JPH06156100A - Driving force distribution control device of four-wheel drive vehicle - Google Patents

Abstract

PURPOSE:To provide a driving force distribution control device for a four-wheel drive vehicle, by which the pressing force can be detected and fed-back to control a variable torque clutch with good accuracy, and which is of a low manufacturing cost and a high degree of freedom of incorporation into a car body. CONSTITUTION:A driving force distribution control device is so constructed that an electric motor (m), the output of which is controlled by a controller, is provided on a pressing force generating mechanism 1, a transmission gear is provided on the output side of the electric motor (m), a converting means is provided for converting the rotary motion of the transmission gear to the rectilinear motion of a push rod 12, the push rod 12 includes a working member provided on the variable torque clutch side for working on the variable torque clutch, and a detecting means is provided for detecting the pressing force to the variable torque clutch through the working member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive force distribution control device for distributing drive force to front wheels and rear wheels in a four-wheel drive vehicle.

[0002]

2. Description of the Related Art As a conventional drive force distribution control device for a four-wheel drive vehicle, for example, one disclosed in Japanese Patent Laid-Open No. 61-157437 is known. This device directly transmits the driving force from the transmission to either the front wheels or the rear wheels,
The driving force is distributed and transmitted to the other front wheel or rear wheel via the variable torque clutch. The variable torque clutch performs the operation of changing the driving force distribution to the front wheels and the rear wheels by continuously controlling the strength of the connection in the so-called half-clutch state. The strength is controlled by the push rod of the pressing force generating mechanism that operates with hydraulic pressure. That is, the pushing force on the variable torque clutch is adjusted by the push rod, the strength of the connection of the variable torque clutch in the half-clutch state is determined according to the pushing force, and the driving force is distributed to the front wheels and the rear wheels. .

The pressing force generating mechanism is controlled by a controller. This controller inputs information from the rotational force sensors provided on the drive shafts of the front and rear wheels,
The difference between the rotational speeds of the front wheels and the rear wheels is compared and calculated. Then, a signal is sent to the electromagnetic proportional solenoid to correct this difference in the number of revolutions. The electromagnetic proportional solenoid activates the pressure control valve in response to a control signal from the controller to determine the pressure applied to the push rod of the pressing force generating mechanism. This pressure exerts a pressing force on the push rod to control the strength of the connection of the variable torque clutch in the half-clutch state, so that an appropriate driving force is distributed to the front wheels and the rear wheels.

[0004]

The conventional driving force distribution control device as described above does not include means for detecting the pressing force of the push rod of the driving force distribution control device. For this reason, since the output state of the actual pressing force of the push rod cannot be fed back, there is a problem that the variable torque clutch cannot be controlled accurately. Also, since the pressing force generating mechanism that operates the variable torque clutch was operated by hydraulic pressure, piping that constitutes the hydraulic circuit, a pressure control valve for controlling the operation of the push rod, etc. are required, and the number of parts is large. Was becoming. Therefore, there is also a problem that the production cost becomes high. Further, due to the large number of parts, there is a problem in that when this device is incorporated into a vehicle body, there is no choice but to place restrictions on the arrangement, and the degree of freedom in arrangement is reduced. The present invention has been made on the basis of such a point, and an object of the present invention is to detect a pressing force and feed it back, thereby accurately controlling the variable torque clutch and producing the same. It is an object of the present invention to provide a drive force distribution control device for a four-wheel drive vehicle that is low in cost and has a high degree of freedom in being incorporated into a vehicle body.

[0005]

In order to achieve the above object, a drive force distribution control device for a four-wheel drive vehicle according to the present invention has a front and rear wheels in the middle of a power transmission system for the front and rear wheels. A variable torque clutch capable of changing driving force distribution is provided, and a pressing force generating mechanism having a push rod and a controller controlling operation of the push rod are provided.
In a drive force distribution control device for a four-wheel drive vehicle in which a changing operation of the drive force distribution of the variable torque clutch is operated by a push rod of a pressing force generation mechanism controlled by a controller, an output is output to the pressing force generation mechanism by a controller. In addition to providing a controlled electric motor, a transmission gear is provided on the output side of the electric motor, and conversion means for converting rotational movement of the transmission gear into linear movement of the push rod is provided. The clutch side is provided with an acting member that acts on the variable torque clutch, and is also configured to have a detection means for detecting the pressing force to the variable torque clutch via the acting member. is there.

At this time, the push rod has a hollow portion extending in the axial direction therein, and the hollow portion forms an opening on the variable torque clutch side, and
The anti-variable torque clutch side is equipped with a pressure detection device that is connected to the controller, and a rod that slides in the hollow portion is projected in the opening, while the hollow portion between the rod and the pressure detection device is filled with hydraulic oil. It is conceivable that the configuration is adapted. Further, the push rod has a hollow portion extending in the axial direction therein, and the hollow portion forms an opening portion on the variable torque clutch side and a pressure for connecting to the controller on the anti-variable torque clutch side. A detection device is provided, and a rod biased to the variable torque clutch side by a coil spring protrudes while the inside of the hollow portion slides in the opening, while an operating member detects pressure on the side opposite to the variable torque clutch of the hollow portion. It is conceivable that the device is arranged in contact with the device, and the hollow space between the rod and the operating member is filled with hydraulic oil.
Further, the push rod has a hollow portion extending in the axial direction therein, and the hollow portion forms an opening portion on the variable torque clutch side and a pressure for connecting to the controller on the anti-variable torque clutch side. Equipped with a detection device,
The rod slides in the hollow portion while protruding the rod urged toward the variable torque clutch by the coil spring, and the operating member is disposed in contact with the rod and the pressure detecting device. It is possible.
Further, it is conceivable that the detecting means is a piezoelectric element arranged in contact with the acting member.

[0007]

When the electric motor whose output is controlled by the controller rotates, the rotation is converted into the linear movement of the push rod via the transmission gear and the converting means. This causes the push rod to generate a pressing force on the variable torque clutch via its acting member. Further, the pressing force is detected by the detecting means and fed back to the controller to control the electric motor.

[0008]

1 to 5 show a first embodiment of the present invention. Here, an electric motor m controlled by a controller (not shown) is attached to the casing 2 of the pressing force generating mechanism 1, and a hypoid pinion 4 is attached to its output shaft 3. The hypoid pinion 4 is rotatably supported on the casing 2 by bearings 5 and 6. A hypoid gear wheel 7 is provided in the casing 2, and the hypoid gear 7a formed therein is meshed with the hypoid pinion 4 to form the hypoid pinion 4 and the hypoid gear wheel 7.
And are used as a transmission gear.

The hypoid gear wheel 7 has a bearing 8
It is rotatably supported by the casing 2. A recess 9 is formed in the lower center of the hypoid gear wheel 7 in the drawing, and the pinion shaft 1 is formed in the recess 9.
One end of 0 is rotatably supported by a bearing. A pinion 11 is formed on the pinion shaft 10 and a rack 1 formed on a push rod 12 as shown in FIG.
It is in mesh with 3. Therefore, when the hypoid gear wheel 7 rotates, the pinion shaft 10 rotates, and the push rod 12 that forms the rack 13 that meshes with the pinion 11 formed on the pinion shaft 10 moves in the axial direction according to the rotation direction of the pinion shaft 10. Move to. As described above, the pinion shaft 10 and the push rod 12 constitute a conversion means, and the rotation of the transmission gear is converted into the linear motion of the push rod 12.

As shown in FIG. 3, the push rod 12 has an oil chamber 14 formed inside in the axial direction. The oil chamber 14 has an opening 14 at one end in the axial direction.
A pressure detecting device 15 is formed at the other end and is connected to the controller. Opening 14a of the oil chamber 14
In this case, a rod 16 that slides in the oil chamber 14 is projected, and the rod 16 is pressed by a cap 17 as shown in the figure. Further, the space between the rod 16 and the pressure detection device 15 is filled with hydraulic oil. Therefore, when the rod 16 moves in the axial direction on the left side in the drawing, pressure acts on the pressure detection device 15 according to the amount of movement of the rod 16. This pressure is sent as information to the controller connected to the pressure detector 15. Reference numeral 18 is a connector for connecting to the controller.

In the pressing force generating mechanism 1 configured as described above, when the electric motor m controlled by the controller rotates, the hypoid pinion 4 provided on the output shaft 3 of the electric motor m rotates and the hypoid gear wheel 7 meshes with the hypoid gear wheel 7. Also rotates. When the hypoid gear wheel 7 rotates, the pinion shaft 10 meshing with the hypoid gear wheel 7 also rotates, and the push rod 1 meshed with the pinion shaft 10.
2 moves linearly in the axial direction. The movement of the push rod 12 serves as a pressing force for a variable torque clutch (not shown). At this time, the rod 16 is pushed into the oil chamber 14 and moves according to the amount of movement of the push rod 12. A pressure is generated in the oil chamber 14 by the movement of the rod 16, and the pressure is detected by the pressure detection device 15 and sent to the controller.

From this information, the controller calculates the pressing force acting on the variable torque clutch. That is, pressure is generated in the oil chamber 14 according to the amount of movement of the push rod 12, but this pressure is due to the reaction of the pressing force, and indicates the pressing force that is actually acting on the variable torque clutch. It's Therefore, if the pressing force that is actually acting is fed back to the controller and the pressing force generated by the rotation of the electric motor m is compared and calculated, in order to obtain the required pressing force, the electric motor m
You can see how much you should rotate. In this way, the pressing force that is actually acting can always be detected,
A highly accurate pressing force can always be generated in the push rod 12, and accordingly, the operation of the variable torque clutch can be performed with high accuracy.

FIG. 4 is a block diagram showing the above operation, and FIG. 5 is a flow chart showing the operation of the controller. First, the controller receives a command from a switch (not shown) or the like, and rotates the electric motor m by an amount corresponding to the value of the command. Then, as the electric motor m rotates, the hypoid pinion 4 and the hypoid gear wheel 7 rotate. Hypoid gear wheel 7
When the pin rotates, the pinion shaft 10 meshing with the pin rotates, and the push rod 12 moves according to the amount of rotation. The pressure generated by the movement of the push rod 12 is detected by the pressure detection device 15 and fed back to the controller.

Then, the controller calculates the actual pressing force of the push rod 12 from the fed back information. The controller controls the rotation of the electric motor m so that the calculated actual pressing force of the push rod 12 becomes a required pressing force. Since the actual pressing force of the push rod 12 is fed back to the controller in this way, the variable torque clutch can be controlled accurately. Also, unlike conventional hydraulic circuits, many parts are not required, so production cost can be reduced and the number of parts is reduced. The degree of freedom of

The pressure detecting device provided on the push rod 12 detects the actual pressing force of the push rod 12 and controls the electric motor m so as to obtain the required pressing force. The pressing force can now be controlled more accurately than in the conventional example in which there is no means for detecting. Also,
Compared to the conventional hydraulic circuit type, it does not require many parts, so the production cost can be reduced and the size can be reduced due to the small number of parts. The degree of freedom of incorporation into

Next, a second embodiment of the present invention will be described with reference to FIG. First, the push rod 12 has a hollow portion 21.
Is formed, and the left side of the hollow portion 21 in the drawing is expanded, and a piston 23 as an operating member is mounted therein. A sensor 25 as a pressure detecting device is mounted on the left side of the piston 23 in the figure. or,
The right side of the hollow portion 21 in the drawing is also enlarged, and a rod 27 is movably mounted therein, and the rod 2
The end of 7 is in a state of protruding from the push rod 12 to the right side in the drawing. A cap 29 is fixed to the outer circumference of the rod 27. A passage 31 is formed in the rod 27, and a valve element 33 is provided on the left side of the passage 31 in the drawing.
Is installed. This valve body 33 is a coil spring 3
It is urged toward the rod 27 side via the support plate 35 by 7. In addition, the hollow portion 2 between the piston 23 and the rod 27
A hydraulic oil 39 is enclosed in the unit 1.

According to the above construction, when the push rod 12 is urged to the right side in the figure by the same action as in the first embodiment, the rod 27 is urged to the left side in the figure. As a result, pressure is generated through the hydraulic oil 39 enclosed,
The piston 23 moves to a position where this pressure is balanced with the spring force of a return spring (not shown) provided in the sensor 25 and the spring force of the coil spring 37 (in this case, the piston 23 is on the left side in the drawing). Move to). The sensor 25 detects the movement of the piston 23. Then, the controller, based on the feedback detection signal of the sensor 25,
The actual pressing force of the push rod 12 is calculated. The controller controls the rotation of the electric motor m so that the calculated actual pressing force of the push rod 12 becomes a required pressing force. Therefore, the same effect as that of the first embodiment can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIG. In the case of this embodiment, the piston 23 is extended to the right side in the drawing, and its tip is in contact with the rod 27. That is, when the push rod 12 moves to the right side in the figure, the rod 27 is biased to the left side in the figure, so that the piston 23 is directly biased to the left side in the figure. It is detected by a sensor 25 having a similar return spring. Therefore, also in this case, the same effect as in the case of the first and second embodiments can be obtained.

Next, a fourth embodiment of the present invention will be described with reference to FIG. First, the rod 27 is movably installed at the right end portion of the push rod 12 in the figure via a metal bush 41. A piezoelectric element 43 is installed on the left side of the rod 27 in the figure. Reference numeral 45 in the drawing denotes a connector of the piezoelectric element 43. According to the above configuration, the push rod 12 moves to the right side in the figure, so that the rod 27 is urged to the left side in the figure, which is detected by the piezoelectric element 43 and a voltage corresponding to the load is output. It is a thing. Therefore, also in this case, the same effect as in the case of the first to third embodiments can be obtained.

[0020]

As described in detail above, according to the drive force distribution control device for a four-wheel drive vehicle of the present invention, when the pressing force is generated in the variable torque clutch via the acting member of the push rod, the pressing force is generated. Since it is detected by the detecting means and is fed back to the controller to control the electric motor, for example, the pressing force can be controlled more accurately than in the conventional case where there is no means for detecting the pressing force. Further, as compared with the conventional hydraulic circuit type, many parts are not required, so that the production cost can be reduced and the size can be reduced due to the small number of parts, and the arrangement of parts on the vehicle body is limited. There is less, and the degree of freedom in assembling into the vehicle body is increased.

[Brief description of drawings]

FIG. 1 is a sectional view of a pressing force generating mechanism as a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a detailed view of the push rod of FIG.

FIG. 4 is a block diagram showing an operation of the driving force distribution device shown in the embodiment.

FIG. 5 is a flowchart showing the operation of the controller in the embodiment.

FIG. 6 is a sectional view of a pressing force generating mechanism according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a pressing force generating mechanism as a third embodiment of the present invention.

FIG. 8 is a sectional view of a pressing force generating mechanism as a fourth embodiment of the present invention.

[Explanation of symbols]

 1 Pressing force generation mechanism 12 Push rod 15 Pressure detection device 16 Rod m Electric motor

Claims (5)

[Claims] 1. A variable torque clutch capable of changing the distribution of driving force to the front wheels and the rear wheels is provided in the middle of a power transmission system for the front wheels and the rear wheels, and a pressing force generating mechanism having a push rod is provided. And a controller for controlling the operation of the push rod, wherein the changing operation of the driving force distribution of the variable torque clutch is operated by the push rod of the pressing force generation mechanism controlled by the controller. In the device, the pressing force generating mechanism is provided with an electric motor whose output is controlled by a controller, and a transmission gear is provided on the output side of the electric motor, while the rotational movement of the transmission gear is converted into a linear movement of the push rod. The push rod is provided with an operating member acting on the variable torque clutch. In addition, a driving force distribution control device for a four-wheel drive vehicle, characterized in that it is provided with a detecting means for detecting the pressing force applied to the variable torque clutch via this acting member. 2. The drive force distribution control device for a four-wheel drive vehicle according to claim 1, wherein the push rod has a hollow portion extending in the axial direction therein, and the hollow portion is a variable torque clutch. Side is provided with an opening, and a pressure detecting device connected to the controller is provided on the anti-variable torque clutch side. A drive force distribution control device for a four-wheel drive vehicle, characterized in that the hollow portion is filled with hydraulic oil. 3. The drive force distribution control device for a four-wheel drive vehicle according to claim 1, wherein the push rod has a hollow portion extending in the axial direction therein, and the hollow portion is a variable torque clutch. And a pressure detecting device connected to the controller on the side opposite to the variable torque clutch, and a rod that slides in the hollow portion and is urged toward the variable torque clutch by a coil spring. While the operating member is in contact with the pressure detecting device on the side opposite to the variable torque clutch of the hollow portion, and the hollow portion between the rod and the operating member is filled with hydraulic oil. A drive force distribution control device for a four-wheel drive vehicle. 4. The drive force distribution control device for a four-wheel drive vehicle according to claim 1, wherein the push rod has a hollow portion extending in the axial direction therein, and the hollow portion is a variable torque clutch. And a pressure detecting device connected to the controller on the side opposite to the variable torque clutch, and a rod that slides in the hollow portion and is urged toward the variable torque clutch by a coil spring. The drive force distribution control device for a four-wheel drive vehicle having a structure in which an actuating member is disposed so as to abut between the rod and the pressure detection device while projecting the vehicle. 5. The drive force distribution control device for a four-wheel drive vehicle according to claim 1, wherein the detection means is a piezoelectric element disposed in contact with the acting member. Control device.