JP2003056673A - Differential device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a differential device having both differential limiting functions of a rotation difference sensitive type and a torque sensitive type in a simple structure and at low cost. SOLUTION: This device is provided with a differential case 3 driven to rotate by driving force of a prime mover, a differential mechanism 5 to distribute rotation of the differential case 3 to the wheel side, a cam mechanism actuated by receiving transmission torque of the differential mechanism 5 to generate cam thrust force, friction clutches 7 and 7 pressed by the cam thrust force, a rotation difference sensitive type coupling 9 to receive differential rotation of the differential mechanism 5, and an amplifier mechanism 11 actuated by receiving the transmission torque between the differential mechanism 5 and the rotation difference sensitive type coupling 9 to press the friction clutches 7 and 7 by generated thrust force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device having a torque sensitive differential limiting function and a rotation difference sensitive differential limiting function.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 9-14166 discloses a "rotary actuator and a differential gear device using the same" as shown in FIG.

This differential gear device 501 includes a differential case 5
03, a bevel gear type differential mechanism 505, a rotary actuator 507 for limiting the differential, and the like.

The differential mechanism 505 is a pinion shaft 50.
9, a pinion gear 511 supported on the pinion shaft 509, side gears 513 and 515 meshing with the pinion gear 511, and the like.
Is connected to a ring 517 fixed inside the differential case 503, and the side gears 513 and 515 are connected to the wheel side via respective spline-connected axles.

The driving force of the engine for rotating the differential case 503 is the side gears 513, 51 from the ring 517 via the pinion shaft 509 and the pinion gear 511.
It is distributed to 5 and transmitted to each wheel.

The rotary actuator 507 is a vane pump, and the shaft portion 5 of the casing 519, which is one side member.
21 is splined to the side gear 515, and the shaft portion 525 of the rotor 523, which is the other side member, is connected to the side gear 513.
Splined to.

As described above, the rotary actuator 507
Is arranged between the side gears 513 and 515, and operates by receiving differential rotation generated between the side gears 513 and 515, and limits the differential of the differential mechanism 505 by its pump work.

The pump work of the rotary actuator 507 (vane pump) increases as the differential rotation speed of the differential mechanism 505 increases, so the rotary actuator 507.
This provides a rotation-sensitive differential limiting function.

When the wheel on one side spins on a bad road or the like, a driving force is sent to the wheel on the grip side by the rotation difference sensitive differential limiting function, so that the running performance of the vehicle on a bad road is improved.

Also, while the differential mechanism 505 is transmitting torque, the side gears 513, 515 and the pinion gear 51.
A cam thrust force is generated by the cam mechanism having the meshing angle of 1, and the side gear 51 is generated by these cam thrust forces.
3, 515 are pressed by the differential case 503, the pinion gear 511 is pressed by the ring 517, and the differential of the differential mechanism 505 is limited by the frictional resistance generated in the sliding portions 527, 529, 531.

Since the cam thrust force generated by the meshing angle of each gear increases as the transmission torque increases, each sliding portion 527, 529, 531 can obtain a torque sensitive differential limiting function.

At the time of starting or accelerating when a large driving torque is applied, the torque sensitive differential limiting function prevents one wheel from idling and stabilizes the behavior of the vehicle body.

[0013]

However, since the conventional differential gear device 501 is constituted by using the rotary actuator 507 of the vane pump for the differential limiting mechanism,
The structure is complicated and expensive.

Further, the rotary actuator 507 has
Since there is no mechanism for enhancing the differential limiting function, the rotary actuator 507 (the casing 519 and the rotor 523) needs to have a large diameter in order to obtain a sufficient rotation difference sensitive differential limiting function. When the diameter of 507 becomes large, it becomes necessary to retreat the position of the pinion gear 511 to the outer side in the radial direction, and accordingly, the side gear 5
The diameter of 13,515 must be large.

In this way, the rotary actuator 507
Incorporation into the differential device involves major changes and increased costs.

In addition, since the differential gear device 501 has a large diameter by incorporating the rotary actuator 507, it is difficult to replace the differential gear device 501 with another differential device in the power transmission system of the vehicle. However, in the case of replacement, it is necessary to change peripheral members such as a casing and a differential carrier, which further increases the cost associated with the change.

A large-diameter rotary actuator 507 is also provided.
Becomes heavier, the differential gear device 501 becomes heavier, and the vehicle mountability deteriorates.

Further, since the sliding portions 527, 529, 531 are merely pressure receiving portions and are not configured to generate a large frictional resistance, a sufficient torque sensitive type differential limiting function cannot be obtained.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a differential device having both a rotation-difference-sensitive type and a torque-sensitive type differential limiting function of a sufficient size, a simple structure, and a low cost.

[0020]

According to another aspect of the present invention, there is provided a differential device including a differential case which is rotationally driven by a driving force of a prime mover, and a differential mechanism which distributes the rotation of the differential case to a wheel side. A cam mechanism that receives the transmission torque of the differential mechanism to generate a cam thrust force, a friction clutch that is engaged by the cam thrust force, and a rotation that receives the differential rotation of the differential mechanism to operate. The amplification is provided by providing a difference-sensitive coupling and an amplifying mechanism which is disposed between the differential mechanism and the rotation difference-sensitive coupling and which operates by receiving a transmission torque between them to generate a thrust force. The thrust force of the mechanism is input to the friction clutch to strengthen the fastening force.

In the differential device of the present invention, when the transmission mechanism receives the transmission torque of the differential mechanism, for example, the cam mechanism constituted by the meshing portion of the differential gear set is actuated, and the cam thrust force presses the friction clutch, and the torque responsiveness is exerted. The differential limiting force (differential limiting function) of the mold is obtained.

Further, an amplification mechanism (for example, a cam mechanism) is activated by receiving a rotation difference (differential rotation torque) between the differential mechanism and the rotation difference sensitive type coupling, and the friction clutch is pressed by the thrust force. Rotational difference sensitive differential limiting force (differential limiting function) can be obtained.

When the differential device of the present invention is arranged on the axle, a rotation-difference-sensitive differential limiting force is immediately generated even if either of the left and right wheels spins, and the driving force of the prime mover is applied to the grip side wheel. When used as a center differential, no matter which of the front and rear wheels spins, a rotation-difference-sensitive differential limiting force is immediately generated, and the driving force of the prime mover is sent to the grip side wheels. In the case of, the driving performance on rough roads is also improved.

Since the thrust force of the amplifying mechanism increases as the differential rotation speed of the differential mechanism applied to the rotation difference sensitive coupling increases, the differential limiting force generated by the friction clutch increases as the differential rotation speed increases. Grows larger.

Regarding the differential rotation sensitive differential limiting function, the amplifying mechanism amplifies the engaging force of the friction clutch, and the differential limiting function of the rotational differential sensitive coupling itself is added to the differential limiting function. You can obtain the motion restriction.

As described above, among the differential limiting forces generated by the friction clutch, the amount generated by the meshing thrust force of the differential gear set becomes the torque sensitive differential limiting force, and the rotation difference sensitive coupling. And the amount generated by the amplifying mechanism becomes a rotation limiting sensitive differential limiting force.

As described above, in the differential device of the present invention, both the torque sensitive type and the rotational difference sensitive type differential limiting functions can be obtained on the same friction clutch, so that the structure is simple and the cost is low. .

The rotation difference sensitive coupling is a means for operating the amplifying mechanism, and does not need to be particularly large, and a small and light rotation difference sensitive coupling provides sufficient effects.

As described above, the small and light rotation-difference-sensitive coupling can be easily incorporated into a differential device having no differential limiting function with a slight modification. It is possible to avoid an increase in the diameter of the differential device and a significant weight increase due to the incorporation of the coupling.

As described above, since the differential device of the present invention can be constructed to have a small diameter and a light weight, it can be easily mounted on a vehicle and can be easily replaced with another differential device. Since it is not necessary to significantly change peripheral members such as the casing and the differential carrier, the change and replacement can be performed at an extremely low cost.

According to a second aspect of the present invention, there is provided the differential device according to the first aspect, wherein the rotation difference sensitive coupling is arranged between a pair of output side members of the differential mechanism and the amplification is performed. The mechanism is arranged between at least one of the output side members and the rotation difference sensitive type coupling, and an operation equivalent to that of the configuration of claim 1.
The effect can be obtained.

Further, in this structure, the rotation difference sensitive coupling is arranged between the output side members of the differential mechanism, and the amplification mechanism is arranged between at least one of the output side members and the rotation difference sensitive coupling. As a result, the reaction force generated when the amplification mechanism operates is applied to both output side members via the rotation difference sensitive coupling, so that the reaction force is prevented from coming off, and the operation efficiency of the amplification mechanism is increased. A rotation-sensitive differential limiting function can be obtained.

Further, by disposing the rotation difference sensitive type coupling between both output side members, a large rotation difference generated between both output side members can be utilized, so that a larger rotation difference sensitive type differential is realized. Limited function is obtained.

According to a third aspect of the present invention, in the differential device according to the first aspect, the rotation difference sensitive coupling is arranged between a pair of output side members of the differential mechanism, and the amplification is performed. The mechanism is arranged between the rotation-difference-sensitive coupling and both output side members, and the same action and effect as the configuration of claim 1 can be obtained.

Also in this configuration, similarly to the configuration of claim 2, the reaction force is prevented from coming off, the operating efficiency of the amplifying mechanism is enhanced, and a large rotation difference sensitive differential limiting function is obtained.

Further, by disposing the rotation difference sensitive type coupling between both output side members, a large rotation difference generated between both output side members can be utilized as in the case of the structure of claim 2. In this configuration in which the amplifying mechanism is arranged between both the output side members and the rotation difference sensitive coupling, the two sets of amplifying mechanisms operate in response to the large rotation difference, and therefore the difference of the rotation difference sensitive type. The motion restriction function becomes extremely large.

The invention according to claim 4 is the differential device according to any one of claims 1 to 3, wherein the differential mechanism is a bevel gear type differential mechanism, and the friction clutch is the bevel gear type. It is a cone clutch provided between the side gear that is the output side member of the differential mechanism and the differential case, or a multi-plate clutch, and the cam mechanism meshes with the side gear and the pinion gear of the bevel gear type differential mechanism. It is a cam mechanism constituted by corners, and the rotation difference sensitive type coupling is arranged between the both side gears, and obtains the same operation and effect as the configuration of claims 1 to 3. be able to.

Further, in this configuration using a bevel gear type differential mechanism as the differential mechanism, a torque sensitive differential limiting function can be obtained in both rotation directions of the differential case (both forward traveling and backward traveling of the vehicle). Therefore, the stability of the vehicle body when the engine brake is applied is improved.

When a cone clutch is used as the friction clutch, a large friction resistance can be obtained by the wedge action of the cone portion (cone portion) even if the friction clutch is small, and therefore both the torque sensitive type and the rotation difference sensitive type are used. With the differential limiting function, a large differential limiting force can be obtained, and the differential device can be made compact and lightweight.

According to a fifth aspect of the present invention, there is provided the differential device according to the fourth aspect, wherein one side member of the rotation difference sensitive coupling is integrated with a pinion shaft side member of the bevel gear type differential mechanism. Since it is formed, it is possible to obtain the same operation and effect as the configuration of claim 4.

Further, in this structure in which the one side member of the rotation difference sensitive coupling is integrally formed with the pinion shaft side member of the bevel gear type differential mechanism, the number of parts and the assembling cost are reduced accordingly.

Further, in this construction in which the rotation difference sensitive type coupling is arranged between the pinion shaft and one of the output side gears, the differential device of the present invention is used for the center differential, and one output where the amplifying mechanism is arranged. When the side member is set to the front wheel side, when the front wheel side idles, a rotation difference sensitive differential limiting force is immediately generated, and the driving force of the prime mover is sent to the rear wheel side to improve running performance on a bad road.

A sixth aspect of the present invention is the differential device according to any one of the first to fifth aspects, wherein the friction clutch is arranged in a large diameter portion, and the rotation difference sensitive coupling is arranged in a small diameter portion. It is characterized in that it is arranged, and it is possible to obtain the same actions and effects as the configurations of claims 1 to 5.

Further, in this structure, since the friction clutch is arranged in the large diameter portion, the friction torque generated in the friction clutch is increased by that much. Therefore, in both the torque sensitive type and the rotation difference sensitive type differential limiting function, A larger differential limiting force can be obtained.

Further, since the rotation difference sensitive type coupling is arranged in the small diameter portion, the pressing force of the friction clutch is amplified by the amplifying mechanism even if the differential torque applied to the rotation difference sensitive type coupling becomes small. A rotation difference sensitive differential limiting function can be obtained.

Further, by arranging in the small diameter portion, the rotation difference sensitive type coupling becomes small in size and light in weight.
It becomes easy to arrange the rotation-sensitive coupling between the side gears of the differential mechanism.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A front differential 1 (first embodiment of the present invention: a differential device) will be described with reference to FIGS.

The front differential 1 has the features of claims 1, 2, 4, and 6. Also, the left and right directions are front differential 1
The vehicle and the left and right directions in FIG. 1 are not shown, and members and the like without reference numerals are not shown.

The power system of this vehicle is an engine (motor),
It consists of a transmission, front diff 1 (differential device that distributes engine drive power to the left and right front wheels), front axle, left and right front wheels, left and right rear wheels, etc. Engine drive power from the transmission to front diff 1 It is sent and distributed from the front differential 1 to the left and right front wheels via the front axle.

The front differential 1 is composed of a differential case 3, a bevel gear type differential mechanism 5, cone clutches 7 and 7 (friction clutch), a rotation difference sensitive coupling 9, a cam 11 (amplifying mechanism) and the like.

The front differential 1 is disposed inside the transmission case 13, and the transmission case 13 has an oil reservoir formed therein.

The differential case 3 is constructed by fixing the casing body 15 and the cover 17 with bolts 18.

The left and right boss portions 19 and 21 of the differential case 3 are supported by the transmission case 13 via bearings. A ring gear is fixed to the differential case 3 with bolts, and the ring gear meshes with the output gear of the transmission. The driving force of the engine is transmitted to the differential case 3 via the transmission and the ring gear.

The oil in the oil sump is stored in the differential case 3.
It is scraped up by the rotation of the (ring gear) and scattered inside the transmission case 13.

The bevel gear type differential mechanism 5 is composed of a plurality of pinion shafts 23, pinion gears 25, left and right output side gears 27, 29 (output side members of the differential mechanism) and the like.

The respective pinion shafts 23 are arranged radially around the ring-shaped boss 31, and the outer ends thereof engage with the through holes 32 of the differential case 3, and the spring pins 33 prevent the pins from coming off and rotating. Has been applied.

The pinion gear 25 is used for each pinion shaft 2
It is rotatably supported on 3.

The side gears 27 and 29 mesh with the respective pinion gears 25 from the left and right, and these are supported from the outside in the radial direction by meshing with the respective pinion gears 25. Also, the boss portions 35, 3 of the side gears 27, 29 are
The bearings 7 are supported by bearings 39 and 41 formed on the differential case 3, respectively.

A spherical washer 43 is arranged between each pinion gear 25 and the differential case 3, and the centrifugal force of the pinion gear 25 and the meshing reaction force generated in the pinion gear 25 by the meshing with the side gears 27 and 29. Is receiving.

The side gears 27 and 29 are provided with bosses 35 and 3 respectively.
7 are connected to the front axle by spline portions 45 and 47, respectively, and are connected to the left and right front wheel sides.

The driving force of the engine for rotating the differential case 3 is distributed from the pinion shaft 23 to the side gears 27, 29 via the pinion gear 25 and transmitted to the left and right front wheels. Further, if a driving resistance difference occurs between the front wheels while traveling on a rough road, the driving force of the engine will be increased by each pinion gear 25.
Is distributed differentially to the left and right front wheels.

Tapered plates 49, 49 are arranged on the left and right sides of the side gears 27, 29. These tapered plates 49, 49 are provided on the casing main body 15 and the cover 17 with convex portions 51, 53 formed on the arm portions. 55,
55 is engaged to prevent rotation.

The cone clutches 7, 7 are formed between the taper plates 49, 49 and the cone portions 57, 59 of the side gears 27, 29.

Each side gear 27, 29 and pinion gear 2
The meshing portion of 5 forms a cam (cam mechanism) according to the meshing angle of each, and the cam is actuated by the torque transmitted by the differential mechanism 5 when the vehicle starts or while the pinion gear is engaged. 25, the side gears 27 and 29 retreat to the left and right in response to the meshing reaction force (cam thrust force) generated between the side clutches 25 and 25, and the cone clutches 7 and 7 are pressed and fastened.

When the cone clutches 7, 7 are engaged, the friction of the cone clutches 7 limits the differential of the differential mechanism 5. Since the meshing reaction force of the side gears 27 and 29 becomes stronger as the transmission torque of the differential mechanism 5 increases, this differential limiting function becomes a torque sensitive type.

Further, in the bevel gear type differential mechanism 5, the meshing reaction force of the side gears 27 and 29 is generated in the same magnitude in both rotation directions of the differential case 3, so that both the forward running and the reverse running of the vehicle are performed. The equivalent torque-sensitive differential limiting function can be obtained at.

Due to the torque-sensitive differential limiting function of the vehicle, one wheel of the front wheel is prevented from idling at the time of starting or accelerating with a large driving torque, the behavior of the vehicle body is stabilized, the maneuverability is improved, and the touring performance is improved. Improves running, stability, and maneuverability inside.

The rotation difference sensitive coupling 9 is a viscous coupling that obtains a differential limiting force according to the rotation difference due to the shear resistance of the viscous fluid, and is provided in the coupling case 61, the coupling hub 63, and the coupling case 61. A large number of outer plates axially movably connected to the formed spline portion, and a large number of outer plates axially movably connected to the spline portion formed on the coupling hub 63 and arranged alternately with the outer plates. An inner plate, a working chamber 65 formed between the coupling case 61 and the coupling hub 63 and accommodating the above-mentioned plates, and composed of high-viscosity silicone oil (viscous fluid) enclosed in the working chamber 65. Has been done.

Further, an X ring 67, which is a seal having an X-shaped cross section, is arranged between the coupling case 61 and the coupling hub 63 to prevent silicone oil from leaking.

As is well known, the differential limiting function of the viscous coupling increases as the differential rotation speed between the plates that rotate relative to each other increases, and the increasing rate of the differential limiting function increases as the differential rotation speed increases. As the differential rotation speed increases to some extent, it becomes almost constant.

The rotation difference sensitive coupling 9 (coupling case 61) is housed inside the boss 31 which is the base of the pinion shaft 23 (small diameter portion) so as to be relatively rotatable.

In the case of the front differential 1, the coupling case 61 is formed integrally with the boss portion 35 of the left side gear 27.

The cam 11 is a meshing portion having a cam angle, and is formed between the coupling hub 63 of the rotation difference sensitive coupling 9 and the boss portion 37 of the right side gear 29.

As described above, the rotation difference sensitive coupling 9
Is arranged between both side gears 27 and 29, and operates by receiving differential rotation of the side gears 27 and 29 input from the coupling case 61 and the cam 11.

At this time, the cam 11 is operated by the differential torque of the side gears 27 and 29 applied to one side and the other side and the differential limiting torque of the rotation difference sensitive type coupling 9,
The generated cam thrust force pushes the side gear 29 to the right to engage the right cone clutch 7, and the cam reaction force pushes the side gear 27 to the left via the rotation difference sensitive coupling 9 to move the left cone clutch 7 to the left. And the differential of the differential mechanism 5 is limited by the frictional resistance of each cone clutch 7.

The engagement force of each cone clutch 7 by the cam 11 becomes larger as the rotation difference (differential torque) of the side gears 27, 29 applied to the rotation difference sensitive coupling 9 increases, so that it depends on the thrust force of the cam 11. The differential limiting force of each cone clutch 7 becomes a rotation difference sensitive differential limiting function.

In addition to this, the rotation difference sensitive type differential limiting function is enhanced by the differential limiting function of the viscous coupling of the rotation difference sensitive type coupling 9 itself.

Further, since the rotation difference sensitive type coupling 9 is arranged between the side gears 27 and 29, a large rotation difference generated between them can be utilized, so that the rotation difference sensitive type differential is realized. The limit function is further increased.

When one of the front wheels spins on a bad road or the like, a driving force is sent to the front wheel on the grip side by the rotation difference sensitive differential limiting function, and the running performance on a bad road is improved.

As described above, of the differential limiting forces generated in each cone clutch 7, the amount generated by the meshing thrust force of the differential mechanism 5 is the torque-sensitive differential limiting force, which is the rotation difference sensitive type. The amount generated by the coupling 9 and the cam 11 is the rotation difference sensitive differential limiting force.

Also, the differential case 3 side and the side gear 27,
With the large-diameter cone clutches 7 and 7 arranged between the large-diameter cone clutch 29 and the large-diameter side 29 (on the large-diameter side of the front differential 1), a large friction torque can be obtained. The function increases.

The rotation-difference-sensitive coupling 9 arranged in the center of the front differential 1 has a small diameter and can be easily arranged between the side gears 27 and 29 and inside each pinion gear 25 (boss 31). is there.

FIG. 4 shows the characteristics of the differential rotation speed (ΔN) and the differential limiting force (F) of the differential mechanism. Graph A shows that the viscous coupling is operated between the side gears 27 and 29. The graph B shows the differential limiting characteristic of the case where the rotation difference sensitive coupling 9 and the cam 11 are used as described above.

In the front differential 1, as described above, the amplifying function of the cam 11, the large diameter of each cone clutch 7, and the rotation-difference-sensitive coupling 9 are used as the side gears 27, 2.
An extremely large differential limiting force is obtained due to the fact that a large rotational difference between 9 is used and the differential limiting function of the rotational difference sensitive coupling 9 itself is obtained. The differential limiting force of 1) is about 5 times that of graph A.

The casing body 15 and the cover 17 of the differential case 3 have openings 6 behind the cone clutches 7, 7.
9, 71 are provided respectively, and further, the boss portion 1
A spiral oil groove is formed on the inner circumference of each of 9 and 21.

The casing body 15 has a boss portion 21.
Is formed with an oil groove 73 communicating with the cone clutch 7 side.
An oil groove 75 communicating with the spiral oil groove and the cone clutch 7 side is formed.

The openings 69, 71 formed in the radially outer portion on the differential case 3 are below the oil level of the oil sump formed in the transmission case 13 and are constantly immersed in oil. The oil flowing in from is efficiently supplied to the cone clutches 7, 7 to lubricate and cool them.

The oil scraped up from the oil sump by the rotation of the differential case 3 and the ring gear moves to the inside of the differential case 3 by the screw pump action of each spiral oil groove and passes through the oil grooves 73 and 75. It is supplied to the cone clutches 7, 7 to improve the lubrication / cooling effect.

Further, the oil supplied to the inside of the differential case 3 lubricates and cools the meshing portions of the gears of the differential mechanism 5 and the spherical washer 43 to improve the durability.

In this way, the front differential 1 is constructed.

As described above, the front differential 1 operates the cam 11 by the differential torque applied to the rotation difference sensitive coupling 9 and presses the cone clutches 7 and 7 to perform the rotation difference sensitive differential limiting function. Among the differential limiting forces obtained by the cone clutches 7 and 7, the amount generated by the meshing thrust force of the pinion gear 25 and the side gears 27 and 29 becomes the torque sensitive differential limiting force, and The difference generated by the differential sensitive coupling 9 and the cam 11 becomes the rotational differential sensitive differential limiting force.

In this way, in the front differential 1, both the torque sensitive type and the rotational difference sensitive type differential limiting functions can be obtained on the same cone clutch 7, 7, and therefore the structure is simple and the cost is low. is there.

With respect to the rotation-difference-sensitive differential limiting function, even if the rotation-difference-sensitive coupling 9 has a small diameter and the differential torque received is small, the engagement force of the cone clutches 7, 7 is increased by the cam 11. In addition to being amplified and obtaining a sufficient differential limiting force, the rotation difference sensitive differential limiting function of the rotation difference sensitive coupling 9 itself is obtained.

Further, by arranging the rotation difference sensitive type coupling 9 between the side gears 27 and 29 and utilizing a large rotation difference, a rotation difference sensitive type differential limiting function is obtained.

Further, since the cone clutches 7, 7 have a large diameter, the generated friction torque becomes large, and a larger differential limiting force can be obtained in both the torque sensitive type and the rotation difference sensitive type differential limiting functions. To be

Even if the cone clutches 7 and 7 are small in size, a large frictional resistance can be obtained by the wedge action of the cone portion, so that both the torque sensitive type and the rotation difference sensitive type differential limiting force are further increased. At the same time, the front differential 1 can be made compact and lightweight.

Further, since the rotation difference sensitive type coupling 9 is arranged between the side gears 27 and 29, the cam 11
The cam thrust force and the cam reaction force are applied to the side gears 27 and 29 via the rotation difference sensitive coupling 9, and the cam force is prevented from coming off. Therefore, the operation efficiency of the cam 11 is increased and the rotation difference sensitive differential The limit function is further increased.

The rotation difference sensitive coupling 9 is a pilot means for actuating the cam 11, and is arranged inside the boss 31 to have a small diameter, so that the differential rotation sensitive coupling 9 is provided with a differential. Even if the torque becomes small, the amplification function of the cam 11 can be obtained. Therefore, if the small rotation difference sensitive coupling 9 is used, a sufficient rotation difference sensitive differential limiting force can be obtained.

As described above, the small rotation-difference-sensitive coupling 9 can be easily incorporated into a differential device having only the cone clutches 7 and 7 by making a slight change. The accompanying increase in the diameter of the differential device and the significant weight increase can be avoided.

Also, a small rotation difference sensitive type coupling 9
As described above, can be accommodated inside the boss 31 that is the base of the pinion shaft 23 (small diameter portion), and can be easily arranged between the side gears 27 and 29.

Further, since the front differential 1 is constructed to be small in diameter and lightweight by using the small and light rotation difference sensitive type coupling 9, it is possible to obtain high vehicle mountability and to be compatible with other differential devices. The replacement is easy, and further, since the peripheral members (for example, the transmission case 13 and the differential carrier) are not required to be largely changed, the change and the replacement can be performed at an extremely low cost.

Further, in the front differential 1 using the bevel gear type differential mechanism 5, the same torque-sensitive differential limiting function can be obtained in both rotation directions of the differential case 3 (advanced traveling and backward traveling of the vehicle). The stability of the vehicle body when the engine brake is applied is improved.

Further, in the front diff 1, the coupling case 61 of the rotation difference sensitive coupling 9 is integrated with the side gear 27, so that the number of parts and the assembling cost are reduced accordingly.

[Second Embodiment] A front differential 101 (second embodiment of the present invention: a differential device) will be described with reference to FIG.

The front differential 101 is defined in claims 1, 3, 4,
It has 6 features.

The front diff 101 is an example in which the rotation difference sensitive coupling 9 is changed to the rotation difference sensitive coupling 103 in the front diff 1 of the first embodiment, and the cam 105 is provided in addition to the cam 11. .

Hereinafter, the difference from the front differential 1 will be described with reference to the members having the same functions as the front differential 1 by giving the same reference numerals.

The front differential 101 includes a differential case 3, a bevel gear type differential mechanism 5, cone clutches 7 and 7, a rotation difference sensitive coupling 103, a cam 11 and a cam 105.
(Amplification mechanism) and the like.

Like the rotation difference sensitive coupling 9, the rotation difference sensitive coupling 103 has a coupling case 61, a coupling hub 63, and a coupling case 61.
Is composed of a large number of outer plates connected to the coupling hub 63, a large number of inner plates connected to the coupling hub 63, a working chamber 65, a high-viscosity silicone oil enclosed in the working chamber 65, and the like. An X ring 67 is arranged between 61 and the coupling hub 63.

The coupling case 61 of the rotation difference sensitive coupling 103 is housed inside the boss 31 (small diameter portion) so as to be rotatable relative to each other.

In the case of the front differential 101, the coupling case 61 is connected to the boss portion 35 of the left side gear 27 via the cam 105.

Thus, the rotation difference sensitive coupling 1
03 is arranged between both side gears 27 and 29, and operates by receiving differential rotation of both side gears 29 and 27 input from the cam 11 and the cam 105, respectively.

At this time, the cams 11 and 105 are operated by the differential torque of the side gears 27 and 29 applied to one side and the other side and the differential limiting torque of the rotation difference sensitive coupling 103, and the cam thrust force of the cam 11 is exerted. Presses the side gear 29 to the right to engage the right cone clutch 7, and the cam 10
The cam thrust force of 5 pushes the side gear 27 to the left to engage the left cone clutch 7, and the frictional resistance of each cone clutch 7 limits the differential of the differential mechanism 5.

In this way, the front differential 101 is constructed.

As described above, the front differential 101 includes the side gears 27 and 29 and the rotation difference sensitive coupling 103.
And the cams 105 and 11 respectively disposed between the side gears 27 and 29 operate by receiving a large rotation difference between the side gears 27 and 29 to amplify the engagement force of the cone clutches 7 and 7, and thus an extremely large rotation difference sensitive differential limit. The function is obtained.

Further, the cams 105 and 11 are connected to the side gear 2
7, 29 and the rotation difference sensitive coupling 103, the front differential 101 is provided with a rotation difference sensitive differential limiting force immediately when either the left or the right front wheel runs idle, and the front wheel on the grip side. The driving force of the engine is sent to improve the running performance on rough roads.

In addition to this, the front differential 101 has the same effects as the front differential 1 except that the coupling case 61 is integrated with the side gear 27.
The same effect can be obtained.

[Third Embodiment] A front differential (third embodiment of the present invention: a differential device) will be described with reference to FIG.

The front differential of the third embodiment is defined by claim 1.
In the front differential 101 of the second embodiment, the configuration of the rotation difference sensitive coupling 103 is changed and the cam 105 is abolished.

The difference from the front differential 101 will be described below by quoting the members having the same function with the same reference numerals.

The front differential of the third embodiment includes a differential case 3, a bevel gear type differential mechanism 5, a cone clutch 7,
It is composed of a rotation difference sensitive coupling 103, a cam 11 and the like.

In the case of the third embodiment, the cone clutch 7 is provided only between the differential case 3 and the right side gear 29. The pinion shaft 23 is formed integrally with the boss 31 (pinion shaft side member), and the boss 31 also serves as the coupling case 61 of the rotation difference sensitive coupling 103.

The cam 11 is formed between the coupling hub 63 and the boss portion 37 of the right side gear 29.

Thus, the rotation difference sensitive coupling 1
03 is a pinion shaft 23 (boss 31) and a cam 11
It operates by receiving differential rotation between the differential case 3 and the side gear 29 which are respectively input from the.

At this time, the cam 11 is actuated by the differential torque between the differential case 3 and the side gear 29, which is applied to one side and the other side, and the differential limiting torque of the rotation difference sensitive coupling 9, and the generated cam thrust force is generated by the side gear. 29 is pressed to the right to engage the cone clutch 7, and the frictional resistance of the cone clutch 7 limits the differential of the differential mechanism 5.

Thus, the front differential of the third embodiment is constructed.

As described above, this front differential uses the boss 31 of the pinion shaft 23 for the coupling case 61 which is one side member of the rotation difference sensitive type coupling 103, so that the number of parts and the assembly cost are increased. Has been reduced.

Further, this structure in which the rotation difference sensitive type coupling 103 is operated between the differential case 3 and one side gear 29 is used for the center differential, and if the side gear 29 on which the cam 11 is arranged is on the front wheel side. When the front wheel side idles, a rotation difference sensitive differential limiting force is immediately generated, and the driving force of the prime mover is sent to the rear wheel side to improve running performance on rough roads.

In the differential device of the present invention, the differential mechanism is not limited to the bevel gear type differential mechanism as in each of the embodiments, but the pinion gear slidably accommodated in the accommodating hole of the differential case is used. A differential mechanism that connects both output side gears may be used.

Further, the friction clutch is not limited to the cone clutch, but may be any type of friction clutch such as a single plate clutch or a multi-plate clutch, and these may be wet type or dry type.

The amplification mechanism is not limited to the cam mechanism.

The differential device of the present invention is
Front differential (differential device that distributes engine drive power to the left and right front wheels) and rear differential (differential device that distributes engine drive power to the left and right rear wheels)
And a center differential (a differential device that distributes the driving force of the engine to the front wheels and the rear wheels).

[0133]

According to the differential device of the first aspect of the present invention, both the torque sensitive type and the rotational difference sensitive type differential limiting functions can be obtained on the same friction clutch, so the structure is simple and the cost is low.

A sufficient differential limiting force can be obtained by the frictional clutch engaging force amplifying function by the amplifying mechanism and the differential limiting function of the rotation difference sensitive coupling itself.

Further, since the rotation difference sensitive type coupling for operating the amplifying mechanism can be made small and lightweight, for example, in a differential device having no differential limiting function,
It can be easily installed by making a slight change, and it is possible to avoid a large diameter of the differential device and a large weight accompanying the installation.

In addition, the differential device of the present invention constructed to have a small diameter and a light weight as described above has a high vehicle mountability and can be easily exchanged with another differential device. Is not required, and the change and the exchange can be performed at an extremely low cost.

Further, regardless of whether it is arranged on the axle or used for the center differential, when one wheel idles, a differential limiting force is immediately generated, and the driving force of the prime mover is sent to the grip side wheel. Driving performance on roads is greatly improved.

The differential device according to claim 2 can obtain the same effect as that of the structure according to claim 1.

Further, the loss of force is prevented, the operating efficiency of the amplifying mechanism is increased, and the rotation difference sensitive differential limiting function is increased accordingly.

Further, since a large differential rotation speed generated between both output side members can be utilized, an even larger differential limiting function can be obtained.

The differential device according to the third aspect can obtain the same effect as that of the configuration according to the first aspect.

Further, the large rotation difference generated between both output side members can be utilized, and the two sets of amplifying mechanisms are actuated in response to the large rotation difference, so that an extremely large rotation difference sensitive differential limiting function is obtained. To be

Further, similarly to the structure of the second aspect, the operating efficiency of the amplifying mechanism is increased and the rotation difference sensitive differential limiting function is further enhanced.

According to the differential device of the fourth aspect, the same effects as those of the configurations of the first to third aspects can be obtained.

Further, in this structure using the bevel gear type differential mechanism, a torque-sensitive type differential limiting function can be obtained in both forward traveling and reverse traveling of the vehicle, and at the same time, the vehicle body when the engine is braked is applied. Improves stability.

The differential device according to claim 5 can obtain the same effect as that of the structure according to claim 4.

Further, in this structure in which one side member of the rotation difference sensitive coupling and the pinion shaft side member are integrally formed, the number of parts and the assembling cost are reduced accordingly.

The differential device according to claim 6 can obtain the same effects as those of the configurations according to claims 1 to 5.

Further, since a large friction torque can be obtained by the friction clutch arranged in the large diameter portion, a large differential limiting force can be obtained by both the torque sensitive differential limiting function and the rotation difference sensitive differential limiting function. .

Even if the rotation difference sensitive type coupling is arranged in the small diameter portion, a sufficient rotation difference sensitive type differential limiting force can be obtained by the amplifying mechanism.

Further, the rotation difference sensitive type coupling arranged in the small diameter portion is small and lightweight, and can be easily arranged between the side gears of the differential mechanism.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment.

FIG. 2 is a cross-sectional view showing a second embodiment.

FIG. 3 is a sectional view showing a part of a third embodiment.

FIG. 4 is a graph comparing a rotation difference sensitive differential limiting characteristic between each embodiment and a conventional differential device.

FIG. 5 is a cross-sectional view of a conventional example.

[Explanation of symbols]

1 front differential (differential device) 3 differential case 5 bevel gear type differential mechanism 7, 7 cone clutch (friction clutch) 9 rotation difference sensitive coupling 11 cam (amplification mechanism) 25 pinion gear (camera thrust by receiving transmission torque) 27, 29 Side gear (cam mechanism that operates by receiving transmission torque to generate cam thrust force) 31 Boss (pinion shaft side member) 101 Front differential (differential device) 103 Rotation difference sensitive coupling 105 Cam (amplification mechanism)

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3D036 GA02 GB08 GC01 GC06 GD06                       GF10 GG40 GH05 GH20 GJ02                 3J027 FA34 FA36 FB01 GA02 GB10                       GC11 GC22 GD04 GD08 HA03                       HB07 HC02 HC17 HF32 HG04                       HH04

Claims (6)

[Claims] 1. A differential device including a differential case that is rotationally driven by a driving force of a prime mover, and a differential mechanism that distributes rotation of the differential case to a wheel side, the differential device receiving a transmission torque of the differential mechanism. A cam mechanism that operates to generate a cam thrust force; a friction clutch that is engaged by receiving the cam thrust force; a rotation difference sensitive coupling that operates by receiving differential rotation of the differential mechanism; An amplification mechanism that is arranged between the rotation-difference-sensitive coupling and operates by receiving a transmission torque between them and that generates a thrust force is provided, and the thrust force of the amplification mechanism is input to the friction clutch. A differential device characterized by enhanced fastening force. 2. The invention according to claim 1, wherein the rotation difference sensitive coupling is arranged between a pair of output side members of the differential mechanism, and the amplification mechanism is provided in at least one of the output side members. A differential device arranged between the output side member and the rotation difference sensitive coupling. 3. The invention according to claim 1, wherein the rotation difference-sensitive coupling is arranged between a pair of output side members of the differential mechanism, and the amplification mechanism is provided with the rotation difference. A differential device characterized in that it is arranged between a sensitive coupling and both output side members. 4. The invention according to claim 1, wherein the differential mechanism is a bevel gear type differential mechanism, and the friction clutch is an output side of the bevel gear type differential mechanism. A cone clutch provided between the side gear that is a member and the differential case, or a multi-plate clutch, and the cam mechanism is a cam that is formed by a meshing angle between the side gear and the pinion gear of the bevel gear type differential mechanism. A differential device, which is a mechanism, wherein the rotation difference-sensitive coupling is arranged between the both side gears. 5. The invention according to claim 4, wherein one side member of the rotation difference sensitive coupling is formed integrally with a pinion shaft side member of the bevel gear type differential mechanism. Differential device. 6. The invention according to any one of claims 1 to 5, wherein the friction clutch is arranged in a large diameter portion and the rotation difference sensitive coupling is arranged in a small diameter portion. Differential device.