JP2008008233A - Rotating angle sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pedal sensor which detects rotation of a magnet 23 noncontactingly by a Hall IC and obtains a linear output signal and a switch output signal. <P>SOLUTION: The pedal sensor is constituted of a movable mechanism part and an electric circuit part. The movable mechanism part rotates a rotational shaft provided with the magnet 23 at the tip end side, according to the operation of a pedal. A plurality of Hall ICs 33A to 33C are provided on a face of a substrate in the electric circuit part opposing the magnet 23, for changing magnetic force variation to a voltage signal. The Hall IC 33A for linear output is provided somewhat on the inner side from the outer periphery of the magnet 23 and near an end on one side of a magnetic pole boundary 23A. The Hall IC 33B for output of a first switch is positioned near the Hall IC 33A and is provided concentrically with the Hall IC 33A. The Hall IC 33C for output of a second switch is provided concentrically with the Hall IC 33B opposing thereto. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation angle sensor that can be used in, for example, an electric accelerator pedal device provided in a dump truck, a wheel loader, or the like.

  For example, construction machines such as dump trucks and wheel loaders are equipped with an electric accelerator pedal device in order to control the fuel injection amount of the engine in accordance with the depression amount of the accelerator pedal. When the operator depresses the accelerator pedal, the operation amount is converted into an electric signal and input to the engine controller. The engine controller controls the fuel injection amount and the like according to the depression position of the accelerator pedal.

As a first conventional technique, there is known a technique that converts a rotation amount of a pedal into an electric signal using a potentiometer (Patent Document 1). As a second conventional technique, there is known a technique that converts a rotation amount of an accelerator pedal into an electric signal using a Hall element (Patent Document 2).
JP-A-6-317213 JP 2003-148908 A

  In the first prior art, since a potentiometer is used, there is a possibility that the conductive pattern and the brush may be worn by long-term use, and there is a problem that the life is short. When the Hall element is used, the rotation angle can be detected in a non-contact manner, so that the reliability is increased. However, in the second prior art, the arrangement of the Hall elements has not been sufficiently studied, and there is room for improvement.

  The present invention has been made in view of the above-described problems, and its object is to separate the electric circuit portion and the movable mechanism portion by using the magnet and the magnetic detection element, and to effectively change the magnetic force of the magnet. The object is to provide a rotation angle sensor that is used and improved in usability.

  The rotation angle sensor according to the present invention is a rotation angle sensor that detects the rotation angle of the operating device for controlling the throttle opening as an electrical signal, and detects the operation amount of the operating device as the rotational motion of the rotary shaft. And an electric circuit unit for detecting the rotational movement of the rotary shaft in a non-contact manner, converting it into an electric signal, and outputting the electric signal. The movable mechanism part is provided in a mechanism part case, and is provided rotatably on the mechanism part case. A rotating shaft connected to an operating device side shaft that rotates in response to an operation on the operating device is connected to the base end side of the rotating mechanism shaft. It is provided with a disk-shaped magnet provided on the end surface on the front end side and magnetized in the radial direction. The electric circuit portion is provided so as to be separable facing the mechanism portion case, and is formed through a circuit portion case formed of a nonmagnetic material, a substrate provided in the circuit portion case, and a wall portion of the circuit portion case. A plurality of magnetic detection elements provided on the substrate so as to face the magnet, and a wiring portion having one end side electrically connected to the magnetic detection element through the substrate and the other end side connected to an external device. The magnetic detection element includes a linear output detection element for outputting a linear signal corresponding to the operation amount of the operation device, and a switch output detection for outputting an on / off signal when the operation device is operated. And an element.

  In a preferred embodiment, the detection element for linear output is arranged on the substrate so as to be located on the magnetic pole boundary of the magnet and closer to the outer peripheral side of the magnet.

  In a preferred embodiment, the detection element for linear output is arranged on the substrate so as to be located on the magnetic pole boundary of the magnet and closer to the outer peripheral side of the magnet, and the detection element for switch output is the detection element for linear output Are arranged on the substrate so as to be located on the same circumference.

  In a preferred embodiment, the detection element for linear output is arranged on the substrate so as to be located on the magnetic pole boundary of the magnet and closer to the outer peripheral side of the magnet, and the detection element for switch output is the detection element for linear output It is located on the inner side and is disposed on the substrate.

  In a preferred embodiment, the detection element for linear output is arranged on the substrate so as to be located on the magnetic pole boundary of the magnet and closer to the outer peripheral side of the magnet, and the detection element for switch output passes through the center of the magnet. They are arranged on the same straight line.

  In a preferred embodiment, the plurality of magnetic detection elements are respectively disposed on both sides of the substrate.

  In a preferred embodiment, power is supplied to the linear output detection element, a first electric circuit for extracting a signal from the linear output detection element, and power is supplied to the switch output detection element. And a second electric circuit for taking out a signal from the detection element.

  In a preferred embodiment, the second electrical circuit compares the output voltage from the switch output sensing element with a reference voltage, and outputs an on / off signal when the output voltage is above or below the reference voltage. And an output terminal for taking out an output voltage before being input from the switch output detecting element to the comparator.

  According to the present invention, the amount of rotation of the magnet provided in the movable mechanism portion can be detected by the magnetic detection element provided in the electric circuit portion, converted into an electric signal, and output. Since the movable mechanism portion and the electric circuit portion can be separated, the waterproof performance of the electric circuit portion can be enhanced. Since at least one or more magnetic detection elements are arranged closer to the outer periphery of the magnet, it is possible to effectively use a region where the change in the magnetic field is large.

  According to the present invention, the linear output detecting element for outputting a linear signal corresponding to the operation amount of the operating device is disposed on the magnetic pole boundary of the magnet so as to be positioned closer to the outer peripheral side of the magnet. To place. Therefore, for example, if the magnetic pole boundary is set near the middle point of the operation amount that can be operated by the operation device, a large magnetic field change according to the operation amount can be used, and a linear signal based on the operation amount can be used. Can be output.

  In addition, according to the present invention, since the magnetic detection elements can be arranged on both sides of the substrate, even when the diameter of the magnet is reduced, a plurality of magnetic detection elements are provided at positions where the magnetic force change is large (near the magnetic pole boundary). Can be arranged. Thereby, it is possible to reduce the size of the entire sensor while increasing the detection sensitivity.

  Furthermore, according to the present invention, the first electric circuit related to the linear output detecting element and the second electric circuit related to the switch output detecting element are made independent from each other, and both electric circuits are separated. As a result, it is possible to prevent one electrical circuit from affecting the other electrical circuit and improve reliability.

  In addition, according to the present invention, since the output terminal for taking out the output voltage before being input to the comparator from the switch output detection element is provided, the voltage signal output from the output terminal can be used. Yes, it improves usability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, as will be described in detail below, a magnet that rotates according to the amount of pedal operation is provided in the movable mechanism portion, and a Hall IC for detecting a change in the lines of magnetic force generated by the magnet is provided in the electric circuit portion. Thus, the movable mechanism portion and the electric circuit portion are separated. In this embodiment, the Hall IC is located near the outer periphery of the magnet and is disposed near the magnetic pole boundary.

  FIG. 1 is a side view of the electric accelerator pedal device 1. The electric accelerator pedal device 1 includes an accelerator pedal 2 and a pedal sensor 3. The electric accelerator pedal device 1 is used for, for example, a dump truck, a wheel loader, and the like.

  As will be described later, the accelerator pedal 2 includes, for example, a support frame 10, a mounting bracket 11, a rotation pin 12, a pedal 13, a pedal side shaft 14, and a lever 15.

  The support frame 10 is formed of, for example, a metal plate and is attached to the floor surface of the cab. The front end side of the support frame 10 is an inclined surface 10 </ b> A that is inclined upward, and a mounting bracket 11 is provided on the base end side of the support frame 10.

  The pedal 13 is pivotally attached to the mounting bracket 11 via a pivot pin 12 at the base end side. As shown in FIG. 2, a shaft mounting portion 13 </ b> A is provided on the lower surface of the substantially intermediate portion of the pedal 13 so as to protrude downward. The surface of the pedal 13 is covered with a resin material such as rubber.

  As shown in FIG. 2, both ends of the pedal-side shaft 14 are rotatably attached to the shaft attachment portion 13A. Further, a thin flat plate-like engagement protrusion 14 </ b> A is provided at an end portion of the both ends of the pedal-side shaft 14 located on the pedal sensor 3 side.

  The lever 15 is provided with a rotation pin 15A on the distal end side and a stopper 15B on the proximal end side. Further, near the base end side of the lever 15, a thick cylindrical shaft insertion portion 15C is provided. A roller 16 is rotatably attached to the tip end side of the lever 15 via a rotation pin 15A. The pedal side shaft 14 is inserted through the shaft insertion portion 15C so as not to rotate. Further, a return spring (not shown) is provided between the shaft insertion portion 15C and the shaft attachment portion 13A for constantly urging the pedal 13 to the idle position (initial position).

  Here, the operation of the accelerator pedal 2 will be described with reference to FIGS. The state indicated by the solid line in FIG. 1 is an initial state in which the operator does not depress the pedal 13. In this initial state, the engine controller 1000 controls the fuel injection amount and the like so that the engine has the idling speed.

  When the operator steps on the pedal 13, the pedal 13 rotates in the direction indicated by the arrow FS. In response to the rotation of the pedal 13, the roller 16 moves in the direction of arrow F along the inclined surface 10 </ b> A of the support frame 10. As the roller 16 moves, the lever 15 rotates counterclockwise in FIG.

  In response to the rotation of the lever 15, the pedal side shaft 14 rotates, and the amount of rotation of the pedal side shaft 14 is transmitted to the rotation shaft 22 described later via the engaging protrusion 14A. The operator can step on the pedal 13 until the lever 15 comes into contact with the receiving portion 2A provided on the lower surface side of the pedal 13. The amount of depression of the pedal 13 is detected by the pedal sensor 3 and transmitted to the engine controller 1000 as will be described later. The engine controller 1000 controls the engine speed in accordance with the depression amount (depression position) of the pedal 13. When the pedal 13 returns in the IDL direction, the stopper 15B comes into contact with a receiving portion (not shown), so that the pedal 13 stops at the idle position.

  When the operator removes his / her foot from the pedal 13, the pedal 13 is rotated in the direction indicated by the arrow IDL by the spring force of the return spring, and is idled from the full throttle position (maximum depression position) indicated by a two-dot chain line in FIG. Return to position. The roller 16 moves backward in the direction indicated by the arrow R, and the pedal-side shaft 14 rotates clockwise in FIG.

  The configuration of the pedal sensor 3 will be described. The pedal sensor 3 is detachably attached to the side surface of the shaft attachment portion 13A via an attachment bolt 28. Please refer to FIG. 2 and FIG. The pedal sensor 3 is roughly divided into a movable mechanism unit 20 and an electric circuit unit 30. The movable mechanism 20 has a mechanical configuration for detecting the operation amount of the pedal 13 (the rotation angle of the pedal-side shaft 14) as the rotation angle of the rotation shaft 22. The electric circuit unit 30 is an electric configuration for converting the rotation angle of the rotary shaft 22 into an electric signal and outputting the electric signal.

  The configuration of the movable mechanism unit 20 will be described first. As will be described later, the movable mechanism unit 20 includes a mechanism unit case 21, a rotating shaft 22, a magnet 23, a compressible torsion spring 24, a bearing 25, a dust seal 26, an O-ring 27, and a mounting bolt. 28 and a washer 29 (see FIG. 4). As the bearing 25, for example, an oil-filled bearing can be used in addition to a normal bearing and a bush.

  The mechanism part case 21 is formed, for example, from stainless steel in a stepped cylinder shape, and a rotating shaft 22 is rotatably supported at the center of the mechanism part case 21 via a bearing 25.

  The rotating shaft 22 rotates together with the pedal-side shaft 14, and is formed in a substantially columnar shape with a hook from, for example, nonmagnetic stainless steel. On the base end side of the rotation shaft 22, an engagement recess 22 </ b> A that is engaged with the engagement protrusion 14 </ b> A of the pedal side shaft 14 is integrally provided. A thin disk-shaped magnet 23 is integrally provided on the distal end side of the rotating shaft 22. As shown in FIG. 6, the magnet 23 is magnetized in the radial direction. That is, the surface of the magnet 23 is divided by a line passing through the center, one divided surface is magnetized to the S pole, and the other divided surface is magnetized to the N pole. The magnet 23 rotates with the rotating shaft 22.

  Near the distal end side of the rotating shaft 22, a flange portion 22B protruding in the radial direction is integrally provided. One end of the compressible torsion spring 24 is in contact with the flange portion 22B, and the other end is in contact with the accommodating portion 31A of the circuit portion case 31 via a washer 29 (see FIG. 4). Further, as shown in FIG. 5, one end side of the compressible torsion spring 24 is detachably fixed to a spring engaging portion 22C provided so as to cut out a part of the flange portion 22B. As shown in FIG. 4, the other end side of the possible torsion spring 24 is detachably fixed to a spring engaging portion 31B provided in the accommodating portion 31A.

  Here, the compressible torsion spring 24 will be described. For example, as shown in FIG. 4, the compressible torsion spring 24 is formed in a coil shape of a total of 3 turns, including end turns 24A and 24B on both ends and one turn 24C positioned between the end turns 24A and 24B. Has been. In a free length state where no load is applied, the torsion spring 24 is formed so that a slight gap is left between the wires. And the torsion spring 24 is arrange | positioned between the accommodating part 31A and the collar part 22B in the state compressed to the axial direction.

  If it is a normal torsion spring biased only in the circumferential direction, it is not necessary to be able to compress it. That is, it is not necessary to provide a gap between the wires in a free length state. This is because if a gap for compressing (biasing in the axial direction) is provided, the torsion spring bends obliquely and a predetermined spring force may not be obtained.

  On the other hand, in the present embodiment, one end winding 24A for engaging with the spring engaging portion 21C of the rotary shaft 22 and the other seat for engaging with the spring engaging portion 31B of the circuit portion case 31. A compressible torsion spring 24 is configured with a minimum configuration of the winding 24B and the intermediate winding 24C provided between the end windings 24A and 24B. Thereby, the torsion spring 24 can always urge the rotating shaft 22 toward the idle position and can urge the rotating shaft 22 in the axial direction. Therefore, both the circumferential position and the axial position of the magnet 23 can be realized by the single torsion spring 24, respectively. In this way, in this embodiment, the positioning of the magnet 23 in the circumferential direction and the axial direction is possible only by providing one compressible torsion spring 24, so that the pedal sensor 3 can be reduced in size.

  A dust seal 26 is provided on the outer peripheral side of the base end of the rotary shaft 22. The dust seal 26 is configured as, for example, a rotation oil seal, and prevents foreign matter from entering the mechanism unit case 21 through a gap between the rotary shaft 22 and the mechanism unit case 21. ing.

  An O-ring 27 is provided between the mechanism unit case 21 and the circuit unit case 31. The O-ring 27 prevents external foreign matter from entering the inside through a gap between the case 21 and the case 31.

  Next, the configuration of the electric circuit unit 30 will be described. As shown in FIGS. 2 and 3, the electric circuit section 30 includes a circuit section case 31, a substrate 32, a Hall IC 33, a wiring section 34, a cover 41, mold sections 42 and 43, and a heat shrinkable tube 44. And an O-ring 45.

  The circuit unit case 31 is formed in a bottomed stepped cylindrical shape from a nonmagnetic material such as PBT (Polybutylene terephthalate) resin, for example. The opening surface of the circuit unit case 31 is covered with a cover 41 made of a metal material having magnetism such as SPCC (cold rolled steel). An O-ring 45 is provided between the cover 41 and the circuit unit case 31, and foreign substances from the outside enter the circuit unit case 31 through a gap between the cover 41 and the circuit unit case 31. Preventing intrusion.

  A substrate 32 is provided in the circuit unit case 31 in parallel with the surface of the magnet 23. A step portion 31 </ b> C is formed on the back side of the circuit unit case 31. The substrate 32 is provided in contact with the step portion 31C. A plurality of Hall ICs 33 are provided on the front side (the magnet 23 side) of the substrate 32. The arrangement of the Hall IC 33 will be described later. A plurality of electric circuit elements 32A, connectors, and the like are provided on the back side of the substrate 32 (on the cover 41 side). Examples of the electric circuit element 32A include a noise protection circuit and a switch circuit.

  One end side of the wiring part 34 is connected to the substrate 32, and the other end side extends outside the circuit part case 31 and is connected to the engine controller 1000. The wiring section 34 supplies power to each Hall IC 33 and transmits an output voltage from each Hall IC 33 to the outside.

  A plurality of types of mold parts 42 and 43 are formed in the circuit part case 31. The first mold part 42 occupies most of the space in the circuit part case 31 so as to wrap around the substrate 32 in the circuit part case 31. The second mold part 43 is provided in a part of the circuit part case 31 so as to surround the wiring part 34 extending from the inside of the circuit part case 31 to the outside.

  The first mold part 42 is made of a relatively soft resin material (for example, SU 3001 (hardness type A8) made by Sanyu REC), and the second mold part 43 is made of a relatively hard resin material (for example, SU1500 made by SANYU REC). (Hardness type D83)). The first mold part 42 protects the substrate 32 from external impacts and prevents external foreign matter (dust, moisture, etc.) from entering the substrate 32. The second mold part 43 is provided in the vicinity of the take-out part of the wiring part 34, prevents disconnection of the wiring part 34, and external foreign matter passes through a gap between the wiring part 34 and the circuit part case 31. Intrusion into the circuit unit case 31 is prevented. In addition, the above-mentioned specific resin material name is an example, Comprising: This invention is not limited to the said material. If there is a hardness difference of the degree shown in the above example, the function of protecting the substrate 32 by the first mold part 42 and preventing the entry of foreign matter and moisture, the prevention of disconnection by the second mold part 43 and the prevention of entry of foreign matter and moisture, Each function can be realized.

  The heat-shrinkable tube 44 is provided so as to cover the vicinity where the wiring part 34 has entered the circuit part case 31. The heat shrinkable tube 44 is preliminarily coated with an adhesive on its inner peripheral surface, and adheres to the surface of the circuit unit case 31 and the wiring unit 34. Then, by blowing hot air, the heat-shrinkable tube 44 contracts and comes into close contact with the surfaces of the circuit unit case 31 and the wiring unit 34.

  Next, the configuration of the Hall IC 33 and the magnet 23 will be described in detail. FIG. 6 is an explanatory diagram schematically showing the positional relationship between the Hall IC 33 and the magnet 23. In this embodiment, a total of three Hall ICs, that is, a linear output Hall IC 33A and switch output Hall ICs 33B and 33C are provided as the Hall IC 33.

  The linear output Hall IC 33A is a Hall IC for linearly outputting a signal corresponding to the accelerator position. For convenience of explanation, the Hall IC 33A may be displayed as APS (Accelerator Position Sensor) in the drawing.

  The switch output Hall ICs 33B and 33C are Hall ICs for outputting on / off whether or not the pedal 13 is in the idle position. For convenience of explanation, in the figure, these switch output Hall ICs 33B and 33C may be displayed as IVS (Idle Validation Signal). Whether or not the pedal 13 is in the idle position can be determined by only one of the Hall ICs 33B and 33C for switch output. However, in this embodiment, in order to increase the reliability of the pedal sensor 3, two switch output Hall ICs 33B and 33C are provided, and the idle voltage determination and failure determination are performed using the output voltages of the Hall ICs 33B and 33C. Can be done.

  Each Hall IC 33A to 33C includes a Hall element 331 which is a detection unit. The linear output Hall IC 33A is attached to the substrate 32 such that the Hall element 331 is positioned on the boundary 23A between the N pole and the S pole of the magnet 23.

  The first switch output Hall IC 33B is attached to the substrate 32 so as to be close to the linear output Hall IC 33A. The second switch output Hall IC 33C is attached to the substrate 32 so as to face the first switch output Hall IC 33B by 180 degrees.

  More specifically, as shown in FIG. 6, for example, the Hall ICs 33 </ b> A to 33 </ b> C are arranged on the substrate 32 so that the Hall element 331 serving as the detection unit is in contact with the outer periphery of the magnet 23. That is, the Hall elements 331 of the Hall ICs 33 </ b> A to 33 </ b> C are arranged so as not to protrude outside the outer periphery of the magnet 23 and close to the outer periphery of the magnet 23. In addition, when some Hall ICs are arrange | positioned adjacently among Hall IC33A-33C, it is preferable to arrange | position IC packages as close as possible.

  FIG. 7 is an explanatory diagram showing a simplified mounting state of the Hall ICs 33A to 33C. The linear output hall IC 33A is attached to the substrate 32 so as to be positioned on the magnetic pole boundary 23A in a state where the pedal 13 is depressed to the intermediate position. That is, when the operator steps on the angle θ1 from the idle position, the Hall IC 33A overlaps the magnetic pole boundary 23A.

  If the pedal 13 can be rotated by an angle θ3 from the idle position to the full throttle position, the angle θ1 is set to about half of θ3, for example. When the operator further depresses the pedal 13 by the angle θ2, the pedal 13 reaches the full throttle position. In this embodiment, it is set so that the relationship of θ3 = θ1 + θ2 (θ1 = θ2) is established.

  The linear output Hall IC 33A is provided closer to the outer peripheral side of the magnet 23 in order to increase sensitivity. Each of the switch output Hall ICs 33B and 33C is disposed on the same circumference as the linear output Hall IC 33A or slightly on the inner circumference of the linear output Hall IC 33A.

  FIG. 8 is a characteristic diagram showing the relationship between the rotation angle of the magnet 23 and the change in magnetic force. When the Hall element is located on the magnetic pole boundary 23A, the magnetic force is zero. The linear output Hall IC 33A uses a magnetic force change in an angle range of about θ3 centering on 0 degree in FIG. As shown in FIG. 7, the change in magnetic force in this angular range has relatively high linearity, and as a result, a linear output corresponding to the position of the pedal 13 can be obtained.

  The first switch output Hall IC 33B uses a magnetic force change different from the magnetic force change used by the linear output Hall IC 33A. The change in magnetic force used by each of the switch output Hall ICs 33B and 33C does not have linearity as much as the change in magnetic force used by the linear output Hall IC 33A, and changes relatively comparatively.

  The change in magnetic force used by each switch output Hall IC 33B, 33C is selected so as not to include the maximum magnetic force. That is, each of the switch output Hall ICs 33B and 33C is arranged at a position not including the angle at which the maximum magnetic force is obtained. Generally, since the magnetic force of the magnet 23 has temperature dependence, if it is used in the vicinity of the maximum magnetic force, the change of the magnetic force due to the temperature change becomes large, and the accuracy of the switch output Hall ICs 33B and 33C may be lowered. It is.

  FIG. 9 is an electric circuit diagram of the pedal sensor 3. This electric circuit is roughly classified into a linear output electric circuit 101 and a switch output electric circuit 102.

  Here, the linear output electrical circuit 101 and the switch output electrical circuit 102 are designed such that the output signal, the power supply, and the ground are all independent and do not affect each other. Therefore, for example, the ground levels may be adjusted in the electric circuits 101 and 102, respectively. Noise and ground level fluctuations generated in the other electric circuits 101 and 102 do not affect the other electric circuit.

  The output voltage of the linear output Hall IC 33A is directly output to the engine controller 1000 as an APS output.

  The output voltage of the first switch output Hall IC 33B is compared with the reference voltage VS1 by the comparator 103A. The output voltage of the comparator 103A is inverted from the off signal to the on signal when the output voltage of the Hall IC 33B exceeds the reference voltage VS1. The ON signal of the comparator 103A is output to the engine controller 1000 via the photo switch 104A. The photo switch 104A converts an input voltage signal into an optical signal, and then converts the optical signal into a voltage signal again. Accordingly, the input side and the output side of the photoswitch 104A are electrically insulated.

  Similarly to the first switch output Hall IC 33B, the output voltage of the second switch output Hall IC 33C is compared with the reference voltage VS2 by the comparator 103B, and is output to the outside via the photoswitch 104B. However, since the second switch output Hall IC 33C and the first switch output Hall IC 33B are provided to face each other by 180 degrees, the phase of the signal is shifted. The output voltage of the comparator 103B is inverted from the on signal to the off signal when the output voltage of the Hall IC 33C falls below the reference voltage VS2.

  FIG. 10 is an explanatory diagram showing the relationship between the output voltage of each switch output Hall IC 33B, 33C and the signal output from the electric circuit 102. In FIG. Here, the reference voltages VS1 and VS2 are set as intermediate voltages of the IVS power supply. For example, when the voltage of the IVS power supply is set to 5 volts, the reference voltages VS1 and VS2 are each set to about 2.5 volts.

  When the pedal 13 is depressed by the operator, the magnet 23 rotates according to the rotation of the pedal 13, and the magnetic force incident on the Hall ICs 33B and 33C changes. As a result, the output voltage of the first switch output Hall IC 33B (IVS1) exceeds the reference voltage VS1, and the signal of IVS1 shifts from the off state to the on state.

  Similarly, since the output voltage of the second switch output Hall IC 33C (IVS2) is lower than the reference voltage VS2 when the angle of the magnet 23 changes according to the rotation of the pedal 13, the signal of IVS2 is turned off from the on state. Transition to the state.

  Therefore, when the IVS1 signal is on and the IVS2 signal is off, the start of the pedal 13 can be detected. The start of depression of the pedal 13 (start of access operation) can be detected by only one of the signals IVS1 and IVS2. However, in this case, if an abnormal signal is output due to disconnection or voltage wraparound, this abnormality cannot be detected. On the other hand, the operation start of the pedal 13 can be reliably detected by using the two types of signals IVS1 and IVS2 whose signals are inverted by the operation start of the pedal 13. Even if one of the signals is abnormal, this abnormal state can be detected by the other normal signal.

  The output signals IVS1 and IVS2 based on the switch output Hall ICs 33B and 33C are used, for example, when a failure occurs in the linear output Hall IC 33A. That is, even when a failure occurs in the linear output hall IC 33A, if the start of operation of the pedal 13 is detected, the engine speed is set to a low speed or a medium low speed, thereby constructing a dump truck or a wheel loader. The machine can be moved to a safe place.

  In the present embodiment, as described above, the pedal sensor 3 is configured as a non-contact type sensor and is completely separated into the movable mechanism unit 20 and the electric circuit unit 30, thereby improving the waterproof performance of the electric circuit unit 30. Can do.

  In the present embodiment, since the compressible torsion spring 24 is disposed between the circuit unit case 31 and the mechanism unit case 21 in a compressed state, the magnet 23 is positioned in the circumferential direction and the axial direction by the single torsion spring 24. Can be performed respectively. Thereby, the number of parts required for positioning of the magnet 23 can be halved, the manufacturing efficiency can be increased, and the cost can be reduced. Moreover, the positioning mechanism of the magnet 23 can be reduced in size by the single torsion spring 24. As a result, the size of the pedal sensor 3 can be reduced in size.

  In the present embodiment, the circuit part case 31 wraps the first mold part 42 made of a relatively soft resin material so as to wrap the substrate 32 and the lead part of the wiring part 34 made of a relatively hard resin material. A second mold part 43 provided in this manner. Therefore, the substrate 32 can be protected by the first mold part 42 and the wiring part 34 can be prevented from being disconnected, and in combination with the configuration in which the electric circuit part 30 is separated from the movable mechanism part 20, the reliability can be further improved. It can be further enhanced.

  In this embodiment, when the pedal 13 is operated to the intermediate position, the linear output Hall IC 33A is arranged so as to overlap the magnetic pole boundary. Thirteen operation amounts can be detected.

  In this embodiment, since the switch output Hall ICs 33B and 33C are used within a range where the magnetic force of the magnet 23 does not take the maximum value, even when the environmental temperature changes and the magnetic force fluctuates, the operation start of the pedal 13 is detected. Can improve reliability.

  Based on FIG. 11, the modification regarding the arrangement | positioning method of Hall IC33 is demonstrated. In the first embodiment, as described with reference to FIG. 7, the linear output Hall IC 33 </ b> A is disposed on the magnetic pole boundary 23 </ b> A so as to be slightly inside the outer periphery of the magnet 23. The case where the first switch output Hall IC 33B is disposed in the vicinity of the linear output Hall IC 33A and the second switch output Hall IC 33C is disposed at a position facing the Hall IC 33B has been described.

  On the other hand, in this embodiment, as shown in FIG. 11, the linear output Hall IC 33A and the switch output Hall ICs 33B and 33C are arranged on the same circumference. In this case, it is preferable to arrange the Hall ICs 33 </ b> A to 33 </ b> C so as to be located slightly inside the outer periphery of the magnet 23. This is because the magnetic force increases as it approaches the outer peripheral side of the magnet 23.

  FIG. 12 is an explanatory diagram showing a method for arranging the Hall ICs 33 according to the third embodiment. In the present embodiment, the linear output Hall IC 33A is disposed on the magnetic pole boundary 23A and slightly closer to the inside of the outer periphery of the magnet 23. Further, the first switch output Hall IC 33B is disposed on the magnetic pole boundary 23A and inside the linear output Hall IC 33A. Then, the second switch output Hall IC 33C is disposed on the magnetic pole boundary 23A at a position facing the linear output Hall IC 33A.

  FIG. 13 is an explanatory diagram showing a method of arranging the Hall ICs 33 according to the fourth embodiment. In this embodiment, the linear output Hall IC 33A and the switch output Hall ICs 33B and 33C are arranged close to one side of the magnetic pole boundary 23A. In other words, the linear output Hall IC 33A is arranged on the magnetic pole boundary 23A and slightly inside the outer periphery of the magnet 23, and the first switch output Hall IC 33B is on the magnetic pole boundary 23A and the linear output Hall IC 33A. The second switch output Hall IC 33C is disposed on the inner side of the first switch output Hall IC 33B on the magnetic pole boundary 23A.

  FIG. 14 is an explanatory diagram showing a method of arranging the Hall ICs 33 according to the fifth embodiment. In this embodiment, the linear output Hall IC 33A is arranged on the magnetic pole boundary 23A and slightly inside the outer periphery of the magnet 23. The first switch output Hall IC 33B is located on the same circumference as the linear output Hall IC 33A, and is disposed in the vicinity of the linear output Hall IC 33A. The second switch output Hall IC 33C is located inside the circumference where the linear output Hall IC 33A and the first switch output Hall IC 33B are located, and is disposed in the vicinity of the first switch output Hall IC 33B.

  FIG. 15 is an explanatory diagram showing a method of arranging the Hall ICs 33 according to the sixth embodiment. In the present embodiment, a plurality of linear output Hall ICs 33A and 33D and a plurality of switch output Hall ICs 33B and 33C are provided.

  Each of the linear output Hall ICs 33A and 33D is disposed so as to face both end sides of the magnetic pole boundary 23A. That is, the first linear output Hall IC 33A is disposed on the magnetic pole boundary 23A and slightly closer to the inner side of the outer periphery of the magnet 23. The second linear output Hall IC 33D is arranged on the same circumference as the first linear output Hall IC 33A on the magnetic pole boundary 23A so as to face the first linear output Hall IC 33A.

  Each of the switch output hall ICs 33B and 33C is located in the vicinity of the linear output hall ICs 33A and 33D and is arranged to face the linear output hall ICs 33A and 33D on the same circumference.

  FIG. 16 is an explanatory diagram showing a method of arranging the Hall ICs 33 according to the seventh embodiment. In this embodiment, Hall ICs 33 </ b> A to 33 </ b> C are provided on both surfaces of the substrate 32. As schematically shown in a partial cross section of the substrate 32, the Hall IC 33 and the magnet 23 on the upper side of FIG. 16, the linear output Hall IC 33 </ b> A faces the magnet 23 so as to face the front surface of the substrate 32 (facing the magnet 23. On the surface to be carried out). The linear output hall IC 33 </ b> A is located slightly inside from the outer periphery of the magnet 23 and is disposed at one end of the magnetic pole boundary 23 </ b> A.

  The first switch output Hall IC 33B is located directly behind the linear output Hall IC 33A, and is provided on the rear surface of the substrate 32 (the surface opposite to the surface facing the magnet 23). The second switch output Hall IC 33C is located on the same circumference as the linear output Hall IC 33A and the first switch output Hall IC 33B, and is disposed at the other end of the magnetic pole boundary 23A. Similar to the first switch output Hall IC 33B, the second switch output Hall IC 33C is provided on the rear surface of the substrate 32.

  Thus, by providing the Hall ICs 33A to 33C using both surfaces of the substrate 32, the area for mounting the Hall ICs 33A to 33C on the substrate 32 can be reduced, and the diameter of the magnet 23 can be shortened. . As a result, the pedal sensor 3 can be made smaller than in the above embodiments.

  FIG. 17 is an explanatory diagram showing a method of arranging the Hall ICs 33 according to the eighth embodiment. In the seventh embodiment, only the linear output Hall IC 33A is disposed on the front surface of the substrate 32, and the switch output Hall ICs 33B and 33C are disposed on the rear surface of the substrate 32. On the other hand, in this embodiment, the linear output Hall IC 33A and the second switch output Hall IC 33C are provided on the front surface of the substrate 32, and the first switch output Hall IC 33B is provided on the rear surface of the substrate 32. Configuring this embodiment like this also achieves the same effects as the seventh embodiment.

  FIG. 18 is a table showing how to use the signal pattern of the pedal sensor 3 according to the ninth embodiment. In the following description, reference is made to FIG. 9 and FIG. First, a signal that can be output from the pedal sensor 3 of this embodiment will be described with reference to FIG.

  The pedal sensor 3 can output a total of five types of signals to the outside. The first signal is a linear voltage signal (APS output) output from the linear output Hall IC 33A. The second signal is an on / off signal (IVS1) output by comparing the output voltage of the first switch output Hall IC 33B by the comparator 103A. The third signal is an on / off signal (IVS2) output by comparing the output voltage of the second switch output Hall IC 33C by the comparator 103B.

  The fourth signal is an output voltage signal (linear output 2) before being input from the first switch output Hall IC 33B to the comparator 103A. The fifth signal is an output voltage signal (linear output 3) before being input from the second switch output Hall IC 33C to the comparator 103B. As shown in FIG. 10, the voltage signals output from the switch output Hall ICs 33 </ b> B and 33 </ b> C change substantially linearly as the magnetic force changes due to the rotation of the magnet 23. Therefore, the output voltage before being input to the comparators 103A and 103B can be used as a linear voltage signal. Hereinafter, “linear output 2” may be referred to as a second linear output signal, and “linear output 3” may be referred to as a third linear output signal.

  Please refer to FIG. As described above, since a total of five types of signals can be used in this embodiment, the pedal sensor 3 is roughly divided into seven types (patterns) as shown in the sensor signal pattern table T1 in FIG. It is available at.

  The first type is a case where the pedal sensor 3 outputs only one APS signal. As described above, the APS signal is a signal that continuously changes in accordance with the operation amount of the accelerator pedal 2. When the pedal sensor 3 is used as the first type, only the output signal of the linear output Hall IC 33A may be input to the engine controller 1000.

  The second type is a case where the pedal sensor 3 outputs one APS signal and one IVS signal. The IVS signal is an on / off signal for detecting the start of operation of the accelerator pedal 2 as described above. When the pedal sensor 3 is used as the second type, the output signal of the linear output hall IC 33A and the comparator 103A connected to the first switch output hall IC 33B (33C may be used) (when using the hall IC 33C, the comparator The output signal (IVS1) from 103B may be input to the engine controller 1000.

  The third type is a case where the pedal sensor 3 outputs one APS signal and two IVS signals. When the pedal sensor 3 is used as the third type, the APS signal from the linear output Hall IC 33A and the IVS signal based on the switch output Hall ICs 33B and 33C are used as described in the above embodiments. 1000 may be input respectively.

  The fourth type is a case where the pedal sensor 3 outputs two APS signals and one IVS signal. When the pedal sensor 3 is used as the fourth type, the output signal of the linear output Hall IC 33A, the IVS signal from the second switch output Hall IC 33C, and the second linear output signal are respectively input to the engine controller 1000. That's fine. Alternatively, the fourth type pedal sensor 3 can be obtained by using the output signal of the linear output Hall IC 33A, the IVS signal of the first switch output Hall IC 33B, and the third linear output signal.

  Here, the rotation of the magnet 23 and the output voltage are proportional to the linear output Hall IC 33A and the first switch output Hall IC 33B. That is, the output voltage of the Hall IC 33A and the output voltage of the Hall IC 33B change in the same manner. Therefore, in the following description, for convenience, two types of APS signals showing the same change are called “same characteristics”, and two types of APS signals showing the opposite changes are called “reverse characteristics”. The reverse characteristic is a case where one APS signal changes proportionally and the other APS signal changes inversely as the magnet 23 rotates. When an APS signal that changes in proportion and an APS signal that shows an inversely proportional change are superimposed on the graph, it looks like an X-shape, so it can also be called an X pattern.

  The fifth type is a case where the pedal sensor 3 outputs only two APS signals. In this case, it can be classified into three types of sub-patterns. First, the APS signal and the second linear output signal (linear output 2) of the linear output Hall IC 33A can be selected. Second, the APS signal of the Hall IC 33A and the third linear output signal (linear output 3) can be selected. Third, the second linear output signal and the third linear output signal can be selected. Note that the third linear output signal output from the Hall IC 33C is used as a signal that varies in proportion to the APS signal and the second linear output signal by shifting the phase by 180 degrees. Therefore, the fifth type outputs a plurality of APS signals with the same characteristics.

  The sixth type outputs a plurality of APS signals with reverse characteristics and outputs one IVS signal. In this case, the APS signal and the second linear output signal of the Hall IC 33A and the IVS signal of the Hall IC 33C are selected. Alternatively, the APS signal and the third linear output signal of the Hall IC 33A and the IVS signal of the Hall IC 33B are selected.

  As in the fifth type, the seventh type outputs two APS signals and one IVS signal. In the fifth type, two APS signals are output with the same characteristics, while in the seventh type, two APS signals are output with opposite characteristics. In the seventh type, first, the APS signal and the second linear output signal of the linear output Hall IC 33A can be selected. Second, the APS signal and the third linear output signal of the Hall IC 33A can be selected. Third, the second linear output signal and the third linear output signal can be selected.

  In this way, the pedal sensor 3 according to the present embodiment has three types of linear output signals (APS signal, APS signal, (Second linear output signal, third linear output signal) and two types of IVS signals can be obtained. Therefore, an appropriate signal corresponding to the control method of the engine controller 1000 can be easily obtained, and various control methods can be handled.

  The present invention is not limited to the above-described embodiment. A person skilled in the art can make various additions and changes within the scope of the present invention.

The side view of the electric accelerator pedal apparatus by the Example of this invention. Sectional drawing seen from the arrow II-II direction in FIG. Sectional drawing which expands and shows a pedal sensor. The exploded perspective view of a pedal sensor. The perspective view which looked at the movable mechanism part from the magnet side. Explanatory drawing which shows the arrangement | positioning relationship between a magnet and Hall IC. Explanatory drawing which simplifies and shows the arrangement | positioning relationship between a magnet and Hall IC. The characteristic view which shows the relationship between the rotation angle of a magnet, and the change of magnetic force. The electric circuit diagram of a pedal sensor. The signal diagram which shows the relationship between the output voltage of Hall IC for switch output, and the signal for detecting the operation start of a pedal. It is explanatory drawing which shows the arrangement | positioning method of Hall IC by 2nd Example. It is explanatory drawing which shows the arrangement | positioning method of Hall IC by 3rd Example. It is explanatory drawing which shows the arrangement | positioning method of Hall IC by 4th Example. It is explanatory drawing which shows the arrangement | positioning method of Hall IC by 5th Example. It is explanatory drawing which shows the arrangement | positioning method of Hall IC by 6th Example. It is explanatory drawing which shows the arrangement | positioning method of Hall IC by 7th Example. It is explanatory drawing which shows the arrangement | positioning method of Hall IC by 8th Example. It is explanatory drawing which shows the arrangement | positioning method of Hall IC by 9th Example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric accelerator pedal apparatus, 2 ... Accelerator pedal, 3 ... Pedal sensor, 10 ... Support frame, 10A ... Inclined surface, 11 ... Mounting bracket, 12 ... Turning pin, 13 ... Pedal, 13A ... Shaft attaching part, 14 ... Pedal side shaft, 14A ... engagement protrusion, 15 ... lever, 15A ... rotation pin, 15B ... stopper, 15C ... shaft insertion part, 16 ... roller, 20 ... movable mechanism part, 21 ... mechanism part case, 22 ... rotation Shaft, 22A ... engaging recess, 22B ... collar, 22C ... spring engaging portion, 23 ... magnet, 23A ... magnetic pole boundary, 24 ... compressible torsion spring, 24A, 24B ... end winding, 24C ... intermediate winding, 25 ... Bearing, 26 ... Dust seal, 27 ... O-ring, 28 ... Mounting bolt, 29 ... Washer, 30 ... Electric circuit part, 31 ... Circuit part case, 31A ... Accommodating part, 31B ... Net engaging part, 31C ... Step part, 32 ... Board, 32A ... Electric circuit element, 33A ... Hall IC for linear output, 33B, 33C ... Hall IC for switch output, 34 ... Wiring part, 41 ... Cover, 42 ... No. 1 mold part, 43 ... second mold part, 44 ... heat shrinkable tube, 45 ... O-ring, 101 ... electric circuit for linear output, 102 ... electric circuit for switch output, 103A, 103B ... comparator, 104A, 104B ... photo switch 331 ... Hall element, 1000 ... Engine controller

Claims (8)

A rotation angle sensor (3) for detecting a rotation angle of an operating device (2) for controlling a throttle opening as an electrical signal,
A movable mechanism (20) for detecting the amount of operation of the operating device as the rotational motion of the rotating shaft (22), and for detecting the rotational motion of the rotating shaft in a non-contact manner, converting it into an electrical signal and outputting it. And an electric circuit section (30).
The movable mechanism (20)
A mechanism case (21);
The rotating shaft (22) provided on the mechanism case so as to be rotatable, and connected to an operating device side shaft (14) that rotates in response to an operation of the operating device on a base end side thereof,
A disc-shaped magnet (23) provided on the end surface of the rotating shaft and magnetized in the radial direction,
The electrical circuit section (30)
The circuit part case (31) formed so as to be separable facing the mechanism part case and made of a nonmagnetic material,
A substrate (32) provided in the circuit unit case;
A plurality of magnetic detection elements (33, 33A, 33B, 33C) provided on the substrate so as to face the magnet (23) through the wall of the circuit unit case;
A wiring portion (34) having one end side electrically connected to the magnetic detection element through the substrate and the other end side connected to an external device;
Configured with
The magnetic detection element outputs a linear output detection element (33A) for outputting a linear signal corresponding to the operation amount of the operating device (2), and outputs an on / off signal when the operating device is operated. And a switch output detecting element (33B, 33C) for rotation angle sensor.   The rotation according to claim 1, wherein the linear output detecting element (33A) is arranged on the substrate so as to be positioned on a magnetic pole boundary (23A) of the magnet and closer to an outer peripheral side of the magnet. Angular sensor. The linear output detecting element (33A) is disposed on the substrate so as to be positioned on the magnetic pole boundary (23A) of the magnet and closer to the outer peripheral side of the magnet,
The rotation angle sensor according to claim 1, wherein the switch output detection element (33B, 33C) is disposed on the substrate so as to be positioned on the same circumference as the linear output detection element. The linear output detecting element (33A) is disposed on the substrate so as to be positioned on the magnetic pole boundary (23A) of the magnet and closer to the outer peripheral side of the magnet,
The rotation angle sensor according to claim 1, wherein the switch output detection element (33B, 33C) is disposed on the substrate so as to be located inside the linear output detection element. The linear output detecting element (33A) is disposed on the substrate so as to be positioned on the magnetic pole boundary (23A) of the magnet and closer to the outer peripheral side of the magnet,
The rotation angle sensor according to claim 1, wherein the switch output detection elements (33B, 33C) are arranged on the same straight line passing through a center of the magnet.   The rotation angle sensor according to claim 1, wherein the plurality of magnetic detection elements are respectively disposed on both surfaces of the substrate.   A power source is supplied to the linear output detection element (33A), and a power is supplied to the first electric circuit (101) for extracting a signal from the linear output detection element and the switch output detection elements (33B, 33C). The rotation angle sensor according to claim 2, wherein the second electric circuit (102) for supplying a signal and taking out a signal from the switch output detecting element is independent of each other. The second electric circuit (102) compares an output voltage from the switch output detection element with a reference voltage, and outputs an on / off signal when the output voltage is higher or lower than the reference voltage. Comparators (103A, 103B);
The rotation angle sensor according to claim 7, further comprising an output terminal for taking out the output voltage before being input to the comparator from the switch output detection element.

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