JPH02117427A - Four-wheel drive vehicle - Google Patents

Abstract

PURPOSE:To make the structure of a four wheel drive vehicle simplified by providing a power transmission means of four-wheel drive regularly engaging with the gear raw of the lower speed stage of a speed change gear mechanism, and preventing the power transmission to another wheel at the time of shifting into the higher speed stage for no need of 2WD/4WD shifting clutch. CONSTITUTION:Behind a speed change gear 2 installed on an engine 1 are arranged a front differential gear (not illustrated here) including a differential gear case which houses a ring gear 31 engaged with an output gear 9 of the speed change gear 2, and at the circumference of an opening 2b formed at rear edge of a speed change gear case 2a is attached a gear case 40 of a four wheel drive power transmission means 61. The power transmission means 61 is engaged with a driven gear 10 for the first shift of the speed change gear by a gear 43, and is constructed to transmit power to respective rear wheels through bevel gear 48, 49, a propeller shaft and so on. On the way to the propeller shaft and so forth is installed a oneway clutch (not illustrated here) servicing as a power transmission preventing means for preventing engine power transmission to respective rear wheels when shifting the speed change gear 2 into the higher speed stage.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a four-wheel drive vehicle, and particularly to one in which a four-wheel drive state is obtained depending on the gear position of a transmission mechanism.

(Conventional technology) Conventionally, as a four-wheel drive vehicle, the power of the engine is divided into four parts in the front and rear.
One is a full-time type that transmits power to two wheels at all times, and the other is a part-time type that is a two-wheel drive mode that always drives one wheel, front and rear, and can be switched to a four-wheel drive mode when necessary. is well known. However, in the former type of full-time four-wheel drive vehicle, the four-wheel drive state is applied regardless of the gear position of the transmission mechanism, so a large torque is applied to the power transmission system in low gears, and on the other hand, in high gears, the power transmission system The system will rotate at high speed, and it is necessary to set the rigidity of the power transmission system in terms of both torque and rotation.

On the other hand, as a part-time 4-wheel drive vehicle of the latter, conventionally,
Some vehicles are designed to switch the drive state to a four-wheel drive state or a two-wheel drive state depending on the gear position of the transmission mechanism. For example, in the system disclosed in Japanese Utility Model Application Publication No. 55-83120, two power transmission systems are provided to transmit engine power from the engine to the front and rear wheels, respectively, and a transmission mechanism is provided downstream of the branch of both power transmission systems. A clutch is provided that connects and disconnects the power transmission system according to the gear position of the transmission mechanism, and the clutch is connected to the low gear position of the transmission mechanism to create a four-wheel drive state in which engine power is transmitted to the front and rear wheels. When the vehicle is shifted to a high speed gear, the clutch is disengaged to create a two-wheel drive state in which power is transmitted to only one of the front and rear wheels.

(Problem to be Solved by the Invention) However, this conventional system has a structure in which a clutch is disposed in the middle of the power transmission system, so a space is required for the clutch, and moreover, it is difficult to connect and disconnect the clutch. A clutch actuation mechanism is also required, which inevitably complicates the structure of the power transmission system.

In addition, since a power transmission system to the front and rear wheels is always provided, a transmission for 4-wheel drive vehicles must be used to distribute power to the front and rear wheels, and a transmission for 2-wheel drive vehicles must be used. It is difficult to use it for both purposes.

The present invention has been made in view of the above, and an object of the present invention is to provide a four-wheel drive system directly from the gear train of the transmission mechanism when switching to a two-wheel drive state or a four-wheel drive state depending on the gear position of the transmission mechanism.
By extracting power for wheel drive, the structure of the power transmission system is simplified by eliminating the clutch for extracting the power, and the transmission mechanism for two-wheel drive vehicles can be changed to four.
The purpose is to make it compatible with wheel drive vehicles.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention extracts power for four-wheel drive from a gear train in a low gear in a transmission mechanism, and in a two-wheel drive state. Switching between the four-wheel drive state and the four-wheel drive state utilizes the original shift operation of the transmission mechanism.

That is, in the present invention, a gear transmission mechanism is provided that has a plurality of gear trains and that changes the speed and transmits the output of the engine to one of the front and rear wheels.

Further, a four-wheel drive power transmission means is provided which meshes with the low gear train of the transmission mechanism and transmits power to the other front and rear wheels.

Further, a power transmission blocking means is provided for blocking power transmission to the other front and rear wheels when the transmission mechanism is shifted to a high speed gear.

(Function) With the above configuration, in the present invention, when the transmission mechanism is shifted to a low gear, the engine output is transmitted to the other front and rear wheels by the four-wheel drive power transmission means meshed with the low gear, This results in a four-wheel drive state in the low gear.

On the other hand, when the transmission mechanism is shifted to a high speed gear, the power transmission blocking means is activated to prevent the power transmission to the other front and rear wheels, and the engine output is transmitted only to the front and rear wheels. It becomes a two-wheel drive state in the second stage.

Therefore, simply by shifting the gear position of the transmission mechanism, the transmission can be switched between the two-wheel drive state and the four-wheel drive state according to the meshing change of the gear train in the transmission mechanism, so there is no need to provide a clutch. Therefore, the structure of the power transmission system can be simplified.

Further, the power transmission system in a four-wheel drive vehicle is constructed by meshing a four-wheel drive power transmission means with a low speed gear in a transmission mechanism for a two-wheel drive vehicle, and providing a power transmission blocking means. Therefore, it is possible to manufacture a four-wheel drive vehicle using a transmission mechanism for a two-wheel drive vehicle, and thus two-wheel drive vehicles can be manufactured.
It becomes possible to share the transmission mechanism between a wheel drive vehicle and a four-wheel drive vehicle.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the overall configuration of a power transmission system in a four-wheel drive vehicle according to an embodiment of the present invention, where 1 is a four-cylinder engine mounted horizontally at the front of the vehicle body, and 2 is on the left side of engine 1. This is a gear type transmission as a transmission mechanism connected to the

The transmission 2 has a plurality of gear trains. To explain the structure in detail with reference to FIGS. 2 and 4, the case 2a of the transmission 2 includes a human power shaft 4 which is drivingly connected to the engine 1 via a clutch 3, and a manpower shaft 4 located diagonally below the rear of the input shaft 4. An output shaft 5 disposed parallel to the side (lower side in FIG. 4) and a counter shaft 6 for retraction disposed parallel to the upper front side of the input shaft 4 are rotatably supported.

The input shaft 4 is integrally formed with drive gears 7.8 for a first forward drive and a second drive gear in order from the right side (clutch 3 side). On the other hand, an output gear 9 is rotatably attached to the right end of the output shaft 5, and the output shaft 5 on the left side of the output gear 9
Driven gears 10 and 11 for first and second speeds, respectively, are rotatably supported in mesh with the first and second forward speed drive gears 7.8, respectively. A clutch hub 12 is rotatably connected to the output shaft 5 between the two wave drive gears 10.11, and the first
A sleeve 13 that can be spline-coupled to the driven gears 10 and 11 of the speed and second transmission gears is slidably and rotatably spline-coupled, and by sliding this sleeve 13, a clutch integrated with the output shaft 5 is formed. By meshing the hub 12 with the first or second transmission driven gear 10.11,
The gear stage is switched to the forward first gear or the second forward gear.

Furthermore, third and fourth forward speed drive gears 14 and 15 are rotatably supported on the input shaft 4 on the left side of the second drive gear 7, respectively. A clutch hub 16 is rotatably connected between the two drive gears 14 and 15, and the clutch hub 16 is connected to the third and fourth drive gears 14 and 14.
．． A sleeve 17, which can be splined to 15, is slidably and rotatably splined to the sleeve 15. On the other hand, the output shaft 5 has third and fourth gears that are always engaged with the third and fourth drive gears 14.15 of the input shaft 4, respectively.
Driven gears 18, 19 for high speed are rotatably connected to each other, and the sleeve 17 of the input shaft 4 is slid to connect the clutch hub 16, which is integral with the input shaft 4, to the third or fourth drive gear 14. 15, the gear is shifted to the third forward gear.
gear or fourth gear.

Furthermore, the left input shaft 4 of the fourth drive gear 15 rotatably supports a fifth drive gear 20 as the highest forward speed gear, while the output shaft 5 supports the fifth drive gear 20 . A fifth speed gear drive gear 21, which is always in mesh with the gear 20, is rotatably connected to the gear 20. In addition, the fifth speed drive gear 1
7 A clutch hub 22 is rotatably coupled to the left input shaft 4, and a sleeve 23 which can be spline-coupled to the fifth linked drive gear 20 is slidably and rotatably spline-coupled to the clutch hub 22. The sleeve 23 is slid to connect the clutch hub 22 which is integrated with the input shaft 4.
By meshing with the fifth continuous drive gear 20, the gear stage is switched to the fifth forward gear stage.

Further, a reverse drive gear 24 is formed on the input shaft 4 between the first and second forward drive gears 7.8.

Further, a reverse counter gear 25 having a sleeve portion 25a is rotatably and slidably supported on the counter foot 6, and by sliding to the left end position, the counter gear 25 is moved to the first gear position and the reverse gear position. Sleeve 1 for switching to second gear
It is provided so as to be able to mesh with the toothed portion 13a formed on the outer periphery of the gear shaft 3 and the reverse drive gear 24 of the human power shaft 4, and this meshing switches the gear stage to the reverse stage.

A front differential 26 consisting of a bevel gear mechanism is disposed at the rear of the transmission 2.

The front differential 26 includes a differential case 27 that is rotatably supported by the case 2a of the transmission 2, and a differential case 27 that is rotatably supported by the case 2a of the transmission 2.
A pair of pinion gears 29.29 rotatably supported by a pinion shaft 28 fixed to the pinion gear 29.2;
A ring gear 31 that meshes with the output gear 9 of the transmission 2 is rotatably attached to the outer periphery of the differential case 27. The side gears 30, 30 are rotatably coupled to the inner ends of left and right axle shafts 32L, 32R rotatably supported by the differential case 27, and the outer ends of the axle shafts 32L, 31 are connected to left and right front wheels 33L, 33R, respectively. Therefore, after the output of the engine 1 is shifted by the transmission 2, the front differential 2 is
6 and front axle shafts 32L, 32R to the left and right front wheels 33L, 33H.

Furthermore, to explain the characteristic part of the present invention, an opening 2b is formed at the rear end of the case 2a of the transmission 2, corresponding to the position of the first speed driven gear 10 on the output shaft 5,
As shown in FIG. 3, the gear case 40 is attached to the case 2a around the opening 2b with bolts 41, 41. It is attached by...

This gear case 40 rotatably supports a rotary shaft 42 whose right end extends parallel to the transmission output shaft 5 to a rear position of the engine 1.
A gear 43 that always meshes with the speed drive gear 10 is rotatably attached.

Further, a gear box 44 is attached to the lower rear surface of the engine 1 via a bracket 45.
A rotary shaft 46 extending in the left-right direction and a rotary shaft 47 extending in the front-rear direction are rotatably supported on the rotary shaft 4 . The left and right rotating shaft 46 is rotatably connected to the right end of the rotating shaft 42 at its left end, and is connected to the gear box 44 of the rotating shaft 46.
A bevel gear 48 is rotatably attached to the inner part,
The bevel gear 48 meshes with a bevel gear 49 formed at the front end of the rotating shaft 47 in the longitudinal direction.

As shown in FIG. 1, the rotating shaft 47 is connected to a rear differential 51 via a rear propeller shaft 50.

This rear differential 52 is composed of the same bevel gear mechanism as the front differential 26, and includes a differential case 53 rotatably supported by a casing 51, and a pair of pinion gears rotatably supported by a pinion shaft 54 fixed to the differential case 53. 55.55, and a pair of left and right side gears 56.5 that mesh with the pinion gear 55.55 inside the differential case 53.
6, and a bevel gear 58 that meshes with a bevel gear 57 attached to the rear end of the rear propeller shaft 50 is rotatably attached to the outer periphery of the differential case 53. Also,
The side gears 56° 56 are rotatably coupled to the inner ends of left and right axle shafts 59L, 59R rotatably supported by the differential case 53, and the left and right axle shafts 59L,
The outer ends of 59R are drivingly connected to the left and right rear wheels 60L and 60R, respectively, and the rotation of the first continuous driven gear 10 in the transmission 2 is connected to the rear differential 52 and the rear axle shaft 59L.
, left and right rear wheels 60L via 59R.

60R. Therefore, in this embodiment, the gear 43, the rotating shaft 42.46°47, the bevel gear 48.49, the rear propeller shaft 50, the rear differential 52, and the rear axle shafts 59L and 59R are used to shift the gear 43 to the lower gear of the transmission 2. mesh with the row, rear wheel 60L, 60
A four-wheel drive power transmission means 61 is configured to transmit power to the vehicle R.

Further, the rear propeller shaft 50 is divided into front and rear propeller shafts 50a and 50b in the middle, and the rear wheel 60L is connected to the divided portion when the transmission 2 is shifted to a high gear.
A one-way clutch 62 is provided as a power transmission blocking means for blocking the transmission of engine power to the engine 60R. That is, this one-way clutch 62 is connected only when the rotational speed of the front propeller shaft 50a becomes faster than the rear propeller shaft 50b, and the transmission 2 is shifted to the low gear of the first forward speed. When running at low speed, the rotational speed of the rear propeller shaft 50b is lower than that of the front propeller shaft 50.
When the temperature drops below a, the one-way clutch 62 is connected and the output of the engine 1 is transferred to the front wheels 33L, 33H.
In addition, the transmission is transmitted to the rear wheels 60L and 60H, resulting in a four-wheel drive state, while the transmission 2 is shifted to a high gear other than the first forward speed, and the rotation of the rear wheels 60L and 60R is increased as the vehicle speed increases. When the rotational speed of the rear propeller shaft 50b becomes faster than that of the front propeller shaft 50a due to an increase in speed, the one-way clutch 62 is disengaged and the rear wheels 60L, 60
Prevents power transmission to R and directs the output of engine 1 to the front wheels 33.
It is configured to transmit only to L and 33R to establish a two-wheel drive state.

Next, the operation of the above embodiment will be explained.

After the output of the engine 1 is shifted by the transmission 2, it is transmitted from the output gear 9 to the left and right front wheels 33L, 33R via the front differential 26 and the left and right front axle shafts 32L, 32R. The first gear, which is a low gear in the transmission 2,
A gear 43 is meshed with the continuous driven gear 1°, and the gear 4
3 is drivingly connected to the front propeller shaft 50a via the rotating shaft 42, 46, bevel gear 48, 49, and rotating shaft 47, so that the front propeller shaft 50a is proportional to the rotational speed of the first gear drive gear 10. rotates at the specified rotational speed. When the transmission 2 is shifted to the first forward speed (low gear), the front and rear wheels 33L, 33R,
The rotation speed of 60L and 60R is low, and as the rotation of the engine 1 increases, the rotation speed of the rear propeller shaft 50b connected to the rear wheels 60L and 60R becomes less than the front propeller shaft 50a, so the one-way clutch 62 is connected. The engine power is also transmitted to the rear wheels 60L and 60R, resulting in a four-wheel drive state.

On the other hand, when the transmission 2 is shifted to a high speed gear other than the first speed, the vehicle shifts to a high speed driving state and the front and rear wheels 33L,
33R, 60L, and 60R become high, the rotation speed of the rear propeller shaft 50b connected to the rear wheels 60L and 60R becomes a rotation speed proportional to the rotation speed of the first gear drive gear 10. The front propeller shaft 50a rotates at
The one-way clutch 62 is switched to the disconnected state. The power transmission interrupting action of the one-way clutch 62 prevents the engine power from being transmitted to the rear wheels 60L, 60R, resulting in a two-wheel drive state in which only the front wheels 33L, 33R are driven.

In this case, by simply shifting the gear position of the transmission 2 between the low speed position of the first forward speed and the high speed position of the second or higher speed, two-wheel drive Since it is possible to switch between the four-wheel drive state and the four-wheel drive state, there is no need to provide a clutch for switching, and the structure of the power transmission system can be simplified. Note that the one-way clutch 62 allows only one direction of rotation, so it is more compact and has a simpler structure than the clutch for switching between two-wheel drive and four-wheel drive, and is effective in transmitting power. Simplification of the structure of the system is not significantly hindered.

In addition, a gear case 40 and a gear box 44 are attached to the case 2a and engine 1 of the transmission 2 for a two-wheel drive vehicle, respectively, and the first gear drive gear 1 of the transmission 2 is
By engaging the gear 43 with 0 and drivingly connecting the rear propeller 50, one-way clutch 62, rear differential 52, rear axle 59L, 59R, etc. to the gear 43,
A power transmission system in a four-wheel drive vehicle is configured. With this configuration, it is possible to manufacture a four-wheel drive vehicle using the transmission 2 for a two-wheel drive vehicle, and therefore the transmission 2 can be used for both two-wheel drive vehicles and four-wheel drive vehicles. Can be done. When the transmission 2 is used for a two-wheel drive vehicle, the opening 2b for taking out the power in the case 2a may be closed with a blind plate or the like.

The one-way clutch 62 is connected to the rear propeller shaft 5.
Instead of 0, two may be provided in the middle of each of the left and right rear axle shafts 59L, 59R.

FIG. 5 shows another embodiment of the present invention.
The same parts as in Figures 1 and 4 are given the same reference numerals and detailed explanations are omitted), which prevents power transmission to the rear wheels 60L and 60R when the transmission 2 shifts to a high gear. Means 62' is provided within the transmission 2.

That is, in this embodiment, in the configuration of the above embodiment,
The one-way clutch 62 on the rear propeller shaft 50 is omitted.

A clutch hub 34 is rotatably connected to the input shaft 4 between the first and second forward drive gears 7.8 in the transmission 2, and the clutch hub 34 is connected to the first and second forward drive gears 7.8. A sleeve 35 that can be splined to the second speed drive gear 7.8 is slidably and rotatably splined to the drive gear 7.8 for second speed, and this sleeve 35 is linked to the sleeve 13 on the clutch hub 12 of the output shaft 5. The clutch hub 34, which is integrated with the input shaft 4, is brought into mesh with the first speed or second speed driving gear 7.8.

Therefore, in the case of this embodiment, when the gear stage of the transmission 2 is shifted to the first speed, the sleeve 13 moves to the right in the figure, and the clutch hub 12 drives the first speed drive gear 10. However, in conjunction with the movement of the sleeve 13, the sleeve 35 also moves to the right in the figure, and the movement of the sleeve 35 connects the clutch hub 34 to the first linked drive gear 7.

In this state, the output of the engine 1 is transmitted to the first series driving gear 10 via the input shaft 4, latch hub 34, sleeve 35, and first speed driving gear 7, and further from this driven gear 10 to the gear 43. , the left and right rear wheels 60L via the rotating shafts 42, 46, bevel gears 48, 49, rear propeller shaft 50, rear differential 52, and rear axle shafts 59L, 59R.
, 60R. Further, the first speed driven gear 1
0 is drivingly connected to the output shaft 5 via the sleeve 35, the output of the engine 1 is transmitted from the driven gear 10 to the output shaft 5, the front differential 26, the front axle shaft 32L,
32R to left and right front wheels 33L.

33H. This causes the gear stage to shift to 1st gear (
When the vehicle is in low gear), it is in four-wheel drive mode.

On the other hand, when the gear stage of the transmission 2 is shifted to a high speed stage higher than the first gear stage, the sleeve 10 moves to the left in the figure, and the clutch hub 12, that is, the output shaft 5 is shifted to the second gear driven gear. The output shaft 5 is drivingly connected to the gear 11, and the driving connection between the output shaft 5 and the first serial driving gear 10 is released. Further, the sleeve 35 also moves to the left in the figure, and due to this movement of the sleeve 35, the clutch hub 34, that is, the input shaft 4 is connected to the second series drive gear 8, and the input shaft 4 and the first series drive gear 7 are connected. The drive connection with is released. Therefore, the output of the engine 1 is transmitted to the second linked driven gear 11 via the input shaft 4, the clutch hub 34, the sleeve 35, and the second linked drive gear 8, and is further transmitted from the driven gear 11 to the output shaft 5, Front differential 26 and front axle shaft 32L
, 32R to the left and right front wheels 33L, 33H. is also shut off, so the output of engine 1 is m
It is not transmitted to the l-speed drive gear 10, and is transmitted to the rear wheels 60L, 6.
0R is not driven. As a result, when the gear position is at a high speed position higher than the second speed position, a two-wheel drive state is established.

Therefore, this embodiment can also provide the same effects as those of the above embodiment.

In this embodiment, a clutch hub 34 is provided on the input shaft 4 of the transmission 2, and the clutch hub 34 is selectively drivingly connected to the first speed drive gear 7 or the second speed drive gear 8 through a sleeve 35. However, instead of this, a clutch hub is provided on the rotating shaft 46, and a sleeve is provided to selectively drive and connect the clutch hub to the gear 43 side or the bevel gear 46 side, and this sleeve is connected to the output shaft 5.
It can also be moved in conjunction with the upper sleeve 13.

Further, each of the above embodiments is an example of a four-wheel drive vehicle based on an FF type two-wheel drive vehicle, but the present invention is a four-wheel drive vehicle based on an FR type or RR type two-wheel drive vehicle. Of course, it can also be applied to

(Effects of the Invention) As described above, according to the four-wheel drive vehicle of the present invention, the gear transmission mechanism that changes the speed of the engine output and transmits it to one of the front and rear wheels, and the gear transmission mechanism that constantly meshes with the low gear train of this transmission mechanism, A four-wheel drive power transmission means that transmits power to the other front and rear wheels, and a power transmission prevention means that prevents power transmission to the front and rear wheels when the transmission mechanism is shifted to a high speed gear. Therefore, the two-wheel drive state and the four-wheel drive state are switched by the shifting operation of the gear position of the transmission mechanism itself,
A clutch for switching is not required, and the structure of the power transmission system can therefore be simplified. Moreover, the power transmission system for a four-wheel drive vehicle can be configured simply by meshing the four-wheel drive power transmission means with the low speed gear of the two-wheel drive vehicle transmission mechanism and providing a power transmission blocking means. It is possible to manufacture a four-wheel drive vehicle using a transmission mechanism for a wheel drive vehicle, and therefore the transmission mechanism can be used in common between a two-wheel drive vehicle and a four-wheel drive vehicle.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and Fig. 1 is a skeleton diagram showing the overall configuration of the power transmission system in a four-wheel drive vehicle, and Fig. 2 schematically shows the gear arrangement structure of the transmission from the vehicle width direction. A side view, FIG. 3 is a detailed sectional view taken along the line ■-■ in FIG. 2, and FIG. 4 is a sectional view taken along the line rV-IV in FIG. FIG. 5 is a skeleton diagram showing the structure of main parts in another embodiment. 1...Engine, 2...Transmission (speed change mechanism),...
・Forward first continuous drive gear, 33L, 33R wheels (one wheel), 60L, 60R... rear wheels), 61・
...Power transmission means for four-wheel drive, ...One-way clutch (power transmission prevention means) 2'...Power transmission prevention means.・°・ ]] (on the other hand.6 Patent applicant Mazda Motor Corporation 1st to 1st agent Patent attorney Mae Hiroshi (and 2 others) figure

Claims (1)

[Claims] (1) A gear transmission mechanism that has multiple gear trains and transmits engine output to one front and rear wheel by changing the speed, and meshes with a gear train in a low gear of the transmission mechanism to transmit power to the other front and rear wheel. A four-wheel drive vehicle, comprising: a four-wheel drive power transmission means for transmitting power to a four-wheel drive; and a power transmission prevention means for inhibiting power transmission to the other front and rear wheels when the transmission mechanism is shifted to a high speed gear. .