JP2001311461A - Differential gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a differential gear which can control a transmitting torque without causing any dragging torque and a ratchet noise while a clutch is connecting. SOLUTION: In the differential gear, a clutch coupling means 11 has a differential mechanism 7 which can distribute an engine driving force to the wheels, and a transmitting torque engaging and disengaging clutch. It is characterized in that the transmitting torque engaging and disengaging clutch is a cone clutch 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a differential device having a power intermittent function.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 5-54574 discloses a differential device 201 as shown in FIG.

[0003] The differential device 201 is disposed on the axle of the front wheel or the rear wheel which is cut off in a two-wheel drive state in a four-wheel drive vehicle.

The differential device 201 is housed in a differential carrier 203, and includes an outer case 205, an inner case 207, a bevel gear type differential mechanism 209,
Meshing clutch 211, pressure type actuator 21
3 and the like.

[0005] The dog clutch 211 is formed between the clutch ring 215 and the outer case 205, and the clutch ring 215 is movably connected to the inner case 207. Also, the actuator 21
Numeral 3 is fixed on the differential carrier 203, moves the clutch ring 215 via the shift fork 217, meshes the meshing clutch 211, and releases the meshing.

The outer case 205 is rotationally driven by the driving force of the engine input through the drive pinion gear 219 and the ring gear 221.

When the meshing clutch 211 is engaged, the driving force of the engine is changed to the inner case 207 and the differential mechanism 20.
9 is distributed to the left and right wheels via axles 223 and 225, and the vehicle is in a four-wheel drive state, so that the running performance and the escape performance on rough roads and the like are improved.

When the engagement of the engagement clutch 211 is released, the inner casing 207 and the left and right wheels are disconnected from the engine side, and the vehicle is driven by two wheels, so that the fuel efficiency of the engine is improved.

[0009]

In the conventional differential device 201 using the meshing clutch 211,
The meshing clutch 211 generates a ratchet sound until the meshing teeth are in phase with each other at the time of meshing at the time of connection, and there is a problem in terms of quietness.

In order to prevent or minimize such ratcheting, a synchro mechanism for adjusting the phase of the meshing teeth is required separately. However, the cost is increased, the structure is complicated, and the apparatus is complicated. And so on.

For example, a 2-4 switching mechanism (transfer or the like) is provided with a synchronization mechanism.

When the clutch is disengaged, the meshing clutch 211 is less likely to be disengaged due to frictional resistance generated at the meshing teeth when torque is applied.
There was also a risk of drag torque being generated.

As described above, when the drag torque is generated, the timing of separating the rear wheels is delayed, the driving force is lost, the engine fuel efficiency is reduced, and the turning performance of the vehicle may be affected. is there.

[0014] Further, in the dog clutch, naturally, unlike a friction clutch such as a multi-plate clutch, the transmission torque cannot be controlled by sliding the clutch.

Accordingly, the present invention is directed to a differential device having a simple structure and a low cost, wherein ratchet noise or the like is not generated when the clutch is connected, drag torque is not generated, and transmission torque can be controlled. For the purpose of providing.

[0016]

According to a first aspect of the present invention, there is provided a differential device including a differential mechanism for distributing a driving force of an engine to a wheel, a clutch for intermittently transmitting torque, and coupling means for the clutch. The clutch is a cone clutch.

As described above, in the differential gear according to the present invention, since the cone clutch is used as the clutch, unlike the conventional dog clutch, there is no ratcheting at the time of connection, so that the quietness is high. Will be kept.

Further, since a synchronizing mechanism for phase adjustment is not required, an increase in cost, a complicated structure, and an increase in the size of the apparatus can be avoided.

Further, unlike the dog clutch, the cone clutch can control the transmission torque by sliding the friction surface, so that the controllability of the vehicle can be greatly improved.

Further, when the clutch is disengaged, no drag torque is generated due to the frictional resistance of the meshing teeth such as the meshing clutch.

Accordingly, since the wheels can be separated at a desired timing, a loss of driving force, a decrease in engine fuel efficiency, a decrease in maneuverability, and the like are prevented.

Further, since the cone clutch has a small number of parts and a simple structure, the differential device becomes lighter and more compact, and the vehicle mountability is improved.

Further, since the cone clutch does not require special consideration for lubrication, the cost is greatly reduced in addition to the effect of the small number of parts.

According to a second aspect of the present invention, there is provided the differential device according to the first aspect, wherein the connecting means receives a torque when the pilot clutch is connected and disconnected with the pilot clutch which is intermittently operated by the operating means. It consists of a cam mechanism that operates and presses the main clutch, characterized in that the cone clutch is this main clutch,
The same operation and effect as those of the first aspect can be obtained.

When the pilot clutch is engaged, the cam mechanism operates by receiving torque (differential limiting torque or transmission torque), and the cone clutch which is the main clutch is engaged by the cam thrust force, thereby limiting the differential. And torque is transmitted.

At this time, when the sliding of the pilot clutch is adjusted by the operating means, the torque applied to the cam mechanism changes and the cam thrust force changes, so that the coupling force (transmission torque) of the cone clutch can be controlled.

When the connection of the pilot clutch is released,
The thrust force of the cam mechanism disappears, the connection of the cone clutch is released, and the transmission of torque is stopped.

In this configuration, since the pressing force of the cone clutch is amplified by the cam mechanism, a sufficient clutch capacity can be obtained even if a small and lightweight cone clutch is used.

Therefore, a sufficient driving force can be transmitted to the wheels by the large clutch capacity.

Further, by using a small and lightweight cone clutch, the differential device becomes compact, and the vehicle mountability is further improved.

According to a third aspect of the present invention, there is provided the differential device according to the second aspect, wherein the operating means is an electromagnet.
The effect can be obtained.

The electromagnet can finely adjust the exciting current.
By adjusting the slip of the pilot clutch and the cam thrust force of the cam mechanism, the coupling force of the cone clutch can be precisely controlled.

As described above, this configuration using the electromagnets as the operating means enables precise control of the transmission torque.

Further, this configuration using an electromagnet as the operating means has a simpler and more compact structure, is further improved in vehicle mountability, and has a lower cost, as compared with a configuration using a fluid pressure actuator such as a hydraulic actuator. Can be implemented.

In addition, it is free from malfunctions due to pressure leaks, and the reliability is greatly improved.

Even if an electromagnet having a relatively small pressing force is used, a sufficient transmission torque can be obtained because the pressing force of the cone clutch is amplified by the cam mechanism as described above.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A front differential 1 (one embodiment of the present invention) will be described with reference to FIG.

This front differential 1 has the features of claims 1, 2 and 3. The left and right directions are front differential 1.
1 and the left and right directions in FIG. 1, and members without reference numerals and the like are not shown.

This vehicle is a rear-wheel drive-based four-wheel drive vehicle, and its power system includes an engine, a transmission,
Transfer, 2-4 switching mechanism built into the transfer, front differential 1 (differential device for distributing the driving force of the engine to left and right front wheels), front axle, left and right front wheels, rear wheel side propeller shaft, rear differential (engine (A differential device that distributes driving force to the left and right rear wheels), a rear axle, left and right rear wheels, and the like.

After the speed of the engine is changed by the transmission, the transmission is transmitted from the transfer and the 2-4 switching mechanism to the front differential 1 and transmitted from the transfer to the rear differential via a propeller shaft.

The transmitted driving force is distributed from the front differential 1 to the left and right front wheels via the front axle, and from the rear differential to the left and right rear wheels via the rear axle.

The front differential 1 is housed in a transfer case and includes an outer case 3, an inner case 5, a bevel gear type differential mechanism 7, a cone clutch 9 (main clutch), a connecting means 11, and the like.

The outer case 3 is constituted by fixing the cover 13, the input member 15, and the casing body 17 with bolts 19.

The input member 15 is integrally formed with a ring gear 21 (input gear: spur gear). The ring gear 21 meshes with an output gear of a transfer (2-4 switching mechanism) to drive the engine to the outer case 3. Transmit power.

The casing body 17 is formed of the cylindrical member 2.
3, a ring 25 of a non-magnetic material, and a rotor 2 of a magnetic material.
The ring 25 is welded to the cylindrical member 23 and the rotor 27, respectively, to integrate them.

The outer case 3 is a boss 2 of the cover 13.
9 and the boss 31 of the rotor 27 are supported on the transfer case by bearings.

The differential mechanism 7 includes a plurality of pinion shafts 33, pinion gears 35 supported on the respective pinion shafts 33, and output side gears 37 and 39 meshing with these pinion gears 35.

The tip of each pinion shaft 33 is movably connected to the axial groove 41 of the inner case 5. The side gears 37 and 39 are respectively connected to left and right front wheels via spline-connected front axles.

The connecting means 11 includes the pilot clutch 4
3, a ball cam 45 (cam mechanism), a cam ring 47, a pressure plate 49, a clutch ring 51, an armature 53, an electromagnet 55 (operation means), a controller, and the like.

The connecting means 11 performs the connecting operation and the releasing operation of the cone clutch 9 as described below, and the cone clutch 9 connects the outer case 3 and the inner case 5 with this, and releases the connecting. I do.

When the outer case 3 and the inner case are connected by the cone clutch 9, the outer case 3
The driving force of the engine for rotating the inner case 5,
The vehicle is distributed to the left and right front wheels from the pinion shaft 33 and the pinion gear 35 via the side gears 37 and 39 and the front axle, so that the vehicle is in a four-wheel drive state. The stability of the vehicle is improved.

When a difference in driving resistance occurs between the front wheels on a bad road or the like, the driving force of the engine is differentially distributed to the left and right front wheels by the rotation of the pinion gear 35.

When the connection of the cone clutch 9 is released, the inner case 5 (differential mechanism 7) to the left and right front wheels are disconnected from the engine, and the vehicle is driven by the rear wheels to be driven by two wheels. Engine fuel efficiency is improved.

At this time, the controller releases the connection of the 2-4 switching mechanism (transfer) to prevent the front wheel drive system from rotating to the outer case 3.

The cone clutch 9 has a cone portion 57 formed between the input member 15 (outer case 3), the clutch ring 51 and the inner case 5 (differential mechanism 7).
57.

The input member 15, the clutch ring 51, and the inner case 5 are made of a sintered metal material and have sufficient wear resistance.

The pilot clutch 43 is
(Outer case 3: casing body 17) and cam ring 47.

The ball cam 45 is disposed between the cam ring 47 and the pressure plate 49. Also,
The ball cam 4 is provided between the cam ring 47 and the rotor 27.
A thrust bearing 59 receiving a cam reaction force of No. 5 and a washer are arranged.

The pressure plate 49 is movably connected to the right side gear 39 by a spline portion 61 provided between the pressure plate 49 and the clutch ring 51 by a spline portion 63 in the casing body 17 (cylindrical member 23). It is movably connected to the circumference.

The pressure plate 49 may be movably connected to the inner case 5 instead of the side gear 39.

The armature 53 includes a pilot clutch 4
3 and a pressure plate 49 so as to be movable in the axial direction, and is axially positioned on the outer case 3 side by a retaining ring.

The core 65 of the electromagnet 55 is connected to the transfer case by a connecting member.
The lead wire drawn from 7 is connected to a vehicle-mounted battery.

An air gap is formed between the core 65 and the rotor 27. The rotor 27 is a magnetic material constituting a part of a magnetic circuit of the electromagnet 55, and is separated by a stainless steel ring 69 to prevent a short circuit of magnetic force. Further, the ring 25 is made of a non-magnetic material as described above, and prevents the magnetic force from leaking to the cylindrical member 23 side.

The controller excites the electromagnet 55, controls the excitation current, and stops the excitation.
(4) The operation and the stop of the switching mechanism are performed in an interlocked manner.

When the electromagnet 55 is excited, the armature 53
Presses and engages the pilot clutch 43, and the cam ring 47 is connected to the outer case 3 by the pilot clutch 43. At this time, when differential rotation occurs in the differential mechanism 7, the differential torque is applied to the ball cam 45 via the cam ring 47 on the outer case 3 side and the pressure plate 49 on the side gear 39 side, and the generated cam thrust force The pressure plate 49 moves to the left, and the cone 5
7, 57 are pressed, and the cone clutch 9 is engaged.

When the cone clutch 9 is engaged, the vehicle enters the four-wheel drive state as described above.

At this time, when the exciting current of the electromagnet 55 is controlled, the pilot clutch 43 slips, the cam thrust force of the ball cam 45 changes, and the cone portions 57, 57
By changing the coupling force of the cone clutch 9 due to the slip, the magnitude of the driving force transmitted to the front wheels can be changed.

If such control of the driving force is performed at the time of turning, the turning performance and the stability of the vehicle body are greatly improved.

When the excitation of the electromagnet 55 is stopped, the pilot clutch 43 is released, the cam thrust force of the ball cam 45 disappears, the connection of the cone clutch 9 is released, and the vehicle enters the two-wheel drive state.

Openings 71 and 73 are provided in the outer case 3, and spiral oil grooves 75 and 77 are provided on the inner periphery of the boss portions 29 and 31, respectively.

As the outer case 3 rotates, these openings 71,
Outer case 3 through 73 and oil grooves 75 and 77
The oil flows in and out, and the inflowing oil sufficiently lubricates and cools the cone clutch 9, the meshing portions of the gears of the differential mechanism 7, the pilot clutch 43, the ball cam 45, the bearing 59, and the like.

The coil 67 of the electromagnet 55 heats the oil in the oil reservoir by the heat to lower the viscosity appropriately, and also heats the surrounding pilot clutch 43 and the ball cam 45, and the heated oil is supplied to the cone clutch 9.
Warm up.

The pilot clutch 43 and the cone clutch 9 are warmed in this way, and the response at the time of releasing the connection is greatly improved by adjusting the viscosity of the oil to be low.

Thus, the front differential 1 is configured.

As described above, since the front differential 1 uses the cone clutch 9 as the clutch for interrupting the power, when the connection is released, a drag torque is generated due to the frictional resistance of the meshing teeth such as the meshing clutch. Absent.

In addition to this, the electromagnet 55 as described above
(Coil 67) The heater function of (Coil 67) lowers the viscosity of the oil, and the pilot clutch 43 and the cone clutch 9
Is heated, the drag torque is further reduced.

Therefore, it is possible to separate the front wheels at a desired timing, and it is possible to prevent a loss of driving force, a decrease in engine fuel efficiency, a decrease in maneuverability (turnability), etc. due to a delay in separating the front wheels.

In order to reduce the drag torque,
Measures such as lowering the oil viscosity, raising the oil temperature, or reducing the amount of oil using special means are no longer required. can avoid.

Further, since the cone clutch 9 has a small number of parts and has a simple structure, the front differential 1 is configured to be lightweight and compact, thereby improving the vehicle mountability.

Further, since the cone clutch 9 does not require special consideration for lubrication, the cost is greatly reduced in addition to the effect of the small number of parts.

Also, unlike the conventional dog clutch, the cone clutch 9 does not generate ratchet noise at the time of dog engagement, so that the quietness is kept high.

Further, since a synchronizing mechanism for phase matching is not required, an increase in cost, a complicated structure, and an increase in the size of the front differential 1 are avoided.

Further, unlike the dog clutch, the cone clutch 9 can control the magnitude of the driving force sent to the front wheels by sliding the cone portions 57, 57 as described above, so that the vehicle Drivability, turning performance, etc. can be greatly improved.

The cone clutch 9 of this embodiment is
Since the pressing force is amplified by the ball cam 45, a sufficient clutch capacity can be obtained, and a large driving force can be transmitted to the front wheels.

Further, as described above, since a large capacity can be obtained, the cone clutch 9 can be made smaller and lighter, and by using the small and light cone clutch 9, the front differential 1 can be made more compact.
The on-board performance is improved.

The electromagnet 55 can finely adjust the exciting current. As described above, the coupling force of the cone clutch 9 is precisely controlled by adjusting the slip of the pilot clutch 43 and the cam thrust force of the ball cam 45. Therefore, by using the electromagnet 55 as the control means, the front differential 1 can precisely control the torque transmitted to the front wheels, and can greatly improve the maneuverability and turning performance of the vehicle.

Further, the front differential 1 using the electromagnet 55 as the operating means has a simpler and more compact structure as compared with a configuration using a fluid pressure actuator such as a hydraulic actuator, and further enhances the vehicle mountability. It can be implemented at low cost.

In addition, malfunctions due to pressure leakage are released, and reliability is greatly improved.

Further, even if the electromagnet 55 having a smaller pressing force than the hydraulic actuator or the like is used as the operating means, the pressing force of the cone clutch 9 is amplified by the ball cam 45 as described above. The torque capacity is obtained.

The differential mechanism used in the present invention is not limited to the bevel gear type differential mechanism as in the embodiment.
What kind of differential mechanism, such as a planetary gear type differential mechanism, a differential mechanism in which both output side gears are connected by a pinion gear slidably housed in the housing hole of the differential case, and a differential mechanism using a worm gear May be.

[0091]

According to the differential device of the first aspect of the present invention, the use of the cone clutch does not cause ratcheting as in the case of the meshing clutch, so that the quietness is kept high.

Further, a synchronizing mechanism for phase adjustment is not required, and an increase in cost, a complicated structure, and an increase in the size of the apparatus are avoided.

Further, by using the cone clutch, the frictional surface is slid to control the differential limiting force, or
It is possible to control the transmission torque, and it is possible to greatly improve the controllability, turning performance, and the like of the vehicle.

Further, since the drag torque is prevented, the fall of the differential limiting force becomes faster, and the maneuverability (turnability) of the vehicle is improved, and the wheels can be separated at a desired timing. Thus, a loss of driving force, a decrease in engine fuel efficiency, and a decrease in maneuverability (turnability) are prevented.

In addition, it is not necessary to take measures to prevent drag torque, so that the cost and the lubricating property are reduced.

The use of a cone clutch which has a small number of parts and a simple structure and does not require special consideration for lubrication makes the differential device light and compact, which improves the vehicle mountability and reduces the cost. It is greatly reduced.

The differential device according to the second aspect can provide the same effect as the configuration according to the first aspect.

Further, the amplifying function of the cam mechanism can provide a sufficient clutch capacity even if a small and light cone clutch is used, and a sufficient driving force can be transmitted to the wheels by the large clutch capacity.

Further, by using a small and lightweight cone clutch, the differential device becomes compact and the mountability on the vehicle is further improved.

The differential device according to the third aspect can obtain the same effect as the configuration according to the second aspect.

Further, by using an electromagnet as the operating means, the differential limiting force and the transmission torque can be precisely controlled.

Further, as compared with the configuration using a hydraulic actuator, the structure is simple and compact, the vehicle mountability is further improved, and it is possible to implement at a low cost. , Greatly improve the reliability.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view of a conventional example.

[Explanation of symbols]

 Reference Signs List 1 front differential (differential device) 7 differential mechanism 9 cone clutch (main clutch) 11 connecting means 43 pilot clutch 45 ball cam (cam mechanism) 55 electromagnet (operating means)

Claims (3)

[Claims] 1. A differential mechanism for distributing the driving force of an engine to a wheel, a clutch for intermittently transmitting torque, and coupling means for the clutch, wherein the clutch is a cone clutch. Differential device. 2. The invention according to claim 1, wherein the connecting means is a pilot clutch which is intermittently operated by the operating means, and a cam which operates by receiving torque and presses the main clutch when the pilot clutch is connected. A differential device comprising a mechanism, wherein the cone clutch is the main clutch. 3. The differential device according to claim 2, wherein the operating means is an electromagnet.