JPH04212633A - Power transmission selector - Google Patents

Abstract

PURPOSE:To select three engaging positions in a good operable manner by forming a taper surface engaging with another taper surface of a third external tooth in the gear-off direction, in a part coming into contact with a second engaging position of an internal tooth and the third external tooth at a third engaging position. CONSTITUTION:External teeth 55a, 50a, 51a engageable with both first and second internal teeth 56a, 56b of a 2/4 sleeve 56 are formed in those of differential lock hub 55, intermediate hub 50 and front-wheel side hub 51. A first taper surface 56t on a tooth side being opposed to a rotational direction at a tip of the second internal tooth 56b is formed in a position contacting with the taper surface t1 of the third external tooth 51a when a tooth side of the second internal tooth 56b is reached to a 4H center differential free position, while a second taper surface 56t2 is formed in a position contacting with the taper surface t1 of the third external tooth 51a when a gear side of the second internal tooth 56b is reached to a 4H center differential lock position. Those of taper surfaces 56t1, 56t2 and taper surface t1 are formed so as to be engaged with one another in the gear-off direction.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a device capable of switching a plurality of power transmission modes between a plurality of rotating shafts disposed in a power transmission system of a vehicle. The present invention relates to a power transmission switching device that can switch power transmission modes by meshing with outer peripheral teeth on each rotating shaft side.

0002

2. Description of the Related Art A power transmission switching device for switching the power transmission mode of a transmission, a transfer, a reduction gear, etc. is disposed within a power transmission system of a vehicle. Among these power transmission switching devices, in particular, a power transmission switching device formed only of a gear train has meshing teeth formed on a plurality of rotating shafts and a rotating body that is integrated with each rotating shaft, so that meshing with each other is possible. It is configured to selectively engage and separate the teeth at appropriate times either directly or via the internal teeth of the sleeve that slides in the axial direction, thereby switching between a plurality of power transmission modes.

For example, various power transmission switching devices are employed in the power transmission system of a vehicle, particularly in the transfer of the power transmission system of a four-wheel drive vehicle. This transfer can be performed in two-wheel drive mode (2WD) or in four-wheel drive mode (4WD mode) at the appropriate time.
Some models use a part-time 4WD system that allows you to select 4-wheel drive (WD), while others use a full-time 4WD system that allows four-wheel drive at all times. Here, in particular, the development of a part-time 4WD transfer system is progressing because it can be applied to a powerful engine and has the advantage of providing enjoyable driving operability.

However, conventional part-time 4WD
Vehicles that use this type tend to suffer from tight braking when a large steering angle is applied while driving at low speeds in four-wheel drive mode. Furthermore, when traveling in a high-speed four-wheel drive state, internal circulation torque is generated due to the difference between the front and rear tire systems, which may damage drive system components.

[0005] In order to solve these problems, it is conceivable to add a center differential to such a part-time 4WD system. However, this center differential is always
If the center differential is working, new problems arise, such as excessive slippage on low-friction roads. For this reason, the center differential to be installed here must be able to be switched to the differential lock state as appropriate.

For example, FIG. 10 is a schematic sectional view showing an example of a two-speed transfer with a center differential. This transfer 1 is a transmission device (transmission device) that can change the rotation of an input shaft 2 receiving power from an engine between high speed and low speed.
H/L switching device) 3 and an output shaft (
main shaft) 4 conveyance, a 2WD/4WD switching device (2/4 switching device) 5 that can selectively transmit the power of this output shaft 4 to rear wheels and front wheels via a center differential 41, and a center differential 41. The differential lock device 60 switches between an operating state and a differential lock state.

Of these, the transmission 3 includes an input shaft side gear 21 and an input shaft side hub 22 that are mounted in series on the end of the input shaft 2 so as to rotate together with the input shaft 2, and an input shaft side gear 21 and an input shaft side hub 22 that are mounted on the end of the input shaft 2 so as to rotate together with the input shaft 2. An output shaft side hub 23 is mounted on the output shaft 2 so as to rotate together with the output shaft 2, and a cylindrical shaft 24 is mounted on the outer periphery of the output shaft 4 so as to rotate together with the cylindrical shaft 24. A hub 25 for shifting, a gear 26 for shifting, and an input shaft 2 mounted on the
a low-speed first gear 27 that is pivotally supported by a countershaft 6 arranged in parallel to the output shaft 4 and meshes with the input shaft side gear 21; and a transmission gear 2 that is pivotally supported by the countershaft 6.
6 and the input shaft side hub 22.
, a speed change switching sleeve (H/L sleeve) 8 that is disposed around the outer periphery of the output shaft side hub 23 and the speed change hub 25 and can mesh with each hub 22, 23, 25 as appropriate.

In particular, the H/L sleeve 8 is operated by a speed change shift fork (H/L shift fork) 9, which will be described later.
High speed position (H position), neutral position (N position) and low speed position (
L position). And H/
When the L sleeve 8 is in the high-speed position, the input shaft side hub 22 and the output shaft side hub 23 are engaged with the H/L sleeve 8, the shifting hub 25 becomes free, and the H/L sleeve 8 is in the neutral position. When only the output shaft side hub 23 engages with the H/L sleeve 8, the input shaft side hub 22 and the transmission hub 25 become free, and when the H/L sleeve 8 is in the low speed position, the output is output to the H/L sleeve 8. The shaft side hub 23 and the speed change hub 25 are set to mesh with each other, and the input shaft side hub 22 is free.

[0009] Here, prior to explaining the 2/4 switching device 5 and the differential lock device 60, the center differential 41 to which these are connected will be explained. A center differential 41 is attached to the tip of the output shaft 4, which receives a driving force from the input shaft 2 side. A rear wheel input shaft 47 that transmits power from the output shaft 4 to the rear wheels, and an intermediate shaft 48 that transmits power to a front wheel input shaft 49 are connected to the center differential 41.

The center differential 41 includes a pinion shaft 42 that rotates around the output shaft 4, pinions 43 and 44 that are pivotally connected to both ends of the pinion shaft 42, and each pinion 43 and 4.
4, side gears 45 are equipped to mesh with each other.
, 46.

[0011]The side gear 45 is connected to the rear wheel side input shaft 4.
7, and the side gear 46 is attached to the rear end of the intermediate shaft 48. Note that the intermediate shaft 48 is a cylindrical shaft disposed on the outer periphery of the output shaft 4, and the front wheel side input shaft 49 is a cylindrical shaft further disposed on the outer periphery of the intermediate shaft 48. These output shaft 4, intermediate shaft 48, and front wheel side input shaft 49 are arranged concentrically so that each can rotate independently.

An intermediate hub 50 is attached to the front end of the intermediate shaft 48, and a front wheel hub 51 is attached to the front end of the front input shaft 49. A synchronizing mechanism 52 is interposed between the intermediate hub 50 and the front wheel hub 51. A differential lock sleeve 53 is disposed on the outer periphery of the output shaft side hub 31 and the intermediate hub 50.
A 2/4 sleeve 54 is disposed around the outer periphery of the 0 and front wheel side hubs 51. These differential lock sleeves 53 and 2/4 sleeves 54 can slide in the axial direction of the output shaft 4.

Of these, the differential lock sleeve 53 forms a main part of the differential lock device 60, and is driven back and forth through a differential lock shift fork (not shown), so that it engages only with the output shaft side hub 31 in the forward position, and engages only with the output shaft side hub 31 in the reverse position. It is set to mesh with both the side hub 31 and the intermediate hub 50. Further, the 2/4 sleeve 54 forms a main part of the 2/4 switching device, and is driven back and forth through a 2/4 shift fork (not shown), so that it engages only with the intermediate hub 50 at the forward position and is intermediate at the reverse position. It is set to mesh with both the hub 50 and the front wheel side hub 51.

With this configuration, when the differential lock sleeve 53 is set to the forward position, the differential lock sleeve 5
3, only the output shaft side hub 31 is engaged, all the power from the output shaft 4 is sent to the center differential 41, the center differential 41 is in a state where it acts (center differential free state), and the differential lock sleeve 53 is moved to the reverse position. When set to
Both the output shaft side hub 31 and the intermediate hub 50 are engaged with the differential lock sleeve 53, and the pinions 43 and 44 of the center differential 41 are prevented from rotating, resulting in a state in which the center differential 41 does not act (center depth lock state). .

Further, when the 2/4 sleeve 54 is set to the forward position, only the intermediate hub 50 meshes with the 2/4 sleeve 54, and the power from the output shaft 4 is not transmitted to the front wheels, resulting in a 2-drive state. When the 2/4 sleeve 54 is set to the reverse position, the intermediate hub 50 and the front wheel side hub 5 are attached to the 2/4 sleeve 54.
1 and 1 mesh, and the power from the output shaft 4 is transmitted to the front wheels as well as the rear wheels, resulting in a 4-wheel drive state.

In addition, reference numeral 12 in FIG. 10 is a front wheel drive power transmission sprocket that is attached to the front wheel input shaft 49 and rotates integrally with the front wheel hub 51, 13 is a front wheel drive shaft that drives the front wheels, and 14 is a front wheel drive A front wheel drive sprocket attached to the shaft, 15 is a transfer chain wound around the front wheel drive power transmission sprocket 12 and the front wheel drive sprocket 14, and includes a 2/4 sleeve 54 and a front wheel hub 51. When the front wheel drive force transmission sprocket 12 rotates through the meshing of the front wheel drive force transmission sprocket 12, this rotational force is transmitted to the front wheel drive sprocket 14 through the transfer chain 15, and the front wheels (not shown) are driven through the front wheel drive shaft 14. .

[0017]

[Problems to be Solved by the Invention] In this way, the above-mentioned problems can be solved by equipping the center differential 41 with a differential lock mechanism, but compared to the conventional one without a center differential, Since the differential lock sleeve 53 is added, there are a total of three switching sleeves, and each sleeve must be equipped with a shift rail, a shift fork, a lug, etc., making the structure complicated.

[0018] Therefore, in order to improve operability and simplify the operation, it is desirable to adopt a configuration in which three meshing positions can be easily selected by switching a single sleeve as a power transmission switching device in the transfer. . Moreover, in conjunction with this, it is desired to reliably prevent the meshing position from changing due to gear disengagement and shifting the power transmission mode, and to further improve the reliability of securing each meshing position.

The object of the present invention was devised in view of the above-mentioned problems, and provides a power transmission switching device that can select three meshing positions with good operability and improve the reliability of holding the meshing position. It's about doing.

[0020]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides rotating bodies for a first rotating shaft and second and third rotating shafts disposed on the axis of the first rotating shaft. The first, second, and third rotating bodies are arranged in this order in the axial direction, and outer teeth of the same shape are formed on each of the rotating bodies. A sleeve is provided in which meshing internal teeth are formed and the sleeve is shifted in the axial direction, and the sleeve simultaneously engages among the first, second, and third outer teeth, and the first and second outer teeth. selectively switching between a first meshing position where they mesh, a second meshing position where they simultaneously mesh with the second and third outer teeth, and a third meshing position where they simultaneously mesh with the first, second and third outer teeth; The driving force is selectively transmitted in three transmission modes, particularly in the second meshing position and the third meshing position among the tooth surfaces facing the rotational direction of the inner tooth. The present invention is characterized in that a tapered surface that engages with the tapered surface of the third outer tooth in the gear disengagement direction is formed at a portion that abuts on each of the three outer teeth.

[0021]

[Function] The second side of the tooth side facing the rotation direction of the internal tooth.
Tapered surfaces are formed in the portions that contact the third outer tooth at the meshing position and the third meshing position, respectively, and the third
Since the tapered surface of the inner peripheral tooth is formed to mesh with the tapered surface of the outer peripheral tooth in the gear disengagement direction, it is possible to prevent gear disengagement of the sleeve at the second meshing position and the third meshing position.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A power transmission switching device according to the present invention will be explained below along with a transfer with a center differential incorporating this device. This transfer with a center differential has a transmission device (H/L switching device) 3 that can change the rotational speed of an input shaft 2 that receives power from the engine and rotates between high and low speeds, and a transmission device 3 that transfers the power to the rear. There is an output shaft (main shaft) 4 installed on the extension of the input shaft 2 to transmit information to the wheels, and an output shaft 4 attached to the tip of the output shaft 4.
a center differential 41 that appropriately distributes and transmits power to the front wheels and rear wheels; a rear input shaft 47 that receives power from the output shaft and transmits this power to the rear wheels; The intermediate shaft 48 that receives power, the front input shaft 49 that receives power from the output shaft 4 via the intermediate shaft 48 and transmits this power to the front wheels, and the center differential 41 are switched between a free state and a locked state. The center differential on/off device (differential lock device) 19 and the front wheel side input shaft 49 transfer the power from the output shaft 4.
It is comprised of a 2WD/4WD switching device (2/4 switching device) 20 that can switch between a 2-wheel drive state and a 4-wheel drive state by transmitting or interrupting the transmission to or from the 4-wheel drive state. Here, center differential on/off device 1
9 and the 2/4 switching device 20 constitute the power transmission switching device of the present invention.

The transmission 3 includes an input shaft side gear 21 and an input shaft side hub 22 which are mounted in series on the end of the input shaft 2 so as to rotate together with the input shaft 2, and an output shaft 4. An output shaft side hub 23 is attached to the end so as to rotate together with the output shaft 2, and a cylindrical shaft 24 installed on the outer periphery of the output shaft 4 is connected in series so as to rotate together with the cylindrical shaft 24. A low-speed first gear 27 is pivotally supported by a counter shaft 6 arranged in parallel to the input shaft 2 and output shaft 4, and meshes with the input shaft side gear 21.
, a low-speed second gear 28 which is pivotally supported by the counter shaft 6 and meshes with the transmission gear 26; 22, 23, and 25, and a speed change switching sleeve (H/L sleeve) 8 that can be engaged with them as appropriate.

In particular, the H/L sleeve 8 is operated by a speed change shift fork (H/L shift fork) 9, which will be described later.
High speed position (H position), neutral position (N position) and low speed position (
When the H/L sleeve 8 is in the high speed position, the input shaft side hub 22 and the output shaft side hub 23 are engaged with the H/L sleeve 8, and the transmission hub 2
5 becomes free, and when the H/L sleeve 8 is in the neutral position, only the output shaft side hub 23 engages with the H/L sleeve 8, and the input shaft side hub 22 and the transmission hub 25 become free.
When the H/L sleeve 8 is in the low speed position, the H/L sleeve 8
The output shaft side hub 23 and the speed change hub 25 are set to mesh with each other, and the input shaft side hub 22 is free.

The center differential 41 also includes a pinion shaft 42 connected to the output shaft 4 and rotating around the same axis, pinions 43 and 44 pivotally supported at both ends of the pinion shaft 42, and pinions 43 and 44, respectively. It is comprised of side gears 45 and 46 that are equipped to mesh with each other.

Note that the side gear 45 is connected to the rear wheel side input shaft 47.
The side gear 46 is connected to the rear end of the intermediate shaft 48. Further, the intermediate shaft 48 is connected to the output shaft 4
A cylindrical shaft disposed on the outer periphery of the front wheel input shaft 4.
Reference numeral 9 denotes a cylindrical shaft disposed around the outer periphery of this intermediate shaft 48. These output shaft 4, intermediate shaft 48, and front wheel side input shaft 49 are arranged concentrically so that each can rotate independently.

The center differential on/off mechanism 19 includes a differential lock hub (output shaft side hub) 55 as a first hub attached to the output shaft 4, and a second differential lock hub (output shaft side hub) attached to the front end of the intermediate shaft 48. An intermediate hub (2/4 hub) 50 as a hub, a switching sleeve (2/4 sleeve) 56 for center differential on/off and 2WD/4WD switching disposed on the outer periphery of these differential lock hubs 55 and intermediate hub 50. It is composed of.

Furthermore, the 2/4 switching mechanism 20 includes an intermediate hub 50, a front wheel hub (front drive sprocket clutch gear) 51 as a third hub attached to the front end of the front wheel input shaft 49, and It is composed of an intermediate hub 50 and a 2/4 sleeve 56 disposed around the outer periphery of the front wheel side hub 51. Note that a synchronizing mechanism 52 is interposed between the intermediate hub 50 and the front wheel hub 51.

The hubs 55, 50, and 51 have tooth surfaces with the same diameter, and are installed in series as shown. In other words, the 2/4 sleeve boob 56 is used for both the center differential on/off mechanism 19 and the 2/4 switching mechanism 20. On the inner peripheral surface of this 2/4 sleeve 56, first internal peripheral teeth 56a are formed at the front part, second internal peripheral teeth 56b are formed at the rear part, and the first internal peripheral teeth 56a are formed. It can mesh with the first outer tooth 55a of the differential lock hub 55,
The second internal tooth 56b is the differential lock hub 55, the intermediate hub 5
0 and the third outer tooth 51a of the front wheel hub 51. And the first of these
A groove 5 that does not come into contact with any of the hubs 55, 50, 51 is provided between the second internal teeth 56a, 56b.
6c is formed.

The 2/4 sleeve 56 is driven by a shift fork (2/4 shift fork) 11 for differential on/off and 2WD/4WD switching, which will be described later, when the H/L sleeve 8 is in the high speed position (H position). The high-speed 2-wheel drive position of the center differential lock (2H position as the first engagement position), the high-speed 4-wheel drive position of the center differential free (4H center differential free position as the second engagement position), and the high-speed center differential lock 4 wheel drive position (4 as 3rd engagement position)
H center differential lock position).

Therefore, the first and second internal teeth 56a, 56b of the 2/4 sleeve 56 are connected to each hub 55, 50, 51.
When the 2/4 sleeve 56 is in the 2nd drive position, the differential lock is applied to the second internal teeth 56b of the 2/4 sleeve 56. The hub 55 and the intermediate hub 50 mesh to form the front wheel hub 5.
1 becomes free, and when the 2/4 sleeve 56 is in the 4H center differential free position, the intermediate hub 50 and the front wheel side hub 51 mesh with the second internal teeth 56b of the 2/4 sleeve 56, and the differential lock hub 55 is free, and when the 2/4 sleeve 56 is in the 4H center differential lock position, the 2/4
The differential lock hub 5 is attached to the first inner tooth 56a of the sleeve 56.
5 mesh with each other, so that the intermediate hub 50 and the front wheel side hub 51 can mesh with the second internal teeth 56b.

[0032] The details of the engagement portion between the 2/4 sleeve 56, the differential lock hub 55, the intermediate hub 50, and the front wheel side hub 51 are constructed as shown in Figs. 7(a) and (b).
Each hub 55, 50, 51 is spline-coupled to the output shaft 4, intermediate shaft 48, and front wheel input shaft 49, respectively, and each hub 55, 50, 51 has a first
and outer teeth 5 that can mesh with the second inner teeth 56a, 56b.
5a, 50a, and 51a are formed.

Here, FIG. 7(b), FIG. 8(b) and FIG.
As shown in (b), first and second tapered surfaces 56t1 and 56t2 are formed at the tip of the second internal tooth 56b and on the side surface of the tooth facing the rotation direction R. Of these, the first
The tapered surface 56t1 is such that the tooth side surface of the second internal tooth 56b is the second
4H center differential free position as the engagement position (Fig. 8 (
b)), it is formed at a position where it comes into contact with the tapered surface t1 of the third outer peripheral tooth 51a. Second tapered surface 56
t2 is a position where the tooth side surface of the second internal tooth 56b comes into contact with the tapered surface t1 of the third external tooth 51a when it reaches the 4H center differential lock position (see FIG. 9(b)), which is the third engagement position. It is formed. These first and second tapered surfaces 56t
1, 56t2 and the tapered surface t1 facing them are formed so that relative displacement in the gear disengagement direction S is restricted within a certain range of displacement force, that is, so that they mesh with each other.

Further, a synchronizing mechanism 52 interposed between an intermediate hub 50 of the intermediate shaft 48 and a front wheel hub 51 of the front wheel input shaft 49 has an outer synchronizing ring 52a spline-coupled to the intermediate hub 50 and an inner synchronizing ring 52a. synchro ring 52
The intermediate hub 50 and the front wheel hub 51 are synchronized through the friction of the synchronizer cone 52b against the outer synchro ring 52a and the inner synchro ring 52c. It's getting wet. In addition, on the outer periphery of the outer synchro ring 52a, 2/
A tooth surface 5 that can fit with the first internal tooth 56a of the 4-three 56
2c is formed. Also, in FIG. 6(a), reference numeral 57
is a thrust bearing, and 58a and 58b are needle bearings.

Further, in FIG. 1, reference numeral 12 is a front wheel drive power transmission sprocket that is attached to the front wheel input shaft 49 and rotates together with the front wheel hub 51, 13 is a front wheel drive shaft that drives the front wheels, and 14 is a front wheel A front wheel drive sprocket attached to the drive shaft, 15 is a transfer chain wound around the front wheel drive power transmission sprocket 12 and the front wheel drive sprocket 14, and includes a 2/4 sleeve 56 and a front wheel hub 51. When the front wheel drive force transmission sprocket 12 rotates through engagement with the front wheel drive force transmission sprocket 12, this rotational force is transmitted to the front wheel drive sprocket 14 through the transfer chain 15, and the front wheels (not shown) are driven through the front wheel drive shaft 13. There is.

The transfer shift pattern carried out through the H/L sleeve 8 and the 2/4 sleeve 56 is as shown in FIG. 4 wheel drive) position and 2H (
(high-speed two-wheel drive) position. In other words, the shift pattern itself is almost the same, with only one 4H center differential free position added to the five setting positions of a conventional 2-speed transfer without a center differential.

Accordingly, H/L sleeve 8 and 2/
4 The shift rail (H/L) that drives the sleeve 56
Shift rail) 16 and 2WD 4WD shift rail (2/
4 shift rail) 17 is configured as shown in FIG.

In other words, H/L shift rail 16 and 2/
Each of the 4 shift rails 17 is provided with an H/L rub 16a and a 2/4 lug 17a.
The L lug 16a and the 2/4 lug 17a have a groove 16b into which the lower end of a transfer lever (not shown) can fit.
17b are formed respectively. Further, the H/L shift rail 16 and the 2/4 shift rail 17 are provided with an H/L shift fork 9 and a 2/4 shift fork 11, respectively. And the H/L shift rail 16 is
It can move forward and backward in three stages in the axial direction to take the 4L (low-speed 4-wheel drive) position, N (neutral) position, and 4H (high-speed 4-wheel drive) position, and the 2/4 shift rail 17 , it moves forward and backward in two stages in the axial direction, allowing it to take a 2-wheel drive position and a 4-wheel drive position.

Note that the lower end of the transfer lever is
In the 4H (high-speed 4-wheel drive) state, it is possible to move between the groove 16b of the H/L lug 16a of the H/L shift rail 16 and the groove 17b of the 2/4 lug 17a of the 2/4 shift rail 17. It has become. Therefore, when the lower end of the transfer lever operates the H/L shift rail 16 side, the 2/4 shift rail 17 is fixed at the 4WD position, and the lower end of the transfer lever operates the 2/4 shift rail 16 side. When operating the 17 side, the H/L shift rail 16 is fixed at the H position.

Therefore, the possible positions of the H/L shift rail 16 are the 4H (high-speed 4-wheel drive) position, the N (neutral position) position, and the 4L (low-speed 4-wheel drive) position; 4 The possible positions of the shift rail 17 are 2H (
(high-speed two-wheel drive) position or 4H (high-speed four-wheel drive) position.

[0041] In order to provide an appropriate sense of moderation when switching the transfer lever between the two shift rails 17 and 16, a mechanism for generating a resistance spring force is provided (not shown). Also, these H/
The L shift rail 16 and the 2/4 shift rail 17 include
A moderation mechanism 18 is provided that can restrain the rail at each shift position with a constant force.

Since the transfer 1 with a center differential incorporating the power transmission switching device of the present invention is constructed as described above, the transfer lever (not shown) can be moved to 2H.
position (see Figure 3), the lower end of the transfer lever moves the 2/4 shift rail 17 to the 2H position (see Figure 2).
(see). At this time, H/L sleeves 8 and 2/
4. The sleeve 56 takes the position shown in FIGS. 1 and 7, and the power input from the input shaft 2 is transferred from the input shaft side hub 22 to the H/L sleeve 8 as shown by the arrow in FIG. The signal is then transmitted at high speed to the output shaft hub 23 through the center differential 41, and further transmitted from the output shaft 4 through the center differential 41 to the rear input shaft 47, thereby driving the rear wheels.

At this time, the second internal teeth 56b of the 2/4 sleeve 56 mesh with the differential lock hub 55 and the intermediate hub 50, and the front wheel hub 51 becomes free. therefore,
The driving force from the output shaft 4 is not transmitted to the front wheel input shaft 49 but only to the rear wheel input shaft 47. Furthermore, since the output shaft 4 and the intermediate shaft 48 rotate together, the pinion 43
, 44 and the rotation of the side gear 46 are synchronized,
The pinions 43 and 44 are prevented from rotating, and the center differential 4
1 becomes locked.

As a result, the driving force from the output shaft 4 is directly transmitted to the rear wheel input shaft 47. Also, move the transfer lever (not shown) to the 4H center differential free position (Figure 3
(see FIG. 2), the lower end of the transfer lever drives the 2/4 shift rail 17 to the 4H center differential free position (see FIG. 2). At this time, the H/L sleeve 8 and the 2/4 sleeve 56 of the 2-speed transfer are positioned as shown in FIGS. 4 and 8, and the power input from the input shaft 2 is transmitted as shown by the arrow in FIG. Then, the high speed is transmitted from the input shaft side hub 22 via the H/L sleeve 8 to the output shaft side hub 23, and further transmitted from the output shaft 4 to the center differential 41, and from this center differential 41 to the rear wheel side input. It is transmitted to the shaft 47 and the front wheel side (intermediate shaft 48).

At this time, the second internal tooth 56b of the 2/4 sleeve 56 meshes with the intermediate hub 50 and the front wheel hub 51, and the differential lock hub 55 becomes free. At this time, the first tapered surface 56t1 meshes with the tapered surface t1 of the front wheel hub 51 (see FIG. 8(b)), thereby preventing the gear from slipping out. As a result, the driving force from the output shaft 4 is transmitted only to the center differential 41, and is transmitted to the front and rear wheels according to the respective loads on the front and rear wheels from the center differential 41 in the free state. Power is distributed. According to the theory, the power to the front wheels is transmitted through the center differential 41 → intermediate shaft 48 → intermediate hub 50 → front wheel side hub 51 →
It is transmitted to the front wheel side input shaft 49, and further, the front wheel drive force transmission sprocket 12→transfer chain 15→
It is transmitted to the front wheel drive sprocket 14, and the front wheel drive shaft 1
3, the front wheels (not shown) are driven.

When the transfer lever (not shown) is operated to the 4H center differential lock position (see FIG. 3), the lower end of the transfer lever moves the 2/4 shift rail 17 or the H/L shift rail 16 to the 4H center differential lock position (see FIG. 3). (see 2). At this time, the H/L sleeve 8 and the 2/4 sleeve 56 of the 2-speed transfer take the positions shown in FIGS. 5 and 9, and the power input from the input shaft 2 is transmitted as shown by the arrow in FIG. As shown, the high speed is transmitted from the input shaft side hub 22 via the H/L sleeve 8 to the output shaft side hub 23, and further transmitted from the output shaft 47 to the rear wheel side input shaft 47 through the center differential 41, and the output It is transmitted from the shaft 4 to the front wheel side input shaft 49 through the 2/4 sleeve 56.

At this time, the center differential 41 is in a locked state, and the power from the output shaft 4 is directly transmitted to the rear input shaft 47 and the front input shaft 49.

In other words, the 2/4 shift rail 17 or H/
When the L shift rail 16 is set to the 4H center differential lock position, the first internal tooth 56a of the 2/4 sleeve 56
meshes with the differential lock hub 55, and the second internal tooth 56b meshes with the intermediate hub 50 and the front wheel hub 51. At this time, the second tapered surface 56t2 meshes with the tapered surface t1 of the front wheel side hub 51 (see FIG. 9(b)), and gear slippage is prevented. As a result, the output shaft 4, intermediate shaft 48, and front wheel side output shaft 49 rotate integrally, and in the center differential 41, the pinion shaft 42 and side gear 46 rotate simultaneously, so the rotation of the pinions 43 and 44 is restricted. Then, the center differential 41 becomes locked, and the side gear 45 rotates integrally with the side gear 46. As a result, the rear wheel side input shaft 47 and the front wheel side input shaft 49 rotate at the same speed as the output shaft 4, and the rear wheels and front wheels are driven.

The power is transmitted to the front wheels in the same manner as described above: front wheel input shaft 49 → sprocket 12 → transfer chain 15 → sprocket 14 → front wheel drive shaft 13.
It is carried out after.

Furthermore, when the transfer lever (not shown) is operated to the 4L position (see FIG. 3), the lower end of the transfer lever moves the H/L shift rail 16 to the 4L position (see FIG. 3).
(see Figure 2). At this time, the H/L sleeve 8 and the 2/4 sleeve 56 of the two-speed transfer take the positions shown in FIG. 6, and the power input from the input shaft 2 is input as shown by the arrow in the figure. Transmitted from the shaft side gear 21 to the low speed first gear 27
From the low-speed second gear 28 to the transmission gear 26, which rotate together with the
is transmitted to the hub 23 on the output shaft side after being decelerated. Further, it is transmitted from the output shaft 4 to the rear wheel side input shaft 47 through the center differential 41, and from the output shaft 4 to the rear wheel side input shaft 47.
It is transmitted to the front wheel side input shaft 49 through the /4 sleeve 56.

At this time, as in the case where the transfer lever is set to the 4H center differential lock position, the center differential 41 is in the locked state, and the power from the output shaft 4 is transmitted to the rear wheel side input shaft 47 and the front wheel side input shaft. The signal is transmitted directly to the shaft 49.

Note that when the transfer lever (not shown) is operated to the N position (see FIG. 3), the lower end of the transfer lever moves the H/L shift rail 16 to the N position (see FIG. 2).
(see). As a result, the H/L sleeve 8 meshes only with the output shaft side hub 23, and the input shaft side hub 22
Since the input shaft 1 does not mesh with the input shaft 1, the power from the input shaft 1 is not transmitted to the output shaft side. Therefore, neither the front wheels nor the rear wheels are driven.

In this way, by providing the switching sleeve 56 for switching on and off the center differential and for switching between 2WD and 4WD, switching between high speed and low speed (H
/L switching) and switching between 2-wheel drive state and 4-wheel drive state (2
/4 switching), and also allows switching of the operating state of the center differential 41 (free/lock switching).

As a result, the transfer device incorporating the power transmission switching device according to the present invention is easy to operate, prevents tight braking phenomenon in four-wheel drive mode, and reduces internal circulation torque when driving in high-speed four-wheel drive mode. This will greatly improve the maneuverability of the vehicle. In particular, the center differential on/off device 19 and the 2/4 switching device 2
The power transmission switching device consisting of 0 has the second internal tooth 5
The cooperative action of the first and second tapered surfaces 56t1 and 56t2 of 6b and the tapered surface t1 of the front wheel hub 51 prevents the gear from slipping out, reliably prevents the power transmission mode from shifting, and increases the reliability of maintaining the meshing position. improves.

[0055]

As described above, in the power transmission switching device of the present invention, when the tooth side surface of the inner tooth on the sleeve side reaches the second and third meshing positions, the power transmission switching device of the present invention Tapered surfaces for preventing gear slippage are formed in the portions that contact the tapered surfaces of the sleeve side, and the second and third
This prevents the gear from coming off between the teeth and the outer teeth, improving the reliability of maintaining the meshing position.

[Brief explanation of the drawing]

FIG. 1 shows a speed transfer with a center differential incorporating a power transmission switching device as an embodiment of the present invention, and is a schematic cross-sectional view of the transfer (a diagram showing a high-speed two-wheel drive state with a center differential lock). be.

FIG. 2 is a configuration diagram of a shift rail for driving the transfer shown in FIG. 1;

FIG. 3 is a diagram showing a shift pattern due to the transfer of FIG. 1;

FIG. 4 is a schematic cross-sectional view showing the transfer in FIG. 1 in a center differential-free high-speed four-wheel drive state.

FIG. 5 is a schematic cross-sectional view showing the center differential lock high-speed four-wheel drive state of FIG. 1;

FIG. 6 is a schematic cross-sectional view showing the center differential lock low-speed four-wheel drive state of FIG. 1;

FIG. 7(a) is a cross-sectional view of essential parts in each center differential lock high-speed two-wheel drive state, and FIG. 7(b) is a cross-sectional view taken along the line XX in FIG. 7(a).

8(a) is a cross-sectional view of essential parts in each center differential-free high-speed four-wheel drive state, and FIG. 8(b) is a cross-sectional view taken along the YY arrow in FIG. 8(a).

9(a) is a sectional view of essential parts in each center differential lock high-speed four-wheel drive state, and FIG. 9(b) is a sectional view taken along the Z-Z arrow in FIG. 9(a).

FIG. 10 is a schematic cross-sectional view of a conventional transfer (a cross-sectional view showing a high-speed two-wheel drive state).

[Explanation of symbols]

1 2-speed transfer with center differential 2 Input shaft 3 Speed change mechanism (H/L switching mechanism) 4
Output shaft (main shaft) 6 Counter shaft 8 Speed change switching sleeve (H/L sleeve)
9 Speed shift fork (H/L shift fork) 11 Shift fork for differential ON/OFF 2WD/4WD switching (2/4 shift fork) 12 Sprocket for front wheel drive power transmission 13
Front wheel drive shaft 14 Front wheel drive sprocket 15 Transfer chain 16 Speed shift rail (H/L shift rail) 17 2
Shift rail for 4WD (2/4 shift rail) 16a H/L lug 17a 2/4 lugs 16b, 17b Groove 18 Moderation mechanism 19 Center differential on/off mechanism 20 2WD 4WD switching mechanism (2/4 switching mechanism )21
Input shaft side gear 22 Input shaft side hub 23 Output shaft side hub 24 Cylindrical shaft 25 Shift hub 26 Shift gear 27 Low speed first gear 28 Low speed second gear 41 Center differential 42 Pinion shaft 43, 44 Pinion 45, 46 Side gear 47 Rear wheel input shaft 48 Intermediate shaft 49 Front wheel input shaft 50 Intermediate hub (2/4 hub) 50a as a second hub Second outer tooth 51 Front wheel hub as a third hub (front drive sprocket) Clutch gear) 51a Third outer tooth t1 Tapered surface 52 Synchronizer mechanism 52a Outer synchro ring 52b Synchronizer cone 52c Outer synchro ring 52d Tooth surface 55 Differential lock hub as first hub (output shaft side hub) 55a First outer tooth 56 Center differential on/off 2WD/4WD switching sleeve 56a First internal teeth 56b Second internal teeth 56c Groove portion 56t1 First tapered surface 56t2 Second tapered surface 57 Thrust bearings 58a, 58b Needle bearing R
Direction of rotation

Claims (1)

[Claims] Claim 1: A rotating body is integrally coupled to a first rotating shaft and second and third rotating shafts disposed on the axis of the first rotating shaft, and each of the first, second and third The rotating bodies are arranged in the axial direction in this order, and each rotating body is formed with outer peripheral teeth of the same shape, and inner peripheral teeth that selectively mesh with the outer peripheral teeth are formed and are shifted in the axial direction. a first meshing position where the sleeve simultaneously meshes with the first and second outer teeth of the first, second and third outer teeth; a second meshing position where they mesh simultaneously; and the first and second meshing positions.
A power transmission switching device in which driving force is selectively transmitted in three transmission modes by selectively switching to a third meshing position in which the third outer tooth simultaneously meshes with the third outer peripheral tooth,
Of the tooth side surfaces facing the rotational direction of the internal tooth, the second
A power source characterized in that a tapered surface that meshes with the tapered surface of the third outer tooth in the gear disengagement direction is formed in a portion that contacts the third outer tooth at the meshing position and the third meshing position, respectively. Transmission switching device.