JPS60179336A - Power transmission switching device of small-sized car - Google Patents

Abstract

PURPOSE:To reduce the manufacturing processes and reduce the cost through the decreased number of parts by adding a dog clutch as a part of the power transmission device set in a crank case and by switching from the four-wheel drive to the two-wheel drive using this clutch. CONSTITUTION:In the center bottom of a crank case 8, an output shaft 31 to drive the front wheels is set, and at the other end of this output shaft 31 a driven bevel gear 40 is fixed, and the gears 40, 41 constitute a bevel gear transmission mechanism 42. In an engine 7, the power of a crank shaft 10 is transmitted to a main shaft 15 through a driven gear 14 and then transmitted to driven gears 22, 23 supported on a counter shaft 21. Between this counter shaft 21 and the driven gear 23, a power transmission on/off clutch mechanism 50 is set, and this mechanism 50 is equipped with a dog clutch 51. Controlling this dog clutch 51 to disengage the counter shaft 21 from the gear 23, the two-wheel drive system is effected.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a power transmission switching device for small vehicles, and more particularly to a power transmission switching device for a four-wheel drive small vehicle called a straddle-type four-wheel vehicle. .

[Prior art]

In general, a four-wheel drive vehicle does not drive only all wheels at all times (used only as a so-called full-time four-wheel drive vehicle), but instead operates as a four-wheel drive vehicle when driving on rough terrain. It drives all wheels, and switches between four-wheel drive and two-wheel drive depending on the vehicle's driving conditions, such as driving only the front or rear wheels as a two-wheel drive vehicle on flat roads.
It is used as a so-called part-time four-wheel drive vehicle. By the way, in conventional part-time four-wheel drive vehicles,
A single device such as a hydraulic clutch is used as the power transmission switching device to switch between the four-wheel drive system and the two-wheel drive system, and this is interposed between the power train between the axle shaft that connects and disconnects the driving force and the engine. I was trying to let him do it. Therefore, in the conventional power transmission switching device described above,
A special case and parts are required to accommodate this, so
The number of parts was large, and the assembly process was complicated, leading to increased costs.

[Purpose of the invention]

In view of the above-mentioned problems, this invention reduces the number of parts,
To provide a power transmission switching device for a small vehicle that can switch to four-wheel drive or two-wheel drive with a simple structure.

[Structure of the invention]

In order to achieve this object, the present invention provides a secondary transmission device for front wheel drive and rear wheel drive, which is installed in the crankcase of a transverse engine installed in a small four-wheel drive vehicle, along the longitudinal direction of the engine. a countershaft having a drive gear that meshes with a driven gear of one of these output shafts is disposed in the crankcase parallel to the crankshaft, and the output shaft is parallel to the crankshaft; A shaft 11-b is provided with a drive gear that meshes with the other driven gear of the transmission, and a driven gear that meshes with the drive gear of the main shaft of the transmission. A flanch mechanism is interposed between the driven gear of the sleeve and the countershaft, and engine power is transmitted from the driven gear of the sleeve to the countershaft via the flanch mechanism.

〔Example〕

Hereinafter, one embodiment of the power transmission switching device according to the present invention will be described in detail.

FIG. 1 is a perspective view of a straddle-type four-wheel vehicle, which is a four-wheel drive small vehicle according to the present invention.

Balloon tires 2 and 3 with low air pressure for traveling on rough terrain are mounted on the front and rear wheels of this saddle type four-wheeled vehicle 1, respectively. Further, direction change of the saddle type four-wheeled vehicle 1 is performed by a bar handle 4IL, and when the bar handle 4 is operated, a wheel steering mechanism (for example, an Ackermann mechanism) (not shown) disposed inside the vehicle body 5 causes the front wheels to change direction. The balloon tires 2 are steered and the direction is changed. Further, the vehicle body frame 6VC of the vehicle body 5 is equipped with a horizontal engine 7 whose crankshaft is disposed at right angles to the traveling direction (arrow A).

FIG. 2 is a cross-sectional view of the main parts of the crankcase 8, showing the power transmission device of the engine 7 described above.

In this engine 7, the power of a crankshaft 10 is transmitted to a primary shaft 12 via a clutch mechanism 11, and the power transmitted to this primary shaft 12 is transmitted via a drive gear 13 and a driven gear 14 meshing with this gear 13. The signal is transmitted to the main shaft 15. A drive gear 1 is supported at one end of the main shaft 15 so as to freely rotate with respect to the shaft 15.
6, 17 and a dog-type clutch that selects one of these gears 16, 17 to engage the main shaft 15]
A gear selection mechanism 19 consisting of 8 and 8 is provided. Further, the power transmitted to the main shaft 15 is transmitted via the gear selection mechanism 19 to the driven gears n, 23 which are freely rotatably supported on the counter shaft 21. These driven gears η,'23 are fixed to a sleeve prisoner attached via a needle bear link fitted to one end of the counter shaft 21, and one end of this sleeve prisoner has a
The drive bevel gear stone is fixed. Also, on one side (left luIlIIIg side) of this crankcase 8, there is a rear wheel drive device connected to a shaft drive mechanism (not shown), which drives the rear wheels of the straddle-type mouth 1 shown in FIG. The joint 1-26 of the secondary transmission device is supported, and this joint 26 is connected to the bevel gear Z'5.
A bevel gear transmission consisting of a driven bevel gear n meshing with the sleeve U is connected to the sleeve U via the groove side. Therefore, the power of the engine 7 is always supplied to the driven gear 2'2.
, 2. The power is transmitted to a shaft drive mechanism (not shown) through a sleeve and the like, and drives the balloon tire 3 of the rear wheel of the straddle-type four-wheel bundle 1 shown in FIG. On the other hand, along the mating surface 8a of the crankcase 8, a straddle-type four-wheel vehicle 1 (not shown in FIG.
Output shaft 31 of a front wheel drive secondary transmission device that drives the front wheels of
is accommodated. This output shaft 31 is located at the front of the engine 7 (as shown in FIG. 3, which is a partially cutaway side view of FIG.
It extends in the direction of arrow A), one end of which protrudes from the crankcase 8, and has a joint 32 fixed thereto that is connected to a shaft drive mechanism (not shown) that drives the front wheels.

In addition, the symbols 33, 34, 35 in FIG. 1 and FIG.
is a bearing that positions and supports the output shaft 3J within the crankcase 8. Further, a driven bevel gear 40 is fixed to the other end of the output shaft 31, and this bevel gear 40 meshes with a drive bevel gear 41 fixed to the other end of the counter shaft 21 (see FIG. 2).
0 and 41 constitute a bevel gear transmission mechanism 42.

On the other hand, a clutch mechanism is disposed between the counter shaft 21 and the driven gear n rotatably supported on the counter shaft 21, which connects and disconnects the power transmission between the gear n and the counter shaft 2J. It is set up. This clutch mechanism blade includes a dog clutch 51 spline-coupled to the counter shaft 21, and a dog 51a formed on one side of the dog clutch 51 is connected to a hole Z3a formed on one side of the gear n. When the gear B is retracted or retracted, the power of the gear B is transmitted to the counter shaft 21, or the transmission is canceled. Therefore, when the dog clutch 51 is operated to connect the gear n and the counter shaft 2, the power of the engine 7 is transmitted to the front wheel drive secondary transmission device and the rear wheel drive secondary transmission device, respectively. It becomes a four-wheel drive system that drives the front and rear balloon tires 2 and 3 shown in FIG.
It is a two-wheel drive system that only drives the vehicle. It goes without saying that the dog clutch 51 described above is operated by a change mechanism such as a shifting fork (not shown).

In addition, in the above example, a case was described in which a seat-foot drive mechanism was adopted as a secondary transmission device for driving the rear wheels. However, the present invention is of course not limited to the above-mentioned embodiments; It is also possible to apply the present invention to a secondary transmission device that employs a gear drive system.

FIG. 4 is a cross-sectional view of the main parts of the crankcase 60 of the engine 7 which employs a gear drive system as a secondary transmission device for driving the rear wheels, and the same parts as in FIG. 2 are designated by the same reference numerals.

A rear axle shaft 61 is disposed behind the crankcase 6o of the engine 7, and the rear axle 61 is supported by the crankcase 60 by bearings 62, 63, and 64. Further, a driven gear 65, which is a secondary transmission device for driving the rear wheels, is integrally formed on this rear axle shaft 61.
A drive gear 66 formed on the circumferential surface between the gears 22 and 23 in a sleeve 66 that supports the gears 22 and 23.
It meshes with a. It should be noted that this sleeve 66 is loosely fitted to one end of the counter shaft 21 in the same way as the sleeve sleeve shown in FIG. Therefore, the power transmitted to the driven gear n, 23 is constantly transmitted to the rear axle shaft 61 via the drive gear 66a and the bungear 65 meshing with the drive gear 66a. In FIG. 4, reference numeral 67 is a brake mechanism for the rear axle shaft 6, and 60a is a case mating surface.

In the power transmission device e having a dual structure, when the dog clutch 51 is operated to connect the counter shaft 21 and the gear z3, the power of the engine 7 is transferred to the secondary transmission device for front wheel drive including the output shaft 31. , gear 65 and rear axle 61
It is a four-wheel drive system that drives the front and rear wheels of the straddle-type four-wheeled vehicle 1 shown in Fig. By activating it and releasing the connection between the counter shaft 21 and the gear shaft, a two-wheel drive system is realized in which only the rear wheels are driven.

In each of the above-mentioned embodiments, a case has been described in which the power transmission switching device of the present invention is applied to a four-wheel drive straddle-type four-wheel vehicle 1, but the present invention is not limited to the above-mentioned embodiments. Of course, it is also possible to implement the present invention in a similar small passenger car or a small four-wheel drive vehicle such as a light truck.

[Effect of idea]

The present invention has a structure in which a dock clutch is interposed in a part of the power transmission device disposed in the 1-space, and the dock clutch is used to switch from a four-wheel drive system to a two-wheel drive system. It is simple, and as a single unit, the number of parts is reduced compared to the conventional structure in which the Tansosen mechanism is interposed between the power trains, and the process area is reduced.
It is possible to reduce costs.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a straddle-type proboscis to which the power transmission switching device of the present invention is applied; FIG. 3 is a partially cutaway side view of FIG. 2, and FIG. 4 is a partially cutaway sectional view of the crankcase showing another embodiment. ■ ・Saddle-type four-wheel vehicle (small vehicle), 2. Engine, 8.
60... Crankcase, 10. Crankshaft, 16° 17. Drive gear, 19. Gear selection mechanism, 21.
...Clutch mechanism, 51 dog multi-latch. Applicant: Suzuki Automatic Industry Co., Ltd.

Claims (2)

[Claims] (1) The output shafts of the front-wheel drive and rear-wheel drive secondary transmissions are respectively disposed along the longitudinal direction of the engine in the crankcase of a transverse engine mounted on a small four-wheel drive vehicle. In addition, a countershaft having a drive gear that meshes with the driven gear of one of these output shafts is disposed in the crankcase in parallel with the crankshaft, and that is provided with a drive gear that meshes with the driven gear of the other output shaft. A sleeve is provided with a drive gear that meshes with the drive gear of the main shaft of the transmission and a driven gear that meshes with the drive gear of the main shaft of the transmission. A power transmission switching device for a small vehicle, characterized in that a flanch mechanism is interposed between the flange mechanism and the power of the engine is transmitted from the driven gear of the sleeve to the countershaft via the Kurasochi mechanism. (2) The power transmission switching device for a small vehicle as set forth in claim (1), wherein the clutch mechanism is a tongue clutch.