JP2005282640A - Electromagnetic coupling - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress power consumption of an electromagnetic clutch for operating an electromagnetic coupling and reduce fuel consumption of a four-wheel-drive vehicle using the electromagnetic coupling. <P>SOLUTION: This electromagnetic coupling is operated by the electromagnetic clutch 9 operated by magnetic force from a magnetic force applying face of a ring-shaped electromagnetic coil 16. The electromagnetic coil 16 is constituted by superposing a plurality of coils 16a, 16b individually controllable in the axial direction of the electromagnetic clutch 9 or concentrically. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is based on a propeller shaft of a four-wheel drive vehicle that is operated by an electromagnetic clutch that is operated by a magnetic force from a magnetic force acting surface of a ring-shaped electromagnetic coil and that can be switched between two-wheel drive and four-wheel drive. The present invention relates to an electromagnetic coupling disposed on the end side or the front end side.

  The electromagnetic coupling is known from, for example, Patent Document 1, and the configuration thereof is as shown in FIG. For example, in the figure, 2 is an input shaft connected to the engine side, 1 is an output shaft that transmits power to the rear wheels, and both shafts are connected so that they can be turned on and off by the main clutch 3. The main clutch 3 has a driven plate 3a whose inner diameter side is spline-engaged with the output shaft 1 side and a drive plate 3b whose outer diameter side is integrally formed with the input shaft 2 and is spline-engaged inside the case 2a. The two shafts 1 and 2 are engaged and released by pressing them against the fixed plate 4 fixed to the distal end side of the case 2a with the pressing plate 6 of the pressing device 5. Is set to OFF.

  The pressing device 5 includes the pressing plate 6, a receiving plate 7 disposed on the rear side of the pressing plate 6, and a thrust force generating mechanism 8 for pressing the pressing plate 6 against the receiving plate 7. It has become.

  An inner diameter side of the push plate 6 is splined to the output shaft 1. The backing plate 7 is rotatably supported by a thrust bearing with respect to the input shaft 2 integrated with the case 2a, and the inner diameter side is slidably fitted to the output shaft 1 side. . The receiving plate 7 is connected to the case 2a of the input shaft 2 via an electromagnetic clutch 9 provided outside the receiving plate 7 so as to be engageable and disengageable in the rotational direction.

  The electromagnetic clutch 9 is formed with a ring-shaped space on the outer side of the receiving plate 7 and the inner side of the case 2a, and the armature 10 is slidably fitted in this space in a range where the armature 10 contacts the stop ring. Between the axial direction of the armature 10 and the case 2a, a clutch plate whose inner diameter side is spline engaged with the receiving plate 7 and a friction plate whose outer diameter side is spline engaged with the case 2a are alternately arranged. The case 2a is provided with a ring-shaped electromagnetic coil 11 for pulling the armature 10 toward the case 2a with an exciting force to press the clutch plate and the friction plate to turn on the electromagnetic clutch 9.

  The electromagnetic coil 11 is accommodated in the core 11a in a ring-shaped recess 12 provided in the case 2a and arranged toward the electromagnetic clutch 9 side. A core 11a for accommodating the electromagnetic coil 11 is rotatably fitted to the output shaft 2 and supported by a cover 13 coupled to the frame side.

  The rotor portion facing the electromagnetic coil 11 of the case 2a is divided radially outside and inside by a non-magnetic stainless steel non-magnetic ring 14, and each clutch plate and friction plate of the electromagnetic clutch 9 are separated from each other. Is provided with a notch and a bridge portion for connecting the notch at a radial position corresponding to the nonmagnetic ring 14, and the nonmagnetic ring 14 and the notch allow the magnetic force in the magnetic loop 15 of the electromagnetic coil 11 to be reduced. Short circuit is prevented.

  The electromagnetic coupling configured as described above has the following effects.

  When energization of the electromagnetic coil 11 is turned ON, a magnetic loop 15 is generated, and the armature 10 is attracted by the exciting force of the electromagnetic coil 11 to press both plates of the electromagnetic clutch 9 toward the case 2a side. 9 is turned ON, whereby the receiving plate 7 of the pressing device 5 is engaged with the case 2a via the electromagnetic clutch 9, that is, the input shaft 2 side. This state is the 4WD state in the case of 4WD coupling.

  In this state, if a difference in rotation occurs between the output shaft 1 and the input shaft 2 due to slippage of the rear wheels, etc., the receiving plate 7 engaged on the input shaft 2 side and the output shaft 1 side are engaged. A rotational difference is generated between the pressing plate 6 and the thrust force generating mechanism 8 and the pressing plate 6 is pressed against the receiving plate 7 by the rotation difference, so that the main clutch 3 is turned on and the output shaft 1 is turned on. And the input shaft 2 are engaged to rotate both shafts integrally.

  The thrust force generating mechanism 8 is as shown in FIG. 2A, and the balls 8a are interposed in the concave cams 6a and 7a provided on the opposing surfaces of the push plate 6 and the receiving plate 7, respectively. It is configured. When a rotational difference occurs between the plates 6 and 7, the ball 8a rides on the concave cams 6a and 7a as shown in FIG. 2B, so that the push plate 6 moves away from the receiving plate 7, As a result, a pressing operation is performed.

JP 2002-266904 A (pages 5-6, FIG. 1)

Torque required in the electromagnetic clutch of the electromagnetic coupling described above is as shown in FIG. 4 (a), becomes the torque T ₁ of the switching from the two-wheel drive to four-wheel drive is large, four-wheel after switching torque T ₂ at the time of driving the travel is reduced. The electromagnetic force required to obtain a torque to the necessary so as shown in FIG. 4 (b), the electromagnetic force F ₁ at the time of the switching is increased, that thereafter the electromagnetic force F ₂ may be small Thus, the power supplied to the coil during the four-wheel drive running after switching is naturally smaller than that during switching.

However, conventional electromagnetic coil 11 is not the one coil used as described above, may require a large torque T ₁ of the time of switching from two-wheel drive to four-wheel drive were switched to four-wheel drive even if a small torque T ₂ requires only from the time of the above drive switching in maintaining the four-wheel drive traveling state after using an electromagnetic coil of the same capacity, the current value according to the magnitude of the torque with the required This was dealt with by controlling the electromagnetic force by increasing or decreasing.

Therefore, the electromagnetic coil 11 of the conventional electromagnetic clutch 9 is capable of outputting the necessary maximum torque, that is, having a large number of turns capable of outputting the torque T ₁ required when switching from two-wheel drive to four-wheel drive. Those with coils were used.

In the case of an electromagnetic coil, the electrical resistance is proportional to the number of turns of the coil, so that a coil with a large number of turns has a large electrical resistance and therefore a large power consumption. Therefore, the current supplied to the conventional electromagnetic clutch coil is as shown in FIG. 4 (c), aside the current value I ₁ at the time of switching to the four-wheel drive, the current value I when the four-wheel drive cars ₂ increased in accordance with the resistance, and the power consumption at this time was large as described above. This was a cause of deterioration in fuel consumption of the four-wheel drive vehicle.

  Further, if the electromagnetic clutch is frequently switched, the coil temperature rises and there is a risk of seizure.

  In order to prevent this, when the coil temperature rises, control is applied to turn off the electromagnetic clutch and release the four-wheel drive. For this reason, when the vehicle is traveling, there may be a case where it is not possible to switch to four-wheel drive even when four-wheel drive is required.

  Although it is conceivable to increase the coil wire diameter to suppress the electrical resistance, this increases the coil space and increases the size of the unit.

  The present invention is intended to provide an electromagnetic coupling that solves the above-described conventional problems and can reduce the fuel consumption of a four-wheel drive vehicle by suppressing the power consumption of the electromagnetic clutch. In an electromagnetic coupling that operates with an electromagnetic clutch that operates with a magnetic force from the magnetic force acting surface of a ring-shaped electromagnetic coil, a plurality of coils that are individually controllable in the axial direction of the electromagnetic clutch, Alternatively, it is configured to be superposed on any one of the concentric shapes.

  In addition, the electromagnetic force control of each of the plurality of coils is controlled so that the main clutch is in the slip state by switching the electromagnetic clutch to the slip state when switching between the two-wheel drive and the four-wheel drive.

  According to the above configuration, the control of the plurality of coils is selectively performed according to the torque fluctuation of the electromagnetic clutch that operates the electromagnetic coupling, thereby comparing with the electromagnetic clutch using one coil. Thus, since the number of turns of each coil is small, the power consumption of the electromagnetic clutch can be suppressed.

  Therefore, the capacity of the generator can be reduced, the power consumption for driving the generator can be reduced, and as a result, the fuel consumption of a four-wheel drive vehicle using an electromagnetic coupling operated by this electromagnetic clutch can be reduced. Can do.

  In addition, at least one of the plurality of coils can be turned off during normal driving by four-wheel drive, so that the temperature of the entire electromagnetic clutch can be prevented from being increased, and switching between normal two-wheel drive and four-wheel drive is always performed. It can be carried out. Furthermore, according to the present invention, it is not necessary to make the coil of the electromagnetic clutch thick in order to suppress the electric resistance thereof, the coil space is not increased, and the unit can be prevented from being enlarged.

  In the electromagnetic coupling described above, by controlling the electromagnetic force of each of the plurality of coils so that the electromagnetic clutch is in a slip state when switching between the two-wheel drive and the four-wheel drive, The main clutch at the time of switching between four-wheel drive can be made into a slip state to be in an intermediate state between two-wheel drive and four-wheel drive, reducing the load on the drive system when switching between two-wheel drive and four-wheel drive. The above switching can be performed smoothly.

  A first embodiment of the present invention will be described with reference to FIGS. In the following description, the same members as those in the prior art shown in FIG.

  The electromagnetic coil 16 for turning the electromagnetic clutch 9 on and off is housed in the core 17 and is provided toward the electromagnetic clutch 9 side. Two electromagnetic coils 16 are stacked in the axial direction of the electromagnetic clutch 9. The first coil 16a and the second coil 16b are housed together. The coils 16a and 16b can be individually turned on and off by a control device (not shown).

Assuming that the electromagnetic forces of the first coil 16a and the second coil 16b are F ₃ and F ₄ , for example, the electromagnetic force F ₃ of the first coil 16a is 4 after switching as shown in FIG. has become the same size as the electromagnetic force F ₂ required during wheel drive cars, also the electromagnetic force F ₄ of the second coil 16b is four-wheel from the electromagnetic force F ₁ at the time of switching shown in FIG. 4 (b) It has the same size as the value obtained by subtracting the electromagnetic force F ₃ at the time of driving the traveling. That is, F ₃ = F ₂ and F ₄ = (F ₁ −F ₂ ). Each of the electromagnetic coils 16a and 16b has the number of turns of the coil corresponding to the electromagnetic force, and the number of turns of each coil is naturally smaller than the number of turns of one conventional electromagnetic coil 11.

In the above configuration, in order to switch from two-wheel drive running to four-wheel drive running, both the first and second coils 16a and 16b are turned on. Thereby, the electromagnetic coil 16 outputs the electromagnetic force in Fig. 5 the coils 16a as shown in (c), the electromagnetic force of the sum of _{16b F 3 + F 4 (=} F 1).

After switching to the 4-wheel drive is turned OFF and the second coil 16b, which continues outputting the electromagnetic force F ₃ is energized only in the first coil 16a.

The magnitudes of the current values I ₃ and I ₄ to the coils 16a and 16b at this time are as shown in FIGS. 5D and 5E, and the total current value I ₅ when the four-wheel drive is switched is shown in FIG. As shown in FIG. 5 (f), I ₃ + I ₄ is obtained.

In this case, although the current value I ₅ upon switching is substantially the same as the current value I ₁ at the time of switching of the conventional electromagnetic coil 11 shown in FIG. 4 (c), the first coil at 4-wheel drive 16a of the current value I ₃ to substantially achieve the same electromagnetic force F ₃ and the electromagnetic force F ₂ in the conventional time 4-wheel drive by an electromagnetic coil 11, the coil turns of the first coil 16a is in the above conventional electromagnetic coil less than the number of turns of the coils of 11, the resistance of the current flowing therethrough is by that amount small, the current value I ₂ is smaller than the conventional electromagnetic coil. That is, I ₅ ≈I ₁ and I ₃ <I ₂ .

  Accordingly, the input power to the electromagnetic coil 16 at the time of switching the four-wheel drive is substantially the same as that of the conventional electromagnetic coil 11, but the input power at the time of four-wheel drive traveling is smaller than that of the conventional electromagnetic coil 11.

  In the above embodiment, the electromagnetic coil 16 is composed of two coils 16a and 16b. However, the number of the coils is two or more, and the number is not limited. Allow control.

  In this plurality of controls, the input power to each when switching from two-wheel drive to four-wheel drive becomes weaker than the electromagnetic force that turns on the electromagnetic clutch 9 described above. In this way, the electromagnetic clutch 9 in the four-wheel drive is brought into the slip state by bringing the main clutch into the slip state, so that the electromagnetic coupling is in an intermediate state between the two-wheel drive and the four-wheel drive. Smooth switching can be performed without imposing a burden on the drive system when switching between two-wheel drive and four-wheel drive.

  Further, the coil turns ratio of the plurality of electromagnetic coils is optimized by, for example, 1: 1.1: 1.2 according to the electromagnetic force to be output by each electromagnetic coil. The electromagnetic coupling can be switched under optimum conditions that do not damage the electromagnetic coil.

  FIG. 6 shows a second embodiment of the present invention. In this embodiment, two (plural) coils 16a 'and 16b' constituting the electromagnetic coil 16 'are concentrically arranged. In this case as well, both coils 16a 'and 16b' are excited when switching from two-wheel drive traveling to four-wheel drive traveling, and after switching, one coil is turned off and the excitation force of the other coil is applied. The four-wheel drive running is continued.

It is sectional drawing which shows the conventional electromagnetic coupling. (A), (b) is sectional drawing which shows a thrust force generation | occurrence | production mechanism part. It is sectional drawing which shows the electromagnetic coupling in the 1st Embodiment of this invention. (A), (b), (c) is a diagram which shows the torque, electromagnetic force, and electric current value which an electromagnetic clutch in the conventional electromagnetic coupling requires. (A), (b), (c), (d), (e), (f) is a diagram showing the electromagnetic force and current value in the electromagnetic coupling according to the present invention. It is sectional drawing which shows the electromagnetic coupling in the 2nd Embodiment of this invention.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Output shaft, 2 ... Input shaft, 2a ... Case, 3 ... Main clutch, 3a ... Driven plate, 3b ... Drive plate, 4 ... Fixed plate, 5 ... Pressing device, 6 ... Pushing plate, 7 ... Receiving plate, 8 ... thrust force generating mechanism, 8a ... ball, 9 ... electromagnetic clutch, 10 ... armature, 11, 16, 16 '... electromagnetic coil, 11a, 17 ... core, 16a, 16b, 16a', 16b '... coil, 12 ... recess , 13 ... cover, 14 ... non-magnetic ring, 15 ... magnetic loop, 21 ... case, 22 ... cover member, 23 ... electromagnetic coil, 24 ... magnetic ring, 25a, 25b ... space.

Claims (2)

In the electromagnetic coupling operated by the electromagnetic clutch that operates by the magnetic force from the magnetic force acting surface of the ring-shaped electromagnetic coil,
An electromagnetic coupling characterized in that the electromagnetic coil has a configuration in which a plurality of individually controllable coils are arranged in the axial direction of the electromagnetic clutch or concentrically. The electromagnetic force control of each of a plurality of coils constituting the electromagnetic coil is controlled so that the main clutch is in a slip state by switching the electromagnetic clutch to a slip state when switching between two-wheel drive and four-wheel drive. The electromagnetic coupling according to claim 1.

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