JPH04113033A - Electromagnetic clutch - Google Patents

Abstract

PURPOSE:To obtain strong coupling force without making a device large-sized by connecting an armature to the one side of a rotating member through a cam mechanism, and making the inertial force of the armature generate operational force for a friction clutch. CONSTITUTION:When an armature 77 is drawn by an electromagnet 89, a pilot clutch 69 is engaged to couple a pressing ring 61 with a drum 41 through a cam 67. The driving force of an engine and torque caused by driving resistance on the side of a rear wheel acts onto the cam 67 to generate thrust force 95 for engaging a main clutch 59 through the pressing ring 61. Reaction force against the thrust force 95 is inputted into a flange part 39 through a bearing 97 and a thrust washer 99, and canceled by the thrust force 95 in the drum ax to thus form a connect-disconnecting device 19. At the time of accelerating, thrust force 85 generated in the armature 77 increases the coupling force of a clutch 69, and the torque acting onto the cam 67 increases to increase the coupling force of the main clutch 59 for strengthening the coupling force of the connect-disconnecting device 19.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an electromagnetic clutch.

(Prior Art) ``Limited Slip Differential Gear Assembly'' is described in Japanese Patent Application Laid-Open No. 63-195449. This is a differential device with a differential limiting function, and differential limiting is performed by an electromagnetic multi-plate clutch.

(Problems to be Solved by the Invention) In this device, the multi-disc clutch 4 and the pressing member are arranged inside the differential case, and the armature is arranged outside the differential case and connected to the pressing member through the differential case. ing.

In this way, the engagement force of the multi-disc clutch is determined by the magnetic force of the electromagnet that attracts the armature, so the device must be enlarged in order to obtain a large engagement force that is only occasionally required. Therefore, an object of the present invention is to provide an electromagnetic clutch that can obtain a large engagement force without increasing the size of the device.

[Structure of the Invention] (Means for Solving the Problems) The electromagnetic clutch of the present invention includes: a friction clutch that connects a pair of rotating members; an electromagnet that moves an armature using magnetic force to engage the friction clutch; A cam mechanism is provided at a connecting portion between the rotating member and the armature, and converts the inertia force of the armature into the operating force of the friction clutch.

(Operation) The inertia force of the armature is converted into the operating force of the friction clutch by the cam mechanism. Therefore, if it works in the fastening direction, a larger latch torque can be obtained, and if it works in the opening direction, the response when opening is improved.

(Example) One embodiment will be explained with reference to FIGS. 1 to 3.

FIG. 1 shows a disconnection device using this embodiment, and FIG. 2 shows a power system of a four-wheel drive (4WD) vehicle using this device. Hereinafter, the front and rear directions are the front and rear directions of this vehicle, and the first
The right side of the figure corresponds to the front of this vehicle (the upper part of Figure 2). Also, members that are not numbered are not shown.

First, the configuration of this power system will be explained with reference to FIG. This power system consists of an engine 1, a transmission 3, a front differential 5 (differential device on the front wheel side), and a front axle 7.
, 9, left and right front wheels 11.13, transfer 15, propeller shaft 17, disconnection device 19 of this embodiment, rear differential 21 (rear wheel side differential equipment Wt), rear axles 23, 25, left and right rear wheels 27. It consists of 29 etc.

The connecting shaft 31 passes through the front end of the carrier 33 of the rear differential 21, is supported by the carrier 33 by a bearing 35, and is connected to the propeller shaft 17 by a spline portion 37.
connected to the side. In this way, the connecting shaft 31 is rotationally driven by the driving force from the engine 1.

A clutch drum 41 (rotating member) is integrally provided at the rear end of the connecting shaft 31 via a flange portion 39 . A hub 43 is rotatably supported inside the clutch drum 41 by a bearing 49 and a shaft support 47 between the boss portion 45 and the connecting shaft 31 .

A drive pinion shaft 51 is connected to the boss portion 45 by a spline. The shaft 51 has a bearing 53.5
3 is supported by the carrier 33, and a drive pinion gear 57 that meshes with the ring gear 55 of the rear differential 21 is integrally formed at the rear end.

A multi-plate main clutch 59 is arranged between the clutch drum 41 and the hub 43 to connect them, and a pressure ring 61 of the main clutch 59 is arranged in front of the clutch drum 41 and the hub 43.
The press ring 61 is spline connected to the hub 43 so as to be movable back and forth. Between the press ring 61 and a cam ring 63 (rotating member) rotatably arranged in front of the press ring 61,
As shown in FIG. 1, a cam 67 is formed with a ball 65 interposed therebetween.

A multi-plate pilot clutch 69 (friction clutch) is arranged between the cam ring 63 and the clutch drum 41 to connect them. The spline on the side of the drum 41 with which the outer plate 71 of the clutch 69 is engaged is a helical gear 73, as shown in FIG. 1(C). Note that the splines 76 of the ring 63 and the main clutch 59 with which the inner plate 75 is engaged
The engaging spline is a spur gear. FIG. 3 shows how the armature 77 is assembled by passing through the spur gear engaged by the main clutch 59.

An armature 77 is disposed on the rear side of the clutch 69, and the armature 77 engages with a helical gear 73 of the drum 41 so as to be movable in the axial direction by a helical gear 79 provided on its outer circumference, as shown in FIG. 1(C). ing. A cam mechanism is composed of helical gears 73 and 79. The armature 77 is restricted from moving rearward by a retaining ring 81.

As shown in FIG. 1C, the tooth traces of the helical gears 73 and 79 are oriented in the direction shown in this figure with respect to the rotational direction (arrow 83) of the drum 41 when the vehicle moves forward.

Therefore, when the drum 41 tries to rotate ahead of the armature 77 as during acceleration, a thrust force 85 is generated in the direction of engaging the clutch 69 due to the negative inertia force of the armature 77, and when the armature 77 is rotated due to the positive inertia force as during braking. When the clutch 69 attempts to rotate ahead of the drum 41, a thrust force 87 is generated in the direction of opening the clutch 69.

Eight ring-shaped electromagnets are arranged in front of the flange portion 39 of the clutch drum 41, and the bolts 91 are connected to the carrier 33.
is fixed. A nonmagnetic ring 93 is embedded in the flange portion 39 in order to prevent the magnetic lines of the electromagnet 89 from shorting and guide them to the armature 77 .

When the armature 77 is attracted by the electromagnet 89, the pilot clutch 69 is engaged by the pressing force thereof, and the pressing ring 61 is connected to the drum 41 side via the cam 67. Therefore, the driving force of the engine 1 and the torque due to the rear wheel side driving resistance act on the cam 67 to generate a thrust force 95, and the main clutch 59 is pressed and engaged via the pressing ring 61. In this way, the driving force of the engine 1 is transmitted to the rear wheels via each clutch 59.69, and the slippage of these allows differential movement between the front and rear wheels.
If the fastening force of 69 is sufficiently large, this differential will be locked.

Further, when the clutch 69 is released, the rear wheel side is disconnected from the engine 1.

The reaction force of the thrust force 95 is input to the flange portion 39 via a bearing 97 and nine thrust washers, and is input to the drum 4.
It is canceled out by the thrust 95 within 1. In this way, the disconnection device 19 is configured.

During acceleration, as described above, the thrust force 85 generated in the armature 77 increases the engagement force of the clutch 69 and reduces slippage), and the increase in torque acting on the cam 67 increases the engagement force of the clutch 59, causing the disconnection device 19 to connect. Power is strengthened. Further, in this way, a larger fastening force can be obtained by the thrust force 85 with the clutch 69 and electromagnet 89 having the same capacity.

Furthermore, even if the armature 77 is magnetized when the clutch 69 is released during braking, the thrust force 8 as described above
7 moves the armature 77 in the opening direction (backward), so the clutch 69 can be quickly and completely opened.

Next, the function of the disconnection device 19 will be explained based on the power performance of the vehicle shown in FIG.

The driving force of the engine 1 is distributed from the transmission 3 to the front wheels 11, 13 via the front differential 5 and rotates the propeller shaft 17 via the transfer 15.

At this time, when the rear wheels 27 and 29 are disconnected by the disconnection device 19, the vehicle enters a front-wheel drive state, which provides the characteristics of a front-wheel drive vehicle and improves fuel efficiency.

When the disconnection device W19 is connected, the vehicle enters the 4WD state, and even if the front wheels spin on rough roads, the driving force from the rear wheels maintains drivability. The thrust force 85 of the armature 77 has a great effect on improving running performance.

Also, if the front wheels spin during front wheel drive, the armature 7
The thrust force 85 of No. 7 generates a fastening force in the pilot clutch 69, automatically setting the vehicle in 4WD mode and improving running performance.

If differential movement between the front and rear wheels is allowed by the slippage of the disconnection device 19, smooth turning can be achieved and tight corner braking phenomena such as when parking the vehicle can be prevented.

If one intermittent device is opened during sudden braking, even if the front wheels lock, the rear wheels will not be locked, and the normal function of the anti-lock braking system (ABS) will not be inhibited.

In addition, the spline 76 of the cam ring 63 may be a helical gear, and a helical gear may be provided on the inner circumferential side of the armature 77 for meshing.

[Effects of the Invention] The electromagnetic clutch of the present invention is configured such that the armature is connected to one of the rotating members via the cam mechanism and the operating force of the friction clutch is generated by the inertia of the armature.The clutch capacity is increased and the electromagnet Combined with the operating force of , a variety of latch operations can be performed.

[Brief explanation of the drawing]

Fig. 1 relates to one embodiment, the same icon) is a cross-sectional view,
) is the same figure (a) +71 A-A sectional view, the same figure (C)
(ii) (7) B-B sectional view, Figure 2 is a skeleton mechanism diagram showing the power system of a vehicle using this embodiment,
FIG. 3 is a side view showing how the armature is assembled. 41... Clutch drum (rotating member) 63... Cam ring (rotating member) 69... Pilot clutch (friction clutch) 73.
79... Helical gear (cam mechanism) 77... Armature 89... Electromagnet

Claims (1)

[Claims] A friction clutch that connects a pair of rotating members, an electromagnet that moves the armature using magnetic force and engages the friction clutch, and an electromagnet that is installed at the connection between one of the rotating members and the armature and uses the inertia of the armature to operate the friction clutch. An electromagnetic clutch characterized by being equipped with a cam mechanism that converts force into force.