JP2727085B2 - Power transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to switching between high (High) and low (Low) speeds, for example, two-wheel drive (hereinafter referred to as 2WD) and four-wheel drive (hereinafter referred to as 4WD). The present invention relates to a power transmission device capable of simultaneously performing connection switching of a load such as switching between the two.

[Prior Art] As a conventional power transmission device, a first switching mechanism for switching between high and low speeds and a second switching mechanism for switching between 2WD and 4WD are provided.
The first and second switching mechanisms are provided independently of each other (for example, see Japanese Utility Model Laid-Open No. 55-138124).

In addition, in Japanese Utility Model Laid-Open No. 60-20929, a high / low switching lever and a 2WD / 4WD switching lever are provided on a common change shaft so as to be integrally rotatable and axially movable. By moving the lever in the direction perpendicular to the change axis and transmitting it to the action section, and by moving the change axis in the axial direction, One of the 2WD / 4WD switching levers is selectively engaged with a corresponding intermediate member.

[Problems to be Solved by the Invention] However, if each switching mechanism is provided independently as described above, an operation member for each switching mechanism is required, the operation becomes complicated, and the number of parts increases, so that the weight is reduced. Relatively large.

In addition, in the case of Japanese Utility Model Publication No. 60-20929, the high / low switching lever and the 2WD / 4WD switching lever are provided so as to rotate integrally with the change shaft and move in the axial direction. Therefore, a large rotation and movement space are required for the rotation and the intermediate member that moves in the direction orthogonal to the change axis, and the intermediate member associated with the rotation mechanism is required. As a result, the size of the entire power transmission device increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a power transmission device that enables a simple operation, reduces the number of parts and weight, and is compact.

[Means for Solving the Problems] In order to solve the above problems, in a power transmission device according to the present invention, a first and a second switching mechanism are provided on a change shaft which is a common single shaft, and the change shaft is provided with the first and second switching mechanisms. The first and second switching mechanisms are selectively movable in the axial direction in conjunction with only the axial movement of the change shaft, respectively. The switching operation is performed independently of the other, and the selection is made by the rotation of the change shaft.

Further, a holding member for holding the relative position with respect to the first and second switching mechanisms when the positioning by the shaft is lost by operating the change shaft by operating the change shaft can be provided.

According to the operation of the invention, when the change shaft is moved in the axial direction, one of the first and second switching mechanisms is selectively and cooperatively moved in the axial direction to be independent of the other. The switching operation is performed. When the change shaft is rotated, one of the first and second switching mechanisms is selectively switched so as to move in the axial direction in conjunction with the change shaft.

Therefore, by a combination of the axial movement and the rotation of the change shaft, any one of the high / low speed switching and the connection switching with one or both loads can be selectively performed, and In these switching operations, neither the first nor the second switching mechanism rotates in conjunction with the rotation of the change shaft.

In addition, when the holding member is provided in the first and second switching mechanisms, even if any of the first and second switching mechanisms is not positioned by the change shaft by operating the change shaft, the holding member is not moved. Exists, so this first or second
The relative position between the switching mechanism and the change shaft is maintained.

FIG. 1 and FIG. 2 show an embodiment of the present invention. FIG. 1 is a cross-sectional view of a power transmission device in a four-wheeled vehicle, and FIG. 2 is an operation explanatory diagram thereof.

This power transmission device has a main shaft 10 that is a power input shaft.
, A counter shaft 20, a final shaft 30 as an output shaft, and a change shaft 40 are provided in parallel with each other.

A driven gear 11 is spline-coupled to the main shaft 10, and a low drive gear 12 and a load driven gear 13 and a counter drive gear 14, which are provided at an interval therefrom and integrally formed, are rotatably mounted on the shaft. .

An engagement recess is formed on each of the facing side surfaces of the low drive gear 12 and the load driven gear 13, and a spline 15 is formed on the main shaft 10 between the load drive gear 12 and the load driven gear 13. A well-known dog clutch-shaped first shifter 16 is provided on the spline 15 so as to be movable in the axial direction by a first shift fork 17. The first shifter 16 and the first shift fork 17 constitute a first switching mechanism of the present invention.

The countershaft 20 is provided with a low idle gear 22 composed of a first gear 21a and a second gear 21b having an integral structure that meshes with the low drive gear 12 and the load driven gear 13, and is rotatably mounted on the shaft. A meshing counter driven gear 23 and a final drive gear 24 provided between the low idle gear 22 and the counter driven gear 23 are spline-coupled.

The final shaft 30 is divided into a front drive shaft 31 and a rear drive shaft 32, and a final driven gear 33, which always meshes with the final drive gear 24, is spline-coupled to the rear drive shaft 32. And is connected to the rear wheel drive section via the.

On the other hand, a bevel gear 34 is formed at the shaft end of the front drive shaft 31, which is also connected to a front wheel drive unit via a front differential (not shown). The same spline 35 is formed at the connection between the front drive shaft 31 and the rear drive shaft 32, and a second shifter 36
The shift fork 37 makes it possible to move in the axial direction. The second shifter 36 and the second shift fork 37 constitute a second switching mechanism of the present invention. The state in which the second shifter 36 is engaged simultaneously with the splines 35 of both the front drive shaft 31 and the rear drive shaft 32 (the state of FIG. 1).
And a state in which it is engaged only with the spline 35 on the rear drive shaft 32 side.

The change shaft 40 is a common shaft for mounting the bases 17a and 37a of the first shift fork 17 and the second shift fork 37, and includes a first guide pin 41 and a second guide pin 42 for regulating the respective positions. Installed. The first guide pin 41 and the second guide pin 42 are attached by press-fitting so that one ends project in opposite directions, respectively, and the first L-shaped groove 18 and the second L-shaped groove formed in the respective bases 17a and 37a, respectively.
Fits inside 38. As shown in FIG. 2, the first L-shaped groove 18 and the second L-shaped groove 38 have the expanded shape as shown in FIG.
It is a groove having substantially the same L-shape, which includes corner portions 18b and 38b and vertical groove portions 18c and 38c. For example, the positional relationship between the first L-shaped groove 18 and the second L-shaped groove 38 is such that when the first guide pin 41 is in the horizontal groove 18a, the second guide pin 42 is in the corner 38b or the vertical groove 3
8c, and the first guide pin 41 has a corner
When located in any of the vertical grooves 18b or 18c, the second guide pins 42 are symmetrically disposed so as to be located in the horizontal grooves 38a.

Further, as shown in FIG. 2, the holding member 4 is attached to the base 37a.
3 is installed. The holding member 43 is attached to the transmission case C (see FIG. 1), and the ball 44 is fitted into a hole opened at the end of the base 37a, and the tip is formed on the front side of the base 37a. With any of the click grooves 45 provided. The interval between the engagement concave portions of the click groove 45 corresponds to the axial movement amount of the change shaft 40. In addition,
The ball 44 is urged in a direction of engagement with the click groove 45 by a spring housed in a hole of the holding member 43. Also,
A similar holding member is provided on the first shift fork 17 side. Further, as shown in FIG.
The axial movement of the body itself is regulated by the holding member 46 attached to the transmission case C having the same structure as that of the holding member 43, and a moderation feeling is given. In the figure, reference numeral 47 denotes a ball and reference numeral 48 denotes a click groove, which are configured similarly to the ball 44 and the click groove 45 of the holding member 43, respectively.

Further, the change shaft 40 is rotatably supported with respect to the transmission case C, and an outwardly extending portion of the transmission case C is connected to a change lever (not shown). A of the position selector 49 shown in the figure
To D are operated.

Next, the operation of the present embodiment will be described. First, in FIG. 1, the power of an engine (not shown) is transmitted from the driven gear 11 to rotate the main shaft 10. 1st shifter 16
When the is engaged with the load driven gear 13, the final shaft 30 is rotated from the counter drive gear 14 through the counter driven gear 23, the final drive gear 24, and the final driven gear 33.

When the first shifter 16 is engaged with the low drive gear 12, the power is supplied to the first and second gears of the low idle gear 22.
The power is transmitted to the load-driven gear 13 via the gears 21a and 21b, and then transmitted to the final shaft 30 as described above. In this way, the speed is switched between high and low by the axial movement of the first shifter 16.

On the other hand, in the final shaft 30, the rear drive shaft 32 is constantly rotating, and the front drive shaft 31 is in either a rotating or non-rotating state.

Therefore, when the second shifter 36 is engaged with both splines 35 formed on the front drive shaft 31 and the rear drive shaft 32 as shown in FIG. 1, the power from the final driven gear 33 is The power is transmitted to both the rear drive shaft 32 and the front drive shaft 31 via the two shifters 36, and further transmitted to the rear wheel and front wheel drive units via the respective differentials, so that a 4WD state in which the rear wheel and the front wheel rotate is established.

When the second shifter 36 is engaged only with the spline 35 formed on the rear drive shaft 32, the power from the final driven gear 33 is transmitted to only the rear drive shaft 32 via the second shifter 36, and The power is transmitted to the rear wheel drive unit via the differential on the rear wheel side, and a 2WD state is achieved in which only the rear wheels rotate.

In this manner, by the axial movement of the second shifter 36,
Switching between 2WD and 4WD is performed.

Each movement of the first and second shifters 16 and 36 is shifted by first and second shift forks 17 and 37 which are operated by movement of a change shaft 40 which is a common support shaft. Hereinafter, this shift method will be described.

First, to change the speed in the 4WD state, change axis 40
Is operated by the system I shown in FIG. In this case, first, the shift position is at A of the position selector 49, and the speed is on the high side. At this time, the first guide pin 41 is
The second guide pin 42 is located in the corner portion 38b of the second L-shaped groove 38 in the lateral groove portion 18a of the V-shaped groove 18 and the movement in the axial direction is restricted. Therefore, if the change shaft 40 is moved in the axial direction and shifted to the position C of the position selector 49, the first guide pin
41 moves the first shift fork 17 in the axial direction, engages the first shifter 16 with the low drive gear 12, and switches to the low side. On the other hand, the second guide pin 42 is a vertical groove 38 of the second L-shaped groove 38.
Since the second shift fork 37 moves along c, the second shift fork 37 does not move, and the shift position on the 4WD side is maintained by restricting the axial movement by the holding member 43. The axial movement of the change shaft 40 itself is positioned by the holding member 46.

Next, in order to switch from 4WD to 2WD, the change shaft 40 is rotated by about 90 ° at the position A of the position selector 49, and is switched to the position B of the position selector 49. At this time, the first and second guide pins 41 and 42 are rotatable in the circumferential direction in the respective lateral groove portions 18a and 38a of the first and second L-shaped grooves 18 and 38, respectively. 2nd guide pin 4 to corner 18b
2 are moved to the lateral groove portions 38a, respectively, so that the operation by the II system in FIG. 2 is possible. Shift position B is A
When the change shaft 40 is moved in the axial direction from this state to the D position of the position selector 49, the second guide pin 42 moves the second shift fork 37 in the axial direction. The second shifter 36 is the rear drive shaft
2W because it only engages with spline 35 formed on 32
Switch to D state. At this time, the first guide pin 41 is
Since the first shift fork 17 is immobile because it moves along the vertical groove portion 18c of the V-shaped groove 18, the high state in which the first shifter 16 engages with the load driven gear 13 is maintained. The axial movement of the first shift fork 17 is regulated by a holding member 43 provided separately from the second shift fork 37 side.

In this way, the combination of the axial movement and the rotation of one change shaft 40 enables the selection of three positions by combining high / low speed and switching between 4WD and 2WD.

In addition, while the change shaft 40 selectively performs a switching operation by a combination of axial movement and rotation, the first shift fork 17 serving as a first switching mechanism
And the second shift fork 37 forming the second switching mechanism is only selectively linked only to the axial movement of the change shaft 40. Even if the change shaft 40 rotates, the first shift fork 17 and the second shift fork 37 Since the two shift forks 37 do not rotate in conjunction with each other, a large rotating space required when the first shift fork 17 and the second shift fork 37 rotate are unnecessary, and furthermore, the rotational movement is not performed. There is no need for various intermediate members for the rotation mechanism provided to move the change shaft in a direction perpendicular to the axis and to transmit the change shaft to the action portion. As a result, the entire power transmission device can be made compact.

[Effects of the Invention] According to the first aspect of the present invention, the first and second switching mechanisms can be separately operated by operating one change shaft, thereby simplifying the change operation. it can.
In addition, the number of parts can be reduced, the weight of the entire apparatus can be reduced, and the cost can be reduced.

In addition, while the change shaft selectively performs the switching operation by a combination of the axial movement and the rotation, the first and second switching mechanisms both perform only the axial movement of the change shaft. If the first and second switching mechanisms rotate, the first and second switching mechanisms do not rotate even when the change shaft rotates. A large rotating space required for the rotating shaft is not required, and various intermediate members for a rotating mechanism provided for transmitting the rotating motion in the direction perpendicular to the axis of the change shaft and transmitting it to the operating portion are not required, As a result, the entire power transmission device can be made compact.

Further, according to the second aspect of the present invention, since the holding member is provided in the first and second switching mechanisms, the switching operation can always be accurately performed without being affected by the operation of the change shaft.

[Brief description of the drawings]

FIG. 1 is a sectional view of the embodiment, and FIG. 2 is an operation explanatory view showing an essential part of the embodiment in an expanded manner. (Explanation of reference numerals) 10: Main axis (input axis), 16: First shifter, 17:
1st shift fork, 18 first L-shaped groove, 20 counter shaft (output shaft), 30 final shaft, 31 front drive shaft, 32 rear drive shaft, 33 final driven gear, 36 … Second shifter, 37… Second shift fork, 38… Second L-shaped groove, 40… Change shaft, 41…
1st guide pin, 42 ... 2nd guide pin ..., 43, 46 ...
Holding member.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location // F16H 59:04

Claims (2)

(57) [Claims] 1. An input shaft connected to a drive source of an internal combustion engine or the like, an output shaft provided in parallel with the input shaft and connected to a load at the front and rear, and a plurality of sets provided between the input shaft and the output shaft. A gear train, a first switching mechanism for selecting any one of the gear trains, and a second switching mechanism for selectively interlocking the output shaft with one load or both loads.
The first and second switching mechanisms are provided on a change shaft, which is a common axis, and the change shaft is rotatable around its axis and movable in the axial direction. Each of them is selectively operated in the axial direction only by interlocking with the axial movement of the change shaft, whereby the switching operation is performed independently of the other, and the selection is made by the rotation of the change shaft. Power transmission device. And a holding member for holding a relative position with respect to the first and second switching mechanisms when the positioning by the shaft is lost by operating the change shaft. The power transmission device according to claim 1, characterized in that: