JPS6387323A - Forced differential gear - Google Patents

Abstract

PURPOSE:To reduce the turning radius of a vehicle to restrain rear wheels from projecting, by providing a mechanism for transmitting a predetermined difference in rotational speed to two shafts, and a means for coupling the transmission mechanism to the drive side when both right and left steered wheels are set at a maximum steering angle. CONSTITUTION:When a running vehicle is turned to, for example, the left with a maximum steering angle, a sensor 54 detects such a condition to energize both solenoid valves 62, 64. Further, a tube 80 is communicated with a vacuum tank 76 to move a diaphragm 90 in an actuator 66 to the left. Further, a rod 94 is rotated about the coupling point between itself and a rod 92 in an actuator 74 to shift a fork 38 to the left in order to engage a clutch 14. Further, a sun gear 18 is fixed by means of a cylindrical shaft 40 to lower the rotational speed of a planetary gear 22. With this arrangement, the rotational speed of a drive shaft 30 is lowered through the intermediary of a transmission means 46 while the rotational speed of a drive shaft 32 is raised by means of a differential gear 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a forced differential, and more particularly, to a forced differential, and more particularly, a differential case, a plurality of pinions disposed within the differential case, and two side gears meshing with these pinions. The present invention relates to a device particularly suitable for rear wheels, which can reduce the turning radius of a vehicle by forcibly causing a differential in a differential device including a drive shaft coupled to each side gear.

(Prior art) When a vehicle with front wheel steering makes a low-speed turn, the turning center is the point where the extension lines of the rotation centers of the inner front wheel and the outer front wheel intersect on a horizontal plane that includes the extension lines of the rotation centers of the two rear wheels. or near that point, the turning radius of the vehicle is
It is determined by the turning angle of the front wheels and the vehicle's wheelbase and tread.

(Problems to be Solved by the Invention) Techniques for reducing the turning radius while keeping the above factors constant include four-wheel steering or braking the inner wheel of the turn.

In the case of four-wheel steering, in order to steer the rear wheels in addition to the front wheels,
Since a complicated steering mechanism must be added to the rear wheel support, and the center of turning moves significantly forward, the outer rear wheel may protrude outward when turning, potentially causing a traffic obstruction.

When braking the inner wheel of a turn, a large amount of slip occurs between the four wheels, so it cannot be used on regular paved roads with high road surface friction.

A vehicle differential device disclosed in Japanese Patent Application Laid-Open No. 60-237244 includes a side gear provided with a centrifugal member that swings outward due to centrifugal force, and a torque transmission member provided between the differential case and the side gear. The centrifugal member is engaged with the torque transmission member in accordance with the rotational speed of the side gear, thereby increasing the torque of the torque transmission member. Although this makes it possible to sufficiently ensure a differential at low speeds, it is not possible to reduce the turning radius of the vehicle.

An object of the present invention is to reduce the turning radius.
To provide a forced differential device capable of suppressing protrusion of rear wheels during turning and preventing slippage of four wheels.

(Means for Solving the Problems) The present invention is a device for forcibly causing differential movement in the shafts of a differential device including two shafts extending left and right from a differential case. A transmission mechanism with a predetermined rotational speed ratio formed to give a rotational speed difference to the two shafts that is larger than the rotational speed difference generated between the two shafts by the action of a differential device, and a transmission mechanism with a predetermined rotational speed ratio that is formed to provide a rotational speed difference greater than a rotational speed difference that occurs between the two shafts due to the action of a differential device, and means for connecting the transmission mechanism to a drive side when the transmission mechanism is activated.

A forced differential is typically placed between a propeller shaft and a pair of drive shafts that transmit power to the left and right rear wheels.

(Action Part and Effect) When a vehicle traveling straight is steered to a maximum steering angle, the transmission mechanism is connected to the drive side, that is, the propeller shaft, by the connection means. As a result, the shafts are forced to be differentially driven so that the rotational speed of the shaft located on the outside of the turn increases, or the rotational speed of the shaft located on the inside of the turn decreases, and the difference in rotational speed between the two shafts is reduced. growing.

Even if the vehicle is steered, the coupling means does not work unless the maximum steering angle is reached, so no forced differential occurs, and only the normal differential during turning occurs.

Since it is not a four-wheel steering system, there is no need to add a rear wheel steering device, and if you try to reduce the turning radius by increasing the turning angle of the wheels, the wheel house will inevitably become larger, reducing the interior space and engine. However, in the present invention, even if the turning angle is kept the same as before, the turning radius is reduced, so the indoor space etc. is not compressed.

(Example) As shown in FIG. 1, the forced differential device 10 includes a differential device 1
2, which forces the differential to operate, and includes two clutches 14, 16, a sun gear 18, an internal gear 20, and a planetary gear 22.

The differential device 12 includes a differential case 24, a plurality of pinions 26 disposed within the differential case 24, two side gears 28 that mesh with these pinions 26, and a drive shaft 30 coupled to one of the side gears 28. The drive shaft 32 is known per se and includes a drive shaft 32 coupled to the other side gear 28.

In the embodiment shown in FIG. 3, the two clutches 14, 16 are of the sleeve type, and include a cylindrical fixed housing 34 disposed surrounding the drive shaft 30, and a sleeve 36 engaging the housing 34. , and a fork 38 that moves the sleeve.

The housing 34 has a spline 35 extending in the axial direction on its outer peripheral surface. On the other hand, the sleeve 36 has splines 37a and 37b extending in the axial direction at both ends of its inner peripheral surface, and the spline 37a engages with the spline 35 of the housing 34.

A cylindrical shaft 40 having a sun gear 18 fixed to one end thereof is rotatably fitted to the drive shaft 30, and a spline 15 extending in the axial direction is provided on the outer peripheral surface of the other end of the cylindrical shaft 40. This spline 15 can be engaged with the spline 37b of the sleeve 36, thereby forming the clutch 14. Further, a cylindrical shaft 42 having an internal gear 20 fixed to one end is rotatably fitted to the cylindrical shaft 40, and a spline 17 extending in the axial direction is provided on the outer peripheral surface of the other end of the cylindrical shaft 42. This spline 17 is the spline 37 of the sleeve 36.
b, and a clutch 16 is configured. That is, when the sleeve 36 moves to the left from the neutral position shown in FIG.
When it moves to the right, the spline 37b of the sleeve 36 engages with the spline 17 of the cylindrical shaft 42. housing 3
4 spline 35 and spline 37a of sleeve 36
The spline 37b of the sleeve 36 is formed to have a length that allows it to move from the neutral position to the left and right as described above.

The planet gear 22 meshes with the sun gear 18 and the internal gear 20. In the embodiment shown in FIG. 1, the planetary gear 22 includes a first gear 23a and a second gear 23a each having a different number of teeth fixed to a cylindrical shaft 44.
The first gear 23a is the sun gear 18.
, the second tooth weight 23b meshes with the internal gear 20.

The means 46 for transmitting the rotation of the planetary gear 22 to the drive shaft 30 includes a shaft 48 fixed to the differential case 24 , a cylindrical shaft 44 is rotatably fitted to the shaft 48 , and a cylindrical shaft 44 is rotatably fitted to the end of the cylindrical shaft 44 . A gear 50 is fixed. On the other hand, a gear 52 is fixed to the drive shaft 30, and this gear 52 meshes with the gear 50. The gear 50 and the gear 52 have the same number of teeth and the same module, so that the rotation of the cylindrical shaft 44 is transferred to the drive shaft 30 in the opposite direction. A transmission mechanism is configured by the gear train.

Two sensors 54 that detect the maximum steering angle for left and right turns.
56 are provided. In the embodiment shown in FIG.
4.56 is mounted in conjunction with the gearbox 58 of the steering device.

Sensors consist of proximity switches, limit switches, and other switches.

The clutch 14.1 is activated by a signal from the sensor 54.56.
6, in the embodiment shown in FIG. 2, two solenoid valves 62.6 associated with the clutch 14
4, an actuator 66, two solenoid valves 68, 70 associated with the clutch 16, and an actuator 72. The sensor, solenoid valve, actuator and clutch constitute the coupling means.

1. Each solenoid valve communicates via a tube 74 to a vacuum tank 76, which in turn communicates via a tube 78 to an engine intake manifold (not shown). Solenoid valve 62 is connected to tube 8
0 to the actuator 66, the solenoid valve 64
is communicated with the actuator 66 via the tube 82 at portions on both sides of the diaphragm, which will be described later.

Also, the solenoid valve 68 is connected to the actuator 72 through a tube 84, and the solenoid valve 70 is connected to the actuator 72 through a tube 84.
6 and to the actuator 72 on both sides of the diaphragm.

Each actuator has a diaphragm 90 and a rod 92 coupled to the diaphragm 90, the rod 92 having a
It is rotatably connected to a rod 94 extending from one side to the other. A fork 38 is rotatably connected to this rod 94, and the fork 38 is moved along a guide 96.

As shown in the figure, the actuator 66 and the actuator 72 do not output signals from both sensors 54 and 56.
When the solenoid valve is not energized, the diaphragms 90 are configured to be biased in opposite directions by negative pressure. Therefore, when the solenoid valve 62 is not excited, it shuts off the tube 74 side and
When the solenoid valve 64 is not excited, the solenoid valve 64 shuts off the atmosphere side, and the negative pressure P
2 is connected so that it is guided to the tube 82. In addition, when the solenoid valve 68 is not energized, the solenoid valve 70 shuts off the atmosphere side and the negative pressure P2 is guided to the tube 84. Atmospheric pressure PI is connected to be guided to the tube 86. The rod 94 is connected to the fork 38 when all solenoid valves are not energized.
in the neutral position of Fig. 3, that is, clutch 14.16.
is formed so as to bring it to a position where it is inactive.

': In the forced differential device shown in Figures JJ5 to Figure 7, 2
gears 110 and 112 are attached to the drive shaft 30,
Gears 114, 116 are secured to the drive shaft 32. On the other hand, a gear 118 that meshes with the gear 110 is fixed to the shaft 120, and a gear 122 that meshes with the gear 112.
is fixed to the cylindrical shaft 124. The cylindrical shaft 124 is appropriately rotatably supported by a differential carrier (not shown), and the shaft 120 is inserted into the cylindrical shaft 124 and rotatably supported. Further, a gear 126 that meshes with the gear 114 is fixed to a shaft 128, and a gear 130 that meshes with the gear 116 is fixed to a cylindrical shaft 132. Cylindrical shaft 13
2 is rotatably supported by a differential carrier, and the shaft 128 is inserted into a cylindrical shaft 132 and rotatably supported. The gears located symmetrically on both sides of the differential 12 have the same number of teeth. These gear trains constitute a transmission mechanism.

The end 121a of the shaft 120 and the end 129a of the shaft 128 are arranged close to each other, as shown in FIG.
A spline 121b extending in the axial direction is provided at the end portion 129a, and a spline 129b extending in the axial direction is provided at the end portion 129a.

Further, a spline 125 extending in the axial direction is provided at the end of the cylindrical shaft 124, and a spline 133 extending in the axial direction is provided at the end of the cylindrical shaft 132.

The sleeve 134 is attached to the end 121a, 1 of the shaft 120.128.
29a, and is disposed so as to be movable in the axial direction.

The sleeve 134 has splines 135a and 135b extending in the axial direction on the inner circumferential surface of both ends. Sleeve 134
moves to the left from the neutral position shown, its spline 135a engages with the spline 125 of the cylindrical shaft 124, and its spline 135b engages with the spline 129b of the shaft 128. Conversely, when the sleeve 134 moves to the right, the spline 135b of the sleeve 134 moves to the spline 13 of the cylindrical shaft 132.
3, the spline 135a is the spline 12 of the shaft 120.
It meshes with 1b. Thus, the sleeve 134 constitutes two sets of clutches.

When the sleeve 134 moves to the left, the drive shaft 3
Two rotations pass from the gear 114, 126 via the shaft 128 to the sleeve 134, and from the sleeve 134 to the cylindrical shaft 124, the gear 122, 112 is rotated. Conversely, when sleeve 134 moves to the right, rotation of drive shaft 30 passes from gear 110.118 through shaft 120 to sleeve 134, and from sleeve 134 to cylindrical shaft 132, causing rotation of gear 130.116. .

The number of teeth of the external gear is selected so that the gear 112 or 116 described above increases the rotational speed of the drive shaft to which the gear is fixed.

Two pumps 140 are installed in the steering gear box 58.
．． 142 is attached. Each pump is in its operating position at maximum steering. The pump 140 and the pump 142 are connected to a cylinder device 144 and a cylinder device 146 through piping, respectively, as will be described later. Each pump consists of a cylinder 148, a piston 150 that slides fluid-tight within the cylinder 148, a rod 152 connected to the piston 150, and a coil spring 154 that biases the piston 150 in one direction. The piston 150 hits a retaining ring (not shown), and the piston 150 is held at a predetermined position. On the other hand, each cylinder device includes a cylinder 156, a piston 158 sliding within the cylinder 156, and a piston 1
58 and a rod 160 connected to each rod 1.
60 is pivotally connected to the cross rod 162. The coupling means is constituted by the clutch, the pump, and the cylinder device.

The pump 140 and the cylinder device 144 are the cylinder 14
The spring-side liquid chamber 149a of No. 8 is connected to the rod-side liquid chamber 157a of the cylinder 156, and the return-side liquid chamber 149b of the cylinder 148 is connected to the push-side liquid chamber 157b of the cylinder 156 so as to communicate therewith. In addition, the pump 142 and the cylinder device 14
6 means that the spring side liquid chamber 149a of the cylinder 148 is the push side liquid chamber 157b of the cylinder 156, and the return side liquid chamber 149b of the cylinder 148 is the rod side liquid chamber of the cylinder 156! 5
7a so as to communicate therewith. When the piston 150 of each pump is held at a predetermined position, the piston 158 of each cylinder device is held at a neutral position.

Rods 160 each extending from cylinder devices 144, 146 are pivotally connected to a cross rod 162, and cross rods 162 and rods 164 are pivotally connected. shift fark 1
66 is attached to rod 164 and engages sleeve 134.

It is assumed that the steering gear box 58 is located behind the axle of the collar. Now, when the handle is rotated to the right, the rack par 170 moves to the left in FIG. When the steering reaches the maximum steering angle, the rack par is 170
The striker (not shown) attached to the right pump 1
42, and push the rod 152 in. Then, hydraulic pressure is generated in the spring-side liquid chamber 149a of the pump 142, and this hydraulic pressure is led to the push-side liquid chamber 157b of the cylinder device 146 to push out the rod 160. As a result, rod 164 moves to the right and sleeve 134 moves to the right. When the handle is returned, the rod 152 of the pump 142 is pushed out by the spring 154, eventually returning the rod 164 to the neutral position shown and the sleeve 134 remaining neutral. When the steering wheel is steered to the left to the maximum steering angle, the pump 140 and cylinder device 144 are similarly activated.

(Effect of Example) The embodiment shown in FIGS. 1 to 3 will be described.

A ring gear 97 is fixed to the differential case 24 of the differential device 12, and a drive gear 98 that meshes with the ring gear 97 is fixed to the propeller shaft 100. Furthermore, the left rear wheel 102 is connected to the drive shaft 30 and the right rear wheel 104 is connected to the drive shaft 32. When the propeller shaft 100 rotates in the direction indicated by the arrow in FIG. 1, the drive shaft 30, 32 rotates in the direction indicated by the arrow B.
The vehicle moves forward.

When a running vehicle takes the maximum steering angle and turns to the left,
A signal is output from the sensor 54, and the solenoid valve 62.
64 are excited together. These solenoid valves are then switched and communicate with the vacuum tank 76 via tube 80 or tube 74, and tube 82 communicates with the atmosphere so that the diaphragm 9 of actuator 66
0 moves to the left under the pressure of (PI +P2).

At this time, since there is no signal output from the sensor 56, the diaphragm 90 of the actuator 72 is in its original position.

As a result, the rod 94 of the actuator 72
2, the fork 38 moves to the left, and the clutch 14 becomes engaged. As a result, the sun center 18 is fixed via the cylindrical shaft 40, so the planetary gear 22 revolves around the sun gear 18 and simultaneously rotates in the opposite direction, reducing its rotational speed. The rotation of the planetary gear 22 is transmitted to the drive shaft 3 via a transmission means 46.
0 and lowers the rotation speed of the drive shaft 30, but the rotation speed of the drive shaft 32 increases due to the action of the differential device 12.

When the turn ends or the turning angle decreases,
Since there is no signal from sensor 54, solenoid 62
．． 64 is demagnetized and the diaphragm 90 of the actuator 66 returns to the position shown in FIG. In this state, the clutches 14 and 16 are inactive, so the left and right rear wheels 10
2.104 allows normal differential operation.

When a running vehicle takes the maximum steering angle and turns to the right,
A signal is output from the sensor 56 and the solenoid valve 68.
70 are excited together. These solenoid valves are then switched, and the tube 86 communicates with the vacuum tank 76 via the tube 74, and the tube 84 communicates with the atmosphere so that the diaphragm 9 of the actuator 72
0 moves to the right under the pressure of (P+ +p2).

At this time, since there is no signal output from the sensor 54, the diaphragm 90 of the actuator 66 is in its original position.

Thus, rod 94 is connected to rod 92 of actuator 66.
The fork 38 moves to the right and the clutch 16 becomes engaged. As a result, the internal gear 20 is fixed, so the planetary gears 22 revolve inside the internal gear 20, simultaneously rotate in the same direction, and their rotational speed increases. The rotation of the planetary gear 22 is transmitted to the drive shaft 30 via the transmission means 46, increasing the rotation speed of the drive shaft 30.
2 is reduced by the action of the differential 12.

FIG. 4 shows qualitatively the effects of the present invention.

If the forced differential device 10 is not provided, the turning center when the front wheels 106 are steered to the maximum steering angle is the intersection point 01 of the extension lines of the rotation axes of the front wheels and the rear wheels. At this time, the rotational speed of the rear wheels is υ1 for the outer wheel 102 and U2 for the inner wheel 104.

When the forced differential 10 is provided, as described above, the rotational speed of the wheels on the outside of the turn increases to U.

This results in a larger vI, and the rotation speed of the wheels on the inside of the turn decreases, resulting in a smaller v2 than U2. Then, the rear wheels try to rotate around 02, but since the front wheels interfere, a slip angle occurs in the four wheels, and the turning center moves to point 03, where the side forces of the four wheels are balanced. That is, in the present invention, a forced differential is added within the allowable range of side slip of the four wheels, and the turning radius is moved to the conventional OL or 603 to reduce the turning radius.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a forced differential device according to the present invention, Fig. 2 is a plan view showing means for operating the clutch, Fig. 3 is a front sectional view of the clutch, and Fig. 4 qualitatively shows the effects of the present invention. 5 is a schematic diagram of another example of a forced differential device, and FIG. 6 is a schematic diagram of another example of a forced differential device.
The figure is a sectional view of the clutch, and FIG. 7 is a plan view showing means for operating the clutch. 10: Forced differential, 12: Differential, 14.16: Clutch, 18 Two sun gears, 20: Internal gear, 22
: Planetary gear, 24: Differential case, 26: Binion, 28: Side gear, 30.32
Nidrive shaft, 46: Transmission means, 60: Operation means, 110.11
2, 114.116: (J car, 118.122.1
26.130: Gear, 120.128: Shaft, 134 Ni sleeve, 140.142: Pump, 144.146: Cylinder device. Agent Patent Attorney Yoshi Matsunaga Figure 1 Δ Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A device that forcibly causes a differential in the shafts of a differential device that includes two shafts extending left and right from a differential case, and the rotation that occurs in the two shafts due to the action of the differential device during maximum steering. A transmission mechanism with a predetermined rotation speed ratio formed to give a difference in rotation speed to these shafts that is larger than the difference in number, and means for connecting the transmission mechanism to a drive side when left and right steering reaches a maximum steering angle. Forced differential devices, including and.