JP5630303B2 - Non-contact power transmission cutoff device - Google Patents

Description

  The present invention relates to a non-contact power transmission cutoff device that is free from impact and wear and has no transmission loss.

  In vehicles and other machines, a power transmission cutoff device capable of turning power transmission on and off is provided in a path for transmitting power from a prime mover that generates rotational force such as an engine (internal combustion engine) or a motor to a load rotated by the rotational force. Intervene. In particular, in a vehicle using an engine as a prime mover, a power transmission cutoff device is indispensable and important.

  The power transmission shut-off device includes a mechanical clutch that transmits rotational power by mechanically pressing a clutch plate attached to an input shaft and a clutch plate attached to an output shaft, and a rotating body on the input side. 2. Description of the Related Art There is known a fluid joint in which a flow of a working fluid that is rotated rotates a rotating body on an output side.

JP 2005-143185 A Japanese Patent Laid-Open No. 11-278076

  In the mechanical clutch, when the clutch plates are connected to each other, an impact due to a rapid rotation is easily generated, and the control for reducing the impact is complicated. In addition, since the mechanical clutch has slippage between the clutch plates, the clutch plates are worn and maintenance becomes complicated.

  On the other hand, the fluid joint has little impact when rotation starts to be transmitted and wear of the member is small, but transmission loss occurs due to internal friction in the working fluid. Generation of transmission loss is not preferable from the viewpoint of energy saving.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a non-contact power transmission cutoff device that solves the above-described problems, has no impact and wear, and has no transmission loss.

  In order to achieve the above object, a non-contact power transmission cutoff device according to the present invention includes an input shaft coil attached to an input shaft, an output shaft coil attached to an output shaft arranged coaxially with the input shaft, A power feeding circuit that applies current to one of the input shaft coil and the output shaft coil, a take-out circuit that extracts induced power from the other one of the input shaft coil and the output shaft coil, and a magnetic field line to the input shaft coil An outer yoke that is attached to the input shaft so as to guide and covers the outer periphery of the output shaft, and an inner yoke that is attached to the output shaft so as to guide the magnetic force lines to the output shaft coil and faces the outer yoke from the inner periphery. And at least a part of the inner yoke is configured to be movable so that a gap with the outer yoke is narrowed as the rotational speed of the output shaft increases.

  You may provide the lock member which locks up the said input shaft and the said output shaft.

  When interrupting power transmission between the input shaft and the output shaft, the lock member is unlocked, current application from the power supply circuit is stopped, and the input shaft and the output shaft are accelerated to accelerate the output shaft. When transmitting power between the output shafts, if the rotational speed difference between the input shaft and the output shaft is greater than or equal to a predetermined value, the lock member is unlocked, current is applied from the power feeding circuit, and A control circuit that performs power extraction to an extraction circuit and locks the lock member and stops current application from the power supply circuit if a difference in rotational speed between the input shaft and the output shaft is less than a predetermined value; You may prepare.

  When transmitting power between the input shaft and the output shaft to decelerate the output shaft, the control circuit locks up the lock member if the rotational speed of the output shaft is equal to or higher than a first predetermined value. If the current application from the power supply circuit is stopped and the rotational speed of the output shaft is less than a first predetermined value and greater than or equal to a second predetermined value (second predetermined value <first predetermined value), the lock member is The lockup is released, the current is applied from the power supply circuit and the power is extracted to the extraction circuit.If the rotation speed of the output shaft is less than a second predetermined value, the lock member is locked up, Current application from the power feeding circuit may be stopped.

  The present invention exhibits the following excellent effects.

  (1) No impact or wear.

  (2) There is no transmission loss.

It is a lineblock diagram of the non-contact power transmission cutoff device showing one embodiment of the present invention. It is an image figure of the electromagnet and inner yoke seen from the axial direction at the time of electric power feeding of the non-contact power transmission cutoff device of FIG. It is a model circuit diagram of the electric power feeding circuit and extraction circuit of the non-contact power transmission cutoff device of FIG. It is a figure which shows the control state at the time of the vehicle stop engine idling of the non-contact power transmission cutoff apparatus of FIG. It is a figure which shows the control state at the time of start acceleration of the non-contact power transmission cutoff device of FIG. It is a figure which shows the control state during acceleration of the non-contact power transmission interruption | blocking apparatus of FIG. It is a figure which shows the control state at the time of constant speed driving | running | working of the non-contact power transmission interruption | blocking apparatus of FIG. It is a figure which shows the control state at the time of the deceleration of the non-contact power transmission interruption | blocking apparatus of FIG. It is a wave form diagram of the vibration of an output shaft.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  The non-contact power transmission cutoff device 1 shown in FIG. 1 is applied to a vehicle having an engine (not shown) as a prime mover. That is, the output shaft of the engine corresponds to the input shaft 2 of the non-contact power transmission cutoff device 1, and the output shaft 3 of the non-contact power transmission cutoff device 1 corresponds to the input shaft of the transmission (not shown).

  The non-contact power transmission cutoff device 1 includes an input shaft coil 4 attached to the input shaft 2, an output shaft coil 5 attached to the output shaft 3 disposed coaxially with the input shaft 2, and current to the input shaft coil 4. A feeding circuit 6 for applying a power, a take-out circuit 7 for extracting induced power from the output shaft coil 5, an outer yoke 8 attached to the input shaft 2 so as to guide magnetic lines of force to the input shaft coil 4 and covering the outer periphery of the output shaft 3. An inner yoke 9 attached to the output shaft 3 so as to guide the magnetic field lines to the output shaft coil 5 and facing the outer yoke 8 from the inner periphery is provided.

  A part of the inner yoke 9 is configured to be movable so that the gap with the outer yoke 8 is narrowed as the rotational speed of the output shaft 3 increases.

  The non-contact power transmission cutoff device 1 includes a lock member 10 that locks up the input shaft 2 and the output shaft 3.

  When the non-contact power transmission cutoff device 1 interrupts the power transmission between the input shaft 2 and the output shaft 3, the lock member 10 is unlocked, and the current application from the power feeding circuit 6 to the input shaft coil 4 is stopped. When power is transmitted between the input shaft 2 and the output shaft 3 in order to accelerate the output shaft 3, the lock member 10 is locked up if the rotational speed difference between the input shaft 2 and the output shaft 3 is greater than or equal to a predetermined value. The current is applied from the power supply circuit 6 to the input shaft coil 4 and the power is extracted from the output shaft coil 5 to the extraction circuit 7 so that the rotational speed difference between the input shaft 2 and the output shaft 3 is less than a predetermined value. If there is a control circuit 11 that locks up the lock member 10 and stops the application of current from the power supply circuit 6.

  When transmitting the power between the input shaft 2 and the output shaft 3 to decelerate the output shaft 3, the control circuit 11 locks up the lock member 10 if the rotational speed of the output shaft 3 is equal to or higher than the first predetermined value. The current application from the power supply circuit 6 to the input shaft coil 4 is stopped, and if the rotational speed of the output shaft 3 is less than the first predetermined value and greater than or equal to the second predetermined value (second predetermined value <first predetermined value). The lock member 10 is unlocked, current is applied from the power supply circuit to the input shaft coil 4, power is extracted from the output shaft coil 5 to the extraction circuit 7, and the rotation speed of the output shaft 3 is a second predetermined value. If it is less, the lock member 10 is locked up, and the current application from the power feeding circuit 6 to the input shaft coil 4 is stopped. Here, the rotational speed of the output shaft 3 being equal to or higher than the first predetermined value means that the vehicle is traveling at a high speed, and the rotational speed of the output shaft 3 being less than the first predetermined value and being equal to or higher than the second predetermined value. This means that the vehicle is traveling at a medium speed, and that the rotational speed of the output shaft 3 is less than the second predetermined value means that the vehicle is traveling at a low speed.

  In the present embodiment, an outer yoke 8 that covers the outer periphery of the end of the output shaft 3 is provided at the end of the input shaft 2, and a plurality of protrusions 12 projecting radially inward are formed on the inner periphery of the outer yoke 8. Is done. The input shaft coil 4 is obtained by winding an electric wire around these protrusions 12. On the other hand, an inner yoke 9 is provided at the end of the output shaft 3. The inner yoke 9 is formed with a plurality of movable pieces 13 that protrude radially outwardly facing the protrusions 12 of the outer yoke 8. In the drawing, the movable piece 13 is located on the innermost circumference and the gap with the projection 12 of the outer yoke 8 is shown to be the widest. When the gap with the projection 12 of the outer yoke 8 is the narrowest, the movable piece 13 is Come to the position of the broken line. The output shaft coil 5 is obtained by winding an electric wire around these movable pieces 13.

  The input shaft coil 4 is connected to the power feeding circuit 6 via a slip ring 14 provided on the input shaft 2. The output shaft coil 5 is connected to the extraction circuit 7 via a slip ring 15 provided on the output shaft 3.

  The power feeding circuit 6 applies a direct current from a battery (not shown) to the input shaft coil 4. The input shaft coil 4 forms a DC electromagnet when a DC current is applied from the power feeding circuit 6.

  As shown in FIG. 2, in this embodiment, twelve protrusions 12 of the outer yoke 8 are provided at a constant pitch in the circumferential direction. The electric wires (not shown) of the projections 12 are wired so that the polarity of the DC electromagnet appearing at the tip of each projection 12 when the DC current is applied from the power supply circuit 6 is alternately reversed in the circumferential direction. In this way, the input shaft coil 4 is formed by winding the electric wire around each protrusion 12.

  Twelve movable pieces 13 of the inner yoke 9 are provided at a constant pitch in the circumferential direction. An electric wire (not shown) of each movable piece 13 is wired so that the induced power for each electric wire of each movable piece 13 is superimposed and taken out. Thus, the output shaft coil 5 is formed by winding an electric wire around each movable piece 13.

  With this configuration, if the input shaft coil 4 forms a DC electromagnet when the rotational speeds of the input shaft 2 and the output shaft 3 are different, inductive power is generated in the output shaft coil 5. Inductive power extracted from the output shaft coil 5 is alternating current.

  The movable piece 13 and the inner yoke 9 are connected via an elastic deformation member 16. The elastic deformation member 16 is biased when the movable piece 13 is moved radially outward of the inner yoke 9 by an external force, and functions to pull the movable piece 13 back radially inward when the external force is released. Specifically, the external force is a centrifugal force that acts on the movable piece 13 by the rotation of the output shaft 3. That is, when the rotation speed of the output shaft 3 is low, the centrifugal force acting on the movable piece 13 is small and the deformation of the elastic deformation member 16 is small, so the movable piece 13 is positioned radially inward. When the rotation speed of the output shaft 3 is increased, the centrifugal force acting on the movable piece 13 is increased, the deformation of the elastic deformation member 16 is increased, and the movable piece 13 is moved radially outward. A member that restricts the movable piece 13 from moving in a direction other than the radial direction and guides the movable piece 13 in the radial direction, a member that restricts the movable piece 13 from moving outward in the radial direction by a predetermined distance, or the like may be provided. Good.

  The take-out circuit 7 in FIG. 1 includes a rectifier circuit (not shown) that rectifies the inductive power into direct current, and a charging circuit (not shown) that charges the battery with the electric power taken out as direct current.

  FIG. 3 shows models of the feeding circuit 6 and the extraction circuit 7.

  The power feeding circuit 6 is a circuit that allows a direct current to flow from the battery to the input shaft coil 4. Although not shown, a switch element for stopping power feeding is inserted. The extraction circuit 7 is a circuit configured to extract electric power from the generator G including the output shaft coil 5 to the extraction destination. As a take-out destination, there is a battery that charges the rectified one, or some load that consumes electric power.

  The lock member 10 shown in FIG. 1 is mechanically composed of a clutch plate (not shown) attached to the input shaft 2 and a clutch plate (not shown) attached to the output shaft 3 in the same manner as a conventional mechanical clutch. It is configured to be locked up by being pressed against and to transmit rotational power.

  The control circuit 11 is realized by software executed by an electronic control unit (hereinafter referred to as ECU) and numerical values, a map, and a table stored in a memory inside the ECU. The rotational speeds of the input shaft 2 and the output shaft 3 are detected by a conventionally known rotational speed sensor and notified to the ECU. The state of the engine and the driving situation of the vehicle are always grasped by the ECU, as is conventionally known.

  Hereinafter, the control by the control circuit 11 and the change of the gap will be described for each control state.

  As shown in FIG. 4, when the vehicle is stopped (engine idling), the control circuit 11 releases the lock member 10 to unlock the power transmission between the input shaft 2 and the output shaft 3, and feeds the power supply circuit 6. Current application to the input shaft coil 4 is stopped. Since the input shaft coil 4 does not become a DC electromagnet, even if the input shaft 2 rotates, the output shaft coil 5 does not change the lines of magnetic force, and no inductive power is generated. As a result, the input shaft 2 rotates at the idling rotational speed, but the output shaft 3 remains stopped.

  Since the output shaft 3 is not rotating, the movable piece 13 is located radially inward and the gap is wide.

  As shown in FIG. 5, when the vehicle starts to accelerate, the input shaft 2 is controlled from an idling rotational speed to a higher rotational speed. When the vehicle starts, the output shaft 3 is stopped. Since the rotational speed difference between the input shaft 2 and the output shaft 3 is equal to or greater than a predetermined value, the control circuit 11 applies a current from the power feeding circuit 6 to the input shaft coil 4 with the lock member 10 being unlocked. At the same time, power is extracted from the output shaft coil 5 to the extraction circuit 7. By applying a current to the input shaft coil 4, a DC electromagnet having a magnetic pole is formed at the tip of each projection 12 of the outer yoke 8 of the input shaft 2. Since this DC electromagnet rotates together with the input shaft 2, a rotating magnetic field is generated. This rotating magnetic field generates induced power in the output shaft coil 5. When this induced power is taken out by the take-out circuit 7, a transmission torque is generated between the input shaft 2 and the output shaft 3, and the output shaft 3 is rotated with respect to the rotating magnetic field.

  The principle of such power transmission and power extraction is similar to that of an electromagnetic retarder that is one of auxiliary brakes used in large vehicles. In the electromagnetic retarder, braking is generated by generating an eddy current in the retarder drum connected to the shaft to be braked, and heat is generated in the retarder drum by the eddy current. That is, braking energy is released as heat. In the present invention, the induction power is extracted by the extraction circuit 7 without being consumed by the internal resistance.

  During this time, since the rotation speed of the output shaft 3 is not sufficiently high, the movable piece 13 has not moved much in the radial direction and the gap is wide.

  When the difference in rotational speed between the input shaft 2 and the output shaft 3 is sufficiently large, a certain amount of electric power is extracted by the extraction circuit 7. As the rotational speed of the output shaft 3 increases and the rotational speed difference between the input shaft 2 and the output shaft 3 decreases, the magnitude of the extracted electric power also decreases. Further, when the rotational speed difference between the input shaft 2 and the output shaft 3 is large, the coupling force between the input shaft 2 and the output shaft 3 is large, but the rotational speed difference between the input shaft 2 and the output shaft 3 decreases. If it comes, the coupling force of the input shaft 2 and the output shaft 3 will become weak.

  However, on the other hand, since the rotational speed of the output shaft 3 increases, the movable piece 13 moves outward in the radial direction. That is, as shown in FIG. 6, during the acceleration from the start acceleration to the constant speed operation, the gap becomes narrow according to the increase in the rotation speed of the output shaft 3. By reducing the gap, the coupling force between the input shaft 2 and the output shaft 3 is increased. Therefore, even if the rotational speed difference between the input shaft 2 and the output shaft 3 is reduced, a certain level of high transmission torque is maintained, and the magnitude of electric power is also maintained to some extent.

  If the rotational speed difference between the input shaft 2 and the output shaft 3 further decreases, the coupling force between the input shaft 2 and the output shaft 3 is weakened even if the gap is narrowed. Therefore, when the difference in rotational speed between the input shaft 2 and the output shaft 3 becomes less than a predetermined value, the control is switched. The predetermined value used for the determination is preferably set by an experiment or the like in consideration of the coupling force between the input shaft 2 and the output shaft 3 and the extracted power.

  As shown in FIG. 7, the difference in rotational speed between the input shaft 2 and the output shaft 3 is small during constant speed operation. If the rotational speed difference between the input shaft 2 and the output shaft 3 is less than a predetermined value, the control circuit 11 locks up the lock member 10 and stops the current application from the power feeding circuit 6. The lock member 10 performs mechanical lockup. However, since the lockup is performed when the difference in rotational speed between the input shaft 2 and the output shaft 3 is small, no impact or wear occurs.

  When the vehicle is decelerated, different control is performed in three stages according to the speed of the vehicle (the rotational speed of the output shaft 3).

  When the vehicle is at high speed, that is, when the rotational speed of the output shaft 3 is equal to or higher than the first predetermined value, the movable piece 13 moves outward in the radial direction, so the gap is narrow. If the lock member 10 is unlocked at this time, the amplitude of the vibration of the output shaft 3 increases, which is not preferable. In order to avoid this, the control circuit 11 keeps the lock member 10 locked up and keeps the current application from the power supply circuit 6 stopped. When the vehicle is decelerating, the input shaft 2 is controlled to the idling rotational speed, so the output shaft 3 is decelerated by the action of the engine brake.

  When the vehicle is at a medium speed, that is, when the rotational speed of the output shaft 3 is less than the first predetermined value and greater than or equal to the second predetermined value, the movable piece 13 moves radially inward and the gap becomes wider. Since the clearance of the output shaft 3 to be described in detail later is secured, the control circuit 11 releases the lock-up member 10 to apply a current from the power supply circuit 6 to the input shaft coil 4 and to take out from the output shaft coil 5. Take out power to 7.

  As shown in FIG. 8, the input shaft 2 is controlled to the idling rotational speed. On the other hand, the rotation speed of the output shaft 3 is medium. A DC electromagnet having a magnetic pole at the tip of each projection 12 is formed by applying current to the input shaft coil 4 as in the case of starting acceleration. Unlike the start acceleration, the rotational speed of the input shaft 2 is the idling rotational speed, whereas the rotational speed of the output shaft 3 is higher than that. Therefore, there is no output between the input shaft 2 and the output shaft 3. A transmission torque for braking the shaft 3 is generated. In this way, the engine brake state where the load is braked by the engine is entered, and the output shaft 3 is decelerated. Even during the deceleration operation, when the difference in rotational speed between the input shaft 2 and the output shaft 3 is sufficiently large as in the start acceleration, a certain amount of electric power is extracted by the extraction circuit 7.

  When the vehicle becomes low speed, that is, when the rotational speed of the output shaft 3 becomes less than the second predetermined value, the rotational speed difference between the input shaft 2 and the output shaft 3 is small, and the gap is widened. This makes it difficult to transmit power and extract power. Therefore, the control circuit 11 locks up the lock member 10 and stops the application of current from the power feeding circuit 6.

  Table 1 summarizes the control states of power supply, power extraction, and lock-up when the vehicle is stopped, when starting and accelerating, when traveling at a constant speed, and when decelerating (three stages).

  On the other hand, the change of the gap is as follows.

  When the rotational speed of the input shaft 2 is high and the rotational speed of the output shaft 3 is low, the rotational speed difference between the input shaft 2 and the output shaft 3 is large, so the frequency of the generated power is high and the power is large. At this time, power is transmitted from the input shaft 2 to the output shaft 3 with a high transmission torque, and accordingly, the amplitude of vibration of the output shaft 3 is large. That is, as indicated by a one-dot chain line in FIG. 9, the output shaft 3 vibrates with a high frequency and a large amplitude. Thus, since the amplitude of the vibration of the output shaft 3 is large, a wide gap is required to ensure the clearance of the output shaft 3 with respect to the input shaft 2. Therefore, if the gap is fixed, a limit is defined from the amplitude of the output shaft 3 when the rotational speed difference is large (fixed gap limit).

  If the rotational speed of the output shaft 3 increases while the gap remains fixed, the rotational speed difference between the input shaft 2 and the output shaft 3 decreases, and the frequency of the generated power decreases and simultaneously the power decreases. The transmission torque from the input shaft 2 to the output shaft 3 also decreases. At this time, as indicated by a broken line in FIG. 9, the output shaft 3 vibrates with a low frequency and a very small amplitude.

  On the other hand, if the gap is narrowed as the rotational speed of the output shaft 3 is increased, the rotational speed of the output shaft 3 is increased, and the difference in rotational speed between the input shaft 2 and the output shaft 3 is decreased. Therefore, the frequency of the generated power is low because the difference in rotational speed is small, but since the gap is narrow, the magnitude of the electric power is secured to a certain level, and the transmission torque is also secured to a certain level. However, since the amplitude of the vibration of the output shaft 3 increases as the transmission torque increases as compared with the case where the gap is fixed, the output shaft 3 has a low frequency and a slightly larger amplitude as shown by the solid line in FIG. Vibrate. At this time, in order to secure the clearance of the output shaft 3 with respect to the input shaft 2, a slightly large amplitude shown by a solid line may be considered. For this purpose, a narrow gap is sufficient as compared with the fixed case, and a limit for narrowing the gap is defined from the amplitude of the output shaft 3 (limit of the variable gap). Therefore, the movable width of the movable piece 13 is determined.

  As described above, according to the non-contact power transmission cutoff device 1 of the present invention, the input shaft coil 4 attached to the input shaft 2 and the output attached to the output shaft 3 arranged coaxially with the input shaft 2. Since the shaft coil 5, the power feeding circuit 6 that applies current to the input shaft coil 4, and the extraction circuit 7 that extracts the induced power from the output shaft coil 5 are provided, there is a difference in rotational speed between the input shaft 2 and the output shaft 3. If there is, power can be transmitted between the input shaft 2 and the output shaft 3 by applying current to the input shaft coil 4 and extracting power from the output shaft coil 5 to the extraction circuit 7. As described above, the non-contact power transmission cutoff device 1 can recover a part of electric power while obtaining a transmission torque between the input shaft 2 and the output shaft 3 by electromagnetic induction. At this time, since the input shaft 2 and the output shaft 3 are not in contact with each other, the non-contact power transmission cutoff device 1 has no impact or wear, and there is no transmission loss because no working fluid is interposed.

  According to the non-contact power transmission cutoff device 1 of the present invention, the power transmission between the input shaft 2 and the output shaft 3 can be cut off as long as the current application from the power feeding circuit 6 to the input shaft coil 4 is stopped. Therefore, an actuator for holding the clutch plate in the clutch disengaged state as in the conventional mechanical clutch is unnecessary, and the configuration is simplified.

  According to the non-contact power transmission cutoff device 1 of the present invention, the outer yoke 8 that is attached to the input shaft 2 and covers the outer periphery of the output shaft 3 so as to guide the magnetic lines of force to the input shaft coil 4, and the magnetic lines of force are guided to the output shaft coil 5. And an inner yoke 9 that is attached to the output shaft 3 and faces the outer yoke 8 from the inner periphery, and the inner yoke 9 is partially spaced from the outer yoke 8 in accordance with an increase in the rotational speed of the output shaft 3. It is configured to be movable so as to narrow. Therefore, when the rotational speed of the input shaft 2 and the output shaft 3 approaches in the process from the start acceleration of the vehicle to the constant speed operation, the gap becomes narrow due to the increase of the rotational speed of the output shaft 3, Power can be maintained. As a result, power transmission and power generation in a non-contact manner can be continued while securing a clearance for vibration of the output shaft 3. Further, when the lock-up is performed by the lock member 10, the difference in rotational speed between the input shaft 2 and the output shaft 3 can be minimized as compared with the case where the gap is fixed, so that impact and friction can be minimized.

  According to the non-contact power transmission cutoff device 1 of the present invention, since the lock member 10 for locking up the input shaft 2 and the output shaft 3 is provided, the rotational speed difference between the input shaft 2 and the output shaft 3 is small, and the input shaft When the coupling force between 2 and the output shaft 3 is weak, the input shaft 2 and the output shaft 3 can be locked up and power transmission can be continued. At this time, the coupling by the lock member 10 is a mechanical coupling like the conventional mechanical clutch, but locks up when the rotational speed difference between the input shaft 2 and the output shaft 3 is small. Absent. Further, the lock member 10 does not require a complicated configuration or control for reducing the impact, and can be configured and controlled more simply than a conventional mechanical clutch.

  According to the non-contact power transmission cutoff device 1 of the present invention, when the control circuit 11 accelerates the output shaft 3, if the rotational speed difference between the input shaft 2 and the output shaft 3 is greater than or equal to a predetermined value, the lock member 10 is unlocked, current is applied from the power supply circuit 6 to the input shaft coil 4 and power is extracted from the output shaft coil 5 to the extraction circuit 7, and the rotational speed difference between the input shaft 2 and the output shaft 3 is reduced. If it is less than the predetermined value, the lock member 10 is locked up, and the current application from the power supply circuit 6 is stopped. Therefore, the power transmission by the electromagnetic induction and the power transmission by the lock-up have respective advantages. The power transmission between the input shaft 2 and the output shaft 3 can be achieved by switching so as to be utilized.

  According to the non-contact power transmission cutoff device 1 of the present invention, the control circuit 11 performs different power transmission control according to the rotational speed of the output shaft 3 when the output shaft 3 is decelerated. Power can be taken out while the speed reaches from the first predetermined value to the second predetermined value.

  In this embodiment, the engine is controlled to the idling rotation speed during the deceleration operation, but the engine may be stopped during the deceleration operation. Even in this case, braking is performed by applying current from the power feeding circuit 6 to the input shaft coil 4 and extracting power from the output shaft coil 5 to the extraction circuit 7.

  In the present embodiment, the non-contact power transmission cutoff device 1 is applied to a vehicle using an engine as a prime mover, but can also be applied to a vehicle using a motor as a prime mover. The non-contact power transmission cutoff device 1 is not limited to a vehicle, and can be installed in a path for transmitting power from a prime mover of any machine to a load.

  In this embodiment, the input shaft coil 4 is configured such that the projections 12 around which the windings are wound are arranged at 12 locations and the N poles and the S poles of the electromagnet are alternately arranged six by six. Any number of can be used.

  In the present embodiment, in the output shaft coil 5, the movable pieces 13 around which the windings are wound are arranged at twelve locations like the protrusions 12 of the input shaft coil 4. The number of protrusions 12 of the input shaft coil 4 is not necessarily the same.

  In the present embodiment, current is applied from the power supply circuit 6 to the input shaft coil 4 and power is extracted from the output shaft coil 5 to the extraction circuit 7. However, current is applied from the power supply circuit 6 to the output shaft coil 5. Even if the power is extracted from the input shaft coil 4 to the extraction circuit 7, the effect of the present invention can be obtained.

DESCRIPTION OF SYMBOLS 1 Non-contact power transmission cutoff device 2 Input shaft 3 Output shaft 4 Input shaft coil 5 Output shaft coil 6 Feed circuit 7 Extraction circuit 8 Outer yoke 9 Inner yoke 10 Lock member 11 Control circuit 12 Protrusion 13 Movable piece

Claims (4)

An input shaft coil attached to the input shaft;
An output shaft coil attached to an output shaft disposed coaxially with the input shaft;
A power feeding circuit for applying a current to one of the input shaft coil and the output shaft coil, a take-out circuit for extracting induced power from the other one of the input shaft coil and the output shaft coil,
An outer yoke attached to the input shaft to guide the magnetic field lines to the input shaft coil and covering an outer periphery of the output shaft;
An inner yoke attached to the output shaft so as to guide magnetic lines of force to the output shaft coil and facing the outer yoke from the inner periphery;
The non-contact power transmission cutoff device, wherein at least a part of the inner yoke is configured to be movable so that a gap with the outer yoke is narrowed as the rotational speed of the output shaft increases.   The non-contact power transmission cutoff device according to claim 1, further comprising a lock member that locks up the input shaft and the output shaft. When interrupting power transmission between the input shaft and the output shaft, the lock member is unlocked, and the current application from the power supply circuit is stopped,
When transmitting power between the input shaft and the output shaft to accelerate the output shaft,
If the rotational speed difference between the input shaft and the output shaft is greater than or equal to a predetermined value, the lock member is unlocked, the current is applied from the power supply circuit and the power is extracted to the extraction circuit,
The control circuit according to claim 1, further comprising a control circuit configured to lock up the lock member and stop current application from the power feeding circuit when a difference in rotational speed between the input shaft and the output shaft is less than a predetermined value. The non-contact power transmission cutoff device according to 2. When the control circuit transmits power between the input shaft and the output shaft to decelerate the output shaft,
If the rotation speed of the output shaft is equal to or higher than a first predetermined value, the lock member is locked up, and current application from the power feeding circuit is stopped,
If the rotation speed of the output shaft is less than a first predetermined value and greater than or equal to a second predetermined value (second predetermined value <first predetermined value), the lock member is unlocked, and current application from the power feeding circuit is performed. And taking out power to the take-out circuit,
4. The non-contact power transmission cutoff device according to claim 3, wherein when the rotational speed of the output shaft is less than a second predetermined value, the lock member is locked up and current application from the power feeding circuit is stopped. .