JP4347877B2 - Automotive radar equipment - Google Patents

Description

  The present invention relates to an on-vehicle radar device mounted on a vehicle such as an automobile.

  In general, an on-vehicle radar device mounted on a vehicle oscillates an antenna within a predetermined angular range, irradiates an electromagnetic wave around the vehicle from the antenna, and receives a reflected wave from the antenna to the distance to an obstacle. It is configured to detect speed, direction, and the like.

  Conventionally, as this type of in-vehicle radar device, an antenna formed of a resin with low dielectric loss is rotatably supported by fulcrum shafts provided on both sides thereof, and the antenna is rocked within a predetermined angle range by a drive unit. It is configured to radiate electromagnetic waves around the vehicle and receive the reflected wave, and to detect the change of magnetic flux from the permanent magnet against the permanent magnet fixed to the antenna and the gap, and output it Provided a magnetic sensor consisting of a detection unit that generates, controls the drive unit based on the output of the detection unit corresponding to the position change of the permanent magnet accompanying the swing of the antenna, and controls the swing angle of the antenna In-vehicle radar devices have been proposed. (For example, see Patent Documents 1 to 4)

JP 2003-318627 A Japanese Patent Laid-Open No. 2004-7122 Japanese Patent Application Laid-Open No. 2004-7882 JP 2002-325416 A

  The conventional vehicular radar configured in this way is installed on the antenna when the antenna made of resin repeatedly expands and contracts due to temperature changes, etc., and the shape of the reflecting surface changes irreversibly or reversibly over time. There has been a problem that the position of the permanent magnet of the magnetic sensor is changed, the facing distance from the detection unit arranged so as to be changed, and the output characteristics of the magnetic sensor become unstable.

  The present invention has been made in order to solve the above-described problems of conventional in-vehicle radar devices. Even if the shape of the antenna changes, the output characteristics of the sensor that detects the swing angle of the antenna are affected. It is an object of the present invention to provide a vehicular radar apparatus which is not provided.

A vehicular radar apparatus according to the present invention includes an antenna that radiates electromagnetic waves and receives a reflected wave thereof, a shaft fixed to the antenna, a bearing fixed to a fixing member and rotatably supporting the shaft, A sensor detection target support portion configured by a member made of the same material as a member constituting the shaft, and integrally fixed to the shaft; a sensor detection target configured by a permanent magnet and fixed to the sensor detection target support portion; and the sensor A sensor detection unit that faces an object to be detected via a gap and generates an output corresponding to a magnetic flux change based on the change in the gap; a sensor detection unit support fixing unit that is fixed to the fixing member and fixes the sensor detection unit; Antenna driving means that is controlled based on the output of the sensor detection unit and swings the antenna around the shaft as a fulcrum.

According to the vehicular radar apparatus of the present invention, the sensor detection target support portion configured by a member made of the same material as the member constituting the shaft and integrally fixed to the shaft, and the sensor detection target support portion configured by a permanent magnet. A sensor detection target fixed to the sensor, a sensor detection unit that faces the sensor detection target via a gap and generates an output corresponding to a magnetic flux change based on the change in the gap, and a sensor detection unit fixed to the fixed member The sensor detection unit supporting and fixing unit for fixing the sensor detection unit is not affected by the change in the shape of the antenna, and therefore the output characteristics of the sensor detection unit can be stabilized. it can.

  7A and 7B show an in-vehicle radar device that is the basis of the present invention. FIG. 7A is a cross-sectional view, and FIG. 7B is a cross-sectional view in the direction of the arrow along the line AA. FIG. 8 is a cross-sectional view showing a state of the on-vehicle radar device shown in FIG. The on-vehicle radar device shown in FIGS. 7 and 8 is a radar that is used to monitor the periphery of the host vehicle, irradiates the periphery of the host vehicle with electromagnetic waves, receives the reflected waves, and surrounds the host vehicle. The distance, relative speed, and direction to the obstacle are detected.

  7A and 7B, the antenna 1 is made of a resin having a low dielectric loss, and fulcrum shafts 21 as axes arranged on opposite sides on a straight line passing through the vicinity of the center of gravity of the center portion thereof. , 22. The fulcrum shafts 21 and 22 are rotatably supported by bearings 31 and 32. The movable magnets 51 and 52 are fixed to the lower part of the opposing peripheral edge of the antenna 1 on a straight line that is substantially orthogonal to the straight line connecting the fulcrum shafts 21 and 22. The electromagnets 71 and 72 include magnetic poles 711 and 721 and coils 712 and 722, respectively, and are fixed to the fixed member 8 at positions corresponding to the movable side magnets 51 and 52, respectively. The fixed side magnets 61 and 62 are fixed to the end portions of the magnetic poles 711 and 721 of the electromagnets 71 and 72, respectively, and are opposed to the movable side magnets 51 and 52 through a gap.

  The movable side magnets 51 and 52 and the fixed side magnets 61 and 62 opposed to the movable side magnets 51 and 52 are arranged so that the same polarity is opposed to each other, and when the electromagnets 71 and 72 are deenergized, The stationary balance of the antenna 1 is maintained in a horizontal state around the fulcrum shafts 21 and 22 by the magnetic repulsive force of the magnet 52 and the fixed side magnets 61 and 62. The coils 712 and 722 of the electromagnets 71 and 72 are connected in series by conductors 731, 732, and 733 so that currents in opposite directions flow, and the rotation direction of the antenna 1 is controlled by the direction of the currents. The swing angle is controlled by the magnitude of the current.

  The magnetic sensor 4 is provided in the vicinity of one fulcrum shaft 21 of the antenna 1, and sensor detection targets 411, 412 including a pair of permanent magnets arranged at positions facing both sides of the fulcrum shaft 21, and these The sensor detection unit 42 is disposed between the sensor detection targets 411 and 412. The sensor detection unit 42 is fixed to the sensor detection unit support fixing unit 9 fixed to the fixing member 8, and is opposed to the sensor detection targets 411 and 412 via a gap, and the facing interval changes. Changes in the magnetic flux from the sensor detection targets 411 and 412 are detected, and an output voltage corresponding to the magnetic flux change is generated.

The vehicular radar apparatus configured as described above controls the direction and magnitude of the current flowing through the coils 712 and 722 of the electromagnets 71 and 72 based on the command value, and swings the antenna 1 around the fulcrum shafts 21 and 22. Control the angle of the electromagnetic wave irradiated to the surroundings from the antenna 1 to irradiate the surroundings of the own vehicle, and receive the reflected waves to the obstacles around the own vehicle, relative speed, direction Etc. are detected.

  As shown in FIG. 8, the relative position between the sensor detection unit 42 and the sensor detection targets 411 and 412 changes according to the angle change around the fulcrum shafts 21 and 22 of the antenna 1. The magnetic flux to be changed changes according to the swing angle of the antenna 1. FIG. 9 is a graph showing the relationship between the rotation angle θ of the antenna 1 and the output voltage e of the magnetic sensor 4. As is clear from FIG. 9, the output voltage e of the magnetic sensor 4 changes in proportion to the swing angle θ of the antenna 1.

  FIG. 10 is a cross-sectional view of another in-vehicle radar device that is the basis of the present invention. In the on-vehicle radar device shown in FIG. 10, the magnetic sensor 4 includes a sensor detection target 41 composed of one permanent magnet, and a sensor detection unit 42 disposed in the vicinity of the magnetic pole center of the sensor detection target 41. It is configured. Other configurations are the same as those of the in-vehicle radar device shown in FIG.

  In the on-vehicle radar device shown in FIGS. 7 to 10, the antenna 1 is made of resin, and the irreversible deformation with time may occur in the reflecting surface shape due to repeated expansion and contraction due to temperature change. A reversible shape change may occur in the reflecting surface shape due to a temperature change. 11A and 11B are explanatory diagrams showing the case where the antenna 1 has such a shape change. FIG. 11A shows the case of the on-vehicle radar device shown in FIG. 7, and FIG. 11B shows the case of the on-vehicle radar device shown in FIG. Is shown. In FIGS. 11A and 11B, the solid line indicates the normal shape of the antenna 1, and the broken line indicates the shape when the shape of the antenna 1 changes.

  In FIG. 11A, when the shape of the antenna 1 changes as indicated by a broken line, the fixed positions of the sensor detection targets 411 and 412 of the magnetic sensor 4 fixed to the antenna 1 change, and the sensor detection target 411 is changed. 412 and the sensor detection unit 42 change. Similarly, in FIG. 11B, when the shape of the antenna 1 changes as indicated by a broken line, the fixed position of the sensor detection target 41 of the magnetic sensor 4 fixed to the antenna 1 changes, and sensor detection is performed. The relative position between the object 41 and the sensor detection unit 42 changes.

  FIG. 12 is a graph showing the relationship between the swing angle θ of the antenna 1 and the output voltage e of the magnetic sensor 4. The solid line shows the sensor output characteristic when the antenna 1 is in a normal shape at the initial stage of assembly, and the broken line shows 2 shows sensor output characteristics when the shape of the reflecting surface of the antenna 1 changes due to irreversible deformation or reversible deformation. When the magnetic flux change due to the change in the position of the sensor detection target 411, 412, or 41 of the magnetic sensor 4 is detected by the detection unit 42 to obtain the swing angle θ of the antenna 1, as is apparent from FIG. When the shape of the antenna 1 changes with respect to the sensor output characteristic in the case of a normal shape, the sensor output characteristic changes, and accordingly, an error occurs in the angle of the electromagnetic wave radiated from the antenna 1. It will be.

Embodiment 1 FIG.
1A and 1B show an in-vehicle radar device according to Embodiment 1 of the present invention, in which FIG. 1A is a cross-sectional view and FIG. 1B is a cross-sectional view in the direction of an arrow along the line AA. 2 shows the configuration of the antenna 1 of the in-vehicle radar device, where (a) is a cross-sectional view, (b) is a cross-sectional view in a direction substantially perpendicular to the cross-sectional view shown in (a), and (c) is a cross-sectional view. It is explanatory drawing of a sensor detection object support part.

  In FIGS. 1A, 1B, and 2A, 2B, 2C, the antenna 1 is made of, for example, a synthetic resin having a low dielectric loss characteristic, and has a parabolic surface. It is formed into a shape. The antenna 1 has a thin linear pattern formed on the inside of a curved surface by nickel plating or the like, and the entire outer surface of the curved surface is plated with nickel or the like. The fulcrum shafts 21 and 22 as shafts are provided on opposite sides of the antenna 1 on a straight line passing through the vicinity of the center of gravity of the substantially central portion of the antenna 1. These fulcrum shafts 21 and 22 are made of a metal member which is a member different from the synthetic resin constituting the antenna 1.

  As a method of fixing the antenna 1 and the fulcrum shafts 21 and 22, a method of fixing the antenna 1 by inserting the fulcrum shafts 21 and 22 into the synthetic resin and molding them integrally when molding the antenna 1 with synthetic resin, A method of fixing the fulcrum shafts 21 and 22 by pressing or welding to the antenna 1 after molding, or by screwing a male screw formed on the shaft portion of the fulcrum shafts 21 and 22 into a female screw formed on the antenna 1. A fixing method or the like can be used.

  The fulcrum shafts 21 and 22 of the antenna 1 are inserted into inner diameter portions of bearings 31 and 32 fixed to the fixing member 8 and are rotatably supported. The bearings 31 and 32 may be constituted by ball bearings or the like. The antenna 1 is supported by fulcrum shafts 21 and 22 located on both sides in the vicinity of the center of gravity of the central portion, and is influenced by gravity, disturbance vibration, and the like with an axis passing through the centers of these fulcrum shafts 21 and 22 as the center. It can be swung without.

  The sensor detection target support unit 100 includes leg portions 110 and 120 that are fixed integrally with the fulcrum shaft 21 and extend downward on both sides of the fulcrum shaft 21. The sensor detection target support unit 100 is formed symmetrically about the fulcrum shaft 21. The fulcrum shaft 21 and the sensor detection target support portion 100 are made of the same material having a small linear expansion coefficient, for example, a metal such as stainless steel or aluminum, or a synthetic resin having a low linear expansion characteristic. As a method of fixing the fulcrum shaft 21 and the sensor detection target support portion 100, a method of fixing by fulcrum or press fitting, a male screw formed on the fulcrum shaft 21 is screwed into a female screw formed on the sensor detection target support portion 100. There is a method to fix it. The fulcrum shaft 21 and the sensor detection target support portion 100 are fixed by, for example, inserting the synthetic resin into the synthetic resin and integrally molding the antenna 1 with the synthetic resin.

  As shown in FIG. 2 (c), sensor detection target fixing for inserting and fixing sensor detection targets 411, 412 to the end portions of the respective leg portions 110, 120 of the sensor detection target support portion 100 is performed. Recesses 111 and 121 are formed. These sensor detection target fixing recesses 111 and 112 include straight wall portions 112 and 122 extending along the side walls of the leg portions 110 and 120, and tapered wall portions 113 and 123 that are inclined with respect to the side walls of the leg portions 110 and 120, respectively. The opening side is formed wider than the bottom side. The straight portions 111 and 122 constitute a reference wall portion serving as a reference for the fixed position of the sensor detection targets 411 and 412, and face the tapered wall portions 113 and 123.

  The pair of sensor detection targets 411 and 412 of the magnetic sensor 4 are configured by permanent magnets. These sensor detection targets 411 and 412 are inserted into the sensor detection target fixing recesses 111 and 121 provided in the leg portions 110 and 120 of the sensor detection target support unit 100, respectively, and the straight walls of the sensor detection target fixing recesses 111 and 121 are inserted. After being positioned in contact with the portions 112 and 122, they are fixed to the leg portions 110 and 120 of the sensor detection target support portion 10 by fixing means such as an adhesive or caulking.

  The minimum value of the width of the space formed by the straight wall portions 112 and 122 of the sensor detection target fixing concave portions 111 and 121 and the tapered wall portions 113 and 123 that are opposite to the linear wall portions 112 and 122 is permanent. It is set to the same value as the minimum value of the dimensional tolerance of the magnet, and the maximum value of the width of the space portion is set to the same value as the maximum value of the dimensional tolerance of the permanent magnet. Therefore, even if there are fluctuations due to variations in processing accuracy in the dimensions of the permanent magnets, the positions where the permanent magnets are fixed are positioned accurately along the straight walls 112 and 122, and fluctuations due to variations in the dimensions of the permanent magnets. It can be absorbed in the space between the tapered wall portions 113 and 123 and the straight wall portions 112 and 122.

  In addition, you may set the width | variety of the space part comprised by the linear wall parts 112 and 122 and the taper wall parts 113 and 123 more than the dimensional tolerance of a permanent magnet. Further, the width of the space portion may be set to be equal to or smaller than the dimensional tolerance of the permanent magnet. In this case, the dimension of the permanent magnet to be inserted is more strictly limited. Functions as a permanent magnet selection means, and the characteristics of the magnetic sensor 4 can be further stabilized.

  When the sensor detection target fixing concave portions 111 and 121 have a shape that does not have the tapered wall portions 113 and 123, the widths of the space portions where the linear wall portions 112 and 122 and the tapered wall portions 113 and 123 face each other are uniform. In this case, since the size of the permanent magnets constituting the sensor detection targets 411 and 412 and the size of the sensor detection target fixing recesses 111 and 121 usually have a dimensional variation in terms of work, the inserted permanent magnet and the sensor detection are detected. A gap of a certain amount or less is generated between the target fixing recess. Since this gap changes with long-term vibration and temperature change, the position and interval of the permanent magnets fluctuate, and the characteristics of the magnetic sensor 4 change, which may be an obstacle to improving detection accuracy. is there.

  On the other hand, according to the first embodiment of the present invention, since the tapered wall portions 113 and 123 are formed in the sensor detection target fixing concave portions 111 and 121, the dimensions of the permanent magnet and the sensor detection target fixing concave portion 111, Variations in the size of 121 can be absorbed based on the tapered wall portions 113 and 123, and the position and interval of the permanent magnet can be kept constant against long-term vibration and temperature change.

  Further, if the sensor detection target support unit 100 is made of a material having a linear expansion coefficient comparable to that of the permanent magnets constituting the sensor detection targets 411 and 412, for example, stainless steel or the like, the sensor detection target support unit 100 is supported. The difference in expansion and contraction due to the temperature change between the part 100 and the sensor detection targets 411 and 412 is almost eliminated, and the change in the position of the fixed part of both can be suppressed in the long term.

  Next, in (a), (b) of FIG. 1 and (a), (b), and (c) of FIG. 2, the sensor detection unit 42 of the magnetic sensor 4 is fixed to the fixing member 8. It fixes to the sensor detection part support fixing | fixed part 9, and is arrange | positioned so that it may oppose a pair of sensor detection object 411,412 through a space | gap. The sensor detection unit 42 is configured by, for example, a Hall IC, detects a change in magnetic flux due to a change in the gap between the sensor detection targets 411 and 412, and generates an output voltage corresponding to the change. The output voltage of the sensor detection unit 42 is proportional to the swing angle θ of the antenna 1.

  The sensor detection unit 42 may be a magnetic sensor other than the Hall IC, for example, an optical sensor that detects a change in the position of the sensor detection target support unit 100 that is not affected by the change in the antenna shape by light. You may comprise.

  The movable side magnets 51 and 52 are fixed to the lower part of the peripheral edge of the antenna 1 on a straight line that is substantially orthogonal to the straight line connecting the fulcrum shafts 21 and 22. The electromagnets 71 and 72 include magnetic poles 711 and 721 and coils 712 and 722, respectively, and are fixed to the fixed member 8 at positions corresponding to the movable side magnets 51 and 52, respectively. The fixed side magnets 61 and 62 are fixed to the end portions of the magnetic poles 711 and 721 of the electromagnets 71 and 72, respectively, and are arranged to face the movable side magnets 51 and 52 through a gap.

  The movable side magnets 51 and 52 and the fixed side magnets 61 and 62 opposed to the movable side magnets 51 and 52 are arranged so that the same polarity is opposed to each other, and when the electromagnets 71 and 72 are deenergized, The stationary balance of the antenna 1 is maintained in a horizontal state around the fulcrum shafts 21 and 22 by the magnetic repulsive force of the magnet 52 and the fixed side magnets 61 and 62. The coils 712, 722 of the electromagnets 71, 72 are connected in series by conductors 731, 732, 733 so that currents in opposite directions flow, and the direction of rotation of the antenna 1 is controlled by the direction of the currents. The swing angle is controlled according to the size of.

  In the on-vehicle radar device according to Embodiment 1 of the present invention configured as described above, the direction and magnitude of the current flowing through the coils 721 and 722 of the electromagnets 71 and 72 are controlled based on the command value, and the antenna 1 is connected. It swings around the fulcrum shafts 21 and 22 and controls the angle of the electromagnetic wave radiated from the antenna 1 to the surroundings to irradiate the surroundings of the own vehicle, and from the reflected waves to the obstacles around the own vehicle. Detect distance, relative speed, and direction.

  According to the on-vehicle radar device according to the first embodiment of the present invention described above, the fulcrum shaft 21 provided on the antenna 1 and the sensor detection target support unit 100 that supports the sensor detection targets 411 and 412 are the same. Since it is composed of members formed of materials and is integrally fixed, the sensor detection target 411, 412 is not affected by the shape change of the antenna 1 formed in a parabolic shape with synthetic resin. Variation of the distance between the position of the fulcrum shaft 21 and the fulcrum shaft 21 can be reduced, and the sensor output characteristics of the magnetic sensor 4 with respect to the swing angle of the antenna 1 can be stabilized. Accordingly, since the accuracy of the swing angle of the antenna 1 driven based on the sensor output is stabilized, the controllability of the antenna drive can be improved.

  In addition, since the fulcrum shaft 21 and the sensor detection target support portion 100 are configured by members formed of the same material and are integrally fixed, the fulcrum shaft 21 and the sensor detection target support portion 10 are formed. Assembly, processing, etc. for fixing become easy, the assembly accuracy of the device does not deteriorate due to the assembly, etc., and further, the rigidity can be improved, and the displacement and disengagement can occur even in the situation where vibration and temperature change occur. In addition, since the sensor output characteristics can be stabilized over a long period of time, the durability of the apparatus can be improved. In addition, since the number of parts can be reduced, the cost can be reduced.

  Further, the fulcrum shaft 21 and the sensor detection target support portion 100 are made of a member made of the same material and fixed integrally. The antenna 1 and the antenna 1 are fixed to the antenna 1 by integral molding with a resin constituting the antenna 1. Therefore, no other fixing means is required, and the cost of the apparatus can be reduced.

  Further, if the sensor detection target support portion 100 provided in the antenna 1 is formed of a magnetic material, a magnetic shield for the sensor detection portion 42 can be configured, so that the influence of electromagnetic noise (disturbance noise) from the outside can be reduced. In addition, the output characteristics of the magnetic sensor 4 can be stabilized with respect to the swing angle of the antenna 1. In this case, the magnetic shielding effect can be optimized by selecting the distance from the fulcrum shaft 21 of the sensor detection target support part 100, the width and thickness of the sensor detection target support part 100.

Embodiment 2. FIG.
3A and 3B show an antenna of a vehicular radar apparatus according to Embodiment 2 of the present invention, in which FIG. 3A is a cross-sectional view and FIG. 3B is a cross-sectional view during rotation. 3A and 3B, the stoppers 413 and 414 are provided at the distal ends of the leg portions 110 and 120 of the sensor detection target support portion 100. These stoppers 413 and 414 are made of the same material as the members constituting the fulcrum shaft 21 and the sensor detection target support part 100 and are made of a metal member having a small linear expansion coefficient, and are welded to the sensor detection target support part 100. Alternatively, they are integrally fixed by means such as press fitting.

  Stopper contact projections 81 and 82 for restricting the left and right swing angles of the antenna 1 are fixed to the distal end portion of the fixing member 8, and as shown in FIG. When the angle reaches the stopper regulation angle, one of the stoppers 413 and 414 comes into contact with the corresponding one of the stopper contact protrusions 81 and 82 to prevent further rotation of the antenna 1.

  When the stoppers 413 and 414 come into contact with the stopper contact protrusions 81 and 82, that is, when the swing angle of the antenna 1 reaches the stopper angle regulation value, the current output value of the magnetic sensor 4 at that position It can be configured to detect a failure by comparing with an initial set value and determining that the deviation is equal to or greater than a predetermined value as a failure. Further, when the output value of the magnetic sensor 4 with respect to the swing angle of the antenna 1 changes, the sensor output value with respect to the swing angle of the antenna 1 is corrected based on the sensor output value at the stopper angle restricting position. be able to. Other configurations are the same as those of the on-vehicle radar device of the first embodiment.

  According to the in-vehicle radar device according to the second embodiment of the present invention, the fulcrum shaft 21, the sensor detection target support unit 100, and the stoppers 413 and 414 for regulating the swing angle range of the antenna are the same with a small linear expansion coefficient. Since they are made of a metal material and are integrally fixed, they are not affected by a change in the shape of the antenna 1 with respect to a stopper that is integrated with a resin that constitutes the antenna as in a conventional in-vehicle radar device. The stopper regulating angle by the stoppers 413 and 414 and the stopper contact projections 81 and 82 can be kept constant. Accordingly, since the angular accuracy of the antenna 1 driven based on the sensor output is always stable, the controllability of antenna driving can be improved.

  Moreover, since the shape of the stoppers 413 and 414 can be changed to a desired shape and fixed to the sensor detection target support portion 100, the stopper angle restriction value can be arbitrarily controlled. If the swing angle of the antenna 1 is excessive, a large load is applied to the antenna 1 and the distance between the sensor detection targets 411 and 412 fixed to the sensor detection target support unit 100 may fluctuate. By setting the value to an appropriate value, excessive rotation of the antenna 1 can be prevented. Therefore, since the output characteristics of the magnetic sensor 4 with respect to the swing angle of the antenna 1 can be stabilized, the accuracy of the swing angle of the antenna 1 driven based on the sensor output is stabilized, and the controllability of the antenna drive is improved. Improvements can be made.

  Further, the fulcrum shaft 21, the sensor detection target support portion 100, and the stoppers 413 and 414 are composed of members made of the same metal material, and these are fixed integrally. Assembling accuracy improves, rigidity can be improved, their positions do not fluctuate due to secular change, etc., and position fluctuations and dropouts do not occur even in situations where vibrations and temperature changes occur, even in the long term The sensor output characteristics can be stabilized, and the durability of the apparatus can be improved. Moreover, since the number of parts can be reduced, cost reduction can be achieved.

Embodiment 3 FIG.
4A and 4B show a sensor detection unit support and fixing portion of a vehicle radar apparatus according to Embodiment 3 of the present invention. FIG. 4A is a cross-sectional view of the sensor detection unit support and fixing portion, and FIG. It is sectional drawing of the sensor detection part support fixing | fixed part in a state. 4A and 4B, a sensor detection unit fixing recess 91 for inserting and fixing the sensor detection unit 42 is formed at the tip of the sensor detection unit support fixing unit 9. The sensor detection unit fixing recess 91 includes a straight wall portion 911 extending along the side wall of the sensor detection unit support fixing unit 9 and a tapered wall unit 912 inclined with respect to the side wall of the sensor detection unit support fixing unit 9. The opening side is formed wider than the bottom side. The straight wall portion 911 constitutes a reference wall portion serving as a reference for the fixed position of the sensor detection portion 42, and faces the tapered wall portion 912. The sensor detection unit support fixing unit 9 is configured integrally with the fixing member 8 that supports the fulcrum shaft 21.

  The sensor detection unit 42 of the magnetic sensor 4 is configured by a Hall IC element or the like, and is inserted into the sensor detection unit fixing recess 91 of the sensor detection unit support fixing unit 9. After being positioned along the position, it is fixed. The reference plane for positioning the normal sensor detection unit 42 is designated by the sensor manufacturer, and the dimensions and tolerances up to the element position of the Hall IC element are managed. Therefore, positioning is performed by bringing the reference wall of the sensor detection unit 42 into contact with the straight wall 911 of the sensor detection unit fixing recess 91, and after the positioning, the sensor detection unit support fixing unit 9 and the sensor detection unit 42 are bonded. Fixing is performed using fixing means such as integral molding with an agent and resin, and caulking.

  The minimum value of the width of the space formed by the straight wall portion 911 of the sensor detection portion fixing recess 91 and the tapered wall portion 912 which is the opposite surface of the straight wall portion 911 is the minimum dimensional tolerance of the Hall IC element constituting the sensor detection portion 42. The maximum value of the width of the space portion is set to the same value as the maximum value of the dimensional tolerance of the Hall IC element. Therefore, even if there is a variation in the dimension of the Hall IC element due to variations in processing accuracy, the position where the Hall IC element is fixed is accurately positioned along the straight wall portion 911, and the variation due to the variation in the dimension of the Hall IC element. Can be absorbed by the space portion between the tapered wall portion 912 and the straight wall portion 911. Note that the width of the space formed by the straight wall portion 911 and the tapered wall portion 912 that is the opposite surface may be set to be equal to or greater than the dimensional tolerance of the sensor detection element 42. Other configurations are the same as those of the on-vehicle radar device according to the first or second embodiment.

  When the sensor detection unit fixing concave portion 91 has a shape without the tapered wall portion 912, the width of the space portion is uniform. In this case, since the dimension of the Hall IC element constituting the sensor detection unit 42 and the dimension of the sensor detection unit fixing recess 91 usually have a dimensional variation due to work, the inserted Hall IC element and the sensor detection unit are fixed. A gap of a certain amount or less is formed between the recess 91. Since this gap changes with long-term vibration and temperature change, the position and interval of the permanent magnets fluctuate, and the characteristics of the magnetic sensor 4 change, which may be an obstacle to improving detection accuracy. is there.

  On the other hand, according to the third embodiment of the present invention, since the tapered wall portion 912 is formed in the sensor detection portion fixing recess 91, the dimension of the Hall IC element and the size of the sensor detection portion fixing recess 91 are The variation can be absorbed by the space between the tapered wall portion 912 and the straight wall portion 911, and the position and interval of the permanent magnet can be kept constant against long-term vibration and temperature change.

  In addition, the member constituting the sensor detection unit supporting and fixing unit 9 is formed of a material having a linear expansion coefficient comparable to the linear expansion coefficient such as an epoxy resin having a low linear expansion coefficient which is a package material of the sensor detection unit 42. For example, there is no difference between expansion and contraction due to a temperature change between the sensor detection unit supporting and fixing unit 91 and the sensor detection unit 42, and it is possible to suppress a change in position of the both fixing units in the long term.

Embodiment 4 FIG.
5A and 5B show a vehicular radar apparatus according to Embodiment 4 of the present invention, in which FIG. 5A is a cross-sectional view showing the configuration of the antenna 1, and FIG. 5B is a direction substantially orthogonal to the cross-sectional view shown in FIG. FIG. 5A and 5B, the sensor detection target support portion 200 is integrally formed of the same member as the fulcrum shaft 21 provided on the antenna 1, and is substantially formed on both sides of the fulcrum shaft 21 in the horizontal direction. It is formed to have a symmetrical shape. The sensor detection targets 411 and 412 and the sensor detection unit 42 are respectively fixed to the sensor detection target support unit 200 and the sensor detection unit support fixing unit 9 by the same method as in the first to third embodiments. Moreover, the part which fixes the sensor detection part 42 of the sensor detection part support fixing | fixed part 9 is facing the sensor detection target support part 200 through the space part on the both sides. Other configurations are the same as those in the first to third embodiments.

  According to the on-vehicle radar device according to the fourth embodiment, the sensor detection target fixing portion of the sensor detection target support portion 200 does not have a certain length of stroke extending from the fulcrum shaft 2 toward the fixing member 8, and therefore the sensor detection target The dimensional accuracy of the sensor detection target fixing portion of the support portion 200 can be improved, and the workability can be improved. Therefore, the distance variation between the positions of the sensor detection targets 411 and 412 and the fulcrum shaft 21 can be reduced, so that the output characteristics of the magnetic sensor 4 with respect to the swing angle of the antenna 1 can be stabilized, and the sensor output of the magnetic sensor 4 can be stabilized. Since the accuracy of the swing angle of the antenna 1 driven based on the above is stabilized, the controllability of the antenna drive can be improved.

Embodiment 5 FIG.
6A and 6B show a vehicular radar apparatus according to Embodiment 5 of the present invention, in which FIG. 6A is a cross-sectional view showing the configuration of an antenna, and FIG. 6B is a direction substantially orthogonal to the cross-sectional view shown in FIG. It is sectional drawing. 6 (a) and 6 (b), the fulcrum shaft 21 provided on the antenna 1 and the sensor detection target support portion 300 that supports the sensor detection targets 411 and 412 are configured by members made of the same material. And it is fixed integrally. Between the sensor detection target support unit 300 and the sensor detection targets 411 and 412, intermediate members 301 and 302 made of a member having a linear expansion coefficient different from that of the members constituting the sensor detection target support unit 300 are arranged. .

  Even if a member having a small linear expansion coefficient is used for the sensor detection target support unit 300, normally, when the temperature change in the usage environment is large, the sensor detection target support unit 300 expands and contracts due to the temperature characteristics of the material, and the sensor detection target support unit 300 The distance between the sensor detection targets 411 and 412 fixed to the support unit 300 changes. In a normal use state, the change in the distance is at a level that does not affect the characteristics. However, in the on-vehicle radar device according to the fifth embodiment, in order to further improve the accuracy, The contraction is corrected by the intermediate members 301 and 302, and the distance variation between the sensor detection targets 411 and 412 is corrected.

For example, when the member constituting the sensor detection target support unit 300 is stainless steel having a linear expansion coefficient of 14 × 10 ⁻⁶ and the distance between the sensor detection targets 411 and 412 is set to 13 [mm], the intermediate The members constituting the members 301 and 302 are formed using a resin having a linear expansion coefficient of 60 × 10 ⁻⁶ , and the thickness sandwiched between the sensor detection target support portion 300 and the sensor detection targets 411 and 412 is 1.5. If it is set to [mm], the distance between the sensor detection targets 411 and 412 can always be kept constant with respect to the temperature change when the linear expansion coefficient of the sensor detection targets 411 and 412 is not considered.

  According to the on-vehicle radar device according to the fifth embodiment described above, the linear expansion coefficient different from the members constituting the sensor detection target support unit 300 between the sensor detection target support unit 300 and the sensor detection targets 411 and 412. Since the intermediate members 301 and 302 configured by members having the above are arranged, it is possible to prevent the interval between the sensor detection targets 411 and 412 from fluctuating even when the temperature change in the usage environment is large. Therefore, since the output characteristics of the magnetic sensor with respect to the rotation angle of the antenna 1 can be stabilized, the accuracy of the swing angle of the antenna 1 driven based on the sensor output is stabilized, and the controllability of the antenna drive is improved. be able to.

BRIEF DESCRIPTION OF THE DRAWINGS The radar apparatus for vehicles by Embodiment 1 of this invention is shown, (a) is sectional drawing, (b) is sectional drawing of the arrow direction which follows the AA line. 1 shows a configuration of an antenna of an in-vehicle radar device according to Embodiment 1 of the present invention, where (a) is a cross-sectional view, (b) is a cross-sectional view in a direction substantially perpendicular to the cross-sectional view shown in (a), and (c) ) Is a detailed view of a sensor detection target support part. The antenna of the radar apparatus for vehicles by Embodiment 2 of this invention is shown, (a) is sectional drawing, (b) is sectional drawing at the time of the rotation. The sensor detection part support fixing | fixed part of the radar apparatus for vehicles by Embodiment 3 of this invention is shown, (a) is sectional drawing, (b) is sectional drawing which shows the state which fixed the sensor detection part. FIG. 5 shows an antenna of a vehicular radar apparatus according to Embodiment 4 of the present invention, in which (a) is a cross-sectional view and (b) is a cross-sectional view in a direction substantially orthogonal to the cross-sectional view shown in (a). 5 shows a vehicular radar apparatus according to Embodiment 5 of the present invention, in which (a) is a cross-sectional view showing the configuration of the antenna 1 and (b) is a cross-sectional view in a direction substantially orthogonal to the cross-sectional view shown in (a). is there. 1 shows an in-vehicle radar device that is the basis of the present invention, where (a) is a cross-sectional view, and (b) is a cross-sectional view in the direction of an arrow along the line AA. FIG. 8 is a cross-sectional view showing a state of the on-vehicle radar device shown in FIG. It is sectional drawing which shows the state at the time of the antenna rocking | fluctuation of the vehicle-mounted radar apparatus used as the foundation of this invention. It is a graph which shows the relationship between the oscillation angle | corner (theta) of an antenna, and the output voltage e of a magnetic sensor. It is sectional drawing of another vehicle-mounted radar apparatus used as the foundation of this invention. FIG. 8A is a diagram illustrating a change in the shape of an antenna of an in-vehicle radar device that is the basis of the present invention, and FIG. 10B is an explanatory diagram of the in-vehicle radar device shown in FIG. 7; It is a graph which shows the relationship between the rocking | fluctuation angle of the antenna of the vehicle-mounted radar apparatus used as the foundation of this invention, and the output voltage e of a magnetic sensor.

Explanation of symbols

Reference Signs List 1 antenna 21, 22 fulcrum shaft 31, 32 bearing 4 magnetic sensor 411, 411 sensor detection target 42 sensor detection unit 51, 52 movable magnet 61, 62 fixed magnet 71, 72 electromagnet 711, 721 magnetic pole 712, 722 coil 731, 732, 733 Conductor 8 Fixing member 9 Sensor detection part support fixing part 91 Sensor detection part fixing concave part 911 Linear part of sensor detection part fixing concave part 912 Tapered part of sensor detection part fixing concave part 100, 200, 300 Sensor detection target support part 111, 121 Sensor detection target fixing recess 112, 122 Linear wall portion of sensor detection target fixing recess 112, 123 Tapered wall portion of sensor detection target fixing recess 413, 414 Stopper 81, 82 Stopper projection 301, 302 Intermediate member

Claims (9)

An antenna that radiates electromagnetic waves and receives reflected waves thereof, a shaft that is fixed to the antenna, a bearing that is fixed to a fixed member and rotatably supports the shaft, and a member that is made of the same material as the members that constitute the shaft A sensor detection target support part configured integrally with the shaft, a sensor detection target configured by a permanent magnet and fixed to the sensor detection target support part, and opposed to the sensor detection target via a gap. Control based on a sensor detection unit that generates an output corresponding to a change in magnetic flux based on a change in the air gap, a sensor detection unit support fixing unit that is fixed to the fixing member and fixes the sensor detection unit, and an output of the sensor detection unit And an on-vehicle radar device comprising antenna driving means for swinging the antenna about the axis as a fulcrum.   The sensor detection target support portion includes a sensor detection target fixing concave portion having a reference wall portion and a tapered wall portion that is inclined and opposed to the reference wall portion, and the sensor detection target is the sensor detection target fixing concave portion. The vehicular radar apparatus according to claim 1, wherein the vehicular radar apparatus is fixed to the sensor detection target support portion in a state of being inserted into the base wall portion and in contact with the reference wall portion.   3. The on-vehicle radar according to claim 1, wherein the antenna is made of resin, and the shaft and the sensor detection target support portion are integrally formed with the antenna by resin constituting the antenna. apparatus.   4. The on-vehicle radar device according to claim 1, wherein the member constituting the sensor detection target support portion is made of a magnetic material. Said sensor detection target support portion includes a stopper for restricting the angular range of rotation of said antenna, said stopper, characterized in that it is constituted by a section member of the member of the same material constituting the sensor detection target support unit The on-vehicle radar device according to any one of claims 1 to 4.   The in-vehicle radar device according to claim 5, wherein the stopper is integrally fixed to the sensor detection target support portion.   The sensor detection unit support fixing unit includes a sensor detection unit fixing recess having a reference wall unit and a tapered wall unit that is inclined and opposed to the reference wall unit, and the sensor detection unit is fixed to the sensor detection unit. The vehicular radar apparatus according to claim 1, wherein the vehicular radar apparatus is fixed to the sensor detection unit support fixing portion in a state of being inserted into a recess and in contact with the reference wall portion.   The on-vehicle radar device according to claim 1, wherein the sensor detection target support portion is configured to be symmetrical about the axis.   The sensor detection target is fixed to the sensor detection target support part via an intermediate member made of a material having a linear expansion coefficient different from that of a member constituting the sensor detection target support part. Item 2. The on-vehicle radar device according to Item 1.

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