JP2001221311A - Crank device and antenna driving device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crank device which equalizes the turning time required when a turning member moves back and forth. SOLUTION: An antenna driving device comprises a crank device which is constituted of a first and a second crank arms 11, 12, a driving motor 1, and an antenna 2. One end of the first crank arm 11 is fixed to an output shaft 9 of the driving motor 1, while one end of the second crank arm 12 is connected to the other end of the first crank arm 11 by means of a connecting pin 10. A turning end of an arm plate 8 is connected to the other end of the second crank arm 12 by means of a connecting pin 13. A turning center C of the driving motor 1 is positioned on a virtual straight line 30 which passes through the both ends (points A, B) of a moving locus 16 of a connecting part for the arm plate 8 and the second crank arm 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank device for converting a rotary motion of a drive device such as a motor into a reciprocating rotary motion of a rotary member, and an antenna drive device using the same.
In particular, the present invention relates to a crank device and an antenna driving device suitable for use in a collision warning device, an inter-vehicle distance control device, and the like mounted on an automobile.

[0002]

2. Description of the Related Art Hitherto, a collision warning device has been proposed which detects a distance, a relative speed, and the like with respect to another vehicle or an obstacle in front of or behind a self-vehicle, thereby preventing a collision during traveling. . Also, in order to reduce the burden on the driver when performing acceleration / deceleration operations, the inter-vehicle distance that automatically follows the preceding vehicle by detecting the traveling speed of the preceding vehicle and automatically changing the speed of the own vehicle. Control devices have also been proposed. This type of device includes a radar unit including an antenna, a device for reciprocatingly rotating the antenna within a predetermined angle range, an antenna position detecting sensor for detecting the position of the antenna, the position of the antenna and the reception data. And an electronic control unit for automatically changing the vehicle speed of the own vehicle by calculating the distance, relative speed, and the like to another vehicle or an obstacle in front of or behind the own vehicle based on the above. The reciprocating rotation of the antenna is usually performed by transmitting the rotation of the driving device by a crank device.

FIG. 5 is a plan view showing a conventional example of a radar unit used in an automobile collision warning device, FIG. 6 is a diagram showing reciprocating rotation of a crank device and an antenna, and FIG. 7 is a relationship between a swing angle of an antenna and time. FIG. In these figures, 1 is a drive motor, 2 is an antenna, and 3 is a crank device for transmitting the rotation of the drive motor 1 to the antenna 2, and these constitute a radar unit 4 of a collision warning device. Reference numeral 5 denotes a frame, on which the drive motor 1 is fixed, and a rotating shaft 6 of the antenna 2 is rotatably supported via a bearing 7. Reference numeral 8 denotes an arm plate fixed to the antenna 2, and the arm plate 8 is connected to the output shaft 9 of the drive motor 1 by the crank device 3. The crank device 3 includes a connecting pin 10
A first end of which is connected to each other so as to be relatively rotatable,
The first crank arm 11 is fixed to the output shaft 9, and the second crank arm 12 is opposed to the rotating end of the arm plate 8 by another connecting pin 13. It is rotatably connected.

In the radar unit 4 having such a structure, when the drive motor 1 is energized to rotate its output shaft 9 clockwise, the first crank arm 11 rotates integrally with the output shaft 9 and The second crank arm 12 is eccentrically rotated about the output shaft 9. As a result, the arm plate 8 reciprocates clockwise and counterclockwise around a rotation center O (rotation axis 6) of the antenna 2 in a certain angular range. In this case, the maximum deflection angle of the arm plate 8 is ± 2θ, and θ = θ when the main surface 2a of the antenna 2 is orthogonal to the front-rear direction of the vehicle body as shown by a solid line in FIG.
When the angle is set to 0 °, the arm plate 8 and the second
Is connected to the crank arm 12 (connection pin 13)
In FIG. 6, it is located at the point A (minimum shake angle point). When the drive motor 1 is driven from this state, the connecting portion rotates the maximum angle clockwise about the rotation center O from the position of the point A to the position of the point B (the maximum deflection angle point) during one rotation of the output shaft 9. After rotating to move to the position of the point B by (+ 2θ), the rotation direction is reversed and the movement returns from the point B to the position of the point A. Therefore, the antenna 2 also rotates integrally with the arm plate 8 and reciprocates by an angle of ± 2θ in the left-right direction. In this case, the initial position of the connecting portion (connecting pin 10) of the first and second crank arms 11 and 12 is set at a point P1 on a circle 15 having a radius equal to the arm length r1 of the first crank arm 11. The point P is located on a straight line connecting the rotation center C of the drive motor 1 and the point B, and passes through the point P2 when the antenna 2 moves forward.
3 to the point P4 during the return operation from the point P3 to the point P4.
And returns to the position of the point P1. In FIG. 6, 1
Reference numeral 6 denotes a movement trajectory of a connection portion (connection pin 13) between the arm plate 8 and the second crank arm 12.

The change in the deflection angle of the antenna 2 is determined by the output shaft 9.
If the rotation is constant, it is regular in design as shown in the deflection angle-time curve shown in FIG. A configuration is employed in which the position of the antenna 2 is detected by an antenna position detecting sensor using this characteristic. That is, the antenna position detecting sensor employs a circuit that detects the position of the antenna 2 based on the elapsed time after reaching the reference position.

[0006]

As described above, in the conventional radar unit 4, the rotation of the drive motor 1 is transmitted to the antenna 2 by the crank device 3, so that the antenna 2 can be moved in a predetermined angular range (right and left). ± 2θ)
To reciprocate. However, points P1 and P3
Is not point symmetric, the first crank arm 11 has a longer forward rotation time α than the backward rotation because the forward rotation angle α is larger than the backward rotation angle β.
As shown in FIG. 7, the rotation time T1 differs between the forward movement and the return movement, and the forward rotation time T1 is longer than the return rotation time T2. As a result, the circuit for detecting the position of the antenna 2 is different between the forward and return times, and it is necessary to design two types of asymmetrical detection circuits. Similarly, two types of asymmetric circuits need to be designed for the processing circuit for calculating the distance, relative speed, and the like to other vehicles or obstacles ahead or behind the own vehicle based on the position of the antenna 2 and the received data. was there. Further, if the time difference is large, the linear regions at the time of going forward and at the time of returning are also different, and there is a problem that the sensor lacks linearity. Further, when rotating at the same angle, the angular velocity increases at the time of return when the time is short, so that there is a problem that the impact is large when stopping to rotate and invert the maximum angle and noise is generated. . When the output shaft 9 of the drive motor 1 is rotated in the counterclockwise direction, the rotation time required for the forward movement of the antenna 2 is shorter than that for the return movement, contrary to the above.

In order to solve the above-mentioned problem, if the length of the first crank arm 11 is made as short as possible and the length of the arm plate 8 is made as long as possible, the connection between the arm plate 8 and the second crank arm 12 is made. Since the movement trajectory 16 of the portion (connection pin 13) can be regarded as a pseudo straight line, the antenna 2
The turning times T1 and T2 required at the time of going forward and returning can be made substantially equal. However, in such a case, a desired shake angle cannot be obtained because the shake angle of the antenna 2 is significantly restricted, and the distance Lf from the rotation center C of the drive motor 1 to the rotation center O of the antenna 2 becomes longer, so that the apparatus itself This is not practical because problems such as an increase in size are caused.

The inventors of the present invention have studied the configuration of the crank device 3 and found that both ends (the minimum deflection angle point A, the maximum deflection angle A) of the motion trajectory 16 of the connecting portion between the arm plate 8 and the second crank arm 12. When the point B) and the rotation center C of the drive motor 1 are positioned on the same straight line, the rotation time T1 required for the forward and backward movements of the arm plate 8, in other words, the antenna 2 even when the movement trajectory 16 is arc-shaped. It has been found that T2 can be made equal.

The present invention has been made on the basis of the above-mentioned conventional problems and the results of the study. The object of the present invention is to make it possible to make the turning time required for the forward and backward rotation of the rotating member equal. An object of the present invention is to provide a crank device and an antenna driving device using the same.

[0010]

According to a first aspect of the present invention, there is provided a first crank arm having one end fixed to an output shaft of a driving device; A second connecting means for connecting the rotating end of the rotating member so as to be relatively rotatable;
And a crank arm for reciprocating the rotating member in a predetermined angle range by rotation transmission of the driving device, wherein both ends of a movement trajectory of a connecting portion between the rotating member and a second crank arm are provided. In which the rotation center of the driving device is positioned on a virtual straight line passing through.

According to a second aspect of the present invention, there is provided an antenna driving device comprising a driving device and a crank device for transmitting the rotation of the driving device to the antenna to reciprocate the antenna in a predetermined angle range. The device comprises a first crank arm having one end fixed to the output shaft of the drive device, and a second crank arm for connecting the other end of the first crank arm and the antenna relatively rotatably. , The rotation center of the driving device is positioned on a virtual straight line passing through both ends of the movement trajectory of the connecting portion between the antenna and the second crank arm.

In the present invention, since the rotation center of the driving device is located on a virtual straight line passing through both ends of the movement trajectory of the connecting portion between the rotating member (or the antenna) and the second crank arm, the connecting portion is provided. Are located on the virtual straight line, the first and second crank arms are aligned and overlap the virtual straight line. Therefore, the turning direction of the turning member (antenna) is switched every half rotation of the first crank arm, and the turning times of the turning member (antenna) at the time of going and returning are equal. As the driving device, a motor, a rotary actuator, or the like is used.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a plan view showing an example in which the present invention is applied to a radar unit of an automobile collision warning device, FIG. 2 is an external perspective view of the radar unit, and FIG.
FIG. 4 is a diagram showing the reciprocating rotation of the crank device and the antenna, and FIG. 4 is a diagram showing the relationship between the swing angle of the antenna and time. The same components as those shown in the section of the prior art are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

In these figures, the radar unit 4
The structure of itself is exactly the same as that of the above-described conventional device, and the drive motor 1, the antenna 2 and the rotation of the drive motor 1 are transmitted to the antenna 2 and the antenna 2 is moved in a predetermined angle range (± 2
θ), a crank device 3 for reciprocating rotation, a position detection sensor (not shown) for detecting the position of the antenna 2, and the antenna 2
An electronic control unit or the like that calculates the distance to a vehicle or an obstacle in front of or behind the own vehicle or an obstacle based on the position and received data, and automatically changes the vehicle speed of the own vehicle. 1, the antenna 2 and the crank device 3 constitute an antenna driving device.

As the drive motor 1, a PM (permanent magnet) type step motor or the like is used.
It is fixed to the frame 5. In addition, a rotating shaft 6 of the antenna 2 is rotatably supported on the frame 5 via a bearing 7.

The crank device 3 comprises first and second crank arms 11 and 12 having different lengths, and one end of the short first crank arm 11 is fixed to the output shaft 9 of the drive motor 1. One end of a second crank arm 12 is connected to the other end via a connecting pin 10 so as to be relatively rotatable. The second crank arm 12 is formed longer than the first crank arm 11, and the other end is connected to a rotating end of an arm plate (rotating member) 8 fixed to the back side of the antenna 2 via a connecting pin 13. They are connected so as to be relatively rotatable. Therefore, when the drive motor 1 is driven, the rotation of the output shaft 9 is transmitted to the arm plate 8 via the crank device 3, whereby the antenna 2 and the arm plate 8 are moved in the left and right directions within a predetermined angle range (± 2θ). It can be reciprocated. At this time, a connection portion (connection pin 13) between the arm plate 8 and the second crank arm 12
Draws an arc-shaped motion trajectory 16 connecting points A and B, where point A is the minimum deflection angle point and point B is the maximum deflection angle point.

Here, in the present invention, the drive motor 1
The drive motor 1 is disposed such that the rotation center C of the drive motor 1 is located on a virtual straight line 30 passing through the points A and B. Therefore, the rotation center O of the arm plate 8 is determined by the motion locus 1
A straight line 3 orthogonal to the virtual straight line 30 at the midpoint Q of 6
2 above. The arm lengths r1, r2 of the first and second crank arms 11, 12 and the drive motor 1
The mounting distance Lf between the antenna and the antenna 2 depends on the mounting space of the position detecting sensor, the shape and size of the drive motor 1, the antenna 2
, The minimum dimension determined from the deflection angle (± 2θ) of the antenna 2 and the like.

In such a radar unit,
Rotation times T3 and T4 of the arm plate 8, in other words, the forward and backward movements of the antenna 2 can be made equal.
That is, the arm plate 8 and the second crank arm 1
In the initial state in which the connection portion (connection pin 13) with the second crank arm 11 and 12 is located at the point A which is the minimum swing angle point, the connection portion (connection pin 10) of the first and second crank arms 11 and 12 One of the crank arms 11 is located at a point P1 on a circle 15 whose radius is the arm length r1. This point P1 is located on the virtual straight line 30. In this state, the drive motor 1 is driven to rotate the first crank arm 11 by 180 °.
When rotated, the first and second crank arms 11 and 12
Moves from the position of the point P1 to the position of the point P3 through the point P2. This point P3 is located on the virtual straight line 30. When the connection point moves from the position of the point P1 to the position of the point P3, the arm plate 8 rotates clockwise by a maximum angle (+ 2θ), and the connection portion (the connection pin 13) with the second crank arm 12 is turned to the point. It moves from the position A to the position of the point B which is the maximum deflection angle point. When the first crank arm 11 further rotates by 180 ° and the connecting portion (connecting pin 10) with the second crank arm 12 returns from the position of the point P3 to the position of the point P1 through the point P4, the arm Plate 8
Is rotated counterclockwise by a maximum angle (−2θ), and the connecting portion (the connecting pin 13) with the second crank arm 12 returns from the position of the point B to the position of the point A. Therefore, if the rotation of the output shaft 9 is constant, the turning times T3 and T4 of the arm plate 8 and the antenna 2 in the forward and backward directions are equal as shown in FIG. As a result, it is easy to design the detection circuit of the sensor for detecting the antenna position, and it is possible to make the detection circuits for forward and backward movements symmetrical. Similarly, a processing circuit for calculating the distance, relative speed, and the like to another vehicle or an obstacle in front of or behind the own vehicle based on the position of the antenna 2 and the received data can also have symmetry, and circuit design can be improved. Easy. In addition, the straight regions at the time of going forward and the time of returning are almost the same, so that the linearity can be improved.

Further, if the rotation times T3 and T4 of the antenna 2 at the time of going forward and at the time of returning are the same, a large impact noise is not generated when the rotation direction is switched due to a small change in the angular velocity, and the antenna 2 is kept quiet. It can be reciprocated.
This is because the rotation center C of the drive motor 1 is positioned on a virtual straight line 30 passing through both ends (points A and B) of the movement trajectory 16 of the rotation end of the arm plate 8. .

In the above-described embodiment, a motor is used as the driving device. However, the present invention is not limited to this, and a rotary actuator may be used. Further, in the above-described embodiment, an example in which the present invention is applied to a radar unit of an automobile collision warning device has been described. However, the present invention is not limited to this. The present invention can be applied to all of various devices and mechanisms that need to be reciprocated in a range.

[0021]

As described above, according to the crank device and the antenna driving device using the same according to the present invention,
Since the rotation center of the driving device is located on a virtual straight line passing through both ends of the movement trajectory of the connecting portion between the rotating member or the antenna and the second crank arm, the forward and backward times of the rotating member or the antenna are equal. can do. In addition, since the impact at the time of reversal is small and the vehicle can be turned quietly, it is particularly suitable for use in radar units such as a collision warning device for a car and an inter-vehicle distance control device.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example in which the present invention is applied to a radar unit of an automobile collision warning device.

FIG. 2 is an external perspective view of the radar unit.

FIG. 3 is a diagram showing reciprocating rotation of a crank device and an antenna.

FIG. 4 is a diagram illustrating a relationship between a shake angle of an antenna and time.

FIG. 5 is a plan view showing a conventional example of a radar unit used for a collision warning device.

FIG. 6 is a diagram showing the reciprocating rotation of the crank device and the antenna.

FIG. 7 is a diagram illustrating a relationship between a shake angle of an antenna and time.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Drive motor, 2 ... Antenna, 3 ... Crank device, 4
... Radar unit, 5 ... Frame, 6 ... Rotating axis, 8 ...
Arm plate, 9 ... output shaft, 10 ... connecting pin, 11 ...
A first crank arm, 12 ... a second crank arm,
13 ... connecting pin, 30 ... virtual straight line.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Fusio Inuchi 1-28-28 Goshodori, Hyogo-ku, Kobe-shi, Hyogo F-term in Fujitsu Ten Limited (Reference) 5J047 AA02 AB00 BF02 BF10 BF10 BF11

Claims (2)

[Claims] A first crank arm having one end fixed to an output shaft of a driving device; and a second crank arm for connecting the other end of the first crank arm and a rotating end of a rotating member to be relatively rotatable. And a crank arm for reciprocatingly rotating the rotating member within a predetermined angle range by rotation transmission of the driving device, wherein both ends of a movement trajectory of a connecting portion between the rotating member and a second crank arm are provided. A rotation center of the driving device is positioned on a virtual straight line passing through the crank device. 2. An antenna drive device comprising: a drive device; and a crank device that transmits the rotation of the drive device to the antenna to reciprocate the antenna within a predetermined angle range. A first crank arm having one end fixed to an output shaft of the device, and a second crank arm connecting the other end of the first crank arm and the antenna so as to be relatively rotatable; An antenna driving device, wherein the rotation center of the driving device is located on a virtual straight line passing through both ends of the movement trajectory of the connecting portion of the second crank arm.