JP2722183B2 - Semi-trailer connection angle detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a connection angle of a semi-trailer.

[0002]

2. Description of the Related Art In a semi-trailer that is towed while traveling with its front part supported by a tractor, when the tractor turns, a change in the connection angle occurring at a connection part (king pin part) with the tractor at the front of the trailer is detected. However, the steered wheel control of the trailer is performed based on the change in the connection angle, and various methods have been conventionally devised for detecting the connection angle of the trailer, as disclosed in Japanese Patent Application Laid-Open No. 62-29471. JP-A-6-87462, JP-A-6-2555
No. 29, JP-A-6-278640, Japanese Utility Model Application Laid-Open No. 3
No. 5,252,285 and Japanese Patent Application Laid-Open No. 4-126675.

[0003]

SUMMARY OF THE INVENTION Among the above prior arts,
Japanese Patent Application Laid-Open No. 62-29471 discloses a trailer connection angle detecting device which includes a gear fixed to a kingpin at a connection portion of a trailer formed by engagement of a tractor-side coupler with a trailer-side kingpin. And a rack formed on the outer cylinder of the spool valve attached to the coupler on the tractor side, and the spool is rotated by a gear that is integral with the kingpin as the relative angle between the coupler and the kingpin changes when the tractor turns. The valve outer cylinder is moved in the axial direction, and the hydraulic circuit for operating the trailer steering device is controlled by the relative position change between the spool valve outer cylinder and the spool inside the spool. The configuration in which the change in the connection angle of the trailer is taken out by the axial movement amount of the spool valve outer cylinder attached to the coupler with respect to the spool is complicated, the assembly is troublesome and very expensive, and the kingpin is a trailer. The most important security component is that it is not preferable from the viewpoint of security to form a gear mounting portion on the component by machining or the like.

Japanese Patent Application Laid-Open Nos. 6-87462 and 6-87462
No. 255529, Japanese Unexamined Patent Publication No. 6-278640 and Japanese Unexamined Utility Model Publication No. 3-52285 are all systems in which the connection angle of the trailer is mechanically taken out. The turntable fixed to the part is rotatably mounted on the trailer, and the turntable and the kingpin rotate integrally with the rotation of the tractor, and the change in the connection angle is taken out by the rotation of the lever fixed to the kingpin. In this configuration, the rotation of the lever taken out is converted into the displacement of a servo valve, a hydraulic cylinder, a link, and the like to control the steered wheels of the trailer. The method of mechanically taking out the connection angle of the trailer by rotating the king pin in this way has been practically used, but the configuration in which the king pin is rotatably attached to the trailer and the king pin is used to change the relative angle of the coupler. It has a very large number of components, such as a configuration that rotates in conjunction with each other, has a complicated structure, is very expensive, and requires processing such as arm mounting on the kingpin, which is preferable for security for the most important security component, the kingpin. There is a problem that there is no.

Recently, as disclosed in Japanese Patent Application Laid-Open No. 4-126675, the connection angle between a tractor and a trailer (semi-trailer) is regarded as that the tractor itself constitutes a single virtual front wheel of the trailer. to, by performing detection and computer processing the actual steering angle [delta] _f of the virtual front wheel sensor, a method of steering the steered wheels of the trailer it has been proposed.

[0006] Japanese Patent Application Laid-Open No. 4-126675 discloses that
Although not described specific example of a sensor for detecting the actual steering angle [delta] _f the virtual front wheels, it is the practice, as is known in the prior art, in conjunction with the relative angle variation of the tractor-side coupler It is conceivable to adopt a method in which a change in the connection angle is extracted by the rotation of the arm of the trailer-side king pin that rotates and used as a trailer steering signal using an angle-electric signal converter such as a rotary encoder. If a specific configuration is adopted, as in the above, the number of components is extremely large, the structure is complicated and expensive, and furthermore, machining and the like for attaching the arm to the kingpin, which is the most important security component, are added, so security is required. This is problematic in that it is undesirable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a trailer connection angle detecting device which addresses the above-mentioned conventional problems.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a semi-trailer coupling device in which a trailer front portion is supported and a kingpin is locked by a tractor-side coupler. A magnetic scale that forms an arc of a predetermined radius R with the center as the center is embedded, and a magnetic sensor facing the side of the coupler with a predetermined gap below the magnetic scale is attached to the side of the coupler. When the magnetic sensor is rotated, the magnetic sensor moves in an arc while facing the magnetic scale to generate an output signal, and the connection angle of the trailer is calculated from the output signal.

[0009]

As described above, the trailer can be used without changing the kingpin, which is the most important security part of the trailer, without affecting the important functions of the trailer front support of the coupler on the tractor side and the kingpin locking. Can be continuously and accurately detected.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a semi-trailer towed while a front portion is supported by a tractor, 1 is a tractor, 2 is a trailer, and approximately the center of the front lower surface of the trailer 2 in the vehicle width direction. A king pin 4 is projected downward from the portion, and the king pin 4 is inserted into and locked by a coupler (coupler) 3 provided on the rear portion of the tractor 1 and the coupler 3 is positioned below the front portion of the trailer. By slidingly contacting the face plate, the trailer 2 is connected to the rear part of the tractor 1 while the front part of the trailer 2 is supported. The coupler 3 includes a saddle portion for supporting the front portion of the trailer 2 and a jaw mechanism mounted on the lower center of the saddle portion and coupled to the kingpin 4 to transmit traction force, braking force, and the like. Although there is a balancer shaft that can move relative to the trailer by pitching and rolling, since the specific structure of this coupler has been well known,
Only the saddle portion is illustrated, and detailed illustration and description of other structures are omitted.

As shown in FIG. 2, the king pin 4 is firmly fixed to a lower surface plate (usually referred to as a sand plate) 21 at the front of the trailer 2 by screwing or riveting. Then, on the lower surface of the lower surface plate 21 of the trailer 2, an arc (center angle) of a radius R (R is set to be larger than W / 2, where W is the width of the coupler 3) with the king pin 4 as the center. θ
(Approximately 60 °) is attached to one side of the king pin 4, and an origin detecting magnet 6 is attached to the other side of the king pin 4.

As shown in FIG. 3, the magnetic scale 5 diffuses a magnetic powder such as barium ferrite into a flexible material such as rubber and magnetizes the N and S poles alternately in the longitudinal direction at an equal pitch ( A protective cover made of a non-magnetic material (for example, aluminum, stainless steel, etc.) includes a tape-shaped rubber magnet 5a formed at a pitch of 2 mm, for example, and a tape-shaped ferromagnetic metal plate 5b to which the rubber magnet 5a is attached. While being covered by 5c, it is mounted in a magnetic scale mounting groove 21a formed on one side lower surface of the lower plate 21 by means such as screwing. When the magnetic scale 5 is mounted in the magnetic scale mounting groove 21a, the depth T of the magnetic scale mounting groove 21a is set so that the magnetic scale 5 including the protective cover 5c does not protrude below the lower surface of the lower plate 21. Must be larger than the thickness t of the magnetic scale 5.
The thickness t of the magnetic scale mounting groove 21 is about 3 mm.
It is desirable that the depth T of a is about 5 mm. Similarly, the magnet 6 for detecting the reference point is
It is mounted in a slightly retracted state in the groove 21b so as not to protrude below the lower surface of.

A magnetic sensor 7 facing the magnetic scale 5 is mounted on one side surface of the coupler 3 on the tractor side which engages with the kingpin 4 by a sensor bracket 9.
On the other side surface of the coupler 3, an origin detection sensor 8 which is located just below the origin detection magnet 6 when the connection angle of the trailer is zero is attached.

As the magnetic sensor 7, for example, two sine-wave output signals whose phases are shifted by 90 ° by electromagnetic induction by sequentially passing magnetic fields of N pole and S pole in the vicinity of the magnetic scale 5 A pair of front and rear magnetic sensors including a magnetic head and a pickup coil are used. The magnetic sensor 7 projects from a side surface of the coupler 3 by a sensor bracket 9 and projects a predetermined amount outward and outward from one side surface of the coupler 3. The magnetic sensor 7 is mounted such that the center of the magnetic sensor 7 is separated from the center of the coupler 3 by a distance R equal to the arc radius R of the magnetic scale 5, and is adjusted by an adjusting mechanism (adjusting screw) 9 a provided on the sensor bracket 9. The mounting height of 7 can be adjusted. In practice, the adjusting mechanism 9 is arranged so that the tip of the magnetic head of the magnetic sensor 7 is located 6 mm ± 2 mm below the upper surface of the coupler 3 (the surface in contact with the lower plate 21).
Adjusted at a.

As the origin detecting sensor 8, for example, a magnetically responsive switch or the like which generates an on (or off) signal in response to the magnetism of the magnet 6 when the magnet is approached and opposed to the origin detecting magnet 6 is employed. The origin detecting sensor 8 is also mounted so as to be located slightly below the upper surface of the coupler 3, similarly to the magnetic sensor 7.

In the above connection, in the connection state between the tractor 1 and the trailer 2, that is, in the connection state in which the king pin 4 is inserted and locked at the center of the coupler 3, the trailer 2 is placed on the coupler 3.
Of the trailer 2 is supported by the sliding contact of the lower surface plate 21. In the connected state, the tractor 1
When the connection angle between the magnetic scale 7 and the trailer 2 is zero (in a state where the magnetic scale 5 is connected straight), the magnetic sensor 7 is positioned at a predetermined gap (8 mm ±
(A gap of about 2 mm), and the origin detection sensor 8 emits an origin detection signal facing the origin detection magnet 6 directly below the origin detection magnet 6 with a predetermined gap, and is installed in the driver's seat of the tractor 1 based on the origin detection signal. The origin lamp (not shown) on the operation panel is turned on, and the driver can confirm that the trailer is connected straight. When the tractor 1 and the trailer 2 are connected, the trailer 2
Is connected at a certain angle, the position of the origin detection sensor 8 is shifted with respect to the origin detection magnet 6, so that the origin lamp is not turned on. In this case, the tractor 1 is steered so that the tractor 1 and the trailer 2 are connected straight, and this is confirmed by turning on the origin lamp.

After confirming that the origin lamp is lit, press the set switch. Then, the computer stores the current position of the magnetic sensor 7 with respect to the magnetic scale 5 as a neutral position (the connection angle is zero).
Is output to the computer via the signal processing circuit, the computer calculates the connection angle change (direction and magnitude) and stores it as the connection angle information, and the connection angle information and other information (E.g., vehicle speed information, feedback information of the trailer steered wheels, etc.), a target value for steering the steered wheels of the trailer 2 is obtained, and a steering command is issued. Is performed.

More specifically, when the tractor 1 is steered from a straight traveling state while the tractor 1 is running while towing the trailer 2, the coupler 3 rotates around the kingpin 4 as the tractor 1 turns. The magnetic sensor 7 attached to one side of the coupler 3 moves circularly under the magnetic scale 5 while maintaining a predetermined gap, and sequentially passes the magnetic fields of the N pole and the S pole of the magnetic scale 5. Thus, the pair of front and rear magnetic sensors 7 output two sine wave signals (see FIG. 4) of the A phase and the B phase which are 90 ° out of phase. As described above, the N pole, S
Assuming that the pole pitch is 2 mm, both the A and B phases become sine wave signals having a wavelength of 4 mm. The sine wave signals of the A and B phases are converted into rectangular wave signals of a predetermined width by the signal processing circuit 10. And inputs the same to the computer 11. The computer 11 counts the number of pulses of the rectangular wave signal to calculate the rotation angle from the count value and the radius R, and calculates the phase difference between the A phase and the B phase. From the tractor 1 and store it as connection angle information of the trailer 2 with respect to the tractor 1, and repeat the above-described calculation, determination and storage continuously until the connection between the tractor 1 and the trailer 2 is released. Thus, accurate connection angle information can always be obtained. In actual use, there is some radial deflection between the king pin 4 and the coupler 3 which fits and locks it, but this deflection is within a negligible range.

As described above, the lower plate 21 at the front of the trailer
A semi-trailer connection angle is detected by an arc-shaped magnetic scale 5 embedded and installed on the lower surface of one side of the coupler and a magnetic sensor 7 mounted on one side of the coupler 3 so as to face the magnetic scale 5 with a predetermined gap. Due to the construction of the device, the king pin 4, which is the most important security part, is not subjected to any processing or the like, and the important functions of the trailer front support of the coupler 3 and the locking of the king pin are not affected at all. And the connection angle of the trailer to the tractor can be continuously and accurately detected.

In the above configuration, the center angle θ of the arc of the magnetic scale 5 is set in consideration of the maximum amount of change in the trailer connection angle based on the maximum steering angle of the tractor steered wheels. The turning angles are usually about 25 ° to the left and right, and about 50 ° for lock-to-lock, so that in practice, setting θ ≒ 60 ° as described above can sufficiently achieve the purpose.

The configuration of the magnetic scale 5 itself is not limited to that of the above-described embodiment, and any conventionally known configuration can be adopted. The magnetic sensor 7 is not limited to the magnetic head type sensor including the magnetic head and the pickup coil described above, but may be any type of magnetic sensor using an electromagnetic induction effect. Any conventionally known magnetic sensor such as an element or an MR element can be employed.

[0023]

As described above, according to the present invention, the connection angle of the semi-trailer can be detected without touching the king pin which is the most important security part of the trailer, supporting the coupler at the front of the trailer and controlling the king pin. It can be performed accurately with an extremely simple structure without affecting the important function of stopping at all, and in combination with its low cost and excellent durability, it has a great effect in practical use. It can bring.

[Brief description of the drawings]

FIG. 1 is a side view of a semi-trailer to which the present invention is applied and a tractor for towing the semi-trailer before being connected.

FIGS. 2A and 2B show an embodiment of the present invention, wherein FIG. 2A is a side view of a trailer before being connected to a kingpin mounting portion of a trailer and a coupler of a tractor, FIG.
(C) is a bottom view of the kingpin portion of the trailer, and (D) is a plan view of the coupler.

3A is a sectional view taken along line AA of FIG. 2C, and FIG. 3B is a view taken in the direction of arrow B of FIG.

FIG. 4 is a diagram illustrating an output signal waveform of a magnetic sensor passing through a magnetic field of an N pole and an S pole alternately on a magnetic scale and an input system of the output signal to a computer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tractor 2 Trailer (semi-trailer) 3 Coupler 4 King pin 5 Magnetic scale 6 Origin detection magnet 7 Magnetic sensor 8 Origin detection sensor 9 Sensor bracket 10 Signal processing circuit 11 Computer 21 Bottom plate 21a Magnetic scale attachment groove 21b For attachment of origin detection magnet Groove

Claims (4)

(57) [Claims] A downwardly projecting king pin is fixed to the front center of the trailer, and the king pin is rotatably locked in a state in which a coupler attached to the tractor is in sliding contact with a lower surface plate at the front of the trailer. In a semi-trailer coupling device in which a tractor is towed while supporting a trailer front, a magnetic scale forming an arc of a predetermined radius R centered on a kingpin is provided on a lower surface of a lower plate of the trailer front. A magnetic sensor facing the magnetic scale is attached to the side of the coupler of the tractor with a predetermined gap below the magnetic scale on the side surface of the tractor, and the magnetic sensor faces the magnetic scale with the rotation of the coupler around the king pin as the tractor turns. The output signal is generated by performing a circular motion while maintaining the angle, and the connection angle of the trailer is calculated from this output signal. A semi-trailer connection angle detector. 2. A semi-trailer connection angle detecting device according to claim 1, wherein a magnet for detecting an origin is attached to a lower surface of a lower surface plate at a front portion of the trailer, and a trailer is connected to a side surface of a coupler of the tractor. When the angle is zero, an origin detection sensor that emits an origin detection signal is attached to a position directly below the magnet and emits an origin detection signal. The connection angle of the semi-trailer is continuously detected by calculating the change direction and the change amount of the connection angle based on the output signal input from the computer. Angle detector. 3. The connection angle detecting device for a semitrailer according to claim 1, wherein the magnetic scale comprises an N pole,
It consists of a tape-shaped rubber magnet in which the S poles are alternately magnetized in the longitudinal direction at an equal pitch, and a tape-shaped ferromagnetic metal plate to which the rubber magnet is attached, and is covered with a protective cover made of a non-magnetic material. A semi-trailer connection angle detecting device, which is embedded and fixed in a magnetic scale mounting groove formed on a lower surface of a front lower surface plate of a trailer in a closed state. 4. The semi-trailer connection angle detecting device according to claim 1, wherein the magnetic sensor comprises:
A semi-trailer connection angle detecting device, which is mounted on a sensor bracket fixed to a side surface of a coupler, and is capable of adjusting a mounting height of a magnetic sensor by an adjusting mechanism.