JP2017223339A - Control device of electromagnetic clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discharge contaminations, such as iron powder, in an electromagnetic clutch, thereby suppressing the deterioration of a performance and durability of a clutch due to the contaminations sandwiched between clutch facings.SOLUTION: Revolution speed difference generating control means 26 is provided which, in switching an electromagnetic clutch 14 from a release condition to an engagement condition, makes a revolution speed difference between two rotary elements 16, 18 more than a predetermined value by operating an electric motor 22 connected to the electromagnetic clutch 14, when a predetermined condition is satisfied.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electromagnetic clutch that performs intermittent transmission of power by exciting an electromagnet.

  Needless to say, magnetic force is used in the electromagnetic clutch, so iron powder and other foreign matters (Contamination, hereinafter referred to as “contamination”) that are generated due to wear of each part tend to accumulate in the device, and contamination between clutch facings when the electromagnetic clutch is engaged. If the clutch is caught, the engagement force of the clutch cannot be sufficiently obtained, and the contact portion such as the clutch facing may be damaged, and so-called durability such as the performance and life of the clutch may be lowered.

  In Patent Document 1, an oil discharge hole (25) is provided in an outer ring (3) of a wet multi-plate electromagnetic clutch, and an oil flow generated by centrifugal force is utilized when the outer ring (3) rotates freely. (Indicated by parentheses are those used in the literature).

Japanese Patent Laid-Open No. 2007-051670

  In the technique disclosed in Patent Document 1, oil is discharged only when the outer ring (3) is freely rotating, and since only the flow generated by centrifugal force is used, the contamination cannot be discharged sufficiently. There is a possibility that deterioration in durability cannot be prevented.

  The present invention was devised to solve the above-described problems, and in an electromagnetic clutch, it efficiently discharges contaminants to prevent pinching between clutch facings and improve the durability of the electromagnetic clutch. With the goal.

  (1) In order to achieve the above object, an electromagnetic clutch control device according to the present invention has one of two rotating elements connected to a drive source for driving a vehicle, the other connected to an electric motor, and at least a clutch. In an electromagnetic clutch configured to allow lubricating oil to flow between facings, when a predetermined condition is satisfied in an operation state in which the electromagnetic clutch is switched from an engaged state to a released state, prior to the transition to the released state, Rotational speed difference generation control means for performing rotational speed difference generation control for operating the electric motor to set the rotational speed difference between the two rotating elements to a predetermined value or more is provided.

(2) It is preferable that the predetermined condition includes that the temperature of the lubricating oil is within a predetermined range.
(3) It is preferable that the predetermined condition includes an initial release of the electromagnetic clutch after the driving source of the vehicle is started.
(4) Preferably, the predetermined condition includes that a predetermined period has elapsed since the execution of the rotational speed difference generation control.
(5) It is preferable that the predetermined condition includes that a predetermined period has elapsed since a rotational speed difference equal to or greater than the predetermined value is generated between the two rotating elements.
(6) It is preferable that the predetermined value is set so as to increase as the viscosity increases based on a parameter relating to the viscosity of the lubricating oil.
(7) Preferably, the parameter is a temperature of the lubricating oil, and the predetermined value is set so as to increase as the temperature decreases.
(8) Further, it is preferable that the holding time for holding the rotational speed difference equal to or greater than the predetermined value is set to be longer as the viscosity becomes higher based on the parameter relating to the viscosity of the lubricating oil.
(9) Preferably, the parameter is the temperature of the lubricating oil, and the holding time is set to be longer as the temperature is lower.

(10) Further, the electromagnetic clutch includes an electromagnet and a permanent magnet, and when the electromagnet is demagnetized, the clutch facing is joined by the magnetic force of the permanent magnet to be engaged. It is preferable that
(11) Moreover, it is preferable that the oil pump always connected with the said electric motor is arrange | positioned between the said electromagnetic clutch and the said electric motor.
(12) Furthermore, it is preferable that the electromagnetic clutch is disposed in lubricating oil stored in an oil pan of a vehicle transmission connected to the drive source.

  According to the present invention, when the electromagnetic clutch shifts from the engaged state to the released state when a predetermined condition is satisfied, the electric motor is operated immediately before the shift to move between the two rotating elements of the electromagnetic clutch (that is, By actively generating a difference in rotational speed between two clutch facings), it is possible to promote the circulation of the lubricating oil, so that the contamination is effectively discharged, and when the clutch is engaged, the contamination is between the clutch facings. It is possible to prevent problems caused by being sandwiched between the two. When the rotational speed difference as described above is generated, a difference occurs between the rotating elements having different rotational speeds due to the viscosity of the lubricating oil existing in the vicinity of the two rotating elements, so that the lubricating oil flows between the clutch facings. As a result, the amount of circulation increases, and contamination can be discharged efficiently.

In addition, the predetermined condition for controlling the rotational speed difference generation is that the temperature of the lubricating oil is within a predetermined range. Therefore, the viscosity of the lubricating oil becomes appropriate, and the viscosity and fluidity capable of transporting contamination. This ensures that the discharge of contamination is further promoted.
Furthermore, the predetermined conditions for executing the rotational speed difference generation control are that the electromagnetic clutch is released for the first time after the drive source of the vehicle is started, the rotational speed difference generation control is performed from the time of execution or the same control is performed. Since the elapsed period from the time point when the rotational speed difference occurs is set to be substantially the same, the execution timing of the rotational speed difference generation control is appropriate, and the contamination is efficiently discharged.

  In addition, since the value of the rotational speed difference and the holding time thereof are set according to the parameter related to the viscosity of the lubricating oil, that is, the temperature, the electric power consumed by the electric motor operation is reduced as much as possible. The discharge can be performed more efficiently.

It is a lineblock diagram showing typically the drive mechanism of vehicles concerning one embodiment of the present invention. It is sectional drawing of the electromagnetic clutch applied to one Embodiment of this invention. It is a flowchart explaining the control means which concerns on one Embodiment of this invention. It is a graph which shows the relationship between the target rotational speed difference set in control by the said control means, and oil temperature. It is a graph which shows the relationship between the time which hold | maintains the target rotational speed difference set in the control by the said control means, and oil temperature. It is a time chart which shows the change of the rotational speed of the input element of an electromagnetic clutch, and the output element at the time of performing control by the said control means.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the following embodiments can be implemented with various modifications without departing from the spirit thereof, and can be selected or combined as appropriate.

  FIG. 1 is a configuration diagram schematically showing the relationship between main components of a vehicle drive mechanism according to the present embodiment. As shown in FIG. 1, an engine (drive source) 2 for running a vehicle includes a torque converter 4 and a planetary gear or a belt-pulley type variator connected to the torque converter 4 and changing a speed ratio. A conventional automatic transmission 6 such as a step AT, CVT or the like having a transmission mechanism 5 is connected, and an output portion of the automatic transmission 6 is connected to the left and right drive wheels 10 via a differential mechanism 8. It is connected.

The engine 2 is connected to an input element 16 (one rotating element) of an electromagnetic clutch 14 via a chain 12. Further, an output element 18 (the other rotating element) of the electromagnetic clutch 14 is connected to an oil pump 20 for supplying a line pressure for operating the automatic transmission 6, and an electric motor 22 is connected to the oil pump 20. ing. Therefore, the oil pump 20 is driven by the engine 2 when the electromagnetic clutch 14 is engaged, and is driven by the electric motor 22 when the electromagnetic clutch 14 is released.
The electromagnetic clutch 14, the oil pump 20, and the electric motor 22 are disposed so as to be immersed in lubricating oil stored in an oil pan (not shown) of the automatic transmission 6.

  The automatic transmission 6 is operated and controlled by an electronic automatic transmission controller 24 based on the load of the engine 2 and the traveling speed of the vehicle. The electromagnetic clutch 14 and the electric motor 22 are incorporated in the automatic transmission controller 24. The operation is controlled by a control means (rotational speed difference generation control means) 26.

  FIG. 2 is a cross-sectional view showing the structure of the electromagnetic clutch 14 applied to this embodiment. As shown in FIG. 2, the electromagnetic clutch 14 includes a chain sprocket 28 as an input element 16 meshing with the chain 12, an output shaft 30 as an output element 18 connected to the oil pump 20, and a boss of the chain sprocket 28. A disk-shaped armature 34 made of a magnetic material spline-coupled to the portion 32 so as to be movable in the axial direction, a rotor 36 fixed to the output shaft 30, and a permanent magnet 38 embedded in the rotor 36; And an electromagnet 42 fixed to the casing 40.

  The sprocket 28 is supported at one end (left end in the figure) of the output shaft 30 by a bearing 44 so as to be relatively rotatable, and the output shaft 30 (right end in the figure) is supported by the casing 40 via a bearing 46 and is shown in FIG. 1 is connected to the oil pump 20 shown in FIG.

The rotor 36 includes a cylindrical boss portion 36a fixed to the output shaft 30, a disk portion 36b extending radially outward from an end portion of the boss portion 36a on the armature 34 side, The ring portion 36c extends along the axial direction from the outer edge of the plate portion 36b. An annular permanent magnet 38 is embedded in the radial intermediate portion of the disk portion 36b.
The armature 34 and the disk portion 36c are arranged so as to face each other, and the faces 34f, 36f facing each other constitute clutch facings.
Further, since the electromagnetic clutch 14 is immersed in the lubricating oil as described above, the lubricating oil flows from between the inner and outer rings of the bearing 44 and is circulated between the clutch facings 34f and 36f.

  The electromagnet 42 has an annular shape and is fixed to the casing 40 so as to be disposed with a slight gap between the outer peripheral surface of the boss portion 36a and the inner peripheral surface of the ring portion 36c.

  In the electromagnetic clutch 14, the demagnetizing operation type electromagnetic wave in which the armature 34 is joined to the disk portion 36 b by the magnetic force of the permanent magnet 38 (both clutch facings 34 f and 36 f are joined) with the electromagnet 42 demagnetized. It is a clutch.

  Further, the electromagnet 42 is configured to generate a magnetic flux that cancels the magnetic force of the permanent magnet 38. Therefore, when the electromagnet 42 is excited, the clutch facings 34f and 36f are disconnected and the electromagnetic clutch 14 is released. Is released.

  The electromagnetic clutch 14 and the electric motor 22 are operated and controlled so that the line pressure supplied to the automatic transmission 6 can be efficiently generated by the oil pump 20, and basically the high speed region of the engine 2 where the friction loss increases. (For example, 2000 rpm or more), the electromagnetic clutch 14 is released and the oil pump 20 is driven by the electric motor 22, and in the low rotation region of the engine 2 (for example, less than 2000 rpm), the electromagnetic clutch 14 is engaged and the oil pump 20 is operated. The engine 2 is controlled so as to be driven.

  Further, the storage unit of the controller 24 incorporates a program for executing the flowchart shown in FIG. The electromagnetic clutch 14 and the electric motor 22 are rotated at a rotational speed of a predetermined value or more between the input / output elements 16 and 18 (between both clutch facings 34f and 36f) of the electromagnetic clutch 14 by the control means 26 as shown in the flowchart of FIG. Operation control (hereinafter referred to as rotational speed difference generation control) is performed so as to cause a difference. Note that the flowchart shown in FIG. 3 shows only the steps for executing the control portion according to the present invention, and the basic on / off control of the electromagnetic clutch 14 described in the previous stage is omitted. As for the control of the electric motor 22, the control means 26 performs a rotational speed difference generation control through a motor control device (not shown).

  This rotational speed difference generation control increases the rotational speed difference between the clutch facings 34f and 36f of the electromagnetic clutch 14 so as to become the target rotational speed difference, and promotes the circulation of the lubricating oil between the clutch facings 34f and 36f. In this control, the contamination that has entered between the clutch facings 34f and 36f is efficiently discharged to prevent the contamination between the clutch facings 34f and 36f, and the durability of the electromagnetic clutch 14 is improved.

  The rotational speed of the clutch facing 34f is the rotational speed of the engine 2 (engine rotational speed Ne), and the rotational speed of the clutch facing 36f is the rotational speed of the electric motor 22 (motor rotational speed Nm). This can be done by controlling the rotation speed of the electric motor 22 with respect to the rotation speed of the engine 2.

  However, the rotational speed difference generation control is different from the original control of the oil pump 20, and unnecessary control can be performed by performing the control when the rotational speed difference generation control is necessary. I want to avoid as much as possible. Therefore, it is determined whether or not the rotational speed difference generation control is necessary, and the control condition (control request condition) is determined that the control is necessary.

  If it is possible to reliably determine that contamination has entered between the clutch facings 34f and 36f, it is possible to make this determination a control requirement condition for rotational speed difference generation control. However, it is not easy to reliably determine the entry of contamination. Therefore, it is conceivable that the control requirement is that the possibility that contamination has entered between the clutch facings 34f and 36f has increased.

  Further, the electric motor 22 has an upper limit rotational speed, and there may be a case where a target rotational speed difference cannot be generated depending on the rotational speed state of the engine 2. Therefore, the condition that the rotational speed of the engine 2 is in a state where the rotational speed difference generation control can be performed is defined as a control condition (executable condition) of the rotational speed difference generation control.

  Further, the rotational speed difference generation control promotes the circulation of the lubricating oil. However, depending on the temperature state of the lubricating oil, there are cases where it is not suitable for the rotational speed difference generation control or other control should be prioritized. Therefore, the fact that the temperature of the lubricating oil is in a predetermined state is also set as a control condition (practicable condition) for rotational speed difference generation control.

In the present control device, from the above viewpoint, each control condition is specifically set, and when these control conditions are satisfied, the rotational speed difference generation control shown in FIG. 3 is performed.
The program according to the flowchart shown in FIG. 3 is repeatedly executed at a constant control cycle while the engine 2 is operating.

In this control, first, in step S01, it is determined whether or not the driving state of the vehicle is a state in which the electromagnetic clutch 14 should be released.
As described in paragraph 0024, the electromagnetic clutch 14 is released in the high speed region of the engine 2 (for example, 2000 rpm or more). Therefore, the determination here is based on whether the rotational speed of the engine 2 is a predetermined value or more. It is determined.
However, when the electromagnetic clutch 14 is engaged even in other operating states, for example, when the state of charge of the battery is lowered (since it is a demagnetization actuating type electromagnetic clutch, the clutch is engaged and the power is reduced by demagnetizing the electromagnet. This is an example.

  If it is confirmed in step S01 that the electromagnetic clutch 14 is to be released (YES), it is determined in step S02 whether the flag F is 0 or not. The flag F is set to 1 when it is determined that the electromagnetic clutch 14 should be released and then the control related to the release of the electromagnetic clutch 14 (clutch release control) is started, and is set to 0 if the clutch release control is not started. . The clutch release control is a control for instructing the motor control device to control the electric motor 22 so that the rotation speed of the oil pump 20 becomes a rotation speed for generating the line pressure required by the automatic transmission 6. is there. If the flag F is 0, that is, before starting the clutch release control, the process proceeds to step S03, and the condition for executing the rotational speed difference generation control between the input / output elements 16 and 18 of the electromagnetic clutch 14 (between the clutch facing) is established. Judge whether or not.

The condition (control condition) for executing the rotational speed difference generation control is determined as “Established (YES)” when both of the following conditions (1) and (2) are YES (AND condition).
(1) Lubricating oil temperature is in a predetermined range (practicable condition). In this range, for example, a temperature around room temperature of the outside air is set as the lower limit temperature, and the heat resistant limit temperature of each device is set as the upper limit temperature. This is set as a range in which a certain amount of viscosity (viscosity capable of transporting contamination) and fluidity are compatible with the lubricating oil. If the oil temperature is lower than the ambient temperature, control is required to increase the oil temperature and ensure fluidity. If the oil temperature is higher than the heat resistance limit temperature, the oil temperature rise is suppressed and each device is protected. Control is required.
(2) Any one of the following three conditions is satisfied (OR condition) (control requirement condition). This condition is for executing this control at appropriate intervals. In other words, this control is to prevent this control from being executed frequently.
(A) Operation control for causing the first differential rotation after the engine 2 is started.
(B) The integrated value of the clutch engagement time after execution of the previous rotational speed difference generation control is equal to or longer than a predetermined time. That is, a predetermined period has elapsed since the previous execution of the rotational speed difference generation control. This control is performed at the release timing of the electromagnetic clutch 14, and when the integrated value of the engagement time of the electromagnetic clutch 14 up to the release timing exceeds a certain level, contamination may enter between the clutch facings 34f, 36f. It is thought that the nature has increased. Therefore, this condition is set.
(C) The integrated value of the clutch engagement time after the operating state in which the rotational speed difference equivalent to the rotational speed difference generation control is generated is equal to or longer than the predetermined time.
The reason for setting the condition (c) is that the oil pump 20 is driven by the electric motor 22 by releasing the electromagnetic clutch 14 in the high speed region of the engine 2 in the normal control, as described in paragraph 0024. Is driven at a substantially constant rotational speed, whereas the rotational speed of the engine 2 changes as the vehicle travels, and a rotational speed difference equal to or greater than that during the rotational speed difference generation control between the clutch facings. This is because, if this rotational speed difference occurs, substantially the same effect as when this control is executed can be obtained.

If it is determined in step S03 that the control condition is satisfied (YES), in step S04, a target rotational speed difference is set according to the lubricating oil temperature at that time, and this target rotational speed difference is achieved. The target rotational speed Nmt of the electric motor 22 for doing so is calculated.
A map of the oil temperature-rotational speed difference based on the graph shown in FIG. 4 is stored in the controller 24, and the target rotational speed difference is set based on the map. As can be seen from the graph of FIG. 4, the target rotational speed difference is set in a range of, for example, 1500 rpm to 2500 rpm so as to increase as the oil temperature decreases, that is, as the viscosity of the lubricating oil increases. This is because the fluidity of the lubricating oil decreases as the viscosity increases, so that the rotational speed difference is increased to ensure fluidity.

  Next, in step S05, it is determined whether or not the target rotational speed Nmt of the electric motor 22 calculated in step S04 is equal to or higher than the limit maximum rotational speed of the electric motor 22 itself (practicable condition), and less than the maximum rotational speed ( If NO is determined, the process proceeds to step S06.

  In step S06, a time for maintaining the rotational speed difference generation control is set according to the lubricating oil temperature at that time. A map of the oil temperature-rotational speed difference holding time based on the graph shown in FIG. 5 is stored in the controller 24, and the holding time is set based on this map. As can be seen from the graph of FIG. 5, the holding time is set to increase as the oil temperature decreases, that is, as the viscosity of the lubricating oil increases. This is because, as described above, since the fluidity of the lubricating oil decreases as the viscosity increases, the holding time is lengthened and the amount of flow in the control period is increased. If the discharge amount of the lubricating oil from the electromagnetic clutch 14 increases, the discharge of contamination is also promoted accordingly.

  Next, in step S07, control for maintaining the rotational speed difference generation control for the set holding time is executed for the target rotational speed difference based on the above setting.

  Then, in step S09, it is determined whether or not the rotational speed difference generation control in step S07 has ended. If the control in step S07 has not ended, the processing of this control cycle is ended, and the control in step S07 ends. The process proceeds to step S10.

  In step S10, the electromagnetic clutch 14 is released or maintained. Then, the process proceeds to step S11, and the clutch that instructs the motor control device to control the electric motor 22 so that the rotational speed of the oil pump 20 becomes the rotational speed for generating the line pressure required by the automatic transmission 6 is reached. Perform release control.

  If the determination in step S01 is NO, the flag F is set to 0 in step S12, and it is determined in step 13 whether the electromagnetic clutch 14 is engaged. In step S13, if it is determined that the electromagnetic clutch 14 is engaged, the control cycle is terminated. If it is determined that the electromagnetic clutch 14 is not engaged, the process proceeds to step S14.

  In step S14, synchronous control of the rotational speed between the input / output elements 16 and 18 of the electromagnetic clutch 14 is executed, and in step S15, it is determined whether or not the rotational synchronous control in step S14 has been completed. If the end of control is not determined in step S15, the process of this control cycle is ended. If the end of control is determined in step S15, the engagement of the electromagnetic clutch 14 is instructed in step S16.

  If the determination in step S03 is NO, and if the determination in step S05 is YES, the electromagnetic clutch 14 is released without executing the rotational speed difference generation control, and therefore the flag F is determined in step S08. Is set to 1 and steps S10 to S11 are executed. Even if the determination in step S02 is NO, steps S10 to S11 are executed.

By executing the program, the rotational speeds of the input / output elements 16 and 18 change, for example, as shown in FIG.
In the figure, the thick broken line is the rotational speed of the input element 16, that is, the engine 2, and the thick solid line is the rotational speed of the output element 18, that is, the electric motor 22 (this is also the rotational speed of the oil pump 20).
ΔN1 is an input / output element before the start of control (that is, the engagement state of the electromagnetic clutch 14) and after the control is completed (that is, when the electromagnetic clutch 14 is released). 16 is a rotational speed difference that occurs when the electromagnetic clutch 14 is switched to the released state without this control. This rotational speed difference ΔN1 can be calculated from the calculated rotational speed of the oil pump 20 because the required rotational speed of the oil pump 20 can be calculated based on the line pressure at the time after the electromagnetic clutch 14 is released. It is calculated from the difference from the current rotational speed of the engine 2.
ΔN2 is the target rotational speed difference set in step S04, and has an absolute value of | ΔN1 | <| ΔN2 |. Further, t1 is a control start time, t2 is a time at which the rotation synchronization control of Step S10 is started, t3 is a control end time, and Δt is a time for holding the target rotational speed difference set at Step S06.

Since this control is completed in a few seconds, the rotational speed of the engine 2 does not change during that time and is substantially constant, so the rotational speed of the input element 16 is also constant as shown by a thick broken line.
On the other hand, the rotational speed of the output element 18 is changed by the electric motor 22 as shown by a thick solid line so as to generate a rotational speed difference of more than a predetermined value (ΔN2) between the input / output elements 16 and 18. After maintaining the rotational speed difference for Δt, synchronous control of the rotational speed between the input / output elements 16 and 18 is executed, and then the electromagnetic clutch 14 is released.

  The electromagnetic clutch control device according to an embodiment of the present invention is configured as described above. When the electromagnetic clutch 14 is released, the input / output elements 16 and 18, that is, the clutch facings 34 f and 36 f, are preceded. Since a difference in rotational speed between the clutch facings 34f and 36f is generated, the flow of lubricating oil between the clutch facings 34f and 36f (discharge to the outside of the clutch) is promoted, and the discharge of contaminants is promoted accordingly. It is possible to efficiently prevent a decrease in clutch performance and durability caused by biting between facings. In particular, by generating a rotational speed difference of a predetermined value or more when the electromagnetic clutch 14 is released, it is possible to effectively promote the discharge of contamination even in an operation state in which the most engagement is performed immediately after the electromagnetic clutch 14 is released. .

  In addition, since the temperature of the lubricating oil is determined to be within a predetermined range as a condition for executing the rotational speed difference generation control, a temperature at which a certain degree of viscosity (a viscosity capable of transporting contamination) and fluidity can be secured in the lubricating oil. By setting the range, the discharge of contamination is further promoted.

  Further, as a condition for executing the rotational speed difference generation control, “(a) Operation control for causing the first differential rotation after the engine 2 is started. (B) Clutch engagement time after the previous execution of the rotational speed difference generation control is performed. The integrated value of the clutch engagement time after the operating state in which the rotational speed difference equivalent to the rotational speed difference generation control is generated is equal to or longer than the predetermined time. Since this is established, this control is executed at an appropriate interval, and contamination can be discharged efficiently.

  Further, since the rotational speed difference and the duration thereof are set so that the rotational speed difference increases and the time increases as the oil temperature decreases, the power consumed by the operation of the electric motor 22 is set. In addition, the fluidity of the lubricating oil can be ensured appropriately, and contamination can be discharged more efficiently.

  Furthermore, since the electromagnetic clutch 14 is a demagnetizing operation type electromagnetic clutch in which the clutch facings 34f and 36f are joined by the magnetic force of the permanent magnet 38 when the electromagnet 42 is demagnetized and the electromagnetic clutch 14 is engaged. Power consumption for operation can be reduced.

  In the above embodiment, since the electromagnetic clutch 14 according to the present invention is interposed between the engine 2 and the oil pump 20 and the oil pump 20 can be driven by the electric motor 22, the operation with a large friction loss is performed. Driving the oil pump 20 by the electric motor 22 in the region can reduce the engine fuel consumption.

  Furthermore, since the electromagnetic clutch 14 is disposed so as to be immersed in the lubricating oil, a lubricating oil supply device for the electromagnetic clutch 14 becomes unnecessary.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the above-described embodiments can be variously modified and applied without departing from the spirit of the present invention. . In particular, the numerical values of the rotational speed and the rotational speed difference shown in the above description are merely examples, and it goes without saying that they are set as appropriate according to the specifications and performance of the engine, electromagnetic clutch, and electric motor.

  Moreover, although the example which applied this invention to the demagnetization operation type | mold electromagnetic clutch was shown in the said embodiment, this invention is applied to the excitation operation type | mold electromagnetic clutch which will be in an engagement state when an electromagnet is excited. Is also possible.

  Furthermore, in the above-described embodiment, an example in which the present invention is applied to an oil pump drive mechanism has been disclosed. However, the present invention intermittently connects the engine and the electric motor in a hybrid vehicle using the engine and the electric motor as drive sources. It is also possible to apply to an electromagnetic clutch.

2 Engine 6 Automatic transmission 14 Electromagnetic clutch 20 Oil pump 22 Electric motor 26 Control means (rotational speed difference generation control means)
34f, 36f Clutch facing

Claims (12)

In an electromagnetic clutch configured such that one of two rotating elements is connected to a drive source that drives a vehicle, the other is connected to an electric motor, and at least lubricating oil flows between clutch facings.
When a predetermined condition is satisfied in the operation state in which the electromagnetic clutch is switched from the engaged state to the released state, the electric motor is operated to shift the rotational speed difference between the two rotating elements prior to the transition to the released state. An electromagnetic clutch control device comprising: a rotation speed difference generation control means for performing a rotation speed difference generation control for setting the rotation speed difference to a predetermined value or more. 2. The electromagnetic clutch control device according to claim 1, wherein the predetermined condition includes that the temperature of the lubricating oil is within a predetermined range. 3. The electromagnetic clutch control device according to claim 1, wherein the predetermined condition includes that the electromagnetic clutch is released for the first time after the drive source of the vehicle is started. 4. The electromagnetic clutch control device according to claim 1, wherein the predetermined condition includes that a predetermined period has elapsed since the execution of the rotation speed difference generation control. 5. 5. The method according to claim 1, wherein the predetermined condition includes that a predetermined period has elapsed from a time when a rotational speed difference equal to or greater than the predetermined value is generated between the two rotating elements. 2. The electromagnetic clutch control device according to item 1. 6. The electromagnetic clutch control according to claim 1, wherein the predetermined value is set so as to increase as the viscosity increases based on a parameter relating to the viscosity of the lubricating oil. apparatus. 7. The electromagnetic clutch control device according to claim 6, wherein the parameter is a temperature of the lubricating oil, and the predetermined value is set to increase as the temperature decreases. The holding time for holding the rotational speed difference equal to or greater than the predetermined value is set to be longer as the viscosity becomes higher based on a parameter relating to the viscosity of the lubricating oil. The electromagnetic clutch control device according to claim 1. 9. The electromagnetic clutch control device according to claim 8, wherein the parameter is a temperature of the lubricating oil, and the holding time is set to become longer as the temperature becomes lower. The electromagnetic clutch includes an electromagnet and a permanent magnet, and when the electromagnet is demagnetized, the electromagnetic clutch is a demagnetizing operation type electromagnetic clutch that is engaged by joining the clutch facing by the magnetic force of the permanent magnet. The control device for an electromagnetic clutch according to any one of claims 1 to 9. The electromagnetic clutch control according to any one of claims 1 to 10, wherein an oil pump that is always connected to the electric motor is disposed between the electromagnetic clutch and the electric motor. apparatus. 12. The electromagnetic clutch according to claim 1, wherein the electromagnetic clutch is disposed in lubricating oil stored in an oil pan of a vehicle transmission connected to the driving source. Electromagnetic clutch control device.

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