JP2009154564A - Lever shaft position detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance durability, and to save space, by enabling smooth lever shaft operation, without adding excessive resistance force to a lever shaft. <P>SOLUTION: A magnet 1 for a bias magnetic field and a magnetic sensor 2 arranged in the bias magnetic field, are arranged in respective positions of the lever shaft 4. The bias magnetic field changes when the lever shaft 4 composed of a magnetic substance approaches the magnet 1, and a change in the magnetic flux is output as an electric signal, and this signal is sent to a computer, to detect the position of the lever shaft. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for detecting the position of a lever shaft of an automatic transmission of an automobile.

  In order to detect the position of the lever shaft in an automatic transmission with a manual shift mode of an automobile, as a conventional example, a contact switch is arranged near the lever shaft, and the shift position is judged by operating each switch on the lever shaft. The thing was known (refer patent document 1). In more detail, this is a mode changeover switch part that is built in an automatic transmission with a manual shift mode and detects that the shift lever is moved from the automatic gate to the manual gate to switch from the automatic shift mode to the manual shift mode. And a shift changeover switch unit that detects that the downshift or upshift is changed by moving the shift lever in the manual gate. The mode changeover switch portion is supported in a rotatable manner in the switch case, a mode input terminal arranged vertically in the switch case, a first ground input terminal arranged away from the mode input terminal, A first lever protruding from the side of the switch case, a common contact mounted on the first lever and constantly contacting the mode input terminal, and an input contacting the first ground input terminal in conjunction with the rotation of the first lever A first contact spring piece having a contact and supported so as to be slidable along the side surface of the switch case, and operated by being pushed by the shift lever at the time of switching operation to the manual shift mode. At this time, the first lever is pushed to rotate. And an operating body to be operated. Further, the shift changeover switch unit is arranged at a symmetrical position of the downshift input terminal arranged horizontally in the switch case, the second ground input terminal arranged apart from the downshift input terminal, and the downshift input terminal. An upshift input terminal, a third ground input terminal arranged at a symmetrical position of the second ground input terminal, a second lever that is rotatably supported in the switch case and protrudes from the upper surface of the switch case; A second contact spring piece having a common contact mounted on the second lever and constantly contacting the downshift input terminal, an input contact contacting the second ground input terminal in conjunction with the rotation of the second lever, and a switch A third lever that is rotatably supported in the case and protrudes from the top surface of the switch case, and is attached to the third lever for upshift input A third contact spring piece having a common contact that is always in contact with the child and an input contact that contacts the third ground input terminal in conjunction with the rotation of the third lever, and a slidable support along the upper surface of the switch case And an operating body that is operated by being pushed by the shift lever at the time of downshift or upshift operation, and at this time pushes one of the second lever or the third lever to rotate. The first lever, the second lever, and the third lever are configured as a common component, and the first contact spring piece, the second contact spring piece, and the third contact spring piece are shared. It is made up of the parts made.

Furthermore, as another conventional example, two rotors with magnets that operate in conjunction with the movement of the shift lever are provided, and the rotation of the rotor is read by a separately installed magnetic detection element to determine the shift position. The thing is known (refer patent document 2). This will be described in more detail. Automatic shift is performed by operating the shift lever along the first lever route, and the shift lever is moved from the first lever route to the second lever route and the second lever route. This is a shift position sensor applied to an automatic transmission that performs manual shifting by operating along the. And a magnet is provided in the 1st rotor rotated independently when a shift lever is operated along one of the 1st lever route and the 2nd lever route, and the shift lever is the 1st lever route and the 2nd lever route. A magnetic body is provided on the second rotor that is rotated integrally with the first rotor when operated along the other of the first rotor and the magnetic body when the first rotor and the second rotor are rotated integrally. The magnet rotation trajectory and the magnetic material rotation trajectory are made to coincide in the radial direction so that the magnetism that has been influenced and reaches the magnetic detection element is detected by the magnetic detection element.
JP 2006-347267 A (pages 5 and 6, FIG. 4) JP 2007-8232 (page 5, FIG. 3)

  In the conventional example described in Patent Document 1, when the contact switch is pressed by the lever shaft, extra resistance force such as friction of the knob, repulsive force of the spring, etc. is applied to the lever shaft, and further the wear of the metal contact portion is reduced. There was also a fear.

  In the conventional example described in Patent Document 2, a magnet must be installed at a position distant from the magnetic detection element (see FIG. 5 of Patent Document 2). Therefore, an expensive strong magnet or a large magnet must be used. There is a risk of increasing the cost and increasing the size of the structure.

  Accordingly, an object of the present invention is to provide a lever shaft position detection device that enables smooth operation of the lever shaft without excessive resistance being applied to the lever shaft, has excellent durability, and saves space. To do.

  In order to achieve the above-described object, the present invention provides a bias magnetic field magnet and a magnetic sensor disposed in the bias magnetic field at each position of the lever shaft, and the lever shaft made of a magnetic material approaches the magnet. A change occurred in the bias magnetic field, and the change in the magnetic flux was output as an electrical signal, and this signal was sent to a computer to detect the position of the lever shaft.

  According to the present invention, a bias magnetic field magnet and a magnetic sensor disposed in the bias magnetic field are provided at each position of the lever shaft, and the bias magnetic field changes when the lever shaft made of a magnetic material approaches the magnet. Because this change in magnetic flux is output as an electrical signal and this signal is sent to the computer to detect the position of the lever shaft, the wear of the contact and the resistance force due to the spring are less than those using a contact switch. The durability and reliability are improved. Further, by using a magnet and a magnetic sensor, it can be configured at low cost and can be downsized.

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

  In FIG. 1, a magnet 1 for a bias magnetic field and a magnetic sensor 2 are arranged in the bias magnetic field of the magnet 1. In this example, the magnet 1 is attached to the magnetic sensor 2, and the magnetic sensor 2 with the magnet 1 is attached to a printed circuit board. 3 shows a state where the lever shaft 4 made of a magnetic material is moving away from the magnet 1. As the magnetic sensor 2, a magnetoresistive element is used and soldered to the printed circuit board 3. The lever shaft 4 is made of a magnetic material such as iron in consideration of strength. FIG. 2 shows a state in which the magnetic body (lever shaft) 4 approaches the magnet 1 and a change occurs in the bias magnetic field.

  Normally, as shown in FIG. 1, a magnetic field generated from the magnet 1 is applied to the magnetic sensor 2, and this state is determined as a state in which the lever shaft 4 is separated. When the lever shaft 4 is approaching, the magnetic flux is concentrated on the lever shaft 4 as shown in FIG. 2, and the magnetic flux density near the magnetic sensor 2 is lowered. Thereby, it is determined that the lever shaft 4 is close. For example, when a magnetoresistive element is used for such a magnetic sensor 2, an internal circuit as shown in FIG. 3 is preferable. In FIG. 3, a bridge circuit is formed by magnetoresistive elements, the midpoint voltages thereof are compared by the comparator 5, and “ON” is output when the lever shaft 4 approaches as shown in Table 1, and when the lever shaft 4 is not approaching. Outputs “OFF”. Further, since the sensor 2 and the magnet 1 are close to each other, the magnet 1 can be downsized or made inexpensive. Examples of the method for attaching the magnet 1 to the magnetic sensor 2 include a method of attaching a sintered magnet or a method of magnetizing after printing a paste magnet. Furthermore, since the lever shaft 4 is used as it is to change the bias magnetic field, it is not necessary to newly provide a magnetic body as a detected body.

  4 to 8 show an embodiment of a shift lever (lever shaft) 4 in an automatic transmission (AT) of an automobile. When shift positions <1> to <5> as shown in FIG. 5 are provided and magnetized magnetic sensors are arranged in the vicinity of each position, FIGS. 6 to 8 show that the shift lever 4 in FIG. The output waveform after moving is shown. When the shift lever 4 moves between the positions as shown in FIGS. 6 to 8, the output waveforms of the sensor 2 before the shift position and the sensor 2 after the movement are turned ON as shown in FIGS. By making sure that the waveforms overlap each other (T1 to T10 in the figure), there is no case where no waveform is output or there are three or more outputs, which is an effective means for error detection.

  FIG. 9 shows a state where the magnetic sensor 2 with the magnet 1 is mounted in a case 6 that houses an AT shift lever (lever shaft) 4. The printed circuit board 3 provided with the magnetic sensor 2 is connected to the printed circuit board 30 on which the determination circuit 7 and the connector 8 are mounted by the wiring material 9. The printed boards 3 and 30 used here were rigid. For example, it is preferable that the sensor 2 is placed in the back of the case 6 as shown in FIG. 9 so that a steel can of drinking water does not affect the sensor. Further, if the printed circuit board 3 on which the sensor 2 is mounted and the printed circuit board 30 on which the position determination circuit provided separately from the printed circuit board 3 is connected by the wiring material 9, the electrical connection of the position is connected to the AT computer. Just send a signal. Further, by using a flexible printed circuit board (FPC) 31 for the printed circuit boards 3 and 30, the wiring material 9 is integrated and the number of parts is reduced (see FIG. 10).

  FIG. 11 is a block diagram of the position determination circuit, in which an AT (automatic transmission) computer receives an electrical signal from the determination circuit 7 and determines any one of the positions <1> to <5> of the AT shift lever 4. To do.

The figure which has a positional relationship with which a magnetic sensor and a lever shaft are distant. The figure which has the positional relationship which the magnetic sensor and the lever shaft adjoined. Sensor circuit diagram. The perspective view which shows the relationship between an AT shift lever and a magnetic sensor. The top view which shows each position explaining operation | movement of an AT shift lever. The output waveform figure of the path | route A. FIG. The output waveform figure of the path | route B. FIG. The output waveform figure of the path | route C. FIG. The figure which shows the example of arrangement | positioning in a case. The figure which shows the other example of arrangement | positioning in a case. The block diagram of a position determination circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnet 2 Magnetic sensor 3, 30, 31 Printed circuit board 4 Lever shaft (shift lever)

Claims (6)

A bias magnetic field magnet and a magnetic sensor arranged in the bias magnetic field are provided at each position of the lever shaft.
When the lever shaft made of magnetic material approaches the magnet, a change occurs in the bias magnetic field, and the change in the magnetic flux is output as an electrical signal, and this signal is sent to a computer to detect the position of the lever shaft. Lever shaft position detection device.   The lever shaft position detecting device according to claim 1, wherein the magnetic sensor is a sensor composed of a magnetoresistive element.   The lever shaft position detecting device according to claim 1 or 2, wherein the magnet is formed by printing a sintered magnet or a paste magnet.   The lever shaft position detecting device according to any one of claims 1 to 3, wherein the lever shaft is an automobile AT shift lever.   5. The lever shaft position detection device according to claim 1, wherein a printed circuit board on which a magnetic sensor with magnet is mounted and a printed circuit board on which a position determination circuit is mounted are connected by a wiring material.   6. The lever shaft position detection device according to claim 5, wherein the printed circuit board is a flexible printed circuit board.

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