KR20090082687A - Belt-Type Electric Power Steering Apparatus - Google Patents

Abstract

A belt type electric power steering system is provided to sense damage to a timing belt by a sensor for informing a driver of the timing belt damage, thereby improving the convenience and the safety of driving. A belt type electric power steering system includes an EPS(Electric Power Steering) motor(202) for generating rotation force for assisting driver's steering, a motor position sensor(210) for sensing the rotation of the EPS motor, a pulley(104) connected to a shaft of the EPS motor to rotate together with the EPS motor, a toothed belt(106) connected to the pulley for transmitting the rotation force of the EPS motor to a rack bar of a vehicle, a toothed sensor unit(204) for sensing damage to the teeth of the belt, and a controller such as an electronic control unit(200) for informing a driver of the abnormal state of the belt through pulse comparison, wherein the abnormality is determined if a pulse width of a signal input from the toothed sensor exceeds that of a signal input from the motor position sensor more than a set ratio.

Description

Belt-type electric power steering device {Belt-Type Electric Power Steering Apparatus}

The present invention relates to a belt-type electric power steering apparatus (EPS). More particularly, the present invention relates to an electric power steering apparatus having a function of detecting when the timing belt transmitting the driving force of the EPS motor is broken and informing the driver.

The power steering device of the vehicle assists steering power so that the driver can steer with less power when the driver steers. Among the power steering devices, an electric power steering device using a function of assisting steering power using a rotational force of a motor is called.

The electric power steering device detects the driver's steering force and rotates the motor to assist the steering force in the direction in which the driver intends to steer. In the case of a belt-type electric power steering device which transmits rotational force of the motor shaft through the timing belt among the electric power steering apparatus, a timing belt is used as a means for connecting with the rack bar driving apparatus so that the rotational speed of the motor shaft is reduced and transmitted.

Therefore, the role of the timing belt that transmits the rotational force of the motor shaft directly affects the steering of the vehicle, and the EPS must properly support the driver's steering only when the timing belt is in perfect condition.

FIG. 1 is a view illustrating a pulley 104 and a pulley belt 106 that transmit rotational force of the EPS motor shaft 102.

Timing belts connected to EPS motors generally use toothed pulleys 104 and toothed belts 106 for accurate angular velocity ratio transmission. When the toothed belt 106 fails, the belt portion 110 of the toothed belt 106 is broken after the teeth 108 of the toothed belt are first broken.

However, even if one or two teeth 108 of the toothed belt are damaged, the steering force is normally transmitted without a big problem as long as the belt portion 110 of the toothed belt 106 is not broken. It is common not to detect that 108 is broken.

Therefore, in general, the number of teeth 108 of the broken toothed belt increases, and at some point, the belt portion 110 of the toothed belt 106 is cut off. That is, a problem arises that it is known that an abnormality has occurred in the timing belt. If the timing belt breaks, the EPS will not be able to deliver normal steering assistance to the wheels, making the steering difficult for the driver. In particular, in the case of a female driver, the steering feels more difficult, and not only there is a problem in the convenience of driving, but also in a severe case, the problem of an accident increases.

In order to solve the above problems, the present invention is to provide a function to notify the driver when the timing belt is broken by providing a sensor to detect that the timing belt that transmits the driving force of the power steering motor to the rack bar. have.

In order to achieve the above object, the present invention, in the belt-type Electric Power Steering System (EPS) of the vehicle, the EPS motor for generating a rotational force for assisting the steering of the driver of the vehicle, the EPS motor Motor position sensor for detecting the rotation of the pulley, which is connected to the axis of the EPS motor to rotate with the EPS motor, the pulley is connected to the pulley to transfer the rotational force of the EPS motor to drive the rack bar of the vehicle. The toothed sensor by comparing the pulse width of the signal obtained from the toothed sensor portion and the motor position sensor and the signal obtained from the toothed sensor portion to detect whether the belt, the teeth of the toothed belt is broken. When the pulse width of the signal obtained from the negative portion exceeds the predetermined ratio of the signal pulse width obtained from the motor position sensor, the toothed belt is It provides a belt-type electric power steering device comprising a control unit for informing the driver of abnormality.

In addition, the present invention to achieve the above object, in the tooth breakage detection device of the toothed belt, a motor for generating a rotational force, a motor position sensor for detecting the rotation of the motor, connected to the shaft of the motor and the motor Pulleys that rotate together, a toothed belt connected to the pulley to transfer the rotational force of the motor, the light emitting portion and the toothed belt teeth are installed so as to generate light but the light penetrates the position where the toothed belt teeth are located A toothed sensor which receives a signal from the light emitting part through a portion to generate a toothed sensor signal, and generates light, but the light passes through a portion where the teeth of the toothed belt are located so that the sensor can detect it. Compare the pulse width of the signal received from the installed light emitting unit and the motor position sensor with the pulse width of the toothed sensor signal. And a controller for indicating that the teeth of the toothed belt are abnormal when the pulse width of the toothed sensor signal exceeds a preset ratio of the signal pulse width obtained from the motor position sensor. Provide the device.

In order to achieve the above object, the present invention is a method of detecting tooth breakage of the toothed belt in the belt-type electric power steering apparatus of the vehicle, (a) detecting the steering torque of the driver of the vehicle, (b) the Driving an EPS motor to assist steering torque; (c) acquiring a signal from a motor position sensor and a toothed sensor; (d) a pulse width of a signal obtained from the toothed sensor is obtained from the motor position sensor. Determining whether the predetermined signal pulse width is exceeded, (e) proceeding to step (g) if the predetermined ratio is exceeded as a result of the determination of step (d), (f) step (d) And a step of (c) alerting the user that the teeth of the toothed belt are broken if the predetermined ratio does not exceed the predetermined ratio. Providing a method for detecting denture breakage.

According to the present invention, it is provided with a sensor for detecting that the timing belt that transmits the driving force of the power steering motor to the rack bar has a function of notifying the driver when the timing belt is broken to drive the case until the timing belt is broken. By preventing it in advance, it has the effect of increasing the driver's convenience and reducing the risk of an accident.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function is obvious to those skilled in the art or may obscure the gist of the present invention, the detailed description thereof will be omitted.

2 is a block diagram showing a belt-type electric power steering apparatus according to a preferred embodiment of the present invention.

Belt type electric power steering apparatus according to a preferred embodiment of the present invention is an EPS motor for generating a rotational force to assist the steering of the vehicle driver, a motor position sensor for detecting the rotation of the EPS motor to transmit a signal to the control unit, the EPS A pulley connected to a shaft of a motor to rotate together with the EPS motor, and a toothed belt and a toothed belt connected to the pulley to transmit the rotational force of the EPS motor to drive the rack bar of the vehicle. It is installed, the teeth sensor unit for transmitting the signal generated by detecting the toothed portion and the toothed portion of the toothed belt while the EPS motor rotates to the control unit; And comparing the pulse width of the signal obtained from the motor position sensor with the pulse width of the signal obtained from the ear sensor, and comparing the pulse width of the signal obtained from the ear sensor with the signal pulse obtained from the motor position sensor. And a control unit for notifying the driver that the toothed belt is abnormal when a predetermined ratio of width is exceeded.

As shown in FIG. 2, the belt type electric power steering apparatus according to the preferred embodiment of the present invention includes a toothed pulley 104, a toothed belt 106, an electronic controller 200, and an EPS motor 202. The sensor 204 may include a light emitting unit 206, a user interface 208, and a motor position sensor 210. Here, among the components of the belt-type electric power steering apparatus of the present invention, the pulley is implemented by the toothed pulley 104, the toothed sensor part is implemented by the toothed sensor 204 and the light emitting unit 206, the control unit is EPS The electronic control device 200 can be implemented.

The EPS motor 202 generates a turning force for assisting the steering of the vehicle driver. On the other hand, in Fig. 2, the axis of the EPS motor 202 is located on the concentric shaft with the toothed pulley 104, so that the overall shape of the EPS motor 202 is not visible because the toothed pulley 104 is hidden. Only the shaft portion of 202 is shown at 202.

In FIG. 2, the EPS motor 202 is controlled by the electronic controller 200 which receives various sensor signals such as a torque sensor (not shown).

The motor position sensor 210 detects the rotation of the EPS motor 202. That is, it detects how much the EPS motor 202 has rotated and transmits a signal to the electronic controller 200. Here, the signal may be periodically transmitted every one revolution of the EPS motor 202.

The toothed pulley 104 is coaxially connected to the axis of the EPS motor 202 and rotates like the EPS motor 202. The toothed pulley 104 is provided at equal intervals on the circumference.

The toothed belt 106 is connected to one side by winding the toothed pulley 104 and the other side is connected to an actuator (not shown) for driving a rack bar so that the rotational force of the EPS motor 202 drives the actuator (not shown). Force to move the rack bar of the vehicle.

The ear sensor 204 and the light emitting unit 206 generate signals to detect whether the teeth of the toothed belt 106 are broken. The light emitting unit 206 generates light, but the light penetrates the portion where the teeth 108 of the belt 106 are attached. The ear sensor 204 detects light received through the portion where the teeth 108 of the toothed belt 106 are placed and converts the light generated from the light emitting unit 206 into an electrical signal to convert the electric signal into an electronic control device. 200).

In FIG. 2, the light generated from the light emitting part 206 penetrates only through the portion where the teeth 108 of the attaching belt 106 pass and passes through the portion of the belt portion 110 of the attaching belt 106. The part 206 is installed.

The electronic control apparatus 200 of the EPS drives the EPS motor 202 in the steering assist direction when the steering torque of the driver is sensed, and the toothed pulley 104 connected coaxially with the axis of the EPS motor 202 and the toothed pulley 104. The driving force of the EPS motor 202 is transmitted to the rack bar through the pasting belt 106.

On the other hand, the electronic controller 200 is a signal obtained from the toothed sensor 204 and the signal obtained from the motor position sensor 210 to check whether the teeth 108 of the toothed belt 106 is normal. Compare.

The ear sensor 204, which receives the light emitted from the light emitting unit 206, converts it into an electrical pulse and transmits it to the electronic controller 200. If the tooth 108 of the toothed belt 106 is normal, the pulse width obtained from the toothed sensor 204 maintains a constant width when the speed of movement of the toothed belt 106 is constant.

The motor position sensor 210 may generate a signal for the rotation angle of the axis of the EPS motor 202.

Here, when the teeth 108 of the toothed belt 106 are normal, the width of the pulse generated by the motor position sensor 210 is multiplied by a predetermined ratio by the pulse width generated by the toothed sensor 204.

For example, suppose that when the teeth 108 of the toothed belt 106 are normal, the length of the portion with the teeth 108 of the toothed belt 106 is the same as the length without the teeth. In this case, when the tooth 108 of the toothed belt is normal, when the toothed sensor 204 receives the light of the light emitting portion 206 and generates a pulse, the toothed tooth of the toothed belt 108 The ratio of the width of the top of the square wave, which is the missing portion, and the bottom of the square wave, which is the portion where the teeth 108 of the toothed belt are present, will be the same.

At this time, if the number of teeth 108 of the toothed belt 106 corresponding to one rotation of the EPS motor 202 is 18, the pulse 1 cycle generated by the toothed sensor 204 is the motor position sensor 210. Will be 1/18 of the pulse width of one cycle. In addition, since the width of the upper end of the square wave pulse generated by the ear sensor 204 is half of one cycle of the pulse generated by the motor position sensor 210, 1/36 of the pulse width of one cycle generated by the motor position sensor 210 is generated. Will be

Therefore, in this case, when the pasting belt 106 is normal, the predetermined ratio of the pulse width of the signal obtained from the pasting sensor 204 to the signal 1 period pulse width obtained from the motor position sensor 210 is 1. (Actually, when the signal obtained from the motor position sensor 210 is a sine wave, the phase change of the sine wave is measured to determine the ratio of the length of the pulse obtained from the pasting sensor 204 to the length of the upper portion of the square wave. Can decide.)

The electronic controller 200 compares the pulse width of the signal obtained from the motor position sensor 210 with the pulse width of the signal obtained from the ear sensor 204 to compare the pulse width of the signal obtained from the ear sensor 204. When the preset position ratio of the signal pulse width obtained from the motor position sensor 210 exceeds the preset belt 106, the user interface 208 is alerted to the driver visually or audibly.

If the tooth 108 of the toothed belt is broken, the ratio of the pulse width generated by the motor position sensor 210 and the pulse width generated by the toothed sensor 204 is changed. Accordingly, when the ratio of the two pulse widths is changed, it can be seen that the tooth 108 of the toothed belt is broken.

In this embodiment, when the measured toothed sensor 204 pulse width differs by more than 5% from the normalized pulse width of the toothed sensor 204, it is determined that the toothed belt 106 has an error. Here, 5% is merely exemplary, but is not limited thereto.

If the tooth 108 of the toothed belt is broken, the electronic controller 200 notifies the user interface 208 to alert the driver.

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2 to show a form in which the ear sensor 204 penetrates the teeth 108 of the toothed belt 106 to sense a signal of the light emitting unit 206. 'Is a view showing a cross section taken.

As shown in FIG. 3, the attaching sensor 204 detects light emitted from the light emitting unit 206 and penetrates the portion of the tooth 108 of the attaching belt 106. On the other hand, it is also possible to use a photo sensor as one of the ways to implement the attachment sensor 204, in this case, the light emitting unit 206 emits light of a wavelength that can be detected by the photo sensor.

4 is a flowchart illustrating a method of detecting tooth damage of a toothed belt in a belt type electric power steering apparatus according to a preferred embodiment of the present invention.

According to a preferred embodiment of the present invention, a tooth breakage detecting method of a toothed belt includes (a) detecting steering torque of a driver of the vehicle, (b) driving an EPS motor to assist the steering torque, and (c) Obtaining a signal from a motor position sensor and a toothed sensor; (d) determining whether the pulse width of the signal obtained from the toothed sensor exceeds a predetermined ratio of the signal pulse width obtained from the motor position sensor; (E) proceeding to step (g) if the predetermined ratio is exceeded as a result of the determination of step (d); (f) if not exceeding the predetermined ratio as a result of the determination of step (d); c) and (g) alerting the user that the teeth of the toothed belt are broken.

4 and 2, when the steering torque of the vehicle driver is sensed (S402), the EPS motor 202 is driven (S404) to assist the steering torque. At this time, when the EPS motor 202 is driven, the driving force of the EPS motor 202 is the toothed pulley 104 and the toothed belt 106 connected to the toothed pulley 104 concentrically with the axis of the EPS motor 202. ) Moves and transmits steering force to move the rack bar (not shown) of the vehicle.

While the EPS motor 202 is driven, a signal is obtained from the motor position sensor 210 and the toothed sensor 204 (S406). If it is determined whether the pulse width of the signal obtained from the attachment sensor 204 exceeds the predetermined ratio of the signal pulse width obtained from the motor position sensor 210 (S408).

In the case where the toothed belt 106 is normal, the formula of the toothed sensor normal pulse width = a * motor position sensor pulse width is satisfied. However, a is a constant determined according to the specification of the motor position sensor 210 and the width of the toothed belt 106.

Therefore, when the measured toothed sensor 204 pulse width differs by more than 5% from the normalized pulse width of the toothed sensor 204, it is determined that the toothed belt 106 is abnormal. Here, 5% is merely exemplary, but is not limited thereto.

If it is determined that the toothed belt 106 is normal, the controller continuously receives a signal from the motor position sensor 210 and the toothed sensor 204 and if it is determined that the toothed belt 106 is abnormal, the user interface 208. Alerts the driver through (S410).

Meanwhile, a preferred embodiment of the belt type electric power steering apparatus illustrated in FIGS. 2 and 3 may be used as a tooth break detection device of a toothed belt according to an embodiment of the present invention.

In the tooth breakage detecting device of the toothed belt according to the exemplary embodiment of the present invention, the motor generating the rotational force may be implemented by the EPS motor 202 of FIG. 2.

The motor position sensor of the tooth breakage detecting device of the toothed belt according to the exemplary embodiment of the present invention for detecting the rotation of the motor may be implemented by the motor position sensor 210 of FIG. 2.

The pulley of the tooth breakage detecting device of the toothed belt according to the embodiment of the present invention, which is connected to the shaft of the motor and rotates together with the motor, may be implemented by the toothed pulley 104 of FIG. 2.

The toothed belt of the tooth breakage detecting device of the toothed belt according to the embodiment of the present invention connected to the pulley to transfer the rotational force of the motor may be implemented by the toothed belt 106 of FIG. 2.

The light emitting unit of the tooth breakage detecting apparatus of the toothed belt according to the embodiment of the present invention installed to generate light but penetrates the portion where the toothed belt tooth is positioned may be implemented by the light emitting unit 206 of FIG. 2. have.

An ear sensor of the tooth breaker detecting apparatus of the toothed belt according to an embodiment of the present invention, which receives a signal from the light emitting part through a portion where the toothed belt tooth is located and generates a toothed sensor signal, is shown in FIG. 2. It may be implemented as a toothed sensor 204 of.

Comparing the pulse width of the signal acquired from the motor position sensor with the pulse width of the ear sensor signal and comparing the pulse width of the ear sensor signal with a predetermined ratio of the signal pulse width obtained from the motor position sensor. The controller of the tooth breakage detecting apparatus of the toothed belt according to the exemplary embodiment of the present disclosure, which indicates that the tooth of the toothed belt is abnormal, may be implemented by the electronic control apparatus 200 of FIG. 2.

Therefore, for description of each component of the tooth breakage detecting device of the toothed belt according to an embodiment of the present invention, refer to the description of FIGS. 2 and 3.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

According to the present invention, it is provided with a sensor for detecting that the timing belt that transmits the driving force of the power steering motor to the rack bar has a function of notifying the driver when the timing belt is broken to drive the case until the timing belt is broken. By preventing it in advance, it has the effect of increasing the driver's convenience and reducing the risk of an accident. In addition, it is possible to detect the case that the teeth of the general toothed belt is broken, so the industrial applicability is very high.

1 is a view showing a toothed pulley and a toothed belt for transmitting rotational force of an EPS motor shaft;

Figure 2 is a block diagram showing a belt-type electric power steering apparatus according to a preferred embodiment of the present invention,

FIG. 3 is a cross-sectional view taken along line A-A` of FIG. 2 to show a form in which a toothed sensor detects a signal to detect tooth damage of a toothed belt;

4 is a flowchart illustrating a method of detecting tooth damage of a toothed belt in a belt type electric power steering apparatus according to a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

102: EPS motor shaft 104: toothed pulley

106: toothed belt 108: tooth of toothed belt

110: belt portion 200: electronic control device

202: EPS motor 204: toothed sensor

206: light emitting unit 208: user interface

210: motor position sensor

Claims (4)

In a belt type electric power steering system (EPS) of a vehicle, EPS motor for generating a rotational force for assisting the steering of the driver of the vehicle; A motor position sensor for detecting rotation of the EPS motor; A pulley connected to the axis of the EPS motor to rotate with the EPS motor; A toothed belt connected to the pulley to transfer the rotational force of the EPS motor to drive the rack bar of the vehicle; An ear sensor unit for detecting whether a tooth of the toothed belt is broken; And The signal pulse width obtained from the motor position sensor is obtained by comparing the pulse width of the signal obtained from the motor position sensor with the pulse width of the signal obtained from the ear sensor section. Control unit for notifying the driver that the toothed belt is abnormal when exceeding a predetermined ratio of Belt type electric power steering device comprising a. The method of claim 1, wherein the ear sensor unit, A light emitting unit generating light but passing through the portion where the teeth of the toothed belt are located; And Photo sensor for detecting the light Belt type electric power steering device comprising a. In the tooth break detection device of the toothed belt, A motor generating a rotational force; A motor position sensor for detecting rotation of the motor; A pulley connected to the shaft of the motor and rotating together with the motor; A toothed belt connected to the pulley to transfer the rotational force of the motor; A light emitting unit generating light but penetrating the portion where the toothed belt tooth is located; A toothed sensor for receiving a signal from the light emitting unit through a portion where the toothed belt tooth is located and generating a toothed sensor signal; And Comparing the pulse width of the signal obtained from the motor position sensor with the pulse width of the ear sensor signal and comparing the pulse width of the ear sensor signal with a predetermined ratio of the signal pulse width obtained from the motor position sensor. Control unit indicating abnormal tooth of belt Tooth breakage detection device of the toothed belt comprising a. In a method of detecting tooth damage of a toothed belt in a belt type electric power steering device of a vehicle, (a) detecting steering torque of a driver of the vehicle; (b) driving an EPS motor to assist the steering torque; (c) obtaining a signal from a motor position sensor and an ear sensor; (d) determining whether a pulse width of the signal obtained from the ear sensor exceeds a predetermined ratio of the signal pulse width obtained from the motor position sensor; (e) proceeding to step (g) if the result of the determination of step (d) exceeds the predetermined ratio; (f) proceeding to step (c) if the determination result of step (d) does not exceed the preset ratio; And (g) alerting the user that the teeth of the toothed belt are broken; Tooth breakage detection method of the toothed belt comprising a.

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