KR20180012671A - Method and apparatus for transfering a power transfer unit in screw type four wheel driven vehicle - Google Patents

Abstract

Disclosed in the present invention are a screw-type four-wheel drive power switching device and method, capable of accurately performing PTU engagement and switching at a release angle by learning a zero point of an angle sensor when a PTU screw is moved using a DC motor in a four-wheel drive vehicle to be coupled to or separated from a fork and a sleeve. The disclosed screw-type four-wheel drive power switching device comprises: a motor control unit for controlling the rotation of a motor; an angle detection unit for detecting a rotation angle of a screw through an angle sensor; a zero angle learning unit for learning a zero angle of the screw and storing the zero angle in a memory; a memory for storing the learned zero angle data and last angle data of a previous ignition cycle; and a control unit for controlling rotation of the motor through the motor control unit to match the initial position of the screw to the learned zero angle on the basis of the learned zero angle.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw type four-wheel drive power switching apparatus and method,

The present invention relates to an apparatus and method for controlling an electric power based on an angle sensor, and more particularly, in a four-wheel drive vehicle, a PTU (Power Transfer Unit) screw is moved using a DC (Direct Current) motor to be fastened to a fork and a sleeve Or disengagement of the angle sensor by learning the zero point of the angle sensor so that switching to the PTU engagement and disengagement angle can be accurately performed.

Generally, a four-wheel drive device is a device that not only distributes the front and rear wheel driving forces, but also controls the operation mechanism in the following manner in order to improve the driving performance, the braking force, A function of absorbing a rotational difference in accordance with the turning radius of the rear wheel, and the like.

Such a four-wheel drive unit is generally referred to as a four-wheel drive transfer (PTU). The four-wheel drive unit includes a four-wheel drive system (Part Time 4WD) and a full-time 4WD have.

The four-wheel drive system temporarily operates in two-wheel drive to improve the driving performance in normal operation, and can switch the four-wheel drive transfer to a four-wheel drive in the rough or bad weather and exert a powerful driving force.

Since the four-wheel drive system always receives driving force from four wheels, it can be steadily operated even in a severe or bad weather, and thus it is mainly applied to general leisure vehicles (RV) and luxury riding.

However, in the conventional four-wheel drive device, when the screw is moved through the PTU, the difference from the engagement angle to the release angle or the engagement angle from the release angle occurs at the time of engagement or disengagement from the fork and sleeve, There is a problem to be done.

This is caused by the difference in angle of the screw generated due to the inability to precisely determine the position of the initial screw, which is a problem of deteriorating the performance of the 4WD system.

Korean Patent Publication No. 2006-0080002 (Disclosure Date: July 7, 2006)

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and it is an object of the present invention to solve the above-mentioned problems, and to provide a PTU- And a disengagement angle can be precisely performed in a screw-type four-wheel drive power switching apparatus and method.

According to an aspect of the present invention, there is provided a screw-type four-wheel drive power switching apparatus including: a drive shaft connected to a transmission case deep case of a vehicle; A driven shaft integrally formed with the first helical gear on an outer circumferential surface of the drive shaft; A sleeve which is synchronized with one end of the driven shaft and is provided between the driven shaft and the drive shaft; A motor provided with a rotating shaft parallel to the driven shaft and having a screw having a variable pitch on an outer peripheral surface of the rotating shaft; And a fork assembly including a pin engaged with the screw, a lug provided on one side of the pin and supported by the transfer case, and a shift fork supported on one side of the lug and on the other side of the sleeve, A power switching device comprising: a motor control unit for controlling a rotating operation of the motor; An angle detector for detecting a rotation angle of the screw through an angle sensor; A zero angle learning unit for learning a zero angle of the screw and storing the zero angle in a memory; A memory for storing the learned zero angle data and last angle data of a previous ignition cycle; And a control unit for controlling the rotation of the motor through the motor control unit to adjust the initial position of the screw based on the learned zero angle to the learned zero angle.

In addition, the motor control unit drives the motor to a low voltage to rotate the screw in an angle decreasing direction.

The zero angle learning unit may set an angle at which a screw angle value is no longer changed to a zero angle or an angle obtained by subtracting a current angle value detected during learning from a currently detected angle value through the angle detection unit Value is set to the above-mentioned zero (0) angle.

When the absolute value | A | of the angular value (A) of the previous ignition cycle is smaller than or equal to the screwing position value of the screw (| A | <= screw fastening position) or And controls to keep the current position of the screw when the screw is less than or equal to the release position value of the screw (| A | <= screw release position).

The apparatus may further include an amplifying unit for amplifying the angle error value so that the engaging speed or the releasing speed is improved through an angle error amplification when the shift fork is fastened to the sleeve or released.

According to another aspect of the present invention, there is provided a screw type four-wheel drive power switching method including: a drive shaft connected to a transmission case deep case of a vehicle; A driven shaft integrally formed with the first helical gear on an outer circumferential surface of the drive shaft; A sleeve which is synchronized with one end of the driven shaft and is provided between the driven shaft and the drive shaft; A motor provided with a rotating shaft parallel to the driven shaft and having a screw having a variable pitch on an outer peripheral surface of the rotating shaft; And a fork assembly including a pin engaged with the screw, a lug provided on one side of the pin, and a lug supported on the transfer case, and a shift fork having one side supported by the lug and the other side engaged with the sleeve. A method for switching a wheel drive power, comprising the steps of: (a) detecting an angle of rotation of the screw through an angle sensor at an angle detector; (b) learning a zero angle of the screw at a zero angle learning unit and storing the zero angle; (c) controlling the motor control unit to adjust the initial position of the screw to the learned zero angle based on the learned zero angle in the control unit; And (d) driving the rotation of the motor in a motor control section.

In the step (d), the motor control unit drives the motor to a low voltage to rotate the screw in an angle decreasing direction.

In the step (b), the zero angle learning unit may set a zero point at which the angle value of the screw no longer changes, or may be set to the zero angle, And an angle value obtained by subtracting the moved angle value is set to the zero angle.

In the step (d), when the absolute value | A | of the angle value A of the previous ignition cycle is smaller than or equal to the screw position value of the screw (| A | = Screw release position) or the screw release position value (| A | <= screw release position), the current position of the screw can be controlled.

Other aspects, advantages and features of the present invention will become more apparent on the basis of the following description in the entire specification, including the following sections: Brief Description of the Drawings, Detailed Description, and Claims.

According to the present invention, accurate switching to the PTU engagement / release angle is possible by learning the zero point of the angle sensor.

In addition, the performance of the 4WD system can be improved by preventing unnecessary switching through the determination of the initial screw position.

In addition, the performance of the 4WD system can be improved by improving the moving speed of the screw through the angular error amplification when the PTU is switched.

Fig. 1 is a schematic diagram showing the configuration of a screw type four wheel drive power switching device according to an embodiment of the present invention.
FIG. 2 and FIG. 3 are perspective views schematically showing an internal shape of a screw type four wheel drive power switching device according to an embodiment of the present invention.
4 is a flowchart illustrating a screw type four wheel drive power switching method according to an embodiment of the present invention.
5 is a diagram showing an example of switching from two-wheel drive to four-wheel drive according to an embodiment of the present invention.
6 is a diagram showing an example of switching from four-wheel drive to two-wheel drive according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

If any part is referred to as being "on" another part, it may be directly on the other part or may be accompanied by another part therebetween. In contrast, when a section is referred to as being "directly above" another section, no other section is involved.

The terms first, second and third, etc. are used to describe various portions, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish any moiety, element, region, layer or section from another moiety, moiety, region, layer or section. Thus, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified and that the presence or absence of other features, regions, integers, steps, operations, elements, and / It does not exclude addition.

Terms indicating relative space such as "below "," above ", and the like may be used to more easily describe the relationship to other portions of a portion shown in the figures. These terms are intended to include other meanings or acts of the apparatus in use, as well as intended meanings in the drawings. For example, when inverting a device in the figures, certain portions that are described as being "below" other portions are described as being "above " other portions. Thus, an exemplary term "below" includes both up and down directions. The device can be rotated by 90 degrees or rotated at different angles, and terms indicating relative space are interpreted accordingly.

Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Fig. 1 is a schematic diagram showing the configuration of a screw type four wheel drive power switching device according to an embodiment of the present invention.

1, a screw type four wheel drive power switching apparatus 100 according to the present invention includes a DC (direct current) motor 102, a motor control unit 110, an angle detection unit 120, a zero angle learning unit 130, a memory 140, a controller 150, and the like.

The DC motor 102 is supplied with DC power and rotates to provide a rotational force.

The motor control unit 110 is an apparatus for operating the DC motor 102 and controls the rotation operation of the DC motor 102. [ That is, the motor control unit 110 moves the screw through the PTU (Power Transfer Unit) using the driving force generated by the rotation of the motor, and engages or disengages the screw to the fork and the sleeve. Here, the PTU means a structure in which a screw is coupled to the DC motor 102.

In addition, the motor control unit 110 drives the DC motor 102 at a low voltage to rotate the screw in the angle decreasing direction.

When the absolute value A | of the angle value A of the previous ignition cycle is smaller than or equal to the screw engagement position value (| A | <= screw engagement position) or (| A | <= screw release position) when the screw position is smaller than or equal to the release position value of the screw.

At this time, the screw fastening position is a position at which the screw is rotated in the two-wheel drive state of the vehicle and the fork is fastened to the sleeve, thereby performing the four-wheel drive, and corresponds to the position of 20 기준 on the basis of the zero angle position of the learned screw .

The screw release position is a time point at which the two-wheel drive is performed by rotating the screw in the reverse direction and releasing the fork from the sleeve in the four-wheel drive state of the vehicle, and the position corresponding to 720 mm to be.

Here, in the case of the expression 'screw fastening position' and 'screw releasing position', fastening or releasing is performed according to the rotation of the screw, so that the screw fastening position and the screw releasing position are expressed, but since the fork is actually fastened or released to the sleeve It can also be expressed as 'fork fastening position' and 'fork release position'.

The angle detection unit 120 detects the rotation angle of the screw through the angle sensor.

The zero angle learning unit 130 learns the zero angle of the screw detected through the angle sensor and stores it in the memory 140. Here, the zero angle learning unit 130 sets a zero point at which the angle value of the screw no longer changes to zero, or changes the angle of the screw during learning from the currently detected angle value through the angle detection unit 120 The value can be learned by setting the angle value to zero (0) angle.

The memory 140 stores the learned zero angle data and the last angle data of the previous ignition cycle (Ignition Cycle).

The control unit 150 controls the rotation of the motor 102 through the motor control unit 110 so that the initial position of the screw is adjusted to the learned zero angle based on the learned zero angle through the zero angle learning unit.

An amplification unit 160 (not shown) amplifies the angle error value so as to improve the fastening speed or the release speed through the angular error amplification when the screw is fastened or released.

FIG. 2 and FIG. 3 are perspective views schematically showing an internal shape of a screw type four wheel drive power switching device according to an embodiment of the present invention.

Referring to FIGS. 2 and 3, the screw type four wheel drive power switching apparatus 100 according to the present invention includes a drive shaft 10 connected to a transmission case deep case (not shown) of a vehicle; A drift shaft 20 provided integrally with the first helical gear 21 on the outer circumferential surface of the drive shaft 10; A sleeve (40) synchronized with one end of the driven shaft (20) and provided between the driven shaft (20) and the drive shaft (10); A motor (50) provided with a rotating shaft in parallel with the driven shaft (20) and provided with a screw (51) having a variable pitch (51a) on the outer peripheral surface of the rotating shaft; A pin 61 which is engaged with the screw 51 and a lug 62 and a lug 62 which are provided at one side and which are supported by a transfer case And a shift fork 63 for holding the fork assembly 60.

A second helical gear 31 which is engaged with the first helical gear 21 is provided integrally with the second helical gear 31 and is connected to a second helical gear 31 And may further include an idle gear (30).

A dog tooth 11 is formed on the circumferential surface of the drive shaft 10 and a spline 22 is formed on the outer circumferential surface of one end of the driven shaft 20.

A groove 40a is formed on the outer circumferential surface of the sleeve 40 so that the other side of the shift fork 63 can be inserted and fixed.

It is preferable that the pitch 51a of the screw 51 is formed so as to become smaller toward the inner side from the end. This is because a shift fork 63 requires an actuating force of about 500 N for the synchronization of the drive shaft 10 and the driven shaft 20 but the actual load of 500 N is about 3 mm which the sleeve 40 engages the dog teeth 11 And it can be transported to 100N or less for the remaining transport distance of 5mm.

One side of the shift fork 63 is elastically supported by a leaf spring 64 provided in the lug 62.

4 is a flowchart illustrating a screw type four wheel drive power switching method according to an embodiment of the present invention.

4, the screw type four wheel drive power switching device 100 according to the present invention detects the rotation angle of the screw 51 through the angle sensor in the angle detection unit 120 (S410).

At this time, the previously learned zero angle data and the last angle data of the previous ignition cycle (Ignition Cycle) are stored in the memory 140.

Next, the zero angle learning unit 130 learns the zero angle of the screw 51 detected through the angle sensor and stores it in the memory 140 (S420).

The control unit 150 controls the motor control unit 110 to adjust the initial position of the screw 51 to the learned zero angle based on the learned zero angle through the zero angle learning unit 130 (S430) .

Accordingly, the motor control unit 110 drives the rotation of the DC motor 102 (S440).

That is, the motor control unit 110 rotates the screw 51 through the DC motor 102 so that the shift fork 63 is fastened to the sleeve 40 as shown in FIG. 5 to perform four-wheel drive, The screw 51 is reversely rotated through the DC motor 102 so that the shift fork 63 is released from the sleeve 40 as shown in FIG.

Here, when the screw 51 is fastened, it becomes four-wheel drive (4WD), and when the screw 51 is released, it becomes two-wheel drive (2WD).

5 is a diagram showing an example of switching from two-wheel drive to four-wheel drive according to an embodiment of the present invention.

5, the screw type four-wheel drive power switching apparatus 100 according to the present invention is configured such that the inter-media shaft S passing through the inside of the drive shaft 10 in the two-wheel mode is connected to the deep- And the intermedia shaft S transmits rotation and driving force to the front wheels.

The drive gear is connected to the differential side case of the transmission and rotates together with the front wheel during driving of the vehicle. In this two-wheel mode, the drive shaft 10 and the driven shaft 20 are separated from each other, so that the vehicle is driven only by the driving force of the front wheels without transmitting power to the rear wheels.

The change to the four-wheel mode uses the rotation torque of the motor 50. When the screw 51 having the variable pitch 51a connected to the output shaft of the motor 50 makes a normal rotation, The fixed shift fork 63 is transferred to the right side (see Fig. 6).

At this time, the shift fork 63 is transferred at a high speed until the synchronization of the dock teeth 11 is performed. In the section where the actual synchronization is performed, a relatively large load is transferred to the shift fork 63 do.

The shift fork 63 is carried while holding the sleeve 40 and the spline 22 of the driven shaft 20 and the sleeve 40 engaging the shift fork 63 are engaged with the dog teeth 11 of the drive shaft 10. [ And synchronization is achieved.

Thus, when the first helical gear 21 of the driven shaft 20 rotates, power is transmitted to the propeller shaft of the vehicle and the rear wheel of the vehicle through the second helical gear 31, the hypoid gear 30 and the pinion shaft F &Lt; / RTI &gt;

6 is a diagram showing an example of switching from four-wheel drive to two-wheel drive according to an embodiment of the present invention.

6, in the screw-type four-wheel drive power switching apparatus 100 according to the present invention, in the four-wheel mode, the drive shaft 10 and the driven shaft 20 are synchronized by the sleeve 40 have.

In this state, when the motor 50 rotates in the opposite direction to the rotational direction at the time of changing the four-wheel mode in the two-wheel mode and the screw 51 is rotated in the reverse direction, the shift fork 63 causes the sleeve 40 to move to the left.

Thus, the drive shaft 10 and the driven shaft 20 synchronized by the sleeve 40 are disconnected by the sleeve 40 moved by a certain distance (see FIG. 5). Thereby, the vehicle enters the two-wheel mode.

As described above, according to the screw type four-wheel drive power switching device 100 of the present invention, a large force can be transmitted to the shift fork when power is connected, and the transfer force of the shift fork is small, The overall system responsiveness can be improved.

As described above, according to the present invention, in a four-wheel drive vehicle, when a PTU screw is moved using a DC motor to be engaged or disengaged from a fork and a sleeve, the zero point of the angle sensor is learned, The four-wheel drive power switching device and the screw-type four-wheel drive power switching device can be realized.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. Only. It is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. .

100: Screw type 4WD power switching device
102: DC motor
110: Motor control unit
120:
130: zero learning unit
140: Memory
150:

Claims (9)

A drive shaft connected to the transmission case side deep case of the vehicle; A driven shaft integrally formed with the first helical gear on an outer circumferential surface of the drive shaft; A sleeve which is synchronized with one end of the driven shaft and is provided between the driven shaft and the drive shaft; A motor provided with a rotating shaft parallel to the driven shaft and having a screw having a variable pitch on an outer peripheral surface of the rotating shaft; And a fork assembly including a pin engaged with the screw, a lug provided on one side of the pin and supported by the transfer case, and a shift fork supported on one side of the lug and on the other side of the sleeve, As a power switching device,
A motor control unit for controlling rotation of the motor;
An angle detector for detecting a rotation angle of the screw through an angle sensor;
A zero angle learning unit for learning a zero angle of the screw and storing the zero angle in a memory;
A memory for storing the learned zero angle data and last angle data of a previous ignition cycle; And
A control unit for controlling the rotation of the motor through the motor control unit so that the initial position of the screw is adjusted to the learned zero angle based on the learned zero angle;
Wherein the screw-type four-wheel drive power switching device comprises:
The method according to claim 1,
Wherein the motor control unit drives the motor to a low voltage to rotate the screw in an angle reducing direction.
The method according to claim 1,
Wherein the zero angle learning unit sets an angle at which the angle of the screw no longer changes to a zero angle or an angle value obtained by subtracting the angle value moved during learning from the angle value currently detected through the angle detector And the learning is performed by setting the angle to zero (0).
The method according to claim 1,
Wherein the motor control unit determines that the absolute value | A | of the angle value A of the previous ignition cycle is smaller than or equal to the screwing position value of the screw (| A | <= screw fastening position) And the current position of the screw is maintained when the current position is smaller than or equal to the release position value of the screw (| A | <= screw release position).
The method according to claim 1,
An amplifying unit for amplifying an angle error value such that a clamping speed or a releasing speed is improved through an angle error amplification when the shift fork is fastened to or released from the sleeve;
Further comprising: a screw-type four-wheel drive power switching device.
A drive shaft connected to the transmission case side deep case of the vehicle; A driven shaft integrally formed with the first helical gear on an outer circumferential surface of the drive shaft; A sleeve which is synchronized with one end of the driven shaft and is provided between the driven shaft and the drive shaft; A motor provided with a rotating shaft parallel to the driven shaft and having a screw having a variable pitch on an outer peripheral surface of the rotating shaft; And a fork assembly including a pin engaged with the screw, a lug provided on one side of the pin, and a lug supported on the transfer case, and a shift fork having one side supported by the lug and the other side engaged with the sleeve. A method for switching a wheel drive power,
(a) detecting an angle of rotation of the screw through an angle sensor at an angle detecting unit;
(b) learning a zero angle of the screw at a zero angle learning unit and storing the zero angle;
(c) controlling the motor control unit to adjust the initial position of the screw to the learned zero angle based on the learned zero angle in the control unit; And
(d) driving the rotation of the motor at a motor control section;
Wherein the screw-type four-wheel drive power switching method comprises:
The method according to claim 6,
In the step (d), the motor control unit drives the motor to a low voltage to rotate the screw in an angle decreasing direction.
The method according to claim 6,
In the step (b), the zero angle learning unit may set a zero point at which the angle value of the screw no longer occurs, or move the zero point angle of the screw from the currently detected angle value through the angle detection unit. And learning is performed by setting an angle value obtained by subtracting an angle value to the zero angle.
The method according to claim 6,
If the absolute value | A | of the angle value A of the previous ignition cycle is smaller than or equal to the screwed position value of the screw (| A | <= screw (A | <= screw release position) when the value of the screw is less than or equal to the release position of the screw.

Images