JP2602992Y2 - Differential device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device mounted on a vehicle.

[0002]

2. Description of the Related Art FIG.
A differential device 101 as shown in FIG. The differential device 101 includes a first pinion gear 103 and a second pinion gear 105 meshed with the first pinion gear 103, and a housing hole 109 provided in a case 107.
The first pinion gear 103 meshes with the first side gear 111, and the second pinion gear 105 meshes with the second side gear 113. These first and second pinion gears 103, 105
The first and second side gears 111 and 113 are formed in a helical shape having spiral angles in opposite directions.

[0003] The driving force of the engine input from the case 107 is distributed from the first and second pinion gears 103 and 105 to the first and second side gears 111 and 113 to drive the left and right wheels. Second pinion gear 1
Due to the rotation of 03 and 105, differential distribution is performed to the left and right. This differential rotation is limited by the rotational resistance of the first and second pinion gears 103 and 105 due to friction with the housing hole 109 and the frictional resistance of the side surfaces of the first and second side gears 111 and 113. You get the limiting power.

FIG. 7 shows the differential device 101.
Shows a state where the vehicle 115 equipped with is turning to the left.

[0005] In such a turning operation, the differential device 101 makes a differential rotation between the left and right side gears, so that a differential limiting force acts inevitably corresponding to the frictional force based on the rotational difference, and this differential limiting force acts. The driving force transmitted to the left and right driving wheels is different due to the limiting force. That is, as shown in FIG. 7A, the driving force FDi transmitted to the inner driving wheel 117 (left side) is larger than the driving force FDo transmitted to the outer driving wheel 119 (right side). In other words, the frictional force generated due to the small rotation on the inside is small, and the differential limiting force, that is,
The driving force FDi increases.

[0006] Such a phenomenon also occurs when the vehicle 115 is turning during coasting operation (a state in which engine braking is applied), and as shown in FIG. The braking force FCi applied to 117 becomes larger than the braking force FCo applied to the outer driving wheel 119.

Thus, the inner and outer drive wheels 117, 119
If the driving forces FDi and FDo and the braking forces FCi and FCo are different,
In the vehicle 105, the following equation is used: Mψ = (Tr / 2r) × ΔF where Mψ: yawing moment Tr: rear wheel tread r: tire radius ΔF: driving force difference or braking force difference between inner and outer wheels (FDi-FDo, FCi- FCo) acts on the yawing moment Mψ. This yawing moment M # is generated in the understeer direction during the driving operation, and is generated in the oversteer direction during the coasting operation.

[0008]

However, in the differential device 101 shown in FIG. 6, as shown in FIG. 8, a device having high responsiveness when switching from driving operation to coasting operation, that is, differential limiting Since the torque switching time is fast and the upper and lower limit torque difference is large, the yawing moment Mψ acting on the vehicle 105 may suddenly change from the understeer direction to the oversteer direction when switching from driving to coasting. There is.

When the direction of the yawing moment M # acting on the vehicle 105 suddenly changes in this manner, the vehicle 105
May suddenly change, giving the driver a sense of discomfort.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to improve the responsiveness at the time of switching from a driving state to a coasting state, thereby enabling a turning operation. It is an object of the present invention to provide a differential device that can reduce a sense of discomfort in vehicle operability at the time.

[0011]

In order to achieve the above object, the present invention provides a case which is rotated by the driving force of an engine mounted on a vehicle, and which is inserted into the case from one end of the case and rotates coaxially with the case. A first shaft, a second shaft inserted into the case from the other end side of the case and rotating coaxially with the case, and provided on the outer periphery of the first shaft and rotating together with the first shaft in the case. A first helical side gear, a second helical side gear provided on the outer periphery of the second shaft and rotating with the second shaft in the case, and the first and second helical teeth A pair or a plurality of pairs of first and second receiving holes formed in the case at predetermined intervals along the outer periphery of the side gear, and the first helical tooth accommodated in the first receiving hole No. meshing with side gear A helical pinion gear; and a second helical pinion gear housed in the second housing hole and meshing with the second helical side gear and meshing with the first helical pinion gear. A differential device, wherein the first and second helical side gears are formed by setting a forming direction of helical teeth when the case is in a coasting rotation state, and the first and second helical side gears and the A first helical side gear opposed to the thrust force on one axial side of the first helical side gear as a side receiving a thrust force due to a meshing reaction force with the second helical pinion gear; Along with providing a pressing member that presses, the other side portion in the axial direction is characterized in that the side gears face each other without the interposition of a pressing member, or that each faces the case. is there.

[0012]

When the drive of the case is released and the state is switched from the drive rotation state to the coasting rotation state, the pressing member receives the reaction force of the engagement between the first side gear and the first pinion gear on the coasting rotation side after the switching. Accordingly, the first side gear is pressed against the meshing reaction force of the side gear, and the second side gear is pressed against the meshing reaction force according to the meshing reaction force between the second side gear and the second pinion gear. Press in opposition. Due to the action of the pressing member, on the coasting rotation side of the case, the generation of the differential limiting torque due to the frictional resistance of the first and second side gear side surfaces is delayed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an essential part of an embodiment of a differential device according to the present invention, FIG. 2 is an exploded perspective view of the differential device of FIG. 1, and FIG. 3 is a vehicle equipped with the differential device of FIG. FIG. 2 is a schematic diagram of the first embodiment, and its configuration will be described.

[0015] As shown in FIG.
, Transmission 3, propeller shaft 5, rear differential 7 (differential device of the embodiment arranged on the rear wheel side), left and right rear axles 9, 11
(First and second shafts), left and right rear wheels 13 and 15, left and right front wheels 17 and 19, and the like. In the rear differential 7, the case 21 is rotatably disposed in the differential carrier 23, and the ring gear 25 fixed to the case 21 meshes with the drive pinion gear 27. The drive pinion gear 27 is formed integrally with a drive pinion shaft 29 connected to the propeller shaft 5 side. The driving force of the engine 2 is transmitted to the rear differential 7 via the transmission 3 and the propeller shaft 5,
Thus, the case 21 is driven to rotate.

As shown in FIGS. 1 and 2, the case 21 comprises a main body 31 fastened by bolts 30 and a cover 33, and the ring gear 25 shown in FIG. ing. The cover 33 has a first shaft hole 37, the body 31 has a second shaft hole 39,
Each is formed concentric with the rotation axis of the case 21.
The first shaft 9 and the second shaft 11 are coaxially rotatable with the case 21 in the first shaft hole 37 and the second shaft hole 39.
And one end of each of the shafts 9 and 11 is
1 is inserted into a storage chamber 41 formed therein.

The first shaft 9 inserted in the storage chamber 41
A first side gear 43 and a second side gear 45 are spline-connected to the outer periphery of the first shaft 11 and the second shaft 11. On the outer periphery of the first and second side gears 43 and 45, helical gears having helical angles in opposite directions are formed.
From the second side gears 43 and 45, first and second cylindrical portions 43a and 45a are integrally extended toward the first and second shafts 9 and 11, respectively. The first cylindrical portion 43a and the second cylindrical portion 45a are formed by a support hole 33a formed in the cover 33 and a support hole 31 formed in the main body 31.
a and slidably fitted to each other, whereby
The first and second side gears 43 and 45 are coaxially rotatable in the storage chamber 41.

In the main body 31, a first housing hole 47 and a second housing hole 49 are paired, and four pairs of housing holes 47, 49 are provided.
Are provided at equal intervals along the outer circumference of the first shaft hole 37 and the second shaft hole 39. First and second receiving holes 47, 4
9 are formed at a predetermined depth from the first shaft hole 37 side, and the second housing hole 49 is formed to be deeper than the first housing hole 47 by substantially the width of the second side gear 45. I have. The paired first accommodation hole 47 and second accommodation hole 49 have a communicating portion (not shown) on the first shaft hole 37 side. In 49, openings 53 and 55 opened to the accommodation room 41 are formed.

The first accommodation hole 47 accommodates a first pinion gear 57, and the second accommodation hole 49 accommodates a second pinion gear 59. The inner peripheral surfaces of the housing holes 47 and 49 are formed so as to generate a predetermined frictional resistance between the inner peripheral surfaces of the first and second pinion gears 57 and 59 and the outer peripheral surfaces of the tooth tips. The second pinion gear 59 is formed to be longer than the first pinion gear 57 by substantially the width of the second side gear 45 and has the intermediate shaft portion 60, and has a helical angle at both ends of the second pinion gear 59. A helical gear is formed. On the other hand, the first pinion gear 57 is entirely formed with a helical gear having a helical angle opposite to that of the second pinion gear 59. The first and second pinion gears 57 and 59 are connected to the main body 31 and the inner wall 31 of the cover 33.
The movement in the axial direction is prevented by b and 33b.

The first pinion gear 57 has the second shaft hole 3
The first pinion gear 59 meshes with the first side gear 43 at the opening 53 on the side of the second shaft hole 39.
5 meshes with the second side gear 45. Also, the first
The side gear 43 and the second side gear 45 are adjacently arranged on the facing surfaces 43b and 45b in the direction of the rotation axis of the case 21, and the first pinion gear 57 and the second
The first pinion gear 59 meshes with the first side gear 43 on the outer side in the rotation axis direction.

Thus, each of the gears 43, 45, 57, 59
, The driving force from the engine 2 is differentially distributed to the left and right shafts 9, 11, and at this time, the first and second pinion gears 5 are caused by friction with the housing holes 47, 49.
7, 59 rotational resistance and the first and second side gears 4
The difference between the left and right differential limiting forces is caused by the difference in the frictional resistance associated with the rotation difference due to the frictional resistance of the side surfaces 3 and 45.

The direction in which the helical teeth of the gears 43, 45, 57, 59 are formed during normal driving of the engine 2, that is, a forward drive force acts on the case 21 in the direction of arrow A as shown in FIG. During the coasting operation, a thrust force (meshing reaction force) is generated to move the first side gear 43 toward the main body 31 and to move the second side gear 45 toward the cover 33. When the reverse driving force in the direction opposite to the direction A is acting, the first side gear 43
To the cover 33 side and the second side gear 4
Thrust force (meshing reaction force) to move 5 to main body 31 side
Is the direction in which

The first cylindrical portion 43a and the second cylindrical portion 45
Disc springs 61 and 63 serving as pressing members are disposed on the outer periphery of “a”. Disc spring 61 on outer periphery of first cylindrical portion 43a
Is positioned between the edge 33c of the cover-side support hole 33a and the first side gear 43, and the second cylindrical portion 45a
The outer disc spring 63 is connected to the edge 31 of the main body side support hole 31a.
c and the second side gear 45. When the first side gear 43 attempts to move toward the cover 33, a pressing force acts on the first side gear 43 from the disc spring 61, and the second side gear 45 is moved to the main body 31.
To move to the side, a pressing force acts on the second side gear 45 from the disc spring 63.

Next, the operation of the differential device according to this embodiment will be described.

FIG. 4 shows the first and second side gears 43 and 4.
It is a schematic diagram which shows the thrust force which concerns on 5, (a) has shown the state at the time of drive operation, and (b) has shown the state at the time of coasting operation. FIG. 5 is a diagram showing a temporal change of the differential limiting torque (which can be said to be the average value of the driving force or the braking force of the left and right wheels) when switching from the driving operation to the coasting operation.

At the time of driving operation, as shown in FIG. 4A, the case 21 is in a driving rotation state, so that the first side gear 43 generates a thrust force in the direction of the main body 31 and the second side gear 43 45 generates a thrust force toward the cover 33. For this reason, the first and second side gears 43, 45
The pressing force from the disc springs 61 and 63 does not act on the first side gear 43 and the opposing surface 43 of the second side gear 45.
b, 45b are abutted.

On the other hand, during the coasting operation, as shown in FIG. 4B, the case 21 is in a coasting rotation state, so that the first side gear 43 generates a thrust force toward the cover 33, and A thrust force toward the main body 31 is generated in the side gear 45. Therefore, the first and second side gears 43,
45, the pressing force of the disc springs 61, 63 acts in opposition to the thrust force according to the generated thrust force, and the side surfaces 43c, 45c of the first and second side gears 43, 45 respectively. 45c delays contact with the case 21.

When the driving operation is switched to the coasting operation, as shown in FIG. 5, on the driving operation side of the engine 2 (the driving rotation side of the case 21), the first and second side gears 4 are driven.
The pressing force from the disc springs 61, 63 does not act on 3, 45,
The differential restriction is released immediately. On the other hand, on the coasting operation side (the coasting rotation side of the case 21), the first and second side gears 4
Since the pressing force from the disc springs 61 and 63 acts on 3, 45, the differential limiting torque gradually increases. That is, high responsiveness is maintained on the driving operation side, and a predetermined delay time t corresponding to the pressing force from the disc spring 61 occurs on the coasting operation side. As shown in FIGS. 1 and 2, the first and second side gears 4
The opposing surfaces 43b, 45b on which 3, 45 slide during driving operation.
Is set so as to be larger than that of the side surfaces 43c and 45c that slide with the main body 31 and the cover 33 of the case 21 during the coasting operation, as shown in FIG. The upper limit of the differential limiting torque is set to be higher than that during coasting operation.

Therefore, as shown in FIG. 3, when the vehicle 1 turning to the left switches from driving operation to coasting operation,
The force transmitted to the inner rear wheel 13 is changed from the driving force FDi to the braking force FCi.
The transmission is delayed immediately by t without changing immediately. Therefore, since the braking force gradually increases on the coasting operation side, the yawing moment M # acting on the vehicle 1 does not suddenly change from the understeer direction to the oversteer direction, and a sudden change in attitude of the vehicle 1 is suppressed, and the turning of the vehicle 1 is suppressed. The performance is improved. Moreover, the upper limit of the differential limiting torque corresponding to the driving force in the state on the driving side is higher than that in the coasting side, and the vertical torque difference between the two states is small, so that the switching is performed smoothly. This allows
The driver can obtain comfortable vehicle operability without feeling uncomfortable.

Further, since the response on the driving operation side is kept high, a quick response can be obtained during acceleration.

The present invention is not limited to the above-described embodiment. For example, the helical teeth of the gears 43, 45, 57, 59 are formed in opposite directions, and the first side gear 43 and the second side gear 43 are formed. A disc spring may be provided between the plates 45 and the other side may be opposed to the case 21 without interposing a disc spring (pressing member), and the pressing member is not limited to the disc spring.

[0032]

As described above, according to the present invention, when the drive side is switched from the drive side to the coasting side during the differential rotation,
On the coasting side, the differential limiting torque between the first and second shafts is generated with a delay. Therefore, when the vehicle is switched from the driving side to the driven side during turning, the yawing moment Mψ acting on the vehicle exceeds the understeering direction. It gradually changes in the steer direction. On the other hand, since the responsiveness is maintained high on the driving side, the responsiveness during vehicle acceleration does not decrease. Therefore, it is possible to improve the turning performance of the vehicle during the turning operation while maintaining high vehicle responsiveness during acceleration, and to obtain comfortable vehicle operability.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a differential device according to the present invention.

FIG. 2 is an exploded perspective view of the differential device of FIG.

FIG. 3 is a schematic view of a vehicle equipped with the differential device of FIG. 1;

4A and 4B are schematic diagrams showing the thrust force applied to the first and second side gears of the present invention, wherein FIG. 4A shows a state during a driving operation, and FIG. 4B shows a state during a coasting operation; FIG.

FIG. 5 is a diagram showing a transmission torque at the time of switching from the driving operation to the coasting operation according to the present invention.

FIG. 6 is a sectional view of a conventional example.

FIG. 7 is a view showing a state in which the vehicle is turning to the left according to the conventional example and the present invention.

FIG. 8 is a diagram showing the responsiveness of the conventional example at the time of switching from driving operation to coasting operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 9 Rear axle (first shaft) 11 Rear axle (second shaft) 21 Case 43 First helical side gear 45 Second helical side gear 47 First accommodation hole 49 Second Housing hole 57 First helical pinion gear 59 Second helical pinion gear 61 Disc spring (pressing member) 63 Disc spring (pressing member)

Claims (1)

(57) [Scope of request for utility model registration] 1. A case which is rotated by the driving force of an engine mounted on a vehicle, a first shaft which is inserted into the case from one end of the case and rotates coaxially with the case, and a case which is coaxial with the case from the other end of the case. A second shaft inserted into the case and rotating coaxially with the case, a first helical side gear provided on an outer periphery of the first shaft and rotating with the first shaft in the case, and the second shaft A second helical side gear provided on the outer periphery of the case and rotating together with the second shaft in the case; and a predetermined interval along the outer periphery of the first and second helical side gears. A pair of first and second receiving holes formed, a first helical pinion gear received in the first receiving hole and meshing with the first helical side gear; Housed in the second hole And a second helical pinion gear meshing with said second helical side gear and meshing with said first helical pinion gear, wherein said first and second helical gears are provided. The side gear is generated by setting the direction in which the helical teeth are formed when the case is in the coasting rotation state. The side gear is formed by a reaction force between the first and second helical side gears and the first and second helical pinion gears. A pressing member that presses the first and second helical side gears in opposition to the thrust force is provided on one side in the axial direction as a side receiving the thrust force, and the other side in the axial direction is provided with: The differential device according to claim 1, wherein the side gears face each other without a pressing member, or each of the side gears faces the case.