JP2010265997A - Screw lock mechanism and shock absorber using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw lock mechanism for easily preventing the looseness of a member having a female screw regardless of the shape of the member having the female screw without damaging the thread. <P>SOLUTION: A spring seat 60 is threaded to a male screw 35 of a head eye portion 30. A cutout portion 37 is formed in part of the male screw 35. The cutout portion 37 has a through-hole 39 and an insertion hole 41, a lock piece 43 whose cross section perpendicular to the axial direction of the male screw is strip-shaped, and a bolt 45 which is threaded to the screw hole of the lock piece 43 and inserted into the through-hole 39 and the insertion hole 41. The lock piece 43 has a lock face 43a having a thread to be threaded to the female screw of the spring seat 60 together with the male screw 35. When the bolt 45 is rotated, the front end of the bolt 45 abuts on the insertion hole 41 to displace the lock piece 43. The male screw 35 and the lock face 43a are pressed against the female screw, and then the spring seat 60 is fixed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a screw lock mechanism and a shock absorber using the same, and more particularly, to a screw lock mechanism for preventing a member having a female screw from loosening against a member having a male screw and a shock absorber using the same.

  Various types of screw lock mechanisms for preventing loosening of a member having a female screw with respect to a male screw are conventionally known.

  For example, there is a screw lock mechanism (a so-called double nut) that tightens a female screw member having a female screw and a nut that is tightened against the female screw member into a male screw member having a male screw.

  There is also a screw lock mechanism that fastens a set screw to a female screw member and fixes the female screw by bringing the tip of the set screw into contact with a thread of a male screw.

  Patent Document 1 discloses a device in which a compression bolt is arranged along the axial direction of a bolt inside a bolt composed of two parts that are movable in the axial direction, and the bolt can be accurately fixed to a female screw. It is disclosed. The bolt is divided into two parts in the axial direction. The compression bolt is supported by one part of the bolt and screwed into the other part. When the compression bolt is tightened, the two parts of the bolt approach each other and the bolt is fixed inside the female thread.

  Further, Patent Document 2 discloses a threaded ring in which a gap having an opening toward the spindle is provided in a ring having a female thread that is screwed into a spindle having a male thread. The female thread portion of the ring is divided into two in the longitudinal axis direction by providing a gap. When the set screw inserted across the gap is tightened, the gap interval changes, the flank face of the female screw is supported by the flank face of the male screw, and the ring is fixed to the spindle.

JP-A-61-73088 Special table 2007-518945

  However, various problems may arise in the conventional mechanism.

  For example, in the case of a so-called double nut, the length of the male screw member having the male screw must have a margin by the thickness of the nut for locking the female screw member, and the device using the screw lock mechanism can be downsized. It becomes difficult. Further, when tightening the nut to the female screw member, it is necessary to tighten the nut so that the female screw member does not rotate, and it may take time to tighten and loosen the double nut. For example, when a screw lock mechanism is used to prevent rotation of a female screw member that is in a state of being easily rotated, it is necessary to tighten a nut by using a plurality of tools. In addition, a large space is required to enable the nut to be tightened using a plurality of tools, and it is difficult to reduce the size of the device using the screw lock mechanism.

  Further, for example, in the screw lock mechanism for screwing the set screw into the female screw member as described above, the set screw must be brought into strong contact with the thread of the male screw in order to securely fix the female screw member. Therefore, depending on how the screw lock mechanism is handled, the thread of the male screw may be damaged. Moreover, it is necessary to provide the thickness which can arrange | position a set screw in the site | part by which a set screw is distribute | arranged among female screw members. Therefore, there is a limit to reducing the thickness of the female screw member. Further, since the set screw is held by the female screw member, the position relative to the male screw is displaced around the axis of the male screw as the female screw member rotates. Depending on the device, the range in which the set screw can be tightened around the external thread may be limited. In this case, it is difficult to allow the set screw to be tightened regardless of the rotational phase of the female screw member with respect to the male screw, so that it is necessary to provide a plurality of set screws.

  Further, in the structure as disclosed in Patent Document 1, the bolt is divided into two parts in the axial direction, so when the axial length of the female screw provided on the female screw member is short It becomes difficult to lock the female screw member to the bolt. Moreover, since the bolt is divided into two parts in the axial direction to the extent that it can be displaced by the compression bolt, there is a problem that the male screw member itself becomes weak against the force applied in the bending direction.

  Further, in the structure disclosed in Patent Document 2, since the set screw must be arranged in the longitudinal axis direction on the female screw member, the size in the longitudinal axis direction and the radial dimension of the female screw member are reduced. I can't. Moreover, it may be difficult to make the set screw tightenable regardless of the rotational phase of the female screw member with respect to the male screw, as in the case where the set screw is brought into contact with the thread of the male screw as described above. .

  The present invention has been made to solve such problems, and can easily prevent loosening of a member having a female screw without damaging the thread regardless of the shape of the member having a female screw. It is an object of the present invention to provide a screw lock mechanism that can be used and a shock absorber using the same.

  In order to achieve the above object, according to one aspect of the present invention, there is provided a screw lock mechanism for preventing a female screw member having a female screw from loosening against a male screw member having a male screw. A notch that is recessed from the outer peripheral surface of the screw and has no thread is formed, and the male screw member includes a bolt arranged so as to have an axis substantially parallel to the axis of the male screw, and a notch. The lock piece is disposed so as to be displaceable in the axial direction of the male screw, and the lock piece is provided with a lock surface provided with a screw thread to be screwed together with the female screw and the female screw, and the bolt is screwed. When the bolt rotates around the axis with the female screw of the female screw member engaged with the male screw and the lock surface, the lock piece is located inside the notch with respect to the male screw member. Displacement in the axial direction of the male screw, thereby The female screw member is prevented from loosening by.

  Preferably, the screw lock mechanism is configured such that when the bolt rotates around the axis, the bolt comes into contact with the male screw member, so that the displacement of the bolt in the axial direction relative to the male screw member is restricted and the lock piece is displaced. ing.

  Preferably, a first hole formed so that the axial direction of the male screw is in the depth direction is formed on the inner surface of the notch, and the bolt is inserted into the first hole. Thus, the bolt and the lock piece are configured not to fall off from the external thread member.

  Preferably, the inner surface of the notch is formed with a second hole that is formed substantially coaxially with the first hole so as to face the first hole and supports a part of the bolt.

  Preferably, in the screw lock mechanism, when the bolt rotates, the front end portion in the advancing direction with respect to the lock piece of the bolt comes into contact with the inner surface of the notch portion, so that the displacement of the bolt in the axial direction is restricted.

  Preferably, the lock piece is formed so that a cross section perpendicular to the axial direction of the external thread has a section shape with the lock surface as an arc.

  According to another aspect of the present invention, the shock absorber has any one of the screw lock mechanisms described above, and the female screw member serves as a seating surface of a coil spring disposed substantially coaxially with the male screw member.

  According to these inventions, the lock piece can be displaced with respect to the external thread member by rotating the bolt around the axis. Thereby, each flank of the external thread and the screw of the lock surface can be brought into contact with the flank of the internal thread member to prevent the internal thread member from loosening. Therefore, it is possible to provide a screw lock mechanism that can easily prevent loosening of a member having a female screw without damaging the thread regardless of the shape of the member having a female screw, and a shock absorber using the same. .

It is a perspective view which shows the shock absorber using the screw lock mechanism in the 1st Embodiment of this invention. It is a disassembled perspective view which shows the structure of a shock absorber. It is a top view which shows a shock absorber. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is the BB sectional view taken on the line of FIG. It is a figure which shows the screw locking mechanism in this Embodiment. It is a top view which shows the screw locking mechanism of 2nd Embodiment. It is CC sectional view taken on the line of FIG.

  Hereinafter, the screw lock mechanism in the embodiment of the present invention will be described.

  [First Embodiment]

  In the first embodiment of the present invention, the screw lock mechanism is applied to, for example, the shock absorber 1.

  [Overall configuration]

  FIG. 1 is a perspective view showing a shock absorber using a screw lock mechanism according to a first embodiment of the present invention.

  First, the overall configuration of the shock absorber 1 will be described. Referring to the drawing, shock absorber 1 includes cylinder 10, piston rod 20, top eye portion (an example of a male screw member) 30, lock nut 50, spring seat (an example of a female screw member) 60, coil And a spring 70. In the present embodiment, the shock absorber 1 is used in, for example, a suspension device for a racing vehicle, and includes a coil spring 70 having a relatively small winding diameter.

  FIG. 2 is an exploded perspective view showing the structure of the shock absorber 1.

  Referring to the figure, the cylinder 10 includes a bearing 11, a collar 13, a rod guide portion 15, an enclosure portion 17, and the like. The bearing 11 is a so-called spherical bearing (spherical plain bearing), and is attached to the bottom of the cylinder 10 (upper left in the figure). The collar 13 is attached to each of the upper and lower surfaces of the bearing 11. The shock absorber 1 is pivotally supported on the vehicle body so that both the collars 13 are sandwiched between brackets on the vehicle body side.

  The cylinder 10 is filled with oil or high-pressure gas as a working fluid. The enclosing portion 17 is used for enclosing high-pressure gas inside the cylinder 10 through a hole that penetrates the inside of the cylinder 10 in an opened state.

  The rod guide part 15 is attached to the upper part (lower right part in the figure) of the cylinder 10. The rod guide portion 15 seals the upper portion of the cylinder 10 so that the piston rod 20 can freely enter and exit the cylinder 10. In the present embodiment, the upper surface of the rod guide portion 15 serves as a spring seat for the coil spring 70. A cylindrical guide portion 15 a having a smaller diameter than the inner diameter of the coil spring 70 is provided at the center portion of the rod guide portion 15. The coil spring 70 is arranged so that the guide portion 15a penetrates at one end thereof. The coil spring 70 supports the chassis.

  The piston rod 20 has a lower end penetrating into the cylinder 10 and protrudes upward from a substantially central portion of the rod guide portion 15. A piston (not shown) that slides while contacting the inner surface of the cylinder 10 is attached to the lower end of the piston rod 20. A screw to which the top eye portion 30 is attached is provided at the upper end portion of the piston rod 20 (see FIG. 4).

  The top eye portion 30 is screwed into the upper end portion of the piston rod 20. The top eye portion 30 is fixed to the piston rod 20 using a lock nut 50 in a state where the entire length of the shock absorber 1 is a predetermined length.

  The top eye portion 30 includes a bearing 31, a collar 33, a male screw 35, a notch portion 37, a through hole (an example of a first hole portion or an example of a second hole portion) 39, and an insertion hole (a first hole). An example of a 2 hole part or an example of a 1st hole part) 41 etc. are provided. The bearing 31 is the same as the bearing 11, and is attached to a case portion 30 a provided at the distal end portion of the top eye portion 30. The collar 33 is attached to each of the upper and lower surfaces of the bearing 31. The shock absorber 1 is attached as a part of a suspension device with both collars 33 sandwiched between bracket portions connected to the wheel side and interlocking with the wheel.

  The top eye portion 30 has a lock surface 43 a and a bolt 45. A more detailed structure of the top eye part 30 will be described later.

  The spring seat 60 is formed in an annular shape having a flange. On the flange portion of the spring seat 60, a hook portion 61 is provided on which a tool can be hooked to rotate the spring seat 60. A female screw 63 is formed on the inner surface of the spring seat 60. The female screw 63 can be screwed onto the male screw 35. A cylindrical guide portion 65 having a smaller diameter than the inner diameter of the coil spring 70 is formed on the spring seat 60 so as to protrude from one surface of the flange portion in the axial direction (the direction indicated by the arrow X in FIG. 2; the same applies to the following drawings). Has been. The coil spring 70 is arranged so that the guide portion 65 penetrates at one end thereof.

  FIG. 3 is a plan view showing the shock absorber 1.

  In the figure, the illustration of the screw thread is omitted. Referring to the figure, the spring seat 60 is formed by screwing a female screw 63 to the male screw 35 in such a direction that the flange surface on the side where the guide portion 65 is provided faces the rod guide portion 15. It is attached to the eye part 30. The coil spring 70 is sandwiched between the flange portion of the spring seat 60 and the upper surface of the rod guide portion 15. The both ends of the coil spring 70 are guided by the guide portions 65 and 15 a and are arranged substantially coaxially with the cylinder 10.

  In the present embodiment, the spring seat 60 is displaced with respect to the top eye portion 30 by being rotated around the axis of the male screw 35 of the top eye portion 30. That is, the preload of the coil spring 70 can be changed by rotating the spring seat 60 and adjusting the position of the spring seat 60 with respect to the top eye portion 30.

  [Structure of Top Eye 30]

  4 is a cross-sectional view taken along line AA in FIG.

  Next, the detailed structure of the top eye part 30 will be described with reference to the drawings. At the tip of the top eye portion 30, a case portion 30a that is widened to the upper end edge of the top eye portion 30 so as to have a thickness necessary to hold the bearing 11 is provided. The top eye portion 30 has a male screw upper end surface 30b formed by forming a two-surface widened portion of the case portion 30a.

  The notch 37 is formed in a part of the male screw 35 of the top eye portion 30 so as to be recessed from the outer peripheral surface of the male screw 35. That is, the screw thread portion of the male screw 35 where the notch 37 is provided is partially deleted in the winding direction of the male screw 35. As shown in FIG. 2, the notch 37 has a cross-section perpendicular to the axial direction of the male screw 35, with a shape obtained by removing a section from a circle corresponding to the male screw 35 in a part of the axial direction of the male screw 35. It is formed to have as a shape. As shown in FIG. 4, the cutout portion 37 is formed so as to have two end faces that face each other and are substantially perpendicular to the axial direction of the male screw 35. The cutout portion 37 can be easily formed by, for example, milling and cutting a portion of the male screw 35 of the top eye portion 30 from one direction perpendicular to the axis of the male screw 35.

  With reference to FIG. 2, the through hole 39 and the insertion hole 41 are respectively formed on two end faces of the cutout portion 37 facing each other. The through hole 39 and the insertion hole 41 are formed so as to be substantially coaxial with each other so that the axial direction of the male screw 35 is in the depth direction. As shown in FIG. 4, in the present embodiment, the through hole 39 is formed so as to penetrate between the inner surface of the notch portion 37 and the male screw upper end surface 30b. On the other hand, the insertion hole 41 is a non-through hole having a predetermined depth. The through hole 39 has a hole diameter slightly larger than the outer diameter of the threaded portion of the bolt 45. Further, the insertion hole 41 has a hole diameter that is slightly smaller than the tip of the bolt 45. Note that the insertion hole 41 may have a hole diameter comparable to that of the through hole 39, for example.

  Referring to FIG. 2, the lock piece 43 has a lock surface 43a and a screw hole 43b. The lock piece 43 is formed such that a cross section perpendicular to the axial direction of the external thread 35 has a section shape with the lock surface 43a as an arc. That is, the lock piece 43 has a shape surrounded by the lock surface 43 a and the three surfaces corresponding to the inner surface of the notch 37. The lock piece 43 is disposed in the notch 37. The lock surface 43 a is provided with a screw thread that is screwed into the female screw 63 of the spring seat 60 together with the male screw 35 of the top eye portion 30. By disposing the lock piece 43 in the cutout portion 37, the top eye portion 30 has a male screw portion having a screw thread formed by the male screw 35 and the lock surface 43a on the entire circumference.

  Since the lock piece 43 has a section shape with the lock surface 43a as an arc, the thread formed on the lock surface 43a is one continuous in the winding direction of the external screw 35, that is, What occupies the whole part of the circumference of the winding direction of the screw 35 is not provided. That is, a thread that occupies a part of one turn in the winding direction of the external thread 35 is formed on the lock surface 43a. A plurality of such screw threads are formed on the lock surface 43a.

  Referring to FIG. 4, lock piece 43 is formed such that axial dimension D <b> 2 of male screw 35 is slightly smaller than axial dimension D <b> 1 of male thread 35 of notch 37. That is, the lock piece 43 is disposed in the notch 37 so as to be displaceable in the axial direction of the external thread 35 inside the notch 37.

  The screw hole 43 b is formed so as to be substantially coaxial with the through hole 39 and the insertion hole 41 in a state where the lock piece 43 is disposed inside the notch 37. The screw hole 43 b passes through the lock piece 43. The screw hole 43b is formed so that the bolt 45 can be screwed together.

  5 is a cross-sectional view taken along line BB in FIG.

  The bolt 45 is arranged at a position away from the axis of the male screw 35, that is, an eccentric position, so as to have an axis substantially parallel to the axis of the male screw 35. Referring to the figure, a hexagonal hole 45 a is formed in the head of the bolt 45. Bolt 45 can be rotated using tools, such as a hexagon stick spanner which can be inserted in hexagon hole 45a. As shown in FIG. 2, the head of the bolt 45 is formed to have an outer diameter that is substantially the same as that of the screw portion. The head of the bolt 45 can penetrate the through hole 39. A rod tip 45 b slightly smaller than the inner diameter of the insertion hole 41 is formed at the tip of the bolt 45. The rod end portion 45 b can be inserted into the insertion hole 41. The rod end portion 45 b has a length substantially the same as the depth of the insertion hole 41 and can hit the bottom of the insertion hole 41.

  Referring to FIG. 4, the bolt 45 has a total length that is substantially equal to or slightly shorter than the dimension between the male screw upper end surface 30 b and the bottom of the insertion hole 41. The bolt 45 is inserted into the through hole 39 from the male screw upper end surface 30 b side in a state where the lock piece 43 is disposed in the notch 37. The bolt 45 is screwed into the screw hole 43 b of the lock piece 43 and is screwed until the rod tip portion 45 b enters the insertion hole 41. As a result, as shown in the figure, the bolt 45 and the lock piece 43 are held in the notch 37 so that both ends of the bolt 45 are held by the through hole 39 and the insertion hole 41 and do not fall off from the top eye portion 30. It is attached. Since the bolt 45 is attached to the top eye portion 30 in a both-sided state, the bolt 45 can be stably rotated. In addition, even when the spring seat 60 is not attached to the top eye portion 30, the bolt 45 and the lock piece 43 do not fall off, so that the coil spring 70 can be easily replaced. Further, since the bolt 45 does not protrude from the surface of the top eye portion 30 such as the male screw upper end surface 30b, the top eye portion 30 can be reduced in size, and the appearance of the shock absorber 1 can be improved.

  The difference between the axial dimension D1 of the external thread 35 and the axial dimension D2 of the external thread 35 (indicated by dimension D3 in FIG. 6) is the depth of the insertion hole 41, the length of the rod end portion 45b, It is desirable not to exceed the length of the penetration portion of the through hole 39 and the bolt 45. In this case, the bolt 45 can be prevented from coming out of the through hole 39 and the insertion hole 41 regardless of the position of the lock piece 43 with respect to the male screw 35, and the bolt 45 and the lock piece 43 are notched 37. Can be securely held.

  The bolt 45 may be, for example, a hexagon socket set screw at the end of a rod. Further, instead of having a hexagonal hole, it may be one with a slot, one with a cross hole, one having a hexalobal hole (Hexalobal internal driving feature), or the like. Further, the rod tip portion 45 b may not be provided, and the tip portion of the screw portion may be configured to penetrate the insertion hole 41.

  [Screw locking mechanism]

  In the present embodiment, the top eye portion 30 and the spring seat 60 constitute a screw lock mechanism that prevents the spring seat 60 from loosening with respect to the top eye portion 30. Hereinafter, the function of the screw lock mechanism will be described.

  FIG. 6 is a diagram showing a screw lock mechanism in the present embodiment.

  Referring to the drawing, the spring seat 60 is in a state where the rod end portion 45b is sufficiently inserted into the insertion hole 41 and the lock piece 43 is close to the insertion hole 41 inside the notch 37 (see FIG. In a state in which the dimension D3 of FIG. In this state, play is provided between the female screw 63 and the male screw 35 and between the female screw 63 and the lock surface 43a. Therefore, the lock piece 43 can move freely so that the friction between the lock surface 43a and the internal thread 63 and between the internal thread 63 and the external thread 35 decreases as the spring seat 60 rotates. Therefore, the spring seat 60 can be easily screwed into the top eye portion 30 with a light force.

  In this state, the user can prevent the spring seat 60 from loosening with respect to the top eye portion 30 by rotating the bolt 45 in the direction of moving downward (leftward in FIG. 6) with respect to the lock piece 43. That is, when the bolt 45 rotates around the axis, the front end of the bolt 45 in the moving direction with respect to the lock piece 43, that is, the rod tip 45 b comes into contact with the inner surface of the cutout portion 37, that is, the bottom surface of the insertion hole 41. The displacement of the bolt 45 in the axial direction relative to 30 is restricted. Therefore, at this time, with the rotation of the bolt 45, the locking piece 43 is in the axial direction of the external thread 35 (the direction indicated by the arrow Y in the drawing (dimension D3 is reduced) inside the notch 37 with respect to the top eye portion 30. Direction)).

  When the lock piece 43 is displaced as described above, the flank on the upper surface side (right side in FIG. 6) of the screw of the lock surface 43a comes into contact with the flank on the lower surface side (left side in FIG. 6) of the female screw 63. Is biased upward. Thereby, the flank on the upper surface side of the female screw 63 comes into contact with the flank on the lower surface side of the male screw 35. In this way, by rotating the bolt 45 and pressing the respective flanks strongly, the spring seat 60 can be prevented from loosening with respect to the top eye portion 30 and the spring seat 60 can be fixed (locked). In other words, the female screw 63 can be prevented from loosening by rotating the bolt 45 and shifting a part of the screw thread (lock surface 43a portion) into which the female screw 63 is screwed in the axial direction of the female screw 63. it can.

  In order to release (unlock) the loosening prevention of the spring seat 60 from the state in which the spring seat 60 is locked as described above, the user only has to rotate the bolt 45 in the reverse direction. That is, when the bolt 45 is rotated in the reverse direction, the pressure contact between the flank is released, and the lock piece 43 becomes movable again. Therefore, the spring seat 60 can be easily rotated with a light force.

  In the present embodiment, the bearing 31 and the male screw upper end surface 30b are formed such that the edge of the bracket portion on the wheel side and the like are not in contact with the male screw upper end surface 30b when the shock absorber 1 is operated. ing. Further, it is desirable that the bearing 31 and the male screw upper end surface 30b be separated to the extent that the hexagon socket wrench can be inserted into the hexagon socket 45a in a state where the shock absorber 1 is attached to the vehicle body. Accordingly, the spring seat 60 can be easily locked / unlocked in a state where the shock absorber 1 is attached to the vehicle body.

  [Second Embodiment]

  The screw lock mechanism in the second embodiment is different from that of the first embodiment in the shape of the notch and the lock piece. Hereinafter, the screw lock mechanism of the second embodiment will be described.

  FIG. 7 is a plan view showing the screw lock mechanism of the second embodiment. 8 is a cross-sectional view taken along the line CC of FIG.

  Referring to FIG. 7, in the second embodiment, shaft (an example of a male screw member) 230 and nut (an example of a female screw member) 260 constitute a screw lock mechanism.

  The shaft 230 includes an external thread 235, a notch 237, a through hole (an example of a first hole; an example of a second hole) 239, and an insertion hole (an example of a second hole; first hole) Example) 241. The shaft 230 has a lock piece 243 and a bolt 245. As shown in FIG. 7, the notch 237 is a hole formed so as to penetrate the central portion of the shaft 230 in a direction substantially perpendicular to the axial direction of the external screw 235 (the arrow X direction in FIG. 6). is there. The through hole 239 is formed so as to penetrate the notch 237 from one end surface of the shaft 230 along the axis of the shaft 230. The insertion hole 241 is a non-through hole having a predetermined depth formed so as to be recessed from the inner surface of the notch 237 substantially coaxially with the through hole 239. The through hole 239 and the insertion hole 241 have an inner diameter into which the bolt 245 can be inserted.

  The lock piece 243 has a lock surface 243 a provided with a screw thread that engages with the female screw 263 of the nut 260 together with the male screw 235 of the shaft 230. The lock surfaces 243a are respectively provided on two surfaces of the lock pieces 243 that are exposed on the peripheral surface of the shaft 230. Each lock surface 243a is formed with a screw thread that occupies a part of one turn in the winding direction of the screw. A plurality of such screw threads are formed on each lock surface 43a. The lock piece 243 has a screw hole 243b into which the bolt 245 is screwed. The lock piece 243 is formed so that the width dimension in the axial direction of the male screw 235 is smaller than the width dimension in the same direction of the notch 237. The lock piece 243 is inserted into the notch 237 and is disposed inside the notch 237 so as to be displaceable in the axial direction of the external screw 235.

  The bolt 245 is, for example, a hexagon bolt, and can be rotated about an axis by applying a tool such as a spanner to the head 245a. When inserted into the shaft 230 from the through hole 239, the tip has a length sufficient to contact the bottom of the insertion hole 241.

  The nut 260 can be screwed onto the shaft 230 with the lock piece 243 disposed inside the notch 237. At this time, the rotation of the bolt 245 can prevent the nut 260 from rotating with respect to the shaft 230.

  The mechanism for preventing rotation of the nut 260 is substantially the same as that for preventing rotation of the spring seat 60 in the first embodiment described above. That is, as shown in FIG. 8, in a state where the nut 260 is screwed to the lock surface 243a and the external thread 235, the bolt 245 is rotated in the direction of moving downward (leftward in FIG. 8) with respect to the lock piece 243. . As a result, the bolt 245 is displaced downward with respect to the nut 260 and the lock piece 243, and the tip of the bolt 245 contacts the bottom of the insertion hole 241. When the bolt 245 further rotates, the bolt 245 is regulated so as not to be displaced downward, so that the lock piece 243 is moved upward in the notch 237 (in the axial direction of the external thread 235; the direction of the arrow Y in FIG. 8). ). Accordingly, the female screw 263 is pressed against the male screw 235 and the lock surface 243a, and the nut 260 is fixed (locked) to the shaft 230. Note that the lock of the nut 260 can also be released in the same manner as in the first embodiment by rotating the bolt 245 in the reverse direction.

  In the second embodiment, the female screw 263 can be prevented from loosening by displacing the two lock surfaces 243a that are substantially symmetrical with respect to the central axis with respect to the male screw 235. Therefore, a force can be applied to the nut 260 in a well-balanced manner, and the distortion of the nut 260 and the shaft 230 and the change in the posture of the nut 260 caused by locking can be reduced.

  [Effects of the embodiment]

  In the screw lock mechanism configured as described above, the lock piece can be displaced with respect to the screw member such as the top eye portion or the shaft by rotating the bolt around the axis. In this way, the flank of the female screw and the lock surface screw are brought into contact with the female thread flank of the female screw member such as a spring seat or nut to prevent the female screw member from loosening. Can do. Therefore, regardless of the shape of the member having the female screw, it is possible to easily prevent the member having the female screw from loosening without damaging the thread.

  With this screw lock mechanism, fewer tools are required to prevent loosening, and even when the male screw member and female screw member are large, the female screw member can be loosened with a small bolt. it can. Further, since the bolt is inserted into the male screw member, it is possible to prevent loosening by always rotating the bolt at substantially the same position regardless of the rotational phase of the female screw member with respect to the male screw. Therefore, the space required for maintenance can be made relatively narrow, and the device using the screw lock mechanism can be downsized.

  In addition, since the male screw member only needs to have a cutout part at a part thereof, it is possible to easily ensure sufficient strength against the force applied in the bending direction of the male screw member. Also, by disposing a locking piece over a wide range in the axial direction of the external thread where the internal thread is applied, even if the range for fixing the internal thread member on the external thread is large, or the axial length of the internal thread Even if is short, the female screw member can be reliably locked. Further, the length of the male screw member in the axial direction does not change regardless of whether or not the female screw member is locked.

  In this screw lock mechanism, the female screw member does not need to be provided with a special structure for preventing loosening, such as a screw or a spring. Therefore, for example, the present invention can be applied even when it is necessary to make the female screw member thinner and smaller in the axial direction and the radial direction of the female screw.

  This screw lock mechanism can be easily prevented from loosening only by rotating the bolt, and is therefore suitable for applications in which the female screw member is frequently locked and unlocked. For example, when it is used for fixing the spring seat of the shock absorber as in the first embodiment, the advantage is particularly great compared with the conventional method using a double nut or the like. That is, it is possible to easily and quickly change the coil spring preload and the coil spring. Moreover, by using a screw lock mechanism on the top eye portion side of the shock absorber, a double nut or the like can be eliminated, and a member attached to the top eye portion side can be made smaller and lighter than before. Therefore, the degree of freedom of layout around the vehicle suspension device can be increased, and the unsprung weight can be reduced.

  Moreover, this screw locking mechanism can arrange | position the bolt in the position eccentric | decentered with respect to the external thread member like 1st Embodiment, for example. Therefore, this screw lock mechanism can also be applied to an apparatus having a structure in which a bolt cannot be disposed in the vicinity of the center portion of the male screw member.

  [Others]

  In addition, the shape of a notch part and a lock piece is not restricted above. Moreover, in 1st Embodiment, a volt | bolt is not restricted to what is embed | buried in a top eye part.

  Further, only one of the through hole and the insertion hole may be provided. For example, when only the insertion hole is provided, a lock piece is arranged in the notch part opened in the axial direction of the male thread at the part where the male thread is provided, and the female thread member is threaded. In the state of being screwed to the member, the tip of the bolt screwed to the lock piece is inserted into the insertion hole and brought into contact therewith. Then, by rotating the bolt, the lock piece can be displaced within the cutout portion to prevent loosening. Since one end of the bolt is inserted into the insertion hole and supported, the bolt can be reliably rotated. In this case, the insertion hole may not be provided. That is, in this case, the position of the bolt in the axial direction can be regulated and the loosening can be prevented by bringing the tip of the bolt into contact with the inner surface of the notch.

  On the other hand, only the through-hole is provided, and the lock piece may be configured to be displaced inside the notch portion when the front end portion of the bolt contacts the inner surface of the notch portion. Since the bolt penetrates the through hole, it is possible to prevent the screw piece from dropping off from the male screw member. Further, the bolt can be easily rotated without disturbing the bolt shaft.

  In addition, the bolt may be configured such that the displacement of the bolt in the axial direction is restricted by the other end portion contacting the male screw member instead of the tip portion contacting the male screw member. The displacement of the bolt in the axial direction only needs to be restricted in one direction. That is, for example, by using a bolt with a seating surface such as a hexagonal bolt or a hexagon socket head bolt, the displacement of the bolt in the direction of the tip is regulated by bringing the seating surface into contact with one end of the through hole of the male screw member. can do. In this case, by rotating the bolt in the tightening direction with respect to the lock piece, the lock piece can be displaced toward the head side of the bolt, that is, the through-hole side, thereby preventing loosening. At this time, a countersunk portion in which the head of the bolt is embedded may be provided in the male screw member.

  Note that the screw lock mechanism as in the second embodiment described above can be applied to, for example, a shock absorber in which the distance between the spring seat and the bearing of the top eye portion is relatively long. Further, the lock mechanism may be configured by combining the first embodiment and the second embodiment described above.

  The screw lock mechanism is not limited to the shock absorber, and can be applied to various devices having a structure for preventing the female screw member from loosening with respect to the male screw member. The shape of each member such as a male screw member set screw member can be appropriately changed. In particular, since the shape of the female screw member is not subject to any restrictions by this screw lock mechanism, the screw lock mechanism can be widely applied.

  In addition, it should be thought that the said embodiment is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Shock absorber 30 Top eye part (Example of male thread member)
35,235 Male thread 37,237 Notch 39 Through hole (an example of the first hole, an example of the second hole)
41 insertion hole (an example of the second hole, an example of the first hole)
43,243 Lock piece 43a, 243a Lock surface 43b, 243b Screw hole 45,245 Bolt 45b Rod end 60 Spring seat (an example of a female screw member)
63,263 female thread 230 shaft (example of male thread member)
260 Nut (Example of female thread member)
239 Through hole (an example of a first hole, an example of a second hole)
241 insertion hole (example of second hole, example of first hole)

Claims (7)

A screw lock mechanism for preventing a female screw member having a female screw from loosening against a male screw member having a male screw,
A part of the male screw member is formed with a notch that is recessed from the outer peripheral surface of the male screw and does not have a thread.
The male screw member is
A bolt arranged to have an axis substantially parallel to the axis of the male screw;
A lock piece disposed in the cutout portion so as to be displaceable in the axial direction of the male screw;
The lock piece has a lock surface provided with a screw thread to be screwed into the female screw together with a male screw of the male screw member, and a screw hole into which the bolt is screwed.
When the bolt rotates around the shaft in a state where the female screw of the female screw member is screwed to the male screw and the lock surface, the lock piece is inside the notch with respect to the male screw member. A screw lock mechanism that is displaced in the axial direction of the male screw, thereby preventing the female screw member from loosening against the male screw member.   When the bolt rotates around the shaft, the bolt comes into contact with the male screw member, whereby the axial displacement of the bolt relative to the male screw member is restricted, and the lock piece is displaced. The screw locking mechanism according to claim 1. A first hole formed so that the axial direction of the male screw is in the depth direction is formed on the inner surface of the notch,
3. The screw lock mechanism according to claim 1, wherein the bolt is inserted into the first hole portion so that the bolt and the lock piece do not fall off the male screw member. 4.   The second hole portion that is formed substantially coaxially with the first hole portion so as to face the first hole portion and supports a part of the bolt is formed on an inner surface of the notch portion. The screw lock mechanism according to 3.   5. The displacement of the bolt in the axial direction is restricted by the front end portion in the traveling direction of the bolt with respect to the lock piece contacting the inner surface of the notch when the bolt rotates. 6. The screw lock mechanism according to the above.   The screw lock mechanism according to any one of claims 1 to 5, wherein the lock piece is formed so that a cross section perpendicular to the axial direction of the male screw has a section shape with the lock surface as an arc. A shock absorber comprising the screw lock mechanism according to any one of claims 1 to 6, wherein the female screw member is a seating surface of a coil spring disposed substantially coaxially with the male screw member.

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