JP2019078395A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorber capable of easily securing a pressure receiving area of a lock piece receiving pressure in a lock case.
SOLUTION: A cylindrical lock case 5b disposed on the outer periphery of a rod 6 and movable in the axial direction with respect to the rod 6, a lock piece 7 slidably accommodated in the lock case 5b, and a lock piece 7 and the rod 6 together with the passage 70 communicating with the inside and outside of the lock case 5b, move relative to the lock case 5b and abut on the lock piece 7 to close the passage 70 and lock the lock piece 7 into the lock case 5b And a stopper 9 to be pushed in.
[Selected figure] Figure 1

Description

  The present invention relates to improvements in shock absorbers.

  Conventionally, a shock absorber used for a suspension such as a front fork includes a telescopic tube member configured to have a car body side tube and an axle side tube, and the shock absorber main body in the tube member; There is one that accommodates a suspension spring that elastically supports a vehicle body. The shock absorber body includes a cylinder and a rod which is movably inserted in the cylinder in an axial direction, and when the shock absorber is extended or contracted, the cylinder and the rod are axially moved relative to each other to generate a damping force. It has become.

  Furthermore, some of such shock absorbers have an oil lock mechanism in order to reduce the shock at the time of the last contraction. Specifically, the oil lock mechanism is mounted on the outer periphery of a cylindrical lock case provided on a head member mounted at one end of the cylinder, and a rod projecting through the head member to the outside of the cylinder to provide a shock absorber. And a lock piece which is inserted into the lock case at the time of the maximum contraction (for example, Patent Document 1).

  Then, when the lock piece intrudes into the lock case at the time of contraction of the shock absorber, the hydraulic oil in the lock case flows out between the lock piece and the lock case to the outside of the lock case to resist the flow of the hydraulic oil. Is granted. For this reason, the pressure in the lock case rises, and a force (hereinafter referred to as oil lock force) by the pressure acts on the rod to stop the contraction operation of the shock absorber.

JP, 2011-094647, A paragraph 0053

  In order to obtain a sufficient oil lock force, it is preferable to increase the outer diameter of the lock piece as much as possible to increase the pressure receiving area for receiving the pressure in the lock case. However, when the lock piece attached to the outer periphery of the rod moves with the rod in a state of being withdrawn from the lock case as in the conventional shock absorber, the increase in diameter of the lock piece is limited by other members provided on the outer periphery of the rod There is something to be done.

  For example, as in the case of the shock absorber described in JP 2011-094647A, in the case where a suspension spring consisting of a coil spring is provided on the outer periphery of the rod, the lock piece moves with the rod inside the suspension spring. Can not set the outer diameter of the lock piece to be larger than the inner diameter of the suspension spring. In addition, the diameter of the tube member is generally predetermined depending on the type of vehicle on which the shock absorber is mounted. For this reason, when the conventional oil lock mechanism is applied to the shock absorber of a thin tube member, a thin (small inner diameter) suspension spring is adopted, so the outer diameter of the lock piece is more than the inner diameter of the thin suspension spring. It must be made smaller and it becomes difficult to secure the pressure receiving area.

  That is, in a shock absorber in which the lock piece moved out of the lock case moves together with the rod as in the prior art, the outer diameter of the lock piece must be reduced by the balance with the suspension spring or the like disposed between the tube member and the rod. As a result, the oil lock force may be insufficient because a sufficient pressure receiving area can not be secured. If the oil lock force is insufficient as described above, the shock at the time of the contraction of the shock absorber can not be sufficiently mitigated, and when the shock absorber is mounted on the vehicle, the ride comfort of the vehicle may be deteriorated.

  Then, an object of the present invention is to provide a shock absorber which can solve such a problem and easily secure a pressure receiving area of a lock piece receiving pressure in a lock case.

  A shock absorber to solve the above problems includes a cylindrical lock case disposed on the outer periphery of the rod and movable in the axial direction with respect to the rod, a lock piece slidably accommodated in the lock case, and the lock piece And a rod that moves relative to the lock case with the rod to abut against the lock piece to close the passage and push the lock piece into the lock case.

  According to the configuration, the lock piece is accommodated in the lock case, so even if the suspension spring or the like is provided on the outer periphery of the rod protruding to the outside of the lock case, the lock piece is enlarged in diameter. It is not restricted by etc. Therefore, since the outer diameter of the lock piece can be increased, the pressure receiving area of the lock piece that receives the pressure in the lock case can be easily secured.

  Furthermore, in the shock absorber, a passage may be formed between the lock piece and the rod. According to this configuration, even if the outer diameter of the stopper is reduced, the flow passage area of the passage can be increased. For this reason, when the stopper moves away from the lock piece and the lock piece moves in the direction to withdraw from the lock case, the liquid outside the lock case is rapidly supplied into the lock case through the passage, so the inside of the lock case has a negative pressure. Can be suppressed.

  Further, in the shock absorber, the lock piece may be formed with a recess that allows the stopper to enter. According to the said structure, generation | occurrence | production of the collision noise at the time of a stopper striking a lock piece can be suppressed.

  Further, when the shock absorber has a return spring housed in the lock case, the return spring positions the lock piece at a predetermined position in the lock case, and the lock piece moves from the predetermined position in the lock case to the back side The lock piece may be urged to return to a predetermined position. According to this configuration, the stroke length of the lock piece when the oil lock force is generated can be reliably ensured.

  Further, in the shock absorber, the lock piece may be formed in an annular shape and be slidably attached to the outer periphery of the rod. According to this configuration, even if the lock piece completely comes out of the lock case, the rod can guide the lock piece back into the lock case. Therefore, the retaining member for preventing the lock piece from coming out of the lock case can be omitted.

  The shock absorber further includes a coil spring supported at one end by the tip of the lock case and disposed on the outer periphery of the rod, and a stopper is mounted on the outer periphery of the rod to be movable inside the coil spring. The inner diameter of the case may be set larger than the inner diameter of the coil spring. According to the said structure, since the outer diameter of a lock piece can be made larger than the internal diameter of a suspension spring, the pressure receiving area of a lock piece can be ensured more reliably.

  According to the shock absorber of the present invention, the outer diameter of the lock piece can be increased, and the pressure receiving area for receiving the pressure in the lock case can be easily secured.

It is the front view which partially cut away and showed a part of buffer which concerns on one embodiment of this invention. It is the top view which showed the oil lock piece of the shock absorber which concerns on one embodiment of this invention. (A) is a partial expanded sectional view which expanded and showed a part of FIG. 1, and shows the state which has a lock piece in the initial position. (B) is a partial expanded sectional view showing a state in which the lock piece of (a) is pushed from the initial position to the back side of the lock case by the stopper.

  Hereinafter, a shock absorber according to an embodiment of the present invention will be described with reference to the drawings. The same reference numerals as in the several figures indicate the same parts.

  A shock absorber D according to an embodiment of the present invention shown in FIG. 1 is used for a front fork that suspends the front wheel of a straddle-type vehicle. In the following description, the state in which the front fork is attached to the vehicle, that is, the upper and lower sides of the shock absorber D in the attached state will be simply referred to as "upper" and "lower" of the shock absorber D unless specifically described.

  The shock absorber D includes a telescopic tube member 1 configured to have an outer tube 10 and an inner tube 11 slidably inserted in the outer tube 10, and a shock absorber accommodated in the tube member 1 And a suspension spring 3.

  In the present embodiment, the tube member 1 is an inverted type, and the outer tube 10 is disposed on the upper side (vehicle body side) and the inner tube 11 is disposed on the lower side (axle side). That is, in the present embodiment, the outer tube 10 is a vehicle body side tube, and the inner tube 11 is an axle side tube.

  The outer tube 10 is connected to the vehicle body of the vehicle via a vehicle body side bracket (not shown), and the inner tube 11 is connected to the axle of the front wheel via an axle side bracket 12. Thus, the shock absorber D is interposed between the vehicle body and the axle, and the inner tube 11 enters and exits the outer tube 10 when the front wheel vibrates up and down due to the vehicle traveling on the uneven road surface or the like. The shock absorber D expands and contracts.

  The tube member 1 may be an upright type, and the outer tube 10 may be an axle tube and the inner tube 11 may be a vehicle tube. Further, the application of the shock absorber D is not limited to the front fork, and may be used for a rear cushion unit that suspends the rear wheel of a saddle-ride type vehicle, a suspension of an automobile, or the like.

  Subsequently, the upper end of the outer tube 10 is closed by the cap 13. Further, the lower end of the inner tube 11 is closed by the axle side bracket 12. Furthermore, the seal member 14 closes the space between the overlapping portion of the outer tube 10 and the inner tube 11.

  Thus, the tube member 1 is sealed, and the shock absorber main body 2 is accommodated inside thereof, and the liquid storage chamber R is formed between the tube member 1 and the shock absorber main body 2. In the liquid storage chamber R, hydraulic oil is stored, and a gas is sealed above the liquid surface. A suspension spring 3 and an oil lock mechanism are provided in the liquid storage chamber R.

  The shock absorber main body 2 is axially supported by the cylinder 4 for containing the hydraulic oil, the annular head member 5 attached to the upper end of the cylinder 4 and the head member 5 so as to move in the cylinder 4 in the axial direction. A rod 6 which can be inserted is provided to resist the flow of hydraulic oil generated when the cylinder 4 and the rod 6 relatively move in the axial direction to generate a damping force.

  Further, in the present embodiment, the shock absorber main body 2 is an upright type, and is disposed with the rod 6 protruding out of the cylinder 4 facing the upper side (the vehicle body side). The rod 6 is connected to the outer tube 10 via the cap 13, and the cylinder 4 is connected to the inner tube 11 via the axle-side bracket 12. Thus, the shock absorber main body 2 is interposed between the outer tube 10 and the inner tube 11, and when the shock absorber D expands and contracts, the cylinder 4 and the rod 6 move relative to each other in the axial direction and the damping force Occur.

  The shock absorber main body 2 may be an inverted type, and the rod 6 protruding out of the cylinder 4 may be disposed toward the lower side (axle side), and the rod 6 may be connected to the axle side tube . Further, the fluid used for the shock absorber main body 2 is not limited to the hydraulic oil, and may be water, a liquid other than the hydraulic oil such as an aqueous solution, or a gas. Further, the liquid stored in the liquid storage chamber R is not limited to the hydraulic oil, and may be a liquid other than the hydraulic oil such as water and an aqueous solution.

  Subsequently, the suspension spring 3 is a coil spring. The upper end of the suspension spring 3 is supported by the cap 13, and the lower end of the suspension spring 3 is supported by the upper end of the lock case 5 b provided on the head member 5. As described above, the cap 13 is connected to the outer tube 10, and the head member 5 is connected to the cylinder 4. For this reason, it can be said that the suspension spring 3 is interposed between the outer tube 10 and the cylinder 4.

  Then, when the shock absorber D, which has been extended, starts a stroke and the cylinder 4 enters the outer tube 10, the suspension spring 3 is compressed and elastically deformed, and an elastic force corresponding to the amount of deformation is exerted. . Then, the cylinder 4 is biased by the suspension spring 3 in a direction to withdraw from the outer tube 10. That is, the shock absorber D is urged in the extension direction by the suspension spring 3. In the shock absorber D according to the present embodiment, the suspension spring 3 elastically supports the vehicle body.

  The head member 5 supporting the lower end of the suspension spring 3 has an annular guide portion 5a in which a bush 50 slidingly contacting the outer periphery of the rod 6 is fitted on the inner periphery and a cylindrical lock case standing up on the upper outer periphery of the guide portion 5a. And 5b. As described above, the lock case 5 b of the present embodiment is fixed to the upper side of the cylinder 4 and disposed on the outer periphery of the rod 6. Then, when the shock absorber D expands and contracts and the rod 6 moves in the axial direction (vertical direction in FIG. 1) with respect to the cylinder 4, the rod 6 moves in the axial direction with respect to the lock case 5b.

  The lock case 5b is provided below the liquid surface of the liquid storage chamber R, and is immersed in the hydraulic oil. The lock case 5b is provided with a lock piece 7 slidably accommodated inside thereof, a return spring 8 for positioning the lock piece 7 at a predetermined position in the lock case 5b, and a lock provided on the outer periphery of the rod 6 An oil lock mechanism is configured together with the stopper 9 that can abut on the piece 7. The respective members constituting the oil lock mechanism will be described in detail below.

  The inner diameter of the lock case 5 b is larger than the inner diameter of the suspension spring 3, and a spring receiver 30 with which the lower end of the suspension spring 3 abuts is fitted to the upper end portion of the lock case 5 b. However, the spring bearing 30 may be eliminated and the suspension spring 3 may be abutted directly on the upper end of the lock case 5b.

  Further, a notch 5c is formed at the upper end portion of the lock case 5b. The notch 5 c ensures the flow of hydraulic oil between the cylinder 4 and the inner tube 11 and the upper side of the cylinder 4. However, if such flow of hydraulic fluid is ensured, the notch 5c may be eliminated.

  Subsequently, the lock piece 7 is annular, is in sliding contact with the inner periphery of the lock case 5b and the outer periphery of the rod 6, and is axially movable with respect to the lock case 5b and the rod 6. A room C surrounded by the lock case 5 b and the lock piece 7 is formed on the outer periphery of the rod 6.

  As shown in FIG. 2, four notches 7 a are formed in the inner peripheral portion of the lock piece 7 along the circumferential direction, and a lock piece is formed between the lock piece 7 and the rod 6 by these notches 7 a. A gap is formed to penetrate 7 in the axial direction. And the channel | path 70 which connects the room C in lock case 5b and the liquid storage chamber R of the outer side is formed of the said clearance gap.

  Further, when the rod 6 shown in FIG. 1 moves downward with respect to the lock case 5b, the stopper 9 abuts on the lock piece 7, and when the stopper 9 abuts on the lock piece 7, the stopper 9 closes the passage 70. (FIG. 3 (b)).

  In the present embodiment, the stopper 9 is formed in an annular shape, and is caulked and fixed to a snap ring 60 mounted on the outer periphery of the rod 6. However, the shape and mounting method of the stopper 9 are not limited to the above, and can be changed as appropriate. For example, the stopper 9 and the rod 6 may be integrally formed. Further, the stopper 9 may be configured by one or more protrusions protruding radially outward from the outer periphery of the rod 6.

  Further, the upper end inner peripheral portion of the lock piece 7 is recessed lower than the outer peripheral side thereof, and a concave portion 7 b which allows the stopper 9 to enter is formed in the upper portion of the lock piece 7. When the passage 70 is opened in the bottom 7c (FIG. 3A) of the recess 7b and the stopper 9 intrudes into the recess 7b and is seated on the bottom 7c, the opening of the passage 70 is closed by the stopper 9 Fig. 3 (b). Conversely, when the stopper 9 is separated from the bottom 7c of the recess 7b, the passage 70 is opened (FIG. 3 (a)).

  Furthermore, in the recess 7b, the peripheral wall 7d (FIG. 3A) rising from the outer peripheral edge of the bottom 7c is tapered so as to be reduced in diameter toward the bottom 7c. Therefore, as the stopper 9 intrudes into the recess 7b, the gap formed between the stopper 9 and the peripheral wall 7d narrows, and is applied to the flow of hydraulic fluid flowing out from the inside to the outside of the recess 7b through the gap. Resistance increases. Therefore, it is possible to suppress the occurrence of abnormal noise (collision noise) due to the stopper 9 vigorously colliding with the lock piece 7.

  Subsequently, the return spring 8 for positioning the lock piece 7 at a predetermined position in the lock case 5 b is a coil spring and is disposed between the lock piece 7 and the guide portion 5 a of the head member 5. More specifically, the lower end inner peripheral portion of the lock piece 7 protrudes downward more than the outer peripheral side thereof, and a convex portion 7 e is formed on the lower portion of the lock piece 7 (FIG. 3A). Then, the upper end portion of the return spring 8 is fitted to the outer periphery of the convex portion 7e. On the other hand, the lower end of the return spring 8 abuts on the guide portion 5a of the head member 5, and is supported by the guide portion 5a.

  According to the above configuration, since the lock piece 7 sinks in the hydraulic oil, the lock piece 7 tries to move downward in the lock case 5 b (back side), but this is restricted by the return spring 8. Therefore, when the stopper 9 is separated from the lock piece 7, the lock piece 7 is positioned by the return spring 8 at a predetermined position in the lock case 5 b. The predetermined position in the lock case 5 b can be arbitrarily determined by the length of the return spring 8, the spring constant, and the like, and the predetermined position is hereinafter referred to as “initial position”.

  When the rod 6 moves downward and the stopper 9 abuts on the lock piece 7 and the rod 6 further moves downward, the lock piece 7 is pushed into the lock case 5 b while compressing the return spring 8. And move downward from the initial position. Then, the return spring 8 biases the lock piece 7 back to the initial position.

  Therefore, even if the lock piece 7 is moved downward from the initial position by receiving the external force from the stopper 9 or the like, the lock piece 7 returns to the initial position by the biasing force of the return spring 8 when the external force is removed. On the other hand, even if the lock pieces 7 move upward from the initial position and the return springs 8 move away from the guide portion 5a, the lock pieces 7 return to the initial position because they sink into the hydraulic oil.

  Further, as described above, the inner diameter of the lock case 5 b of the present embodiment is larger than the inner diameter of the suspension spring 3. Then, the outer diameter of the lock piece 7 in sliding contact with the inner periphery of the lock case 5 b is also larger than the inner diameter of the suspension spring 3. Therefore, the upward movement of the lock piece 7 is limited by the suspension spring 3, so the lock piece 7 does not come off the lock case 5b.

  That is, in the present embodiment, the suspension spring 3 functions as a retaining member for the lock piece 7, and the lock piece 7 is always guided by the lock case 5b. Therefore, the inner diameter of the lock piece 7 may be made larger than the outer diameter of the rod 6, and the lock piece 7 may be loosely fitted on the outer periphery of the rod 6. In this case, an annular gap formed between the lock piece 7 and the rod 6 may be used as the passage 70, and the passage 70 may be opened and closed by the stopper 9. Also, the spring support 30 may be used as a retaining member for the lock piece 7, and the configuration of the retaining member can be changed as appropriate.

  Further, as in the present embodiment, when the lock piece 7 is guided by the rod 6, the lock piece 7 is guided by the rod 6 even if the lock piece 7 completely comes out of the lock case 5b. Return to the lock case 5b naturally. Therefore, when the lock piece 7 is guided by the rod 6, the retaining member of the lock piece 7 can be omitted.

  Further, in the present embodiment, the lock piece 7 is positioned at the initial position in the lock case 5b, and the bias is applied to bias the lock piece 7 in the direction of suppressing the displacement of the lock case 5b from the initial position to the back side. The return spring 8 is used as a means. And the return spring 8 of this embodiment is a coil spring. However, of course, the return spring 8 may be a spring other than a coil spring.

  Furthermore, in the case where the shock absorber main body 2 is inverted by turning the shock absorber main body 2 upside down shown in FIG. 1, the lock piece 7 moves in a direction to withdraw from the lock case 5 b when the lock piece 7 sinks. Therefore, the retaining member of the lock piece 7 may be provided to eliminate the return spring 8. Furthermore, even when the shock absorber main body 2 is erected as in the present embodiment, when the lock piece 7 floats on the hydraulic oil, the retaining member for the lock piece 7 is provided and the return spring 8 is provided. You may discard it. Thus, the energizing means for returning the lock piece 7 to the initial position can be changed as appropriate.

  The operation of the shock absorber D according to the present embodiment will be described below. In the following description, the stroke amount of the shock absorber D is the amount of stroke of the shock absorber D in the contraction direction from the reference with the maximum extension (stretching cut off) state of the shock absorber D as a reference (stroke amount = zero). .

  At the time of expansion and contraction of the shock absorber D, the rod 6 moves vertically (axially) with the stopper 9 with respect to the lock case 5b. At the time of expansion and contraction of the shock absorber D, when the stroke amount of the shock absorber D is less than a predetermined amount, the stopper 9 moves away from the lock piece 7 as shown in FIG. 3 (a). In this case, the lock piece 7 is maintained at the initial position by the return spring 8 and the rod 6 moves up and down relative to the lock piece 7.

  Subsequently, at the time of contraction of the shock absorber D, when the stroke amount of the shock absorber D becomes a predetermined amount or more, the stopper 9 moves downward with the rod 6 with respect to the lock case 5b as shown in FIG. 3 (b). Then, it abuts on the lock piece 7 and pushes the lock piece 7 into the lock case 5 b. Then, the return spring 8 is compressed to bias the lock piece 7 back to the initial position.

  Further, when the stopper 9 abuts on the lock piece 7, the passage 9 is closed by the stopper 9. Therefore, when the lock piece 7 is pushed into the lock case 5b by the stopper 9, the hydraulic oil in the room C in the lock case 5b passes between the lock piece 7 and the lock case 5b (the outer peripheral side of the lock piece 7). As a result, the fluid flows out to the fluid reservoir R outside the lock case 5b, and resistance is given to the flow of the hydraulic fluid.

  Then, the pressure in the chamber C in the lock case 5b increases, and the resultant force of the pressure (oil lock force) and the biasing force of the return spring 8 acts on the rod 6 to reduce the contraction operation of the shock absorber D. Let it stop. For this reason, the impact at the time of the last contraction of shock absorber D is eased.

  Subsequently, when the shock absorber D which has contracted fully starts to extend and the stopper 9 moves upward with the rod 6 with respect to the lock case 5b and is separated from the lock piece 7, the lock piece 7 is operated according to the biasing force of the return spring 8. Returns to the initial position. Also, when the stopper 9 separates from the lock piece 7, the passage 70 is opened. Therefore, when the lock piece 7 returns to the initial position, the hydraulic oil outside the lock case 5b is supplied into the lock case 5b through the passage 70.

  Hereinafter, the operation and effect of the shock absorber D according to the present embodiment will be described.

  The shock absorber D of the present embodiment is a cylindrical lock case 5b disposed on the outer periphery of the rod 6 and movable in the axial direction with respect to the rod 6, and a lock slidably accommodated in the lock case 5b. The piece 7 and the passage 70 which penetrates the lock piece 7 to communicate the inside and the outside of the lock case 5b, moves together with the rod 6 with respect to the lock case 5b and contacts the lock piece 7 to close the passage 70 and lock piece 7 And a stopper 9 for pushing the lock into the lock case 5b.

  As described above, in the present embodiment, the lock piece 7 is accommodated in the lock case 5 b and does not move together with the rod 6 in a state where the lock piece 7 is withdrawn from the lock case 5 b. Therefore, even if the suspension spring (coil spring) 3 is disposed between the inner tube (shaft side tube) 11 for storing the hydraulic oil (liquid) for oil lock and the rod 6, the lock piece 7 The increase in diameter of the spring is not limited by the suspension spring 3.

  Therefore, according to the above configuration, since the outer diameter of the lock piece 7 can be increased, the pressure receiving area of the lock piece 7 that receives the pressure in the lock case 5 b can be easily secured. When the pressure receiving area of the lock piece 7 is secured, a sufficient oil lock force can be easily obtained, and the shock when the shock absorber D is fully contracted can be sufficiently relieved. Therefore, when the shock absorber D is mounted on a vehicle such as a straddle-type vehicle as in the present embodiment and interposed between the vehicle body and the axle, the ride comfort of the vehicle can be improved.

  Furthermore, according to the above configuration, even if the lock piece 7 is accommodated in the lock case 5b and the clearance (sliding gap) between the lock piece 7 and the lock case 5b is narrow, the contraction of the shock absorber D is minimized. At the same time, the lock piece 7 does not fail in the lock case 5b. That is, according to the above configuration, the clearance between the lock piece 7 and the lock case 5b can be narrowed, and the setting freedom of the clearance can be increased.

  Further, the shock absorber D of the present embodiment is provided with a suspension spring (coil spring) 3 supported at the lower end (one end) by the upper end (tip end) of the lock case 5 b and disposed on the outer periphery of the rod 6. The stopper 9 is mounted on the outer periphery of the rod 6 so as to be movable inside the suspension spring (coil spring) 3, and the inner diameter of the lock case 5 b is set larger than the inner diameter of the suspension spring 3.

  As described above, when the inner diameter of the lock case 5 b is larger than the inner diameter of the suspension spring 3, the outer diameter of the lock piece 7 can be larger than the inner diameter of the suspension spring 3. Therefore, the pressure receiving area of the lock piece 7 can be secured more reliably. Furthermore, the suspension spring 3 can function as a retaining member to prevent the lock piece 7 from coming out of the lock case 5b. For this reason, the lock piece 7 is maintained in the state accommodated in the lock case 5b.

  However, the coil spring supported by the lock case 5b may not be a suspension spring that elastically supports the vehicle body, as a matter of course that the lock piece 7 may be prevented from coming off by a member other than the suspension spring 3. When the lock piece 7 is held by a member other than the suspension spring (coil spring) 3, the suspension spring 3 may be replaced by an air spring.

  Further, as in the present embodiment, when the lock piece 7 is formed in an annular shape and is slidably attached to the outer periphery of the rod 6, the lock piece 7 completely comes out of the lock case 5b. Also, the lock piece 7 is guided by the rod 6 and returns into the lock case 5b. Therefore, in such a case, the retaining member of the lock piece 7 can be omitted. Thus, the configuration for accommodating the lock piece 7 in the lock case 5b can be changed as appropriate.

  Further, in the present embodiment, a passage 70 communicating the inside and the outside of the lock case 5 b is formed between the lock piece 7 and the rod 6. Therefore, even if the outer diameter of the stopper 9 is smaller than the inner diameter of the suspension spring 3, the flow passage area of the passage 70 can be widened. Therefore, when the lock piece 7 moves upward in the lock case 5 b and returns to the initial position, the negative pressure in the lock case 5 b can be prevented.

  Furthermore, in the present embodiment, a notch 7a is formed in the inner peripheral portion of the lock piece 7, and a gap is formed between the lock piece 7 and the rod 6 by the notch 7a, and the gap A passage 70 is formed. Therefore, while the lock piece 7 is guided by the rod 6, a passage 70 can be formed between the lock piece 7 and the rod 6.

  Further, in the present embodiment, the notches 7 a are formed in a fan shape, and four notches 7 a are formed in the circumferential direction of the lock piece 7 at equal intervals. However, the shape and number of the notches 7a can be changed as appropriate.

  When the lock piece 7 does not completely come out of the lock case 5 b as in the present embodiment, the lock piece 7 may not be guided by the rod 6. Therefore, when the lock piece 7 is prevented from coming off, the inner diameter of the lock piece 7 is made larger than the outer diameter of the rod 6, and the passage 70 is formed by the annular gap formed between them. It is also good.

  Furthermore, as long as the negative pressure in the lock case 5 b can be suppressed, a hole may be formed in the lock piece 7 so as to pass vertically, and the hole may be used as the passage 70. As described above, the configuration of the passage 70 that communicates the inside and the outside of the lock case 5b can be appropriately changed according to the configuration for accommodating the lock piece 7 in the lock case 5b. And such a change of the channel | path 70 is possible irrespective of the presence or absence of the coiled spring supported by the lock case 5b.

  Moreover, the shock absorber D of this Embodiment is provided with the return spring 8 accommodated in lock case 5b. Then, the return spring 8 positions the lock piece 7 at the initial position (predetermined position) in the lock case 5b, and when the lock piece 7 moves from the initial position in the lock case 5b to the lower side (back side), The lock piece 7 is urged to return to the initial position. According to this configuration, since the lock piece 7 can be reliably and promptly returned to the initial position by the return spring 8, the stroke length of the lock piece 7 when the oil lock force is generated can be reliably ensured.

  In addition, although the return spring 8 of this Embodiment is a coiled spring, you may change into springs other than a coiled spring, or rubber etc. When the lock piece 7 returns to the initial position by floating or sinking in the hydraulic oil (liquid), the return spring 8 may be eliminated. In this case, the number of parts is It can be reduced. Such a change is possible regardless of the presence or absence of a coil spring supported by the lock case 5b, the configuration for accommodating the lock piece 7 in the lock case 5b, and the configuration of the passage 70.

  Moreover, the recessed part 7b which accept | permits the penetration | invasion of the stopper 9 is formed in the lock piece 7 of this Embodiment. For this reason, it is possible to suppress the generation of the collision sound when the stopper 9 abuts on the lock piece 7. Furthermore, in the present embodiment, the peripheral wall 7d of the recess 7b is tapered, and the diameter is reduced toward the bottom 7c. Therefore, the resistance increases as the stopper 9 goes to the back side in the recess 7b. In addition, since the inlet of the recess 7b is wide, the stopper 9 does not fail to intrude into the recess 7b.

  However, the shape of the recess 7 b can be changed as appropriate. Also, the recess 7 b may be eliminated to make the upper end of the lock piece 7 flat. In this case, for example, a rubber sheet is attached to one of the opposing surfaces of the stopper 9 and the lock piece 7 or at least one of the stopper 9 and the lock piece 7 is formed of rubber or the like to suppress the generation of collision noise. You may Such a change is made by the presence or absence of a coil spring supported by the lock case 5b, the configuration for accommodating the lock piece 7 in the lock case 5b, the configuration of the passage 70, and the lock piece 7 returned to the initial position. It is possible regardless of the configuration for

  Further, in the present embodiment, the oil lock mechanism configured to include the lock case 5b, the lock piece 7, the stopper 9 and the like described above is used to reduce the shock at the time of the contraction of the shock absorber D. ing. However, the above-mentioned oil lock mechanism may be used to reduce the impact at the time of the maximum extension of the shock absorber D, and the purpose of using the oil lock mechanism can be changed appropriately.

  While the preferred embodiments of the present invention have been described above in detail, modifications, variations and changes are possible without departing from the scope of the claims.

D: shock absorber, 3: suspension spring (coil spring), 5b: lock case, 6: rod, 7: lock piece, 7b: recess, 8: return spring , 70 ... passage, 9 ... stopper

Claims (6)

A cylindrical lock case disposed on the outer periphery of the rod and axially movable with respect to the rod;
A lock piece slidably accommodated in the lock case;
A passage passing through the lock piece and communicating the inside and the outside of the lock case;
A shock absorber comprising: a stopper which moves with the rod relative to the lock case and closes the passage when it abuts on the lock piece and pushes the lock piece into the lock case. The shock absorber according to claim 1, wherein the passage is formed between the lock piece and the rod. The shock absorber according to claim 1 or 2, wherein the lock piece is formed with a recess for allowing entry of the stopper. A return spring housed in the lock case;
The return spring positions the lock piece at a predetermined position in the lock case, and returns the lock piece to the predetermined position when the lock piece moves from the predetermined position in the lock case to the back side. The shock absorber according to any one of claims 1 to 3, characterized in that The shock absorber according to any one of claims 1 to 4, wherein the lock piece is formed in an annular shape and is slidably attached to the outer periphery of the rod. A coil spring supported at one end by the tip of the lock case and disposed on the outer periphery of the rod;
The stopper is mounted on the outer periphery of the rod so as to be movable inside the coil spring,
The shock absorber according to any one of claims 1 to 5, wherein an inner diameter of the lock case is larger than an inner diameter of the coil spring.

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