Abstract:
It is an object of the present invention to provide a non-contact rotary movement sensor capable of, by making magnetic fields from a plurality of permanent magnets not mutually affected, independently implementing an output signal and a switching signal using the same. It is another object of the present invention to provide a non-contact rotary movement sensor provided with an independent switch which outputs an output signal by using a permanent magnet and a Hall device and outputs a switching signal using a contact switch. The non-contact rotary movement sensor with an independent switch includes: a rotating body, provided with a first permanent magnet installed on an upper part, a key slot installed on a lower part, and a second permanent magnet installed on a trigger which is projected on a part of an external circumference, for being rotatably driven by an external force, wherein the first permanent magnet and the second permanent magnet are installed not to be affected by mutual magnetic fields; and a printed circuit board provided with at least one Hall device for outputting a linear output signal by detecting a direction change of a magnetic field of the first permanent magnet and at least one lead switch for outputting a switching signal by detecting a strength change of a magnetic field of the second permanent magnet.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a non-contact rotary movement sensor capable of independently implementing an output signal and a switching signal by corresponding two permanent magnets which have different magnetic flux directions respectively to a Hall device and to a lead switch or by corresponding one permanent magnet to the Hall device and using a contact switch as a switching signal. 
   2. Background of the Related Art 
   Generally, a rotary movement sensor is used for applying a amount of physical change of a continuously changing rotating body to an electric circuit, and a rotary position displacement sensor with a linear electric signal output function is used in various ways in each field of industry. 
   A rotary movement sensor is used mainly in position control of engine throttle valve of a vehicle, control of a steering wheel, height control of a vehicle, variable vane position control of an intake and exhaust valves of an engine, or speed control of an engine corresponding to the movement of an accelerator pedal. Also, a rotary movement sensor is used in control of the engine rotation speed of an agricultural machine or a heavy equipment and measurement of opening and closing of a fluid supply valve. 
   Many methods are used for measuring a rotary displacement, such as a potentiometer method which proportionally outputs the rotary angle of a rotating body which relatively moves to a fixed body, an encoder method which outputs as an optical code, an induced magnet measurement method, and an integrated circuit method using a Hall effect of a magnetic resistance. 
   A rotary movement sensor should be able to be used at the temperature of −40□ to 70□ which is required in rough working condition of a vehicle for commercial use or a heavy equipment and maintaining the durability which exceeds five million operation times which is required in an environmental condition such as dust and working. 
   A conventional contact type variable resistance sensor has weak points that the electric characteristic is not constant according to the temperature, and that the durability or the life span is shortened by the abrasion of the electric resistance track which is a contact part of a variable resistance and a brush. Especially, the contact type variable resistance sensor has a difficulty in working as the initially set electric resistance value changes during usage. 
   Korean registered patent No. 0504106 and No. 0458375 and U.S. Pat. No. 6,597,168 suggest non-contact type rotary movement sensors for making up for the weak points of a contact type rotary movement sensor. However, the non-contact type rotary movement sensors of the above-mentioned patents have the weak points that the production structure is complex as a balanced sensing bar with multiple openings is included in the configuration, and that switching is dependent on signal outputting. 
   SUMMARY OF THE INVENTION 
   Technical Problem 
   The present invention has been proposed in order to overcome the above-described problems in the related art. It is, therefore, an object of the present invention to provide a non-contact rotary movement sensor capable of, by making magnetic fields from a plurality of permanent magnets not mutually affected, independently implementing an output signal and a switching signal using the same. 
   It is another object of the present invention to provide a non-contact rotary movement sensor provided with an independent switch which outputs an output signal by using a permanent magnet and a Hall device and outputs a switching signal using a contact switch. 
   It is still another object of the present invention to provide a non-contact rotary movement sensor capable of protecting an inner structure from a foreign material from outside by forming a separating plate which physically separates multiple permanent magnets, a Hall device and a lead switch. 
   It is still another object of the present invention to provide a non-contact rotary movement sensor capable of protecting an inner structure from an external magnetic or electric disturbance by including a shielding cover which covers and wraps a printed circuit board in a configuration. 
   Technical Solution 
   In accordance with an aspect of the present invention, there is provided a non-contact rotary movement sensor with an independent switch, including: a rotating body, provided with a first permanent magnet installed on an upper part, a key slot installed on a lower part, and a second permanent magnet installed on a trigger which is projected on a part of an external circumference, for being rotatably driven by an external force, wherein the first permanent magnet and the second permanent magnet are installed not to be affected by mutual magnetic fields; and a printed circuit board provided with at least one Hall device for outputting a linear output signal by detecting a direction change of a magnetic field of the first permanent magnet and at least one lead switch for outputting a switching signal by detecting a strength change of a magnetic field of the second permanent magnet. 
   In accordance with another aspect of the present, there is provided a non-contact rotary movement sensor with an independent switch, including: a rotating body, provided with a permanent magnet installed at an upper part, a key slot installed at a lower part, and a pushing rod installed on a trigger which is projected on a part of an external circumference, for being rotatably driven by an external force; and a printed circuit board connected with at least one Hall device for outputting a linear output signal by detecting a direction change of a magnetic field of the permanent magnet, a common contact part which moves by the pushing rod according to the rotation of the rotating body, and a first contact part and a second contact part which are contacted with the common contact part, alternatively. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which: 
       FIG. 1  is a perspective view illustrating a non-contact rotary movement sensor with an independent switch in accordance with one embodiment of the present invention; 
       FIG. 2  is a perspective view showing a back side of  FIG. 1  in accordance with one embodiment of the present invention; 
       FIG. 3  is an exploded perspective view illustrating a non-contact rotary movement sensor with an independent switch in accordance with one embodiment of the present invention. 
       FIG. 4  is an exploded perspective view showing a back side of  FIG. 3  in accordance with one embodiment of the present invention; 
       FIG. 5  is a cross-sectional view illustrating a rotating body and a printed circuit board in accordance with one embodiment of the present invention; 
       FIG. 6  is a logic circuit diagram illustrating steps of processing a linear output signal and a switching signal in accordance with one embodiment of the present invention; 
       FIG. 7  is a graph illustrating the linear output signal and the switching signal corresponding to a rotary angle of a rotating body in accordance with one embodiment of the present invention; 
       FIG. 8  is a perspective view illustrating a rotating body in accordance with another embodiment of the present invention; and 
       FIG. 9  is a perspective view illustrating a non-contact rotary movement sensor with an independent switch in accordance with another embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. 
   Before describing the embodiments of the present invention, the terms and words used in the specification and claims must not be interpreted in their usual or dictionary sense, but are to be interpreted as broadly as is consistent with the technical thoughts of the invention disclosed herein based upon the principle that the inventor can define the concepts of the terms properly in order to explain the invention in the best way. 
   Accordingly, the embodiments described in this specification and the construction shown in the drawings are nothing but one preferred embodiment of the present invention, and it does not cover all the technical ideas of the invention. Thus, it should be understood that various changes and modifications may be made upon the point of time of this application. 
     FIG. 1  is a perspective view illustrating a non-contact rotary movement sensor with an independent switch in accordance with one embodiment of the present invention and  FIG. 2  is a perspective view showing a back side of  FIG. 1  in accordance with one embodiment of the present invention. As shown in  FIG. 1  and  FIG. 2 , the non-contact rotary movement sensor in accordance with one embodiment of the present invention includes a housing  100  which is connected to a fixed part of a car body such as a chassis. At this time, one side of the housing  100  is partly covered with a first housing cover  110 , and the other side is covered with a second housing cover  200  where a penetrating hole is formed for a key slot  210  where a working area of a pedal of a valve is inserted to be exposed. Also, on a side part of the housing  100 , a connector  120  is formed through which a wire  333  is capable of being connected to an external counter connector  130 . 
     FIG. 3  is an exploded perspective view illustrating a non-contact rotary movement sensor with an independent switch in accordance with one embodiment of the present invention and  FIG. 4  is an exploded perspective view showing a back side of  FIG. 3  in accordance with one embodiment of the present invention. As shown in  FIG. 3  and  FIG. 4 , the non-contact rotary movement sensor in accordance with one embodiment of the present invention comprises a housing  100 , a rotating body  310 , a restoring spring  320 , a printed circuit board  330 , a shielding cover  340  and other components. 
   A separating plate  303  is formed at an inside of the housing  100  in accordance with one embodiment of the present invention housing  100 , to separate the inside of the housing  100  into a first area  301  and a second area  302 . And, the first area  301  including an upper part is covered with the first housing cover  110 , and the second area  302  including a lower part is covered with the second housing cover  200  where the penetrating hole  201  is partly formed. Also, the connector  120  with the inside penetrated, is externally projected at a side part of the housing  100 . 
   A rotating body  310  in accordance with one embodiment of the present invention includes a first permanent magnet  312  which is fixed at an upper part  311 , a key slot  210  which is formed at a lower part  313 , a trigger  314  which is projected on a part of a circumference part with the second permanent magnet  315  fixed. At this time, the upper part of the rotating body  310  is combined with a separating plate  303  which exists at the second area  302  of the housing  100 , and the lower part  313  of the rotating body  310  is combined to the penetrating hole  201  at the second housing cover  200  and projects the key slot  210  to the outside. 
   At this time, in accordance with one embodiment of the present invention, it is desirable to have the trigger  314  which is projected at a part of the external circumference to a direction of the upper part  311  of the rotating body  310 . 
   Also, in accordance with one embodiment of the present invention, it is desirable that a plane of a magnetic field of the first permanent magnet  312  which is fixed at the upper part  311  of the rotating body  310  is perpendicular to a plane of a magnetic field of the second permanent magnet  315  which is fixed at the trigger  314 . 
   Also, in accordance with one embodiment of the present invention, the first permanent magnet  312 , wherein polarity is arranged to the circumference direction of the rotating body  310 , plays a role of providing a direction change of the magnetic field resulting from a rotation of the rotating body  310  to the Hall device  311 . And, the second permanent magnet  315 , wherein polarity is arranged to the central axis direction of the rotating body  310 , plays a role of providing a strength change of the magnetic field resulting from a rotation of the rotating body  310  to the lead switch  332   
   The restoring spring  320  in accordance with one embodiment of the present invention is located between the upper part  311  of the rotating body  310  and the separating plate  303 , and plays a role of restoring the rotating body  310  to an original position when the rotating body  310  has rotated. 
   In accordance with one embodiment of the present invention, the rotating body  310  is capable of securing a stable movement against a vibration of a sensor or an external vibration by receiving an one-sided rotary power which always tries to return to the original position. Therefore, the sensor uniformly and securely provides the direction or the strength of the magnetic field to the Hall device  331  and the lead switch  332 . 
   A printed circuit board  330  in accordance with one embodiment of the present invention has one side combined to the other side of the separating plate  303  which exists at the first area  301  of the housing  100 , and has at least one Hall device  331  and at least one lead switch  332  attached to the side of the printed circuit board. Also, the wire  333  is formed on a part of the printed circuit board  330 . The wire  333  is connected to the counter connector  130  at the outside penetrating through the connector  120  which is formed on the side part of the housing  100 . 
   At this time, in accordance with one embodiment of the present invention, it is desirable that the lead switch  332  which is formed on one side of the printed circuit board  330  is equipped with a short-circuit switch signal with at least one contact point. 
   Also, in accordance with one embodiment of the present invention, the Hall device  331  which is attached to one side of the printed circuit board  330  is formed right above the first permanent magnet  312 , having the separating plate  303  in between. Such a Hall device  331  plays a role of outputting the direction change of the magnetic field which is provided at the first permanent magnet  312  as a linear output signal. 
   Also, in accordance with one embodiment of the present invention, the lead switch  332  which is attached to one side of the printed circuit board  330  is formed right above the rotation circumference on which the second permanent magnet  315  moves, having the separating plate  303  in between. The lead switch  332  plays a role of outputting a switching signal at a place where the magnetic field which is provided from the second permanent magnet  315  makes a biggest change, and at this time, the lead switch  332  and the second permanent magnet  315  are on a straight line. 
   And, the Hall device  331  and the lead switch  332  are connected to the other related devices which are formed on the printed circuit board  330  through an electric wire, and, through an appropriate treatment such as amplification, filtering noise, switching signal, A/D, controller area network (CAN) communication transformation, sends the output signal to the wire  333 . The wire  333  which conveys the output signal is connected to the external counter connector  130  and provides the sensor signal to the external devices. 
   At this time the separating plate  303  in accordance with one embodiment of the present invention plays a role of protecting the components which are formed inside of the housing  100  from the external dust and moisture at the atmosphere by physically separating the rotating body  310  and the lead switch  332 . 
   The shielding cover  340  in accordance with one embodiment of the present invention plays a role of wrapping the first area  301  of the housing  100  where the printed circuit board  330  exists and securing the functional characteristic of the sensor by blocking the external magnetic or electric disturbance. 
   In accordance with one embodiment of the present invention, it is desirable that the shielding cover  340  includes a permalloy material which is made from Ni—Fe. 
   The signal of the Hall device  331  and the lead switch  332  which are outputted corresponding to the change of the magnetic field of the first permanent magnet  312  and the second permanent magnet  315  in accordance with one embodiment of the present invention is explained in detail hereinafter. 
     FIG. 5  is a cross-sectional view illustrating a rotating body and the printed circuit board in accordance with one embodiment of the present invention. When the rotating body  310  rotates in one side, the first permanent magnet  312  which is fixed to the upper part of the rotating body  310  provide the influence of a magnetic field  500  in the circumference direction of the rotating body  310  to the Hall device  331  which is attached to the printed circuit board  330 . Therefore, the Hall device  331  is capable of linearly outputting the output signal corresponding to the rotation angle of the sensor. At this time, it is desirable that the distance between the first permanent magnet  312  and Hall device  331  is 8 mm or less than 8 mm. 
   Also, when the rotating body  310  rotates to one side against the housing  100 , the second permanent magnet  315  which is projected on the circumference of the rotating body  310  provides influence of the magnetic field  510  on the lead switch  332  attached to the printed circuit board  330  in the central axis direction of the rotating body  310 . Therefore, the lead switch  332  is capable of outputting a short circuit switching signal which operates independently of the linear output signal, corresponding to the strength of the magnetic field which is generated by the second permanent magnet  315 . 
     FIG. 6  is a logic circuit diagram illustrating steps of processing a linear output signal and a switching signal in accordance with one embodiment of the present invention and  FIG. 7  is a graph illustrating the linear output signal and switching signal corresponding to a rotary angle of a rotating body in accordance with one embodiment of the present invention. As shown in  FIG. 6  and  FIG. 7 , the linear output signal of the Hall device  331  corresponding to the change of magnetic field of the first permanent magnet  312  and the switching signal of the lead switch  332  corresponding to the change of magnetic field of the second permanent magnet  315  are outputted independently. At this time, the lead switch  332  is designed to get at least one contact of short circuit switching signal, and the on/off status of the short circuit switching signal can be appropriately changed as needed. 
     FIG. 8  is a perspective view illustrating a rotating body of non-contact rotary movement sensor with an independent switch including a contact switch in accordance with another embodiment of the present invention. As shown in  FIG. 8 , according to another embodiment of the present invention, at the initial state when the rotating body  313  does not rotate, the pushing rod  400  moves the common contact part  401  comprising a coil spring by the restoring force of the restoring spring  320  to make the common contact part  401  to constantly contact a first contact part  403  of a cylinder shape. When the rotating body  313  is rotated by an external force, the pushing rod  400  recedes from the common contact part  401 , and a portion of common contact part  401  contacts a second contact part  402  of a plate shape, returning to the original position by the restoring force. At this time, the common contact part  401  remains touching the first contact part  403  by switch spring release for a predetermined time before touching the second contact part  402 . The contact switch by the process is capable of outputting the same switching signal with the lead switch  332  using the second permanent magnet  315  in accordance with the one embodiment of the present invention. 
   At this time, it is desirable that the common contact part  401  in accordance with another embodiment of the present invention is elastic enough to make a repeated contacting and separating with the first contact part  403  or the second contact part  402 . Such elasticity can be acquired using a coil spring. 
     FIG. 9  is a perspective view illustrating a non-contact rotary movement sensor with an independent switch in accordance with another embodiment of the present invention. As shown in  FIG. 9 , the non-contact rotary movement sensor in accordance with another embodiment of the present invention utilizes a mechanical contact switch instead of the lead switch  332  which uses the second permanent magnet  315 . At this time, the mechanical contact switch can include a spring. 
   The non-contact rotary movement sensor with an independent switch including a contact switch in accordance with another embodiment of the present invention has a permanent magnet (the same with the first permanent magnet  312  of one embodiment of the present invention), a Hall device  331  which senses it, and a trigger  314  which is projected on a part of the circumference of the rotating body and a pushing rod  400  installed on the trigger  314 , and includes a common contact part  401  with a portion moving corresponding to the rotation of the rotating body  313 , and a first contact part  403  and a second contact part  402  for outputting the switching signal by contacting or detaching from the common contact  401 . 
   At this time, a common contact in accordance with another embodiment of the present invention can comprises a coil spring, thereby being operated by elastic force. Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this invention is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents. 
   The non-contact rotary movement sensor with an independent switch of the present invention is capable of outputting a normal signal even with one of signal transformers out of order, by providing a Hall device and a non-contact lead switch or a contact switch, which operates independently of the Hall device. 
   Also, the non-contact rotary movement sensor with an independent switch of the present invention is capable of extending a life span of the rotary movement sensor as a separating plate is formed to protect the electric components of the sensor from the external dust and atmospheric moisture. 
   Also, the non-contact rotary movement sensor with an independent switch of the present invention is capable of protecting the circuit from external magnetic or electric disturbance by including a shielding cover in its configuration. This results in the effect of reducing distortion of output signals, which is caused by the irregularity and nonlinearity of a magnetic field by electromagnetic waves. 
   While the invention has been shown and described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.