JP2014047882A - Fastened member, coupling device using fastened member, and accelerator device using fastened member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fastened member capable of keeping a fastened state with a base material by a tamper-proof set screw.SOLUTION: A second cover 15 fastened with a housing 12 by a tamper-proof set screw 24 has a contact surface 17 to which the tamper-proof set screw 24 is contacted and a projection wall 171 near the contact surface 17. A side face 172 of the projection wall 171 is formed to become an arcuate shape having a central angle θ of 180° around an axis φ of the tamper-proof set screw 24 after the second cover 15 is fastened to the housing 12 and at the same time a distance L1 between a point 174 nearest to the outer-most point 245 of a head part 241 of the tamper-proof set screw 24 and the outer-most point 245 becomes 1.3 mm. With the foregoing, it does not become possible to insert a tool such as a radio pinch between the head part 241 of the tamper-proof set screw 24 and the side face 172 of the projection wall 171, resulting in that a fastened state between the housing 12 and the second cover 15 can be maintained.

Description

  The present invention relates to a member to be fastened, and particularly to a member to be fastened to a base material by a tinker set screw.

  2. Description of the Related Art Conventionally, there is known a set screw that makes it difficult to release the fastening once the base material and the fastened member are fastened. For example, in Patent Document 1, torque in the rotational direction of the head (hereinafter referred to as “clamping direction”) that is formed perpendicular to the seating surface of the tamper-proof screw and fastens the base member and the fastened member acts. A plurality of engaging walls, and a rotation direction of the head (hereinafter referred to as “the direction of rotation of the head when releasing the fastening between the base member and the member to be fastened” formed so as to be inclined from the front end side of the head toward the seat surface side). There is described a tamper-proof screw in which an inclined surface for releasing a torque in the “anti-tightening direction” is formed on the head.

Japanese Patent Laid-Open No. 10-220453

  However, in the tamper-resistant screw described in Patent Document 1, the head of the tamper-resistant screw can be sandwiched with a tool such as radio pliers and the head can be rotated in the anti-tightening direction, so that the base material and the member to be fastened can be easily Can be released.

  The objective of this invention is providing the to-be-fastened member which can maintain the fastening with the base material by a tampering stop screw.

  The present invention is a fastened member to be fastened to a base material by a tamper-proof screw, and has a main body having a contact surface with which a seat surface of a head of the tamper-proof screw can abut on one surface, A protruding wall provided so as to stand up on one surface in the vicinity of the abutting surface, the protruding wall of the tamper-proof screw with respect to the head of the tamper-proof screw after the main body is fastened to the substrate. It is characterized in that it is formed so as to be able to prevent a tool other than a dedicated tool capable of rotating a tamper-proof screw between the head and the protruding wall in the anti-tightening direction from being inserted.

  In general, except for a special tool that can rotate the anti-tampering screw head in the anti-tightening direction in a normal operation, when trying to rotate the anti-tampering screw in the anti-tightening direction, tools other than the exclusive tool, such as radio pliers A method is conceivable in which the head of the tamper-proof screw is sandwiched and rotational torque in the anti-tightening direction is applied to the head. The to-be-fastened member of this invention forms the protrusion wall so that tools other than an exclusive tool cannot be inserted between the head of the tamper-proof screw after the main body is fastened to the base material, and the protrusion wall. Thereby, since the head of the tamper-proof screw cannot be sandwiched, it is further difficult to release the fastening between the fastened member and the base material, and the fastening between the fastened member and the base material can be maintained.

It is a side view of the accelerator apparatus to which the to-be-fastened member by 1st Embodiment of this invention is applied. It is sectional drawing of the accelerator apparatus to which the to-be-fastened member by 1st Embodiment of this invention is applied. It is the III-III sectional view taken on the line of FIG. (A) The IVa part enlarged view of FIG. 1, (b) It is the bb sectional view taken on the line. It is a figure which shows the positional relationship of the to-be-fastened member and tampering screw by 1st Embodiment of this invention, Comprising: (a) Sectional drawing when a tool is inserted in the both sides of the head of a tampering screw, (b) It is the b section enlarged view. It is a characteristic view which shows the relationship between the diameter of the head of the tamper-proofing screw in the accelerator device to which the to-be-fastened member by 1st Embodiment of this invention is applied, and the distance between walls. It is an enlarged view of the to-be-fastened member by 2nd Embodiment of this invention.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
The fastened member according to the first embodiment is applied to, for example, an accelerator device. The accelerator apparatus to which the member to be fastened according to the first embodiment is applied is shown in FIGS. The accelerator device 1 is an input device that is operated by a driver of a vehicle in order to determine a valve opening degree of a throttle valve of a vehicle engine (not shown). The accelerator device 1 is an electronic device, and transmits an electric signal indicating the depression amount of the accelerator pedal 28 to an electronic control device (not shown). The electronic control device drives the throttle valve by a throttle actuator (not shown) based on the depression amount and other information.

  The accelerator device 1 includes a support member 10, a shaft 20, an operation member 30, a return spring 39, a rotation angle sensor 40, a hysteresis mechanism 50, and the like. In the following description, the upper side of FIGS. 1 to 3 is referred to as the “top side” and the lower side of FIGS.

  The support member 10 includes a housing 12, a first cover 14, and a second cover 15. The support member 10 forms an internal space 11 that accommodates the shaft 20, the return spring 39, the rotation angle sensor 40, the hysteresis mechanism 50, and the like. A communication hole 111 corresponding to a movable range of the operation member 30 described later is formed in the lower portion of the support member 10 so as to communicate the internal space 11 and the outside.

  The housing 12 includes a bearing portion 13 that rotatably supports one end portion 201 of the shaft 20, a front portion 122 that is connected to the bearing portion 13 and is positioned on the front side of the accelerator device 1, and a rear portion that faces the front portion 122. 123 and a top member 121 that connects the bearing part 13, the front part 122, and the back part 123 on the top side of the accelerator device 1. The outer walls of the bearing portion 13, the front portion 122, the back portion 123, and the upper surface portion 121 are provided with mesh-like irregularities for maintaining durability against external forces acting on the housing 12. The housing 12 corresponds to a “base material” recited in the claims.

  An opening through which one end 201 of the shaft 20 is inserted is formed in the bearing portion 13, and the shaft 20 is rotatably provided in the opening. That is, the inner wall of the opening becomes the bearing 130 of one end 201 of the shaft 20.

  As shown in FIG. 1, mounting portions 131, 132, and 133 are formed in the housing 12. Bolt holes are formed in the attachment portions 131, 132, 133, respectively. The accelerator device 1 is attached to the vehicle body 5 by a bolt (not shown) inserted through the bolt hole.

  A concave fully open stopper portion 19 is formed on the ground side of the back surface portion 123. The fully open stopper portion 19 abuts a convex fully open stopper 31 provided on the operation member 30 to restrict the rotation angle of the operation member 30 at the accelerator fully open position. The accelerator fully open position is a position that is set such that the degree of depression of the operation member 30 by the driver, that is, the accelerator opening is 100%.

The first cover 14 and the second cover 15 are provided so as to be substantially parallel to the bearing portion 13 of the housing 12.
The first cover 14 is formed in a rectangular flat plate shape. The first cover 14 is locked to the second cover 15 so that the upper surface portion 121, the back surface portion 123, and the front surface portion 122 abut against the end portion on the opposite side to the side connected to the bearing portion 13. The first cover 14 prevents foreign matter from entering the internal space 11.

  The second cover 15 includes a main body 151, projecting walls 161, 171, and 181 that project from the main body 151.

  The main body 151 is a resin member formed in a triangular flat plate shape. A concave portion that rotatably supports the other end portion 202 of the shaft 20 is formed in the inner wall 152 of the main body 151. That is, the inner wall of the recess serves as the bearing 150 of the other end 202 of the shaft 20. As shown in FIG. 1, the outer wall 153 of the main body 151 is formed with mesh-like irregularities for maintaining durability against an external force acting on the second cover 15. The outer wall 153 corresponds to “one surface” recited in the claims.

  The main body 151 has three through holes as “holes” into which the three tampering screws 23, 24, 25 are inserted. FIG. 4B shows a through hole 154 into which the tamper-proof screw 24 is inserted among the three through holes. The vicinity of the opening on the outer wall 153 side of the through hole is a contact surface with which the seat surface of the tamper-proofing screw contacts. FIG. 4B shows the contact surface 17 with which the seat surface 244 of the tamper-proof screw 24 contacts. Protruding walls 161, 171, and 181 are formed in the vicinity of the contact surface. The detailed shape around the contact surface will be described later.

  The tamper-proof screws 23, 24, 25 are tapping screws having heads 231, 241, 251 on which only torque in the tightening direction acts. The tamper-proof screws 23, 24, and 25 are positioned with respect to the second cover 15 by through holes formed in the main body 151. The diameters of the heads 231, 241, and 251 of the tamper-proof screws 23, 24, and 25 of the accelerator device 1 to which the member to be fastened according to the first embodiment is applied are 8.0 mm.

  The second cover 15 is fixed to the back surface portion 123 and the front surface portion 122 by tamper-proof screws 23, 24 and 25. The second cover 15 prevents foreign matter from entering the internal space 11. The second cover 15 corresponds to a “fastened member” described in the claims.

  The shaft 20 is provided in the horizontal direction on the ground side of the accelerator device 1. At one end 201 of the shaft 20, a sensor housing recess 22 that houses the detection unit of the rotation angle sensor 40 is formed.

  The shaft 20 rotates in a predetermined angular range from the accelerator fully closed position to the accelerator fully open position in accordance with the torque input from the operation member 30 as the driver depresses. The accelerator fully closed position is a position set so that the degree of depression of the operation member 30 by the driver, that is, the accelerator opening is 0%.

  Hereinafter, the rotation direction of the operating member 30 from the accelerator fully closed position toward the accelerator fully open position will be referred to as “accelerator open direction”. Further, the rotation direction of the operating member 30 from the accelerator fully open position toward the accelerator fully closed position is described as “accelerator close direction”.

  The operating member 30 includes a rotating body 38 in which a boss portion 32, an arm connecting portion 34, a spring receiving portion 35, and a fully closed stopper portion 36 are integrally formed, an accelerator pedal 28, and a pedal arm 26.

  The boss portion 32 is formed in an annular shape, is provided between the bearing portion 13 and the second cover 15, and is fixed to the outer wall of the shaft 20 by, for example, press fitting.

  First helical teeth 321 are integrally formed on a side surface of the boss portion 32 on the second cover 15 side. A plurality of first helical teeth 321 are formed at equal intervals in the circumferential direction. The first helical tooth 321 has an inclined surface that protrudes toward the rotor 54 side of the hysteresis mechanism unit 50 in the circumferential direction in the accelerator closing direction and approaches the rotor 54 in the tip end portion in the accelerator closing direction.

  A first friction member 323 is provided on the side surface of the boss portion 32 on the bearing portion 13 side. The first friction member 323 is formed in an annular shape, and is provided between the boss portion 32 and the inner wall of the housing 12 in the radially outward direction of the shaft 20. When the boss part 32 is pushed away from the rotor 54, that is, in the direction of the bearing part 13, the boss part 32 is frictionally engaged with the first friction member 323. The frictional force between the boss part 32 and the first friction member 323 becomes the rotational resistance of the boss part 32.

  The arm connecting portion 34 is formed so that one end thereof is connected to the radially outer side surface of the boss portion 32 and the other end extends to the outside of the support member 10 through the communication hole 111.

  The spring receiving portion 35 is formed to extend from the boss portion 32 in the top direction in the internal space 11. The spring receiving portion 35 engages one end of the return spring 39.

  The fully closed stopper portion 36 is formed so as to extend further upward from the spring receiving portion 35 in the internal space 11. The fully closed stopper portion 36 abuts against the inner wall of the back surface portion 123 to restrict the rotation of the operating member 30 in the accelerator closing direction at the accelerator fully closed position.

  As shown in FIGS. 1 and 2, the pedal arm 26 is formed such that one end is fixed to the arm connecting portion 34 and the other end extends in the ground direction. The other end of the pedal arm 26 is connected to an accelerator pedal 28. The accelerator pedal 28 as a “stepping portion” converts the driver's pedaling force into a rotational torque centered on the rotational axis of the shaft 20 and transmits it to the shaft 20 via the rotating body 38.

  When the accelerator pedal 28 rotates in the accelerator opening direction, the rotation angle of the shaft 20 in the accelerator opening direction with the accelerator fully closed position as a base point increases, and the accelerator opening corresponding to this rotation angle increases. Further, when the accelerator pedal 28 rotates in the accelerator closing direction, the rotation angle of the shaft 20 decreases, and the accelerator opening decreases.

  The return spring 39 is composed of a coil spring, and the other end is locked to the inner wall of the front portion 122. The return spring 39 biases the operation member 30 in the accelerator closing direction. The biasing force that the return spring 39 as the “biasing means” acts on the operation member 30 increases as the rotation angle of the operation member 30, that is, the rotation angle of the shaft 20 increases. The urging force is set so that the operation member 30 and the shaft 20 can be returned to the accelerator fully closed position regardless of the rotation position of the operation member 30.

  The rotation angle sensor 40 includes a yoke 42, a pair of magnets 44 and 46 having different magnetic poles, a Hall element 48, and the like. The yoke 42 is made of a magnetic material and is formed in a cylindrical shape. The yoke 42 is fixed to the inner wall of the sensor receiving recess 22 of the shaft 20. The magnets 44 and 46 are disposed so as to face each other across the rotation axis of the shaft 20 in the radially inward direction of the yoke 42, and are fixed to the inner wall of the yoke 42. The hall element 48 is disposed between the magnet 44 and the magnet 46. The rotation angle sensor 40 corresponds to “rotation angle detection means” described in the claims.

  When a magnetic field is applied to the hall element 48 through which a current flows, a voltage is generated in the hall element 48. This phenomenon is called the Hall effect. The magnetic flux density penetrating the Hall element 48 is changed by rotating the magnets 44 and 46 around the rotation axis φ1 of the shaft 20 together with the shaft 20. The magnitude of the generated voltage is proportional to the magnetic flux density through the Hall element 48. The rotation angle sensor 40 detects a voltage generated in the Hall element 48 and detects a relative rotation angle between the Hall element 48 and the magnets 44 and 46, that is, a rotation angle of the shaft 20 with respect to the support member 10. The rotation angle sensor 40 transmits an electrical signal representing the detected rotation angle to an external electronic control device (not shown) via an external connector 49 provided on the upper portion of the accelerator device 1.

  The hysteresis mechanism 50 includes a rotor 54, a second friction member 58, a hysteresis spring 59, and the like.

  The rotor 54 is provided between the boss portion 32 and the inner wall of the second cover 15 in the radially outward direction of the shaft 20. The rotor 54 is formed in an annular shape, can rotate relative to the shaft 20 and the boss portion 32, and can approach or separate from the boss portion 32. Second helical teeth 541 are integrally formed on the side surface of the rotor 54 on the boss portion 32 side. A plurality of second helical teeth 541 are formed at equal intervals in the circumferential direction. The second helical tooth 541 has an inclined surface that protrudes toward the boss portion 32 toward the boss portion 32 in the circumferential direction in the circumferential direction and approaches the rotor 54 toward the distal end in the accelerator opening direction.

  The first helical teeth 321 and the second helical teeth 541 can transmit rotation between the boss portion 32 and the rotor 54 by causing the inclined surfaces to contact each other in the circumferential direction. That is, the rotation of the boss portion 32 in the accelerator opening direction can be transmitted to the rotor 54 via the first helical teeth 321 and the second helical teeth 541. The rotation of the rotor 54 in the accelerator closing direction can be transmitted to the boss portion 32 via the second helical teeth 541 and the first helical teeth 321.

  Further, when the rotation position of the boss portion 32 is closer to the accelerator fully open position side than the accelerator fully closed position, the first helical teeth 321 and the second helical teeth 541 are engaged with each other between the inclined surfaces so that the boss portion 32 and the rotor 54 are separated from each other. At this time, the first helical teeth 321 push the boss 32 toward the housing 12 with a greater force as the rotation angle of the boss 32 from the accelerator fully closed position increases. Further, the second helical tooth 541 pushes the rotor 54 toward the second cover 15 with a larger force as the rotation angle of the boss portion 32 from the accelerator fully closed position increases.

  The second friction member 58 is formed in an annular shape and is provided between the rotor 54 and the inner wall of the second cover 15 in the radially outward direction of the shaft 20. When the rotor 54 is pushed away from the boss portion 32, that is, in the direction of the second cover 15, the rotor 54 frictionally engages with the second friction member 58. The frictional force between the rotor 54 and the second friction member 58 becomes the rotational resistance of the rotor 54.

  The hysteresis spring 59 is constituted by a coil spring. One end of the hysteresis spring 59 is locked to the spring receiving member 552. The spring receiving member 552 is engaged with a spring locking portion 55 formed so as to extend from the rotor 54 in the top direction in the internal space 11. The other end is locked to the inner wall of the front portion 122. The hysteresis spring 59 urges the rotor 54 in the accelerator closing direction. The biasing force of the hysteresis spring 59 increases as the rotation angle of the rotor 54 increases. Torque received by the rotor 54 by the biasing force of the hysteresis spring 59 is transmitted to the boss portion 32 via the second helical teeth 541 and the first helical teeth 321.

  The accelerator device 1 according to the first embodiment is characterized by the shapes of the protruding walls 161, 171, and 181. Therefore, the shape of the protruding walls 161, 171, and 181 will be described in detail with reference to FIGS. FIG. 4A is an enlarged view of the IVa portion of FIG. 1 and shows an enlarged view of the vicinity of the contact surface 17 of the second cover 15 fastened by the tamper-proof screw 24. FIG. 4B is a sectional view taken along line bb in FIG. For convenience of explanation, the relationship between the tamper-proof screw 24 and the protruding wall 171 will be described here, but the relationship between the tamper-proof screw 23 and the protruding wall 161 and the relationship between the tamper-proof screw 25 and the protruding wall 181 are the same. .

  On the head 241 of the tamper-proof screw 24, when the tamper-proof screw 24 is turned clockwise, that is, when it is turned in the tightening direction, the vertical surface 242 on which the rotational torque acts substantially vertically, and the tamper-proof screw 24 is turned counterclockwise, that is, counterclockwise. An inclined surface 243 on which rotational torque acts obliquely when turning in the tightening direction is formed. Thereby, when the tamper-proof screw 24 fastens the housing 12 and the second cover 15, the rotational torque acts on the head 241 reliably, while when the fastening between the housing 12 and the second cover 15 is released, The rotational torque does not act reliably on the head 241 and it is difficult to release the fastening between the housing 12 and the second cover 15.

  The protruding wall 171 is formed to rise from the outer wall 153 toward the outside. The protruding wall 171 has a side surface 172 that faces the head 241 of the tamper-proof screw 24 after the second cover 15 is fastened to the housing 12 and is centered on the axis φ of the tamper-proof screw 24 as shown in FIG. As a circular arc having a central angle θ of 180 °. Further, as shown in FIG. 4B, the protruding wall 171 is formed lower than the height of the head portion 241, and is located at the outermost point 245 on the outer side in the radial direction of the head portion 241 of the tamper-proof screw 24 of the side surface 172. The distance L1 between the near point 174 and the outermost point 245 of the head 241 is formed to be 1.3 mm.

  FIG. 5 is a schematic diagram when the tool T is to be inserted between the head 241 and the side surface 172 of the protruding wall 171 so as to sandwich the head 241 of the tamper-proof screw 24. The tool T shown in FIG. 5 is a tool having a function of sandwiching a member such as pliers, for example, and is a tool other than a dedicated tool capable of rotating the tamper stop screw 24 in the anti-tightening direction.

  As shown in FIG. 5A, when the tip T0 of the tool T is to be inserted between the head 241 and the side surface 172, as shown in the enlarged view of FIG. 5B, a point T1 inside the tip T0. Contacts the outermost point 245 of the head 241, while the point T 2 outside the tip T 0 of the tool T interferes with the corner 173 of the protruding wall 171. Thereby, the tool T cannot pinch the head 241.

As shown in FIG. 5, the applicant conducted an experiment on the relationship between the head and the protruding wall of the anti-screw screw and the tip of the tool, and the inner wall of the protruding wall facing the diameter of the head where the tip of the tool cannot be inserted. The relationship between the distances between the walls was calculated. The result is shown in FIG. FIG. 6 shows the relationship between the head diameter D1 and the inter-wall distance D2, where the diameter of the head of the tamper-proof screw is D1 (mm) and the distance between the inner wall surfaces of the protruding walls is D2 (mm). The solid line C is expressed by Equation 1 below.
D2 = 0.936 × D1 + 3.652 Formula 1

If the distance between the point closest to the outermost point of the head of the tamper-proofing screw on the side surface of the protruding wall and the outermost point of the head is L0 (mm), the following equation 2 derived from equation 1 is At the satisfying distance L0, the head of the tamper-proof screw cannot be pinched by the tool.
L0 <1.826−0.032 × D1 Equation 2
The diameters of the heads 231, 241, and 251 of the tamper-proof screws 23, 24, and 25 used in the accelerator device 1 of the first embodiment are 8.0 mm and are closest to the outermost point 245 and the outermost point 245. The distance L1 from the point 174 is 1.3 mm. Therefore, the accelerator device 1 of the first embodiment is formed with a protruding wall that satisfies the magnitude relationship of Equation 2.

  Next, the operation of the accelerator device 1 will be described.

  When the accelerator pedal 28 is depressed, the operation member 30 rotates in the accelerator opening direction around the rotation axis of the shaft 20 together with the shaft 20 in accordance with the depression force applied to the accelerator pedal 28. At this time, in order for the operating member 30 and the shaft 20 to rotate, the sum of the torque due to the biasing force of the return spring 39 and the hysteresis spring 59 and the resistance torque due to the frictional force of the first friction member 323 and the second friction member 58 The pedaling force that produces a large torque is also required.

  The resistance torque due to the frictional force of the first friction member 323 and the second friction member 58 acts to suppress the rotation of the accelerator pedal 28 in the accelerator opening direction when the accelerator pedal 28 is depressed. As a result, as for the relationship between the pedaling force when the accelerator pedal 28 is depressed and the rotation angle, the pedaling force is larger even when the rotation angle is the same than when the pedal is returned.

  In order to maintain the depression of the accelerator pedal 28 after the accelerator pedal 28 is depressed, the torque by the urging force of the return spring 39 and the hysteresis spring 59 and the anti-torque by the friction force of the first friction member 323 and the second friction member 58 are maintained. What is necessary is just to add the treading force that produces a torque larger than the difference. That is, the driver may depress the pedaling force somewhat when he / she wants to maintain the depression of the accelerator pedal 28 after depressing the accelerator pedal 28. That is, the resistance torque due to the frictional force of the first friction member 323 and the second friction member 58 acts to suppress the rotation of the accelerator pedal 28 in the accelerator closing direction when the accelerator pedal 28 is kept depressed.

  In order to return the depression of the accelerator pedal 28 to the accelerator fully closed position side, the difference between the torque due to the urging force of the return spring 39 and the hysteresis spring 59 and the resistance torque due to the frictional force of the first friction member 323 and the second friction member 58 The pedal force that produces a smaller torque is applied. Here, when the accelerator pedal 28 is quickly returned to the accelerator fully closed position, the depression of the accelerator pedal 28 may be stopped, and the driver is not burdened. That is, the burden placed on the driver when the accelerator pedal 28 is depressed is reduced. The resistance torque due to the frictional force of the first friction member 323 and the second friction member 58 acts so as to suppress the rotation of the accelerator pedal 28 in the accelerator closing direction when the accelerator pedal 28 is returned.

  In the accelerator device 1 using the second cover 15, projecting walls 161, 171, and 181 are formed in the vicinity of the contact surfaces with which the tamper-proof screws 23, 24, and 25 contact. The projecting walls 161, 171, 181 are arranged so that the side surfaces of the projecting walls 161, 171, 181 facing the heads 231, 241, 251 of the tamper-proof screws 23, 24, 25 after the second cover 15 is fastened to the housing 12 It is formed to have an arc shape having a central angle of 180 ° or more about 25 axes. The protruding walls 161, 171, and 181 are located on the side surfaces of the side faces of the tamper-proofing screws 23, 24, 25 that are closest to the outermost points of the heads 231, 241, 251, and the heads of the tamper-proofing screws 23, 24, 25. The distance between the outermost point and the outermost point is smaller than 1.826-0.032 × D. As a result, a tool other than the dedicated tool is interposed between the heads 231, 241, 251 and the side surfaces of the projecting walls 161, 171, 181 so as to sandwich the heads 231, 241, 251 of the tampering screws 23, 24, 25. Since it cannot be inserted, it becomes difficult to turn the tamper-proof screws 23, 24, 25 in the anti-tightening direction. Therefore, the fastening between the housing 12 and the second cover 15 can be maintained.

(Second Embodiment)
Next, a fastened member according to a second embodiment of the present invention will be described with reference to FIG. The second embodiment differs from the first embodiment in the shape of the protruding wall. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 1st Embodiment, and description is abbreviate | omitted.

  A projecting wall 671 is formed in the vicinity of the contact surface 67 on the outer wall 653 of the second cover 65 according to the second embodiment. The height of the protruding wall 671 is formed so as to be higher than the height of the head 741 of the tinker set screw 74. Thereby, when it is going to insert the front-end | tip of the tool T between the head 741 and the side surface 672 of the protrusion wall 671, the front-end | tip of the tool T tends to interfere with the protrusion wall 671, and the front-end | tip of a tool cannot be inserted. Therefore, the fastening between the housing 12 and the second cover 65 can be further maintained.

(Other embodiments)
(A) In the above-described embodiment, the fastened member is the second cover of the accelerator device. However, the type of member to be fastened is not limited to this. The to-be-fastened member should just be a member fastened with the tamper-proof screw with respect to a base material.

  (B) In the above-described embodiment, the second cover is fastened to the housing by three tamper-proof screws. However, the number of tinker screws that fasten the second cover to the housing is not limited to this.

  (C) In the above-described embodiment, the tamper-proof screw is a tapping screw. However, the type of the tinker set screw is not limited to this. It may not be a tapping screw.

  (D) In the above-described embodiment, the through hole into which the tamper-proof screw is inserted is formed in the main body. However, when the tamper-proof screw is a tapping screw, the through hole may not be formed.

  (E) In the above-described embodiment, the diameter of the head of the tamper-proof screw is 8 mm. However, the diameter of the tamper screw head is not limited to this. The distance between the outermost point of the head and the inner wall surface of the protruding wall only needs to satisfy the expression 2.

  (F) In the above-described embodiment, the accelerator device includes the hysteresis mechanism. However, the hysteresis mechanism part may not be provided.

  (G) In the above-described embodiment, when the tamper-proof screw is turned in the tightening direction, the vertical surface on which the rotational torque acts substantially perpendicularly, and when the tamper-proof screw is turned in the anti-tightening direction, An inclined surface on which the rotational torque acts obliquely is formed. However, the shape of the tinker set screw is not limited to this. A screw that has a specially shaped hole such as a star shape or a hexagonal shape at the top of the head and that only the dedicated tool cannot rotate in the anti-tightening direction may be used.

  As mentioned above, this invention is not limited to such embodiment, It can implement with a various form in the range which does not deviate from the summary.

1 ... Accelerator device,
5 ... car body,
12 ・ ・ ・ Housing (base material),
15 ... 2nd cover (fastened member),
151... Main body,
153, 653 ... Outer wall (one surface)
161, 171, 181, 671 ... projecting wall,
17, 67 ... Contact surface,
171, 671 ・ ・ ・ side surface,
20 ... shaft,
23, 24, 25, 74 ... tamper-proof screws,
231, 241, 251, 741 ... head,
26 ... Pedal arm,
38 ・ ・ ・ Rotating body,
39 ・ ・ ・ Return spring (biasing means),
40: Rotation angle sensor (rotation angle detection means).

Claims (8)

A fastened member (15) fastened to a base material (12) by a tamper-proof screw (23, 24, 25, 74),
A main body having a contact surface (17, 67) with which a seat surface (244) of the head (231, 241, 251, 741) of the tamper-proofing screw of one surface (153, 653) can contact;
A protruding wall (161, 171, 181, 671) provided to stand on the one surface in the vicinity of the contact surface of the main body;
With
The projecting wall is anti-tightening the tamper-proof screw between the head of the tamper-proof screw and the projecting wall with respect to the head of the tamper-proof screw after the main body is fastened to the substrate. A member to be fastened, which is formed so as to prevent insertion of a tool other than a dedicated tool that can rotate in a direction.   2. The protruding wall according to claim 1, wherein a side surface (172, 672) facing the head of the tamper-proofing screw is formed in an arc shape after the main body is fastened to the base material. Fastened member.   The side surface of the protruding wall is formed in an arc shape having a central angle (θ) of 180 ° or more about the axis (φ) of the tamper-proof screw when the main body is fastened to the base material. The member to be fastened according to claim 2.   The distance between the outermost point (245) on the outer side in the radial direction of the head of the tamper-proof screw and the point (174) closest to the outermost point among the side surfaces of the protruding wall is L0 (mm), and 4. The fastened according to claim 2, wherein the distance L0 and the diameter D1 satisfy a relationship of L0 <1.826−0.032 × D1 when the diameter of the head is D1 (mm). Element.   The to-be-fastened member as described in any one of Claim 1 to 4 whose height of the said protrusion wall is higher than the height of the said head of the said tinker set screw.   The member to be fastened according to any one of claims 1 to 5, wherein the main body has a hole (154) into which the tamper-proof screw is inserted in the contact surface. The substrate;
The fastened member according to any one of claims 1 to 6, fastened to the base material,
The tamper-proof screw for fastening the fastened member and the base material;
A fastening device comprising: The base material attachable to the vehicle body;
The member to be fastened according to any one of claims 1 to 6, wherein an inner space is formed by fastening with the base material,
The tamper set screw for fastening the base material and the fastened member;
A shaft housed in the internal space and rotatably supported by the base member and the fastened member;
A rotating body that rotates integrally with the shaft;
A pedal arm having one end portion fixed to the rotating body and having a stepping portion on which the driver can step on the other end;
Rotation angle detection means for detecting the rotation angle of the shaft relative to the substrate;
An urging means located in the internal space and urging the rotation of the shaft in the accelerator closing direction;
An accelerator device comprising:

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