JP2000118257A - Differential gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a switching operation between 4WD/2WD by setting the driving source of a switching mechanism as an electric motor fixed to a case. SOLUTION: In a differential gear 1 provided with a differential gear mechanism 30 rotatably supported in a differential carrier 17 to receive the driving force of an engine and provide differential distribution to a pair of side gears 37 and 39 a differential case is composed of outer and inner differential cases 3 and 5 arranged in dual layers rotatably relative to each other, a sliding ring 41 is provided to be fixed onto the outer differential case 3 in a rotational direction disposed movably in an axial direction, and to selectively disconnect a connection with the inner differential case 5, and an operation mechanism 40 is provided to include a standby mechanism intermittently operated. An electric motor 43 is provided, where the driving source of the operation mechanism 40 is fixed to the differential carrier 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a part-time 4W
The present invention relates to a differential device that is released from driving during 2WD traveling of a D car.

[0002]

2. Description of the Related Art Conventional 4WD of a part-time 4WD car
As a hub device having a switching mechanism between / WD and 2WD, for example, a hub device shown in FIG. 12 is disclosed in Japanese Patent Application Laid-Open No. Sho 62-143737.

[0003] The hub device 201 includes an electric motor 203.
By intermittently connecting the axle 205 and the wheel hub 207, the switching operation between 4WD / 2WD is facilitated. That is, the motor 203 is connected to the wheel hub 20.
7 and is connected to a battery of a power supply via a slip ring 209, and rotates with the operation of a changeover switch.

[0004] The rotation of the motor 203 is converted into a cam action through the engagement of a pinion 213 at the tip end of a motor shaft 211 and a handle 215, and the rotation of the motor 203 is transmitted between a clutch ring 217 on a wheel hub 207 and a sleeve 219 on an axle 205. The engagement is interrupted.

[0005]

As described above, the motor 2
Since 03 is provided in the wheel hub 207 and rotates, the slip ring 209 is required, and therefore, reliability may be impaired.

Further, since the cam portion is of a two-point pressing type, it is liable to be inclined, and the cam operation may not be smooth.

Therefore, the present invention provides an electric motor fixed to a case as a drive source of a switching mechanism, and a 4WD / 2WD
The purpose is to improve the reliability of the switching operation between the two.

[0008]

In order to solve the above-mentioned problems, an invention according to a first aspect of the present invention includes a differential case rotatably supported in a differential carrier and rotated by receiving a driving force of an engine, and a differential case of the differential case. In a differential device including a differential gear mechanism that differentially distributes rotation to a pair of output members, the differential case includes an inner case and an outer case that are disposed in a double rotatable manner relative to each other, and is provided on the outer case. A moving member fixed in the rotation direction and arranged to be movable in the axial direction and selectively connecting and disconnecting the connection with the inner case; and an operating mechanism for moving the moving member, and driving the operating mechanism The source is an electric motor fixed to a differential carrier.

Therefore, since the electric motor is fixed to the differential carrier, unlike the conventional example, no special electric wiring is required, and the reliability of the operating mechanism is improved.

The invention according to claim 2 is the differential device according to claim 1, wherein the moving member is
The inner and outer cases can be connected to one of the output members.

Therefore, the same operation and effect as those of the first aspect can be obtained, and for example, in the 4WD state,
Since the differential case and the output member can be connected to each other, a differential lock state is obtained, and traveling performance on a rough road or the like is further improved.

According to a third aspect of the present invention, there is provided the differential device according to the first or second aspect, wherein the operating mechanism includes a waiting mechanism that operates when the operation is interrupted.

Therefore, the same operation and effect as those of the first or second aspect of the invention can be obtained, and the intermittent operation by the operation mechanism can be smoothly performed by the operation of the waiting mechanism.

According to a fourth aspect of the present invention, in the differential device according to the third aspect, the waiting mechanism includes a tension spring and a compression spring.

Therefore, the same operation and effect as those of the third aspect of the invention can be obtained, and a waiting mechanism can be provided with a simple structure using a spring, so that the cost can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a differential device for a part-time 4WD vehicle, where the upper half shows a 4WD state and the lower half shows a 2WD state.

As shown in FIG. 1, the differential device 1 is of a bevel gear type. An inner differential case (inner case) 5 is supported in an outer differential case (outer case) 3 so as to be relatively rotatable. Have. The outer differential case 3 is composed of left and right cases 3a and 3b connected by bolts 7, and the ring gear 9 is fastened together by the bolts 7.

The driving force from the engine is input to the outer differential case 3 via the ring gear 9 meshing with the drive pinion gear 11. The drive pinion gear 11 is rotatably supported by a differential carrier 17 by bearings.

The outer differential case 3 includes bearings 21 and
3 rotatably supported in the differential carrier 17, and a spline is formed on the outer periphery of the hollow shaft portion at the right end. The hollow shaft at the right end of the inner differential case 5 is the outer differential case 3.
Extends rightward from the right end, and a spline is formed on the outer periphery of the tip. The sleeve 25 is fitted to the spline of the inner differential case 5 and is prevented from coming off. A spline having the same specifications as the spline of the outer differential case 3 is formed on the outer periphery of the sleeve 25.

A hollow cylindrical slide ring (moving member) 41 is provided so as to be fitted and disengaged from the spline at the right end of the outer differential case 3 and the spline on the outer periphery of the sleeve 25 by axial movement.

A pinion shaft 31 is integrated with the inner differential case 5 by a pin 33, and the pinion shaft 3
1, a pinion gear 35 is rotatably supported.
The pinion gear 35 meshes with left and right side gears 37 and 39 which are disposed opposite to each other in the inner differential case 5. Left and right output shafts (not shown) are spline-connected to the inner circumferences of the side gears 37 and 39, respectively. Thus, the bevel gear type differential gear mechanism 30 is configured.

As shown in the upper half of FIG. 1, the slide ring 41 is fitted over the right end of the outer differential case 3 and the sleeve 25 on the right end of the inner differential case 5, and 5, the differential gear mechanism 30 is connected to the engine side, the differential device 1 can transmit power, and the vehicle
The state becomes the D state.

On the other hand, as shown in the lower half of FIG. 1, when the slide ring 41 moves rightward and is connected only to the sleeve 25 (inner differential case 5), the differential gear mechanism 30 is disconnected from the engine side. And differential device 1
Becomes impossible to transmit power, and the vehicle enters the 2WD state.

The 4WD / 2WD switching operation mechanism 40 is configured as follows.

That is, the case 17 is attached to the differential carrier 17.
a and the adapter 45 are fastened together by a bolt 47, and the electric motor 43 as a drive source of the operation mechanism 40 is fixed to the adapter 45. A gear 5 is provided on the rotating shaft of the motor 43.
1 is fixed. A cam ring 53 meshes with the gear 51 at a gear portion on the outer periphery thereof, and the cam ring 53 rotates as the motor 43 rotates.

The inner circumference of the cam ring 53 is formed as a small-diameter stepped hollow cylinder on the left side, and a cam 53a is formed in the circumferential direction on the ring-shaped end face on the right end of the small-diameter cylindrical portion. Cam 53a
As shown in FIG. 2 (A-A view in FIG. 1), three sets are provided in the present embodiment at equal intervals in the circumferential direction.
As shown in FIG. 1), it is formed in two steps of an upper part ◇ and a lower part ◆ toward the right in the axial direction of FIG. 1, and the middle between them is formed on a slope (☆ part).

On the other hand, the slide ring 41 is provided with a retainer 57 at the left end via washers 55 at both ends in the axial direction.
A tension spring 6 sandwiched between the cam follower 59 and the right end, the end of which is locked between the retainer 57 and the cam follower 59.
1 pinched. And as shown in FIG.
An abutting portion 59a is provided on the outer periphery of the substantially ring-shaped cam follower 59 so as to extend radially outward in three equal parts in the circumferential direction. The abutting portion 59a is urged by the compression spring 63 to move leftward. The cam rings 53 are in contact with the cams 53a.
The cam follower 59 does not rotate but can move in the axial direction.

The above-mentioned tension spring 61 and compression spring 63 serve as a waiting mechanism 6 when the slide ring 41 is connected to the outer differential case 3 and the inner differential case 5 and when the connection is released.
5.

Next, the operation will be described focusing on the operation of the switching operation mechanism 40.

When the cam ring 53 rotates by a predetermined amount due to the rotation of the motor 43, the contact portion 59a (2WD) of the cam follower 59 that has been in contact with the upper portion of the cam 53a up to that point.
1) is urged by the compression spring 63 and moves to the left in the axial direction of FIG. 1 to come into contact with the lower portion ◆ via the slope (（) of the cam 53a. At this time, the slide ring 41 meshes with both the outer differential case 3 and the inner differential case 5 as shown in the upper half of FIG. 1, and a 4WD state is obtained.

At the time of switching from the 2WD state to the 4WD state, since the driving force from the engine is not transmitted to the differential device 1 by the switching means (not shown) in the 2WD state, the vehicle is driven by the wheels. There is a rotation speed difference between the inner differential case 5 and the stopped outer differential case 3. Therefore, since the slide ring 41 is smoothly connected to the outer differential case 3, the above-described waiting mechanism 65 operates.

FIG. 4 shows the operation state of the waiting mechanism 65. That is, the cam follower 59 presses the slide ring 41 to the left by receiving the urging force of the compression spring 63 which is in a compressed state at the time of 2WD by the cam action, and waits for the timing of connection with the outer differential case 3.

Next, when the cam ring 53 rotates a predetermined amount in the reverse direction by the reverse rotation of the motor 43, the cam 5
The contact portion 59a of the cam follower 59, which has contacted the lower portion 3a of FIG. 3a, moves rightward in the axial direction in FIG. 1 against the urging force of the compression spring 63, and passes through the slope (☆ portion) of the cam 53a. It touches the upper part of ◇. At this time, the slide ring 41 is pulled by the tension spring 61 so that the connection with the outer differential case 3 as shown in the lower half of FIG. 1 is released, and the slide ring 41 is connected only with the inner differential case 5 to obtain a 2WD state.

FIG. 5 shows the operation state of the waiting mechanism 65 at the time of this switching. That is, as the cam follower 59 moves to the right, the pulling force of the tension spring 61 to the right waits for the slide ring 41 to be disconnected from the outer differential case 3.

As described above, according to the present embodiment, the motor 43 serving as the drive source of the switching operation mechanism 40 is connected to the fixed adapter 4.
5, unlike the conventional example,
No special electrical wiring is required, and the reliability of the operation mechanism 40 is improved.

Further, since the contact portion 59a of the cam follower 59 contacts the cam 53a at three equally spaced locations in the circumferential direction, unlike the above-described conventional example, there is no possibility that the cam follower 59 will be inclined and the operation will be smooth. .

Further, since the waiting mechanism 65 is provided, the switching operation of the slide ring 41 is smoothly performed.

Further, since the waiting mechanism 65 is composed of the tension spring 61 and the compression spring 63, the structure is simple and the cost can be reduced accordingly.

Further, even if a failure occurs in the operation mechanism 40, the state is maintained by stopping the motor 43, so that safety is increased.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS. This embodiment is a differential device for a part-time 4WD vehicle and capable of obtaining a so-called differential lock state.

The operation of the switching operation mechanism of this differential device 101 is different from that of the first embodiment, for example, a differential lock state and a free state can be obtained, and the other configuration is the same as that of the first embodiment. Therefore, the differences will be mainly described, and the same members will be denoted by the same reference numerals and description thereof will be omitted.

The switching operation mechanism 140 of the differential device 101 is configured as follows.

As shown in FIG. 6, the right output shaft 4 is provided on the inner periphery of the right side gear 39 of the bevel gear type differential gear mechanism 30.
2 are spline-connected. The spline portion of the output shaft 42 is extended, and a differential lock member 8 is spline-connected to a right end of the hollow shaft end of the inner differential case 5. The outer periphery of the differential lock member 8 is formed with splines having the same specifications as the splines on the outer periphery of the outer differential case 3 and the sleeve 25.

FIG. 6 shows a state in which the slide ring 141 is held at a position connecting the right and left ends of the outer differential case 3 and the sleeve 25 on the right end of the inner differential case 5 to connect the two to each other. 4WD state is shown.

As shown in FIG. 7, cams 153a formed on the cam ring 153 are formed in three stages. 4W
In the state D, the contact portion 159a of the cam follower 159
Is in contact with the middle flat portion 153b of the cam 153a.

With such a configuration, the cam ring 153 rotates by a predetermined amount, for example, with the forward rotation of the motor 43, and the contact portion 159a of the cam follower 159 contacts the middle flat portion 153b of the cam 153a (FIG. 7). Then, the slide ring 141 moves rightward from a free state position to be described later, and is positioned over the outer differential case 3 and the inner differential case 5 to connect the two cases 3 and 5, thereby obtaining a 4WD state (FIG. 6). .

As shown in FIG. 8, when the motor 43 reversely rotates by a predetermined amount from the 4WD state, the cam follower 15
9 abuts on the lower flat portion 15a of the cam 153a.
3c (FIG. 9), the slide ring 141 moves to the left most and is located on the outer differential case 3. In this state, the function of the differential device 101 for transmitting the driving force of the engine to the output shaft is lost, the inner differential case 5 is driven from the wheel side, and the outer differential case 3 is stopped.

Thus, in the free state (2WD) where the outer differential case 3 stops, it is possible to prevent power loss and reduce noise.

In the 4WD state, when the cam ring 153 rotates by a predetermined amount in accordance with the forward rotation of the motor 43, the contact portion 159a of the cam follower 159 contacts the upper flat portion 153d of the cam 153a (FIG. 11). The slide ring 141 moves to the rightmost position and is newly connected to the differential lock member 8. Thus, the vehicle is in the 4WD state and is in the differential locked state, and the left and right output shafts rotate the same.

Also, from the differential locked 4WD state, when the cam ring 153 rotates a predetermined amount with the reverse rotation of the motor 43, the contact portion 159a of the cam follower 159 contacts the middle flat portion 153b of the cam 153a. (FIG. 7), the slide ring 141 moves to a position connecting the two cases 3 and 5 across the outer differential case 3 and the inner differential case 5 and returns to the 4WD state where the differential lock is not performed.

In the above-described operation of the switching operation mechanism 140, a waiting action is performed by the compression spring 163 when the slide ring 141 moves to the left, and a waiting action is performed by the tension spring 161 when moving the slide ring 141 to the right. It is done smoothly.

Thus, according to the present embodiment, the same operation and effect as those of the first embodiment can be obtained, and 4W
Since the differential lock state is obtained in the D state, the running performance on rough roads and the like is further improved.

Further, in the 2WD state of the vehicle, the differential device 101 is in the free state, so that improvement in fuel efficiency and noise reduction can be obtained.

[0054]

As is apparent from the above description, according to the first aspect of the present invention, the electric motor of the drive source of the switching operation mechanism is fixed to the differential carrier. No special electrical wiring is required, and the reliability of the operating mechanism is improved.

According to the invention described in claim 2, according to claim 1,
The same effect as that of the present invention can be obtained, and in the 4WD state, for example, the differential case and the output member can be connected, so that the differential lock state is obtained, and the running performance on rough roads and the like is further improved.

According to the invention described in claim 3, according to claim 1
Alternatively, the same effect as that of the second aspect is obtained, and the intermittent operation of the operation mechanism is smoothly performed by the operation of the waiting mechanism.

According to the invention described in claim 4, according to claim 3,
The same effect as that of the invention described above can be obtained, and a waiting mechanism can be provided with a simple configuration using a spring, so that the cost can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a view taken in the direction of arrows BB in FIG. 2;

FIG. 4 is an operation explanatory diagram of the first embodiment.

FIG. 5 is an operation explanatory diagram of the first embodiment.

FIG. 6 is a sectional view of a second embodiment of the present invention.

FIG. 7 is an operation explanatory view of the second embodiment.

FIG. 8 is an operation explanatory view of the second embodiment.

FIG. 9 is an operation explanatory view of the second embodiment.

FIG. 10 is an operation explanatory view of the second embodiment.

FIG. 11 is an operation explanatory view of the second embodiment.

FIG. 12 is a sectional view of a conventional example.

[Explanation of symbols]

 Reference Signs List 3 outer differential case (outer differential case) 5 inner differential case (inner differential case) 8 differential lock member 25 sleeve 30 differential gear mechanism 40, 140 switching operation mechanism 41, 141 slide ring (moving member) 43 electric motor 53, 153 cam ring 53a, 153a Cam 59, 159 Cam follower 59a, 159a Contact portion 61, 161 Tension spring 63, 163 Compression spring 65 Waiting mechanism

Claims (4)

[Claims] 1. A differential device comprising: a differential case rotatably supported in a differential carrier and rotated by receiving a driving force of an engine; and a differential gear mechanism for differentially distributing the rotation of the differential case to a pair of output members. The differential case comprises an inner case and an outer case which are arranged in a double manner so as to be rotatable relative to each other. The differential case is fixed on the outer case in the rotational direction and arranged so as to be movable in the axial direction. A differential device comprising: a moving member for selectively interrupting connection; and an operation mechanism for moving the moving member, wherein a driving source of the operation mechanism is an electric motor fixed to a differential carrier. 2. The differential device according to claim 1, wherein the moving member is capable of connecting the inner and outer cases and one of the output members. 3. The differential device according to claim 1, wherein the operation mechanism includes a waiting mechanism that operates when the operation is interrupted. 4. The differential device according to claim 3, wherein the waiting mechanism comprises a tension spring and a compression spring.