shown in FIG. 5 ends.

  As described above in detail with a specific example, according to the freeze release apparatus of the second embodiment of the present invention, the operation of the electromagnetic relay 10 is similar to the freeze release apparatus of the first embodiment described above. The control unit 20 that controls the internal combustion engine 10 determines whether or not freezing has occurred in the housing 17 of the electromagnetic relay 10, specifically in the vicinity of the contact 16a of the fixed terminal 16, and when freezing has occurred, By repeatedly applying and stopping the voltage to the exciting coil 11 and repeatedly moving the movable terminal 15 in the direction of approaching and separating from the fixed terminal 16, the fixed terminal 16 in which freezing has occurred is vibrated to release the freezing. Thus, it is possible to effectively prevent problems such as poor contact between the movable terminal 15 and the fixed terminal 16 of the electromagnetic relay 10 due to freezing inside the housing 17.

  Further, in the freeze release device of this example, the freeze is released by mechanically vibrating the fixed terminal 16 or the like where the freeze occurs, as in the freeze release device of the first embodiment described above. For example, it is possible to quickly release the freeze in a short time as compared with the case of releasing the freeze by heating the freezing occurrence portion.

  In addition, in the freeze release device of this example, as with the freeze release device of the first embodiment described above, vibrations having a frequency matching the resonance frequency of the self are generated in the fixed terminal 16 where the freeze is generated. Therefore, the fixed terminal 16 can be vibrated with a large amplitude, and freezing can be efficiently released.

  Further, in the freeze release device of the present example, as in the freeze release device of the first embodiment described above, the freeze is released by the operation of the electromagnetic relay 10 itself. For example, dedicated heating for releasing the freeze is performed. Since it is not necessary to separately install a device or the like, it is possible to effectively avoid problems such as an increase in the size of the system and an increase in cost, which are a concern when such a heating device or the like is separately installed.

  Further, in the freeze release device of this example, as in the freeze release device of the first embodiment described above, the electromagnetic relay 10 is energized only when it is determined that freezing has occurred inside the housing 17 of the electromagnetic relay 10, Since the freezing is released by mechanically vibrating the fixed terminal 16 or the like where the freezing occurs, for example, the exciting coil is energized for a long time to generate heat in order to prevent the freezing itself. Compared to the case, energy loss can be greatly reduced.

  Further, in the freeze release device of this example, when the application of the voltage to the excitation coil 11 of the electromagnetic relay 10 and the stop thereof are repeated to vibrate the fixed terminal 16 or the like where the freezing occurs, the voltage is applied to the excitation coil 11. Since the voltage value is set to be higher than the voltage value applied to the exciting coil 11 during normal switching operation, the kinetic energy of the movable terminal 15 is increased to make the fixed terminal 16 have a larger amplitude. It can be vibrated and freezing can be released efficiently in a shorter time.

  Furthermore, in the freeze release apparatus of this example, when the application of the voltage to the excitation coil 11 of the electromagnetic relay 10 and the stop are repeated to vibrate the fixed terminal 16 or the like that is the place where freezing occurs, the voltage application time T1 to the excitation coil 11 Is set longer than the voltage application stop time T2, so that the freezing can be released by utilizing the temperature rise effect of the exciting coil 11 in addition to the vibration of the fixed terminal 16 and the like. Freezing can be released efficiently.

[Third embodiment]
Next, a freeze releasing apparatus according to a third embodiment of the present invention will be described. The freeze release device of this example is realized as one function of the control unit 20 that controls the operation of the electromagnetic relay 10 as in the first and second embodiments described above. 15 is repeatedly moved in the direction of approaching and separating from the fixed terminal 16 to vibrate the fixed terminal 16 and the like where the freezing occurs, thereby releasing the freezing.

  However, in the first and second embodiments described above, the frozen state is generated each time the vibration generating means 22 of the control unit 20 repeats the voltage application to the exciting coil 11 of the electromagnetic relay 10 and stops once. The determination means 21 performs the determination of the frozen state (determination of whether or not the freezing has been released). However, in the freeze releasing apparatus of this example, every time the voltage application to the excitation coil 11 and the stop are repeated a predetermined number of times, The frozen state determination means 21 performs determination of the frozen state (determination of whether or not the freezing has been released).

  In the freeze release apparatus of this example, the control unit 20 performs the above processing, so that the control unit 20 can be used even when the resonance frequency of the fixed terminal 16 or the like where the freeze occurs is a relatively high frequency. Without significantly increasing the processing capacity, the fixed terminal 16 or the like where the freezing occurs is caused to vibrate at a frequency matching the resonance frequency of the self, so that the freezing can be efficiently released.

  That is, in the freeze release apparatus of the present example, as in the first and second embodiments described above, the fixed terminal 16 that is the freezing occurrence location generates vibrations having a frequency that matches the resonance frequency of the self-resonance frequency. However, when the resonance frequency of the fixed terminal 16 or the like is high, depending on the processing capability of the control unit 20, the determination of the frozen state is performed in accordance with the resonance frequency of the fixed terminal 16. It may be difficult to do. Assuming such a situation, the freeze release apparatus of this example performs determination of the frozen state (determination of freeze release) every time the voltage application and stop to the excitation coil 11 are repeated a predetermined number of times. Without significantly increasing the processing capacity, the fixed terminal 16 or the like where the freezing occurs is caused to vibrate at a frequency matching the resonance frequency of the self, so that the freezing can be released efficiently.

  FIG. 6 is a flowchart showing a flow of a series of processes executed by the control unit 20 in order to release the freezing inside the casing 17 of the electromagnetic relay 10 in the freeze releasing device of this example. The processing flow shown in FIG. 6 is started, for example, when the ignition switch of the vehicle is switched from OFF to ON, or when the electric four-wheel drive system using the electromagnetic relay 10 is activated.

  When the processing flow of FIG. 6 is started, first, the control unit 20 initializes the value of the number of repetitions m at a predetermined number of times of applying and stopping the voltage to the exciting coil 11 of the electromagnetic relay 10 to 0 in step S301. . Next, in step S <b> 302, the control unit 20 applies a predetermined voltage to the excitation coil 11 of the electromagnetic relay 10, and moves the movable terminal 15 in a direction close to the fixed terminal 16. Then, the control unit 20 sets the circuit voltage Vs on the power source 1 side connected to one of the pair of fixed terminals 16 of the electromagnetic relay 10 in step S303 in a state where the movable terminal 15 is brought close to the fixed terminal 16. The circuit voltage Vl on the electric load 2 side connected to the other of the pair of fixed terminals 16 is measured, and in step S304, the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is measured. That is, it is confirmed whether or not the potential difference between one and the other of the pair of fixed terminals 16 of the electromagnetic relay 10 is equal to or less than a predetermined threshold value V0.

  If the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is equal to or less than the threshold value V0 in step S304, the electrical continuity between the movable terminal 15 and the fixed terminal 16 is good. Therefore, the control unit 20 determines that freezing has not occurred in the housing 17, and ends the processing flow shown in FIG. On the other hand, if the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side exceeds the threshold value V0 in step S304, the process proceeds to step S305.

  Next, in step S305, the control unit 20 stops applying voltage to the exciting coil 11 of the electromagnetic relay 10, and in step S306, the temperature detection value detected by the temperature sensor 31 is a predetermined threshold T. It is determined whether it is below ℃.

  If the detected value of the temperature sensor 31 exceeds the threshold value T ° C in this step S306, it is between the movable terminal 15 and the fixed terminal 16 even though the inside of the casing 17 of the electromagnetic relay 10 is not in a temperature state leading to freezing. Therefore, the control unit 20 proceeds to step S310 and determines that a failure has occurred in the electromagnetic relay 10 due to some factor other than freezing inside the housing 17. Then, for example, processing such as notifying the vehicle occupant to that effect by displaying a warning light or the like is performed, and the processing flow shown in FIG.

  On the other hand, if the detected value of the temperature sensor 31 is equal to or lower than the threshold T ° C. in step S306, the control unit 20 continues to apply and stop the voltage to the exciting coil 11 in a predetermined predetermined number of times in the next step S307. repeat. At this time, the control unit 20 sets the repetition frequency when applying and stopping the voltage to the exciting coil 11 to a member that is expected to be frozen inside the housing 17, specifically in this example. The resonance frequency f0 of the fixed terminal 16 is set. As a result, with the movement of the movable terminal 15 due to the electromagnetic induction action of the exciting coil 11, vibration with a frequency matching the resonance frequency f0 of the fixed terminal 16 is generated, and the fixed terminal 16 vibrates with a large amplitude. . It should be noted that the number of times of voltage application to the exciting coil 11 repeatedly stopped in step S307 is set in advance in accordance with the processing capability of the control unit 20 and the resonance frequency f0 of the freezing location such as the fixed terminal 16. deep.

  Next, in step S308, the control unit 20 increments the value of the number of repetitions m every predetermined number of times of applying and stopping the voltage to the exciting coil 11. Then, in step S309, the control unit 20 determines whether or not the value of the number of repetitions m for each predetermined number of times of applying and stopping the voltage to the exciting coil 11 has reached a predetermined specified value M, and If the value of the number of repetitions m for each predetermined number of times of voltage application and stop does not reach the specified value M, the process returns to step S302 to apply a voltage to the exciting coil 11 and bring the movable terminal 15 close to the fixed terminal 16. The frozen state is determined again in the above state.

  When the control unit 20 repeatedly performs the above processing, if the icing layer or the like on the surface of the contact 16a is removed by the vibration of the fixed terminal 16, the electrical continuity between the movable terminal 15 and the fixed terminal 16 is good. Therefore, in step S304, the control unit 20 confirms that the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is equal to or less than the threshold value V0, and ends the processing flow shown in FIG. To do.

  On the other hand, if the electrical continuity between the movable terminal 15 and the fixed terminal 16 is not recovered even after the above processing is repeated until the value of the number of repetitions m at a predetermined number of times reaches the specified value M, the control is performed. The unit 20 shifts the process to step S310, determines that the electromagnetic relay 10 has failed due to some factor other than freezing inside the casing 17, and for example displays the warning light to the vehicle occupant. Processing to notify that effect is performed, and the processing flow shown in FIG. 6 is ended.

  As described above in detail with specific examples, according to the freeze release apparatus of the third embodiment of the present invention, the freeze release apparatus of the first embodiment and the freeze release apparatus of the second embodiment described above. Similarly, the control unit 20 that controls the operation of the electromagnetic relay 10 determines whether or not the inside of the casing 17 of the electromagnetic relay 10, specifically, the vicinity of the contact 16 a of the fixed terminal 16 is frozen, When freezing has occurred, the application of the voltage to the exciting coil 11 and the stop are repeated, and the movable terminal 15 is repeatedly moved in the direction of approaching and separating from the fixed terminal 16, thereby fixing the freezing. Since the terminal 16 is vibrated to release the freezing, the problem of poor contact between the contact between the movable terminal 15 of the electromagnetic relay 10 and the fixed terminal 16 due to freezing inside the housing 17 is effectively obtained. It can be stopped.

  Further, in the freeze release device of this example, similarly to the freeze release device of the first embodiment and the freeze release device of the second embodiment described above, the fixed terminal 16 or the like where the freeze occurs is mechanically vibrated. Since the freezing is released, for example, it is possible to release the freezing quickly in a short time compared to the case where the freezing occurrence portion is heated to release the freezing.

  Further, in the freeze release device of this example, similar to the freeze release device of the first embodiment and the freeze release device of the second embodiment described above, the fixed terminal 16 or the like where the freezing occurred matches the resonance frequency of its own. Since the vibration of the frequency is generated, the fixed terminal 16 can be vibrated with a large amplitude, and the freezing can be efficiently released.

  Further, in the freeze release device of the present example, the freeze release is released by the operation of the electromagnetic relay 10 itself, similarly to the freeze release device of the first embodiment and the freeze release device of the second embodiment described above. Since there is no need to install a dedicated heating device to release the freeze, it is possible to effectively avoid problems such as an increase in the size of the system and an increase in cost that are a concern when such a heating device is installed separately. Can do.

  Further, in the freeze release device of this example, it was determined that the freeze occurred inside the casing 17 of the electromagnetic relay 10 as in the freeze release device of the first embodiment and the freeze release device of the second embodiment. Only when the electromagnetic relay 10 is energized and the freezing is released by mechanically vibrating the fixed terminal 16 or the like where the freezing occurs, for example, in order to prevent the freezing itself, Energy loss can be greatly reduced compared to the case where heat is generated by energizing for a long time.

  Furthermore, in the freeze release apparatus of this example, the freeze state is determined (determining whether the freeze has been released) every time the voltage application and stop to the excitation coil 11 are repeated a predetermined number of times. Even when the resonance frequency of the fixed terminal 16 that is a location is a relatively high frequency, the fixed terminal 16 that is the location where the freeze occurs is set to its own resonance frequency without significantly increasing the processing capability of the control unit 20. Freezing can be efficiently released by generating vibrations with matching frequencies.

[Fourth embodiment]
Next, a freeze release apparatus according to a fourth embodiment of the present invention will be described. As shown in FIG. 7, the freeze release apparatus of the present example has a vibration motor 32 as vibration generation means attached to the outside of the casing 17 of the electromagnetic relay 10, and the vibration generated by the vibration motor 32 is transmitted to the electromagnetic relay 10. By transmitting the vibration from the housing 17 to the place where the vibration is generated inside the housing 17, freezing inside the housing 17 is released. In the freeze release apparatus of this example, the control unit 20 is provided with a function as the vibration motor control means 23 for controlling the operation of the vibration motor 32 instead of the function as the vibration generation means 22 described above. I have to.

  As shown in FIG. 8, the vibration motor 32 has a weight 32c attached to a tip portion of a motor rotating shaft 32b protruding from a motor body 32a such as a DC motor so that the weight balance is biased. In the vibration motor 32 having such a structure, when a current is supplied to the motor main body 32a to rotate the motor rotation shaft 32b, the vibration of the motor rotation shaft 32b due to the weight 32c being attached causes vibration. Will occur. The frequency of vibration generated by the vibration motor 32 can be adjusted by controlling the rotation speed of the vibration motor 32.

  In the freeze release device of the present example, the vibration motor 32 of the control unit 20 is configured so that the vibration motor 32 generates a vibration that matches the resonance frequency of the fixed terminal 16 that is a freezing occurrence location in the casing 17 of the electromagnetic relay 10. The control means 23 controls the operation of the vibration motor 32. The vibration generated by the vibration motor 32 is transmitted from the casing 17 of the electromagnetic relay 10 to the fixed terminal 16 inside the casing 17, so that the resonance frequency of the fixed terminal 16, which is a freezing occurrence location, is increased. Even in the case of a high frequency exceeding the physical limit point due to the weight and inertia of the 10 movable parts, the fixed terminal 16 is vibrated at a frequency matching the resonance frequency of its own, so that it can be efficiently frozen. It can be released.

  That is, as in the first to third embodiments described above, the movable terminal 15 is repeatedly moved in the direction of approaching and separating from the fixed terminal 16 to thereby fix the fixed terminal 16 and the like where the freezing occurs. When freezing is released by vibrating, the speed at which movable parts such as the movable terminal 15 and the iron core 13 can move is physically limited due to its weight, inertia, etc., so the fixed terminal 16 that is the place where freezing occurs. The maximum vibration frequency that can be generated is determined by the physical limit of the movable part. Therefore, when the resonance frequency of the fixed terminal 16 or the like where the freezing occurs is a high frequency exceeding the physical limit point of such a movable part, the first to third embodiments described above are used. According to the technique, it is impossible to generate a vibration having a frequency that matches the resonance frequency of the fixed terminal 16 or the like where the freezing occurs.

  Assuming such a situation, the freeze release device of this example uses a vibration motor 32 capable of generating a vibration of a relatively high frequency as the vibration generating means, and this vibration motor 32 is connected to the housing of the electromagnetic relay 10. The vibration generated by the vibration motor 32 attached to the body 17 is transmitted from the casing 17 of the electromagnetic relay 10 to the fixed terminal 16 inside the casing 17, so that the resonance frequency of the fixed terminal 16, etc. where the freezing occurs. Even at a high frequency exceeding the physical limit point of the movable part of the electromagnetic relay 10, it is possible to generate a vibration with a frequency matching the resonance frequency of the fixed terminal 16 or the like so that the freezing can be efficiently released. I have to.

  In this example, the vibration motor 32 is illustrated as the vibration generating means for transmitting the own vibration from the casing 17 of the electromagnetic relay 10 to the freezing location in the casing 17, but such a vibration generating means. In addition to the vibration motor 32, various vibration generators can be applied. For example, a vibration generator using a piezoelectric ceramic having a property that distortion is generated by application of a voltage can be effectively applied.

  FIG. 9 is a flowchart showing a flow of a series of processes executed by the control unit 20 in order to release the freezing of the inside of the casing 17 of the electromagnetic relay 10 in the freeze releasing device of this example. The processing flow shown in FIG. 9 is started, for example, when the ignition switch of the vehicle is switched from OFF to ON, or when the electric four-wheel drive system using the electromagnetic relay 10 is activated.

  When the processing flow of FIG. 9 is started, the control unit 20 first initializes the value of the number of operations 1 of the vibration motor 32 to 0 in step S401. Next, in step S <b> 402, the control unit 20 applies a predetermined voltage to the excitation coil 11 of the electromagnetic relay 10, and moves the movable terminal 15 in a direction close to the fixed terminal 16. Then, the control unit 20 sets the circuit voltage Vs on the power source 1 side connected to one of the pair of fixed terminals 16 of the electromagnetic relay 10 in step S403 in a state where the movable terminal 15 is brought close to the fixed terminal 16. The circuit voltage Vl on the electric load 2 side connected to the other of the pair of fixed terminals 16 is measured, and in step S404, the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is measured. That is, it is confirmed whether or not the potential difference between one and the other of the pair of fixed terminals 16 of the electromagnetic relay 10 is equal to or less than a predetermined threshold value V0.

  If the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is not more than the threshold value V0 in step S404, the electrical continuity between the movable terminal 15 and the fixed terminal 16 is good. Therefore, the control unit 20 determines that freezing has not occurred in the housing 17, and ends the processing flow shown in FIG. On the other hand, if the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side exceeds the threshold value V0 in step S404, the process proceeds to step S405.

  Next, in step S405, the control unit 20 stops applying the voltage to the exciting coil 11 of the electromagnetic relay 10, and in step S406, the temperature detection value detected by the temperature sensor 31 is a predetermined threshold T. It is determined whether it is below ℃.

  If the detected value of the temperature sensor 31 exceeds the threshold value T ° C in step S406, the space between the movable terminal 15 and the fixed terminal 16 is not affected by the temperature inside the casing 17 of the electromagnetic relay 10 being frozen. Therefore, the control unit 20 proceeds to step S410 and determines that the electromagnetic relay 10 has failed due to some factor other than freezing inside the housing 17. Then, for example, processing such as notifying the vehicle occupant of the fact by displaying a warning light or the like is performed, and the processing flow shown in FIG. 9 is ended.

  On the other hand, if the detected value of the temperature sensor 31 is equal to or lower than the threshold T ° C. in step S406, the control unit 20 operates the vibration motor 32 attached to the casing 17 of the electromagnetic relay 10 for a predetermined time in the next step S407. . At this time, the control unit 20 causes the vibration motor 32 to generate a vibration that matches the resonance frequency f0 of the member that is expected to be frozen inside the housing 17, more specifically, in this example. The number of rotations of the vibration motor 32 is controlled. As a result, the vibration of the vibration motor 32 is transmitted from the housing 17 of the electromagnetic relay 10 to the fixed terminal 16 inside the housing 17, and a vibration having a frequency matching the resonance frequency f 0 is generated on the fixed terminal 16. The terminal 16 vibrates with a large amplitude.

  Next, in step S408, the control unit 20 increments the value of the number of operations 1 of the vibration motor 32. In step S409, the control unit 20 determines whether or not the value of the number of operations 1 of the vibration motor 32 has reached a predetermined value L, and the value of the number of operations 1 of the vibration motor 32 is the specified value L. If not, the process returns to step S402 to apply a voltage to the exciting coil 11, and the frozen state is determined again in a state where the movable terminal 15 is brought close to the fixed terminal 16.

  When the control unit 20 repeatedly performs the above processing, if the icing layer or the like on the surface of the contact 16a is removed by the vibration of the fixed terminal 16, the electrical continuity between the movable terminal 15 and the fixed terminal 16 is good. Therefore, in step S404, the control unit 20 confirms that the difference between the circuit voltage Vs on the power source 1 side and the circuit voltage Vl on the electric load 2 side is equal to or less than the threshold value V0, and ends the processing flow shown in FIG. To do.

  On the other hand, if the electrical continuity state between the movable terminal 15 and the fixed terminal 16 is not recovered even after the above processing is repeated until the value of the number of actuations l of the vibration motor 32 reaches the specified value L, the control is performed. The unit 20 proceeds to step S410 and determines that the electromagnetic relay 10 has failed due to some factor other than freezing inside the housing 17, and for example, displays a warning light to the vehicle occupant. Processing such as notifying that effect is performed, and the processing flow shown in FIG. 9 ends.

  As described above in detail with a specific example, according to the freeze release apparatus of the fourth embodiment of the present invention, the control unit 20 that controls the operation of the electromagnetic relay 10 includes the housing of the electromagnetic relay 10. 17, specifically, whether or not freezing has occurred in the vicinity of the contact 16 a of the fixed terminal 16, and if freezing has occurred, the vibration of the vibration motor 32 is transferred from the housing 17 to the inside of the housing 17. The fixed terminal 16 that has been frozen is vibrated and released from freezing, so that it is fixed to the movable terminal 15 of the electromagnetic relay 10 due to freezing inside the housing 17. Problems such as poor contact between the contacts with the terminal 16 can be effectively prevented.

  Further, in the freeze release device of this example, similarly to the freeze release device of the first embodiment to the freeze release device of the third embodiment described above, the fixed terminal 16 or the like where the freeze occurs is mechanically vibrated. Since the freezing is released, for example, it is possible to release the freezing quickly in a short time compared to the case where the freezing occurrence portion is heated to release the freezing.

  Further, in the freeze release device of the present example, similar to the freeze release device of the first embodiment to the freeze release device of the third embodiment described above, the fixed terminal 16 or the like where the freezing occurs matches the resonance frequency of its own. Since the vibration of the frequency is generated, the fixed terminal 16 can be vibrated with a large amplitude, and the freezing can be efficiently released.

  In the freeze release device of this example, the vibration motor 32 is operated only when it is determined that freezing has occurred inside the casing 17 of the electromagnetic relay 10, and the fixed terminal 16 or the like where the freezing occurs is mechanically vibrated. Since the freezing is released by the operation, for example, in order to prevent the freezing itself, the energy loss can be greatly reduced as compared with the case where the exciting coil is energized for a long time to generate heat. .

  Further, in the freeze release device of this example, the vibration of the vibration motor 32 is transmitted from the casing 17 of the electromagnetic relay 10 to the fixed terminal 16 in the casing 17 so as to vibrate the fixed terminal 16 in which freezing has occurred. Therefore, even if the resonance frequency of the fixed terminal 16 or the like where the freezing occurs is a high frequency exceeding the physical limit point due to the weight or inertia of the movable part of the electromagnetic relay 10, the fixed terminal 16 or the like. Freezing can be efficiently released by generating a vibration having a frequency matching the resonance frequency of the self.

  In the above description, it is assumed that the fixed terminal 16 inside the casing 17 of the electromagnetic relay 10 is frozen. However, as in the freeze release device of this example, its own vibration is reduced. When using a vibration generator such as the vibration motor 32 that transmits from the housing 17 to the freezing location in the housing 17, for example, the iron core 13 in the housing 17 is frozen and the movable terminal 15 is fixed. Even when the terminal 16 cannot be repeatedly moved in the direction of approaching and separating from the terminal 16, the freezing can be released by appropriately generating vibration at the freezing occurrence location inside the housing 17.

  In the above description, the vibration generating device such as the vibration motor 32 is caused to generate a vibration having a frequency that matches the resonance frequency of the freezing occurrence location inside the casing 17 of the electromagnetic relay 10. Even if the casing 17 is vibrated with a large amplitude by generating a vibration having a frequency matching the resonance frequency of the casing 17, it is effective in releasing the freezing inside the casing 17.

  Specific examples of the electromagnetic relay freeze release device according to the present invention have been described in detail as the first to fourth embodiments. However, each of the above embodiments is an example of application of the present invention. The technical scope of the invention is not limited to the contents disclosed in the description of each of the above embodiments, and various alternative techniques that can be easily derived from these disclosures are also included.

  For example, in each of the above-described embodiments, the control unit 20 has a temperature at which the electrical continuity between the movable terminal 15 and the fixed terminal 16 is poor and the inside of the casing 17 of the electromagnetic relay 10 is frozen. When it is estimated that the state is in the state, it is determined that the inside of the casing 17 of the electromagnetic relay 10 is frozen. However, only the electrical conduction state between the movable terminal 15 and the fixed terminal 16 is determined. It may be determined whether or not the inside of the casing 17 of the electromagnetic relay 10 is frozen based on the above, or based on only the temperature state inside the casing 17 of the electromagnetic relay 10 It may be determined whether or not freezing has occurred.

  The determination as to whether or not the inside of the casing 17 of the electromagnetic relay 10 has been frozen is made, for example, by detecting a collision sound between the movable terminal 15 and the fixed terminal 16 with a sound collecting microphone, and a normal collision sound and freezing. You may make it carry out by the method of comparing with the collision sound at the time of generation | occurrence | production.

  Further, for example, by confirming the operating state of the electric load 2 electrically connected to one of the pair of fixed terminals 16 of the electromagnetic relay 10, the inside of the casing 17 of the electromagnetic relay 10 is frozen. You may make it employ | adopt the method of determining whether it exists.

It is sectional drawing which shows typically the internal structure of the electromagnetic relay used as the application object of this invention. It is sectional drawing which shows the state which the movable terminal of an electromagnetic relay moves to the direction which adjoins to a fixed terminal, and the contacts are contacting. It is a block diagram for demonstrating the freeze release apparatus of 1st Example. 6 is a flowchart showing a flow of a series of processes executed by a control unit in order to release the freezing inside the casing of the electromagnetic relay in the freeze releasing device of the first embodiment. It is a flowchart which shows the flow of a series of processes performed by the control unit in order to cancel freezing inside the housing | casing of an electromagnetic relay in the freezing release apparatus of 2nd Example. It is a flowchart which shows the flow of a series of processes performed by the control unit in order to cancel freezing inside the housing | casing of an electromagnetic relay in the freeze release apparatus of 3rd Example. It is a block diagram for demonstrating the freeze release apparatus of 4th Example. It is a perspective view which shows the vibration motor used as a vibration generation means in the freezing release apparatus of 4th Example. In the freeze release apparatus of 4th Example, it is a flowchart which shows the flow of a series of processes performed by the control unit in order to release the freeze inside the housing | casing of an electromagnetic relay.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electromagnetic relay 11 Excitation coil 15 Movable terminal 16 Fixed terminal 17 Case 20 Control unit 21 Frozen state determination means 22 Vibration generating means 23 Vibration motor control means 31 Temperature sensor 32 Vibration motor

Claims (9)

An electromagnetic relay in which an exciting coil, a movable terminal, and a fixed terminal are housed in a housing, and switching is performed by moving the movable terminal in a direction approaching and separating from the fixed terminal by electromagnetic induction action of the exciting coil. A freeze release device,
Frozen state determining means for determining whether or not freezing has occurred inside the housing;
And a vibration generating means for generating vibration at the freezing occurrence location in the casing or in the casing when it is determined by the freezing state determining means that the casing is frozen. Electromagnetic relay freeze release device.   The said vibration generation means generates the vibration of the frequency corresponding to the resonance frequency of these housing | casing or freezing occurrence location in the housing | casing or the freezing occurrence location inside the said housing | casing. Freezing release device for electromagnetic relays.   The vibration generating means repeatedly applies and stops the voltage to the exciting coil, and repeatedly moves the movable terminal in a direction approaching and separating from the fixed terminal, thereby freezing the casing or the interior of the casing. The electromagnetic relay freeze release device according to claim 1 or 2, wherein vibration is generated at an occurrence location.   The said vibration generation means makes the voltage applied with respect to the said excitation coil higher voltage than the voltage applied with respect to the said excitation coil in the case of normal switching operation. Electromagnetic relay freeze release device.   4. The electromagnetic relay freeze release apparatus according to claim 3, wherein the vibration generating unit sets a time for applying a voltage to the excitation coil to be longer than a time for stopping the application of the voltage. .   The vibration generating unit transmits vibrations of the vibration generating unit itself to the freezing occurrence location in the housing or the housing, thereby generating vibration at the freezing occurrence location in the housing or the housing. The freeze release apparatus of the electromagnetic relay of Claim 1 or 2 characterized by these.   The frozen state determining means determines the electrical continuity state between the movable terminal and the fixed terminal when the movable terminal is moved in a direction approaching the fixed terminal. 2. The electromagnetic relay freeze release device according to claim 1, wherein it is determined whether or not the internal freeze has occurred.   The frozen state determining means determines whether or not freezing has occurred inside the casing based on a temperature of the casing or a temperature of a member exposed to the outside of the casing. Item 2. The electromagnetic relay freeze release device according to item 1. An electromagnetic relay in which an exciting coil, a movable terminal, and a fixed terminal are housed in a housing, and switching is performed by moving the movable terminal in a direction approaching and separating from the fixed terminal by electromagnetic induction action of the exciting coil. A freezing release method for releasing freezing of the electromagnetic relay when freezing occurs inside the housing,
A first step of determining whether or not freezing has occurred inside the housing;
A second step of generating a vibration at the freezing location in the case or in the case when it is determined in the first step that the case has been frozen. The method of releasing the freeze of the electromagnetic relay.

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