JPH0858413A - Drive force shift gear for rear two-axle device vehicle - Google Patents

Abstract

PURPOSE: To provide such a drive force shaft gear for a rear two-axle drive vehicle whose number of parts is reduced whose structure is simplified, and whose weight, and cost may be reduced. CONSTITUTION: A drive gear 25 is directly connected to an input shaft 20, torque is transmitted from the drive gear 25 to a rear-front axle side differencial gear 13 via a changeover mechanism 38, the tip side of the input shaft 20 is connected to a through shaft 17 via a sleeve 27, and the torque is transmitted to a rear- back axle side differencial gear via the through shaft 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive force switching device for a rear two-axis drive vehicle, and more particularly to a drive force switching device for a rear two-axis drive vehicle that is configured to switch between rear two-axis drive and rear one-axis drive. .

[0002]

2. Description of the Related Art In a rear two-axle truck, a rear two-axle drive vehicle is used in which a rear front axle and a rear two axles forming the rear two axles are used as drive axes in order to obtain a reliable drive force. It is designed to be used. The rear two-axle drive vehicle transmits the torque on the output side of the transmission to the interaxle diff via the propeller shaft, and transmits the torque to the front and rear axles and the rear-to-rear axle via the interaxle diff. The interaxle diff absorbs the difference in rotation speed between the front and rear axles and the rear and rear axles.

[0003]

According to the rear two-axle drive vehicle having such an interaxle diff, the interaxle diff increases the number of parts and complicates the structure.
Weight also increases. This also leads to an increase in cost. If the coefficient of friction between the rear front wheel and one of the rear rear wheels and the road surface is low, the wheels will spin due to the differential motion of the interaxle diff and the vehicle will not start. Further, due to the differential motion of the inter-axle differential, the total torque may be applied to one of the rear front axle differential and the rear front axle differential.

The present invention has been made in view of the above problems, and solves the problems caused by providing an interaxle diff in a rear two-axle drive vehicle, and has a simple structure, a light weight, and oil. It is an object of the present invention to provide a driving force switching device for a rear two-axis drive vehicle, which prevents temperature rise, helps improve fuel efficiency, and leads to cost reduction.

[0005]

According to the present invention, there is provided a switching mechanism to the input side of a rear front axle side differential which is driven not through an interaxle differential but through a power take-out means provided in the middle of a power line. The switching mechanism is switched to the shut-off state when it is detected that the gear used in the transmission is on the high speed side or when the vehicle speed is equal to or higher than a predetermined value. The present invention relates to a drive force switching device for a rear two-axis drive vehicle, in which sometimes the rear axle is driven by a single axis so that the problem caused by eliminating the interaxle diff can be minimized.

[0006]

When the detecting means for detecting the used stage of the transmission detects that it is on the high stage side, or when the detecting means for detecting the vehicle speed detects that the vehicle speed is equal to or higher than a predetermined vehicle speed, the control means operates. The switching means is switched to the shut-off state, so that the one-axis drive of the rear axis is performed during high speed traveling.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a rear two-axle structure of a vehicle equipped with a drive force switching device according to an embodiment of the present invention.
The rear front wheel 11 and the rear rear wheel 12 are respectively the rear front axle side differential 13
It is driven by a rear front shaft 15 and a rear rear shaft 16 which are connected to the rear rear shaft differential 14. That is, the torque from the transmission is applied to the rear front axle side differential 13
After that, it is transmitted to the shaft side differential 14, and these differentials 13, 1
The rear biaxial drive of the rear front wheel 11 and the rear rear wheel 12 is achieved via the drive shaft 4.

The structure of the rear front shaft side differential 13 will be described. As shown in FIGS. 3 and 4, an input shaft 20 is provided in the gear box of the rear front shaft side differential 13, and the input shaft 20 is mounted on the input shaft 20. Is provided with a power take-out means. The power take-out means is for taking out the power directly from the power line without passing through the interaxle differential, and is composed of a drive gear 25 fixed to the input shaft 20. The drive gear 25 is constantly meshed with the pinion drive gear 37.

Next, the switching mechanism 38 of the pinion drive gear 37 meshing with the drive gear 25 will be described. As shown in FIGS. 4 and 2, this switching mechanism is provided on the shaft of the hypoid pinion 39. A hub 40 is provided. The sleeve 41 is supported by a spline formed on the hub 40 so as to be movable in the axial direction, and the sleeve 41 is engaged with or disengaged from the dog gear 42 on the side surface of the pinion drive gear 37 to generate a driving force. I am trying to switch. That is, the air cylinder 43 is provided below the hub 40.
The fork 45 fixed to the piston rod 44 of the air cylinder 43 is attached to the sleeve 41.
The groove 41 is engaged with the groove 41 to move the sleeve 41 in the axial direction.

Next, the structure of the rear / front axle side differential 13 will be described. A ring gear 48 driven by the hypoid pinion 39 is provided at the center of the differential 13. The ring gear 48 includes a differential case 49, and the differential case 49 supports the spider 50. The spider 50 revolves while rotatably supporting the differential pinion 51. The diff pinion 51 meshes with the side gear 52 attached to the tip of the rear front shaft 15.

The rear front shaft 15 extends into the axle housing 55 as shown in FIG. 3, and is connected to a wheel hub 57 which is supported on the axle housing 55 via roller bearings 56. Wheel hub 5
7 holds the wheel 58 via a hub bolt 59. The hub bolt 59 fixes the brake drum 60 to the wheel 58. And wheel 5
The rear front wheel 11 is configured by the tires mounted on the rim of No. 8.

Next, the rear-rear axle side differential 14 for driving the rear-rear wheel 12 will be described. As shown in FIG. 5, the front end portion of the through shaft 17 of the rear-rear axle-side differential 13 and the rear-rear axle-side differential 14 are arranged. The hypoid pinion 64 is connected to the tip of the propeller shaft 63 to be connected. The hypoid pinion 64 meshes with the ring gear 65. The ring gear 65 is adapted to revolve around the shaft 16 afterwards, and the differential case 66
It is stuck to. Spider 6 by differential case 66
7, the spider 67 rotatably supports the differential pinion 68. The differential pinion 68 is a side gear 69 attached to the shaft 16 afterward.
Is meshing with.

The rear shaft 16 having the side gear 69 attached to the center side end thereof extends into the axle housing 72 as shown in FIG. And axle housing 72
The wheel hub 74 is rotatably supported by the tip of the roller hub 73, and the tip of the shaft 16 is connected to the wheel hub 74.
The wheel hub 74 supports the wheel 75 via a hub bolt 76, and the hub bolt 76 fixes a brake drum 77. And wheel 7
The rear tire 12 is constituted by the tires mounted on the rim portion of No. 5.

Next, as shown in FIGS. 6 and 7, the transmission 81 of this vehicle is provided with a detection switch 82. The detection switch 82 is for detecting when the transmission 81 is used at a high speed side use stage (for example, 6th speed or 7th speed of a 7-speed transmission), and as shown in FIG. Is attached to the lower side of the top cover 83, and detects the position of the fork 85 fixed to the shifter shaft 84.

The detection switch 82 is connected to the input side of the controller 89 together with the changeover switch 88 as shown in FIG. The controller 89 controls the opening / closing of the solenoid valve 91. The solenoid valve 91 is for controlling the supply and interruption of compressed air to the air cylinder 43 of the switching mechanism 38 shown in FIG.

Next, the operation of this apparatus having the above structure will be described. When the driver switches the changeover switch 88 shown in FIG. 8 to the two-axis drive side as shown by the solid line, and when the detection switch 82 of the transmission 81 detects that it is in the low speed stage, the controller 89 turns on the solenoid valve 91. When opened, compressed air is supplied to the air cylinder 43 shown in FIG. 2 to move the sleeve 41 of the switching mechanism 38 to the chain line position shown in FIG. 2, and the sleeve 41 is engaged with the dog gear 42. Therefore, the hypoid pinion 39 and the drive gear 37 are connected to each other, and the switching mechanism 38 is switched to the connected state.

Therefore, the torque from the transmission 81 is taken out by the drive gear 25 through the input shaft 20 shown in FIGS. 3 and 4, and this torque is further passed through the pinion drive gear 37, the dog gear 42, the sleeve 41, the hub 40, and the hypoid pinion 39. It is transmitted to the rear front axle side differential 13.

Hypoid pinion 3 on the rear front axle side differential 13
9 drives the ring gear 48 shown in FIG. 3, which drives the differential case 49. Therefore, the differential pinion 51 on the spider 50 supported by the differential case 49 rotates while hooking the left and right side gears 52, and the rear front shaft 15 is driven.

When the rotational resistance of the left and right rear front wheels 11 changes, such as when the vehicle turns, the diff pinion 51 supported by the spider 50 revolves around its own axis, which causes the wheel with the larger resistance. The rotation speed of 11 decreases, the rotation speed of the wheel 11 on the opposite side increases, and the difference between the left and right rotation speeds is absorbed.

The output torque of the transmission 81, which is the torque transmitted through the input shaft 20, is input to the differential 14 on the rear side of the shaft 16 via the sleeve 27, the through shaft 17, and the propeller shaft 63 shown in FIG. It That is, the hypoid pinion 64 of the differential 14 drives the ring gear 65. Therefore, the diff pinion 68 on the spider 67 supported by the diff case 66 to which the ring gear 65 is fixed hooks the left and right side gears 69 to rotationally drive the shaft 16 afterwards. Therefore, the rear-end wheel 12 attached to the tip of the rear-end shaft 16 is driven by this. The operation of the differential motion for absorbing the difference in the rotational speeds of the left and right rear wheels 12 is
This is the same as that of the rear front shaft side differential 13 for absorbing the difference between the left and right rotational speeds of the rear front shaft 11. In this way, the rear two axes are driven without using the interaxle differential 21.

When the changeover switch 88 shown in FIG. 8 is changed over to the one-axis drive side as shown by the chain line, or when the detection switch 82 detects that the used stage of the transmission 81 is the low speed stage, the controller 89 Opens the exhaust port of the solenoid valve 91, and the air cylinder 43 shown in FIG.
Exhaust compressed air from. Therefore, this air cylinder 43
The return spring moves the fork 45 to the left in the figure, and the sleeve 41 moves in the same direction as shown by the solid line to release the engagement with the dog gear 42. That is, the switching mechanism 38 is switched to the cutoff state. Therefore, the transmission of torque from the drive gear 25 to the rear front axle side differential 13 is cut off.

Therefore, the rotation of the input shaft 20 depends on the sleeve 27, the through shaft 17, and the propeller shaft 6.
3 (see FIG. 1) to the hypoid pinion 64 of the rear axle shaft differential 14, and the rear rear wheel 12 is driven via the rear axle shaft differential 14. That is, in this case, only the rear wheel 12 is driven by one axis.

In this way, when the rear 1-axis drive is used, since the torque is transmitted directly to the rear-side shaft-side differential 13 via the power line without using the interaxle differential, the rear 1-axis drive is performed. Pinion drive gear 3
It is possible to prevent 7 from spinning idly at twice the number of rotations and the torque is not transmitted to the shaft side differential 14 later, and the torque is reliably transmitted only to the rear side differential 14.
As a result, driving by the rear wheels 12 becomes possible. That is, all the output torque of the transmission 81 can be transmitted to the rear wheels 12 to achieve the uniaxial drive.

As described above, according to the drive force switching device of this embodiment, the drive gear 25 constituting the power take-out means is directly connected to the input shaft 20 shown in FIG. 4, and the drive gear 25 forms the switching mechanism 38. The drive force is transmitted to the rear-front shaft-side differential 13 via the through shaft 17, and the drive force is transmitted to the rear-rear shaft-side differential 14 via the through shaft 17 and the propeller shaft 63 that are connected to the input shaft 20 via the sleeve 27. By this, the drive of the shaft 16 is achieved later, and the number of parts is reduced, the structure is simplified, and the weight is reduced without providing an interaxle differential on the input shaft 20. In addition, the oil temperature is prevented from rising and the fuel consumption is improved, and the cost is reduced.

Conventionally, the role of the interaxle diff provided in this type of two-axis drive vehicle is to absorb the rotation difference generated by the difference in the outer diameters of the tires of the rear front wheel 11 and the rear rear wheel 12, and It prevents the fuel consumption from being deteriorated and the tire from being worn due to the drag. However, in general, 90% or more of the total traveling distance of the vehicle is high-speed traveling, and in such a case, the switching mechanism 38 drives the vehicle by uniaxial drive.
Therefore, the travel for absorbing the difference in the number of rotations between the rear-front shaft 15 and the rear-rear shaft 16 becomes 10% or less of the whole, and therefore the switching mechanism 38 is provided and the single-axis drive is performed on the high speed side. As a result, it becomes possible to minimize the problems associated with the elimination of the inter-axle diff, and it is possible to provide a low-cost rear two-axle drive vehicle with no practical problems.

If an interaxle differential is provided between the rear front shaft 15 and the rear rear shaft 16, the rear front wheel 11 and the rear rear wheel 12 are provided.
When a large resistance is applied to one of the wheels, the torque transmission to the wheel to which the resistance is applied is interrupted by the interaxle diff, and the total torque is transmitted to the other wheel. This means that an excessive torque is applied to the rear-front shaft side differential 13 or the rear-front shaft differential 13. Therefore, when the above phenomenon occurs at extremely low speed, the rear front axle side differential 1
3 or later the shaft side differential 14 may be damaged. However, by eliminating the inter-axle diff, torque is evenly transmitted to the rear front shaft side diff 13 and the rear-rear shaft side diff 14, so that the excessive torque described above is transmitted to one diff. You will be able to prevent it from being damaged.

The control of the controller 89 for switching the solenoid valve 91 is performed based on the switching of the changeover switch 88 shown in FIG. 8 and the detection of the detection switch 82, as shown in FIG. Changeover switch 8
It is also possible to omit 8 and use only the detection switch 82. That is, the solenoid valve 91 may be switched via the controller 89 in accordance with the detection of the used stage of the transmission 81. In this case, automatic switching between one-axis driving and two-axis driving is performed according to the stage of use of the transmission 81.

In the configuration shown in FIG. 10, the changeover switch 88 and the vehicle speed sensor 94 are connected to the input side of the controller 89. Therefore, in this case, when the changeover switch 88 selects the 1-axis drive and the vehicle speed sensor 94 detects that the vehicle speed is equal to or higher than a predetermined value, the 1-axis drive is performed and the changeover switch 88 is operated. When the vehicle is switched to the two-axis drive or when the vehicle speed sensor 94 detects that the vehicle speed is equal to or lower than a predetermined vehicle speed, the two-axis drive is switched to.

In the structure shown in FIG. 11, only the vehicle speed sensor 94 is connected to the input side of the controller 89. With such a configuration, the solenoid valve 91 is controlled by the controller 89 so that the one-axis drive and the two-axis drive are automatically switched according to the detection of the vehicle speed by the vehicle speed sensor 94. That is, when the vehicle speed is equal to or higher than the predetermined vehicle speed, the single-axis drive is selected, and when the vehicle speed is lower than the predetermined vehicle speed, the double-axis drive is selected.

[0030]

As described above, according to the present invention, the mechanism for switching to the input side of the rear front shaft side differential is driven not through the interaxle differential but through the power take-out means provided in the middle of the power line. Is provided, and if it is detected that the gear used in the transmission is a high speed gear or if the vehicle speed is equal to or higher than a predetermined vehicle speed, the switching mechanism is switched to the cut-off state, and only one axis is used afterward. It is designed to be driven.

Therefore, according to the present invention, the rear two-axis drive can be performed only during low-speed traveling, and the two-axis rear-axis drive can be switched after high-speed traveling, so that the fuel consumption can be improved. Further, the interaxle diff is abolished to reduce the number of parts, simplify the structure, and reduce the weight, thereby achieving the cost reduction. Since most of the traveling is performed by the single-axis drive by the above switching mechanism, it is possible to minimize the trouble caused by the elimination of the inter-axle diff. It will be possible to provide axle driven vehicles.

[Brief description of drawings]

FIG. 1 is an overall side view showing a drive force transmission mechanism of a rear two-axis drive vehicle.

FIG. 2 is a sectional view of a main part of a switching mechanism.

FIG. 3 is a cross-sectional view of a rear front axle side differential.

FIG. 4 is a longitudinal sectional view of a rear front axle side differential.

FIG. 5 is a transverse cross-sectional view of the rear-to-left shaft side differential.

FIG. 6 is a side view of the transmission.

FIG. 7 is a sectional view of a main part of a transmission.

FIG. 8 is a block diagram showing a control circuit.

FIG. 9 is a block diagram of a control circuit of a modified example.

FIG. 10 is a block diagram of a control circuit of another modification.

FIG. 11 is a block diagram of a control circuit according to still another modification.

[Explanation of symbols]

 11 Rear Front Wheel 12 Rear Rear Wheel 13 Rear Front Shaft Side Diff 14 Rear Front Shaft Side Differential 15 Rear Front Shaft 16 Rear Front Shaft 17 Through Shaft 20 Input Shaft 25 Drive Gear 27 Sleeve 37 Pinion Drive Gear 38 Switching Mechanism 39 Hypoid Pinion 40 Hub 41 Sleeve 42 Dog Gear 43 Air Cylinder 44 Piston Rod 45 Fork 48 Ring Gear 49 Differential Case 50 Spider 51 Differential Pinion 52 Side Gear 55 Axle Housing 56 Roller Bearing 57 Wheel Hub 58 Wheel 59 Hub Bolt 60 Brake Drum 63 Propeller Shaft 64 Hypoid Pinion 65 Ring 67 Gear Diff 66 Spiff Diff 66 Diff 66 Side gear 72 Axle housing 73 Roller bearing 74 Hoi Hub 75 Wheel 76 Hub bolt 77 Brake drum 81 Transmission 82 Detection switch 83 Top cover 84 Shifter shaft 85 Fork 88 Changeover switch 89 Controller 91 Electromagnetic valve (for changeover mechanism) 94 Vehicle speed sensor

Claims (2)

[Claims] 1. A drive force switching device for a rear two-axis drive vehicle, which is configured to switch between rear two-axis drive and rear one-axis drive, and a power provided midway in a power line without an interaxle differential. A rear front axle side differential that is driven through the take-out means and transmits a drive force to the rear front axle; a rear front axle differential that is connected to an end of the power line and transmits a drive force to the rear rear axle; A switching mechanism which is provided on the input side of the shaft side differential and switches between transmission and interruption of the driving force to the rear and front shafts, detection means for detecting the stage of use of the transmission, and stage of use of the transmission by the detector. And a control means for turning off the switching means when it is detected that the vehicle is in a high speed stage. 2. A drive force switching device for a rear two-axis drive vehicle, which is configured to switch between rear two-axis drive and rear one-axis drive, wherein a power provided in the middle of a power line without an interaxle differential. A rear front axle side differential that is driven through the take-out means and transmits a drive force to the rear front axle; a rear front axle differential that is connected to an end of the power line and transmits a drive force to the rear rear axle; A switching mechanism which is provided on the input side of the shaft side differential and switches between transmission and interruption of the driving force to the rear and front shafts, a detection means for detecting the vehicle speed, and a vehicle speed higher than a predetermined vehicle speed detected by the detection means. A drive force switching device for a rear two-axis drive vehicle, comprising: a control means for turning off the switching mechanism when it is detected.