JP2009014159A - Shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shock absorber capable of minimizing impact in a limited overall stroke length. <P>SOLUTION: The shock absorber comprises a cylinder 10, a piston 16 inserted in the cylinder 10, a coil spring 18 to urge the piston 16 to the proximal-end side, a seal member sealing the cylinder 10 to form a sealed space 38, and a fluid filled in the sealed space 38. The piston 16 comprises a piston rod 22 slidably passing through the seal member, a piston ring 26 connected to the piston rod 22 to slide in contact with the inner surface of the cylinder 10, a passage communicating the sealed spaces ahead of and behind the piston ring 26 with each other, and a valve for opening and closing the passage. The valve closes when the piston 16 moves toward the bottom portion of the cylinder 10 and opens when the piston 16 moves to the side of the opening portion of the cylinder 10 in response to a biasing force of the coil spring 18. This shock absorber is provided with an auxiliary spring 50 in parallel with that valve to urge the valve to its closing direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shock absorber that absorbs collision energy by using a flow resistance of a fluid flowing through a narrow gap and relaxes the impact of the collision.

  In factory assembly lines, etc., there are cases where parts are moved to a certain place on the transfer table and stopped or pressed there. In this case, if the transfer speed of the transfer table is high, When the table is stopped, parts or the like may hit the other party and break, the other party may be broken, a loud noise may be produced, or the transport table may be deformed in some cases.

  Therefore, in an assembly line of a factory or the like, when the transfer table is stopped, the moving speed of the transfer table is gently reduced by a shock absorber so that such an inconvenience does not occur.

  And as a shock absorber used for such a use, the thing of a structure as shown, for example in FIG. 3, FIG. 4 is known.

  In FIG. 3A, reference numeral 10 denotes a substantially bottomed cylindrical cylinder. The cylinder 10 is open on one side (the lower side in the figure) and on the other side (the upper side in the figure: the bottom side). Blocked. A screw hole for filling silicon oil (fluid) into a sealed space 38, which will be described later, is coaxially formed at the end of the other side of the cylinder 10, and a small screw 12 is inserted through the O-ring 14 into the screw hole. Are screwed together. A screw is engraved around the center of the cylinder 10, and a pair of hexagon nuts (not shown) are screwed together.

  The piston 16 is inserted into the inside of the cylinder 10 from one side of the cylinder 10, that is, from the opening side, and the piston 16 is inserted between one end of the piston 16 and the bottom of the cylinder 10, that is, the piston 16. A cylindrical coil spring 18 that is biased toward the base end side (the lower side in the figure) is inserted coaxially.

  The piston 16 includes a rod-shaped piston rod 22 provided with a flange 20 at a position that is a predetermined length away from the distal end, and a distal end side (the bottom of the cylinder 10) from the flange 20 of the piston rod 22. The E-ring 24 is coaxially fitted at a predetermined interval on the side), and is slid in a longitudinally coaxial manner between the flange portion 20 of the piston rod 22 and the E-ring 24. The piston ring 26 is movably fitted.

  The piston ring 26 has a flow path through which silicone oil can pass between the piston rod 22 and a valve is formed by the piston ring 26, the flange 20, and the E-ring 24. That is, when the piston 16 moves toward the bottom of the cylinder 10 by an external force, the piston ring 26 comes into close contact with the flange portion 20 as shown in FIG. When the piston 16 moves to the opening side of the cylinder 10 by the urging force of the coil spring 18, the flow path opens away from the flange portion 20 as shown in FIG. It is like that.

  The piston rod 22 is slidably surrounded by a sleeve 28 at the base end side portion from the flange portion 20, and the base end portion projects out of the cylinder 10 from the opening of the cylinder 10 in an unloaded state. A protective cap (not shown) is put on the end of the piston rod 22 on the base end side.

  An accumulator 30 and an O-ring 32 are inserted outside the sleeve 28, that is, between the sleeve 28 and the cylinder 10, and a rod packing 34 is inserted inside the sleeve 28, that is, between the sleeve 28 and the piston rod 22. ing. A ring-shaped gap between the opening of the cylinder 10 and the piston rod 22 is closed by a ring-shaped plug 36. In the space inside the cylinder 10, a region on the bottom side of the sleeve 28 becomes a sealed space 38, and the sealed space 38 is filled with silicon oil.

  The shock absorber is installed, for example, so that the base end portion of the piston rod 22 projecting outward from the opening of the cylinder 10 collides with the transport table on which the component is placed via the protective cap immediately before the stop position. And use it.

  When the conveying table on which the parts are placed collides with the protective cap at the base end of the piston rod 22, as shown in FIG. 3B, the piston rod 22 is pushed into the cylinder 10 and the flange 20 is moved to the piston ring. 26, the silicon oil is pushed by the piston ring 26, and the pushed silicon oil flows backward through the gap between the piston ring 26 and the cylinder 10, and the flow resistance of the silicone oil at this time is reduced. The kinetic energy of the piston rod 22 is absorbed, the pushing of the piston rod 22 is gently decelerated, and the transfer table stops at a desired position together with the parts.

  When the transfer table moves away from the end of the piston rod 22, the force for pushing the piston rod 22 into the cylinder 10 is released, and the piston rod 22 is moved to the cylinder by the biasing force of the coil spring 18 as shown in FIG. 10 is pushed to the opening side, the flange portion 20 is separated from the piston ring 26, and a flow path connecting the spaces before and after the piston ring 26 is formed as indicated by arrows, and the piston ring 26 is pushed by the E-ring 24. The silicon oil outside the piston ring 26 flows into the space inside the piston ring 26, that is, the bottom side of the cylinder 10 through this flow path, and the piston 16 moves to the base end side and returns to the original position. It will be.

  In FIG. 4A, reference numeral 10 denotes a substantially bottomed cylindrical cylinder. The cylinder 10 is open on one side and closed on the other side (bottom side). A screw hole for filling a later-described sealed space 38 with silicone oil is formed coaxially at the other end (bottom side) of the cylinder 10, and a small screw 12 is inserted through the O-ring 14 into the screw hole. Are screwed together. A screw is formed around the cylinder 10 and a pair of hexagon nuts (not shown) are screwed together.

  The piston 16 is inserted into the inside of the cylinder 10 from one side of the cylinder 10, that is, from the opening side, and the piston 16 is urged to the base end side between the distal end portion of the piston 16 and the bottom portion of the cylinder 10. A cylindrical coil spring 18 is inserted coaxially.

  The piston 16 includes a rod-shaped piston rod 22, a piston ring 26 that is integrally provided on the tip end side of the piston rod 22, one side of the piston ring 26 (tip end side of the piston rod 22), and the other side. The communication passage 40 communicating with the side (the base end portion side of the piston rod 22) and the opening 42 on one side of the communication passage 40 and closing the communication passage 40 when the piston 16 is compressed. It consists of a steel sphere 44 that opens the communication path 40 away from the opening 42, and a sphere holder 46 that holds the sphere 44. A valve is formed by the communication path 40, the sphere 44, and the sphere holder 46.

  The piston rod 22 is slidably surrounded by a sleeve 28 at a portion close to the piston ring 26, and a portion far from the piston ring 26 protrudes from the opening of the cylinder 10, and a protective cap (not shown) is put on its end. It has been.

  An accumulator 30 and an O-ring 32 are inserted outside the sleeve 28, that is, between the sleeve 28 and the cylinder 10, and a rod packing 34 is inserted inside the sleeve 28, that is, between the sleeve 28 and the piston rod 22. ing. A ring-shaped gap between the opening of the cylinder 10 and the piston rod 22 is closed by a ring-shaped plug 36. In the space inside the cylinder 10, a region on the bottom side of the sleeve 28 becomes a sealed space 38, and the sealed space 38 is filled with silicon oil.

  The shock absorber is installed and used so that, for example, the base end portion of the piston rod 22 projecting outward from the opening of the cylinder 10 collides with a transfer table on which components are placed at a position immediately before stopping.

  When the conveying table on which the parts are placed collides with the base end portion of the piston rod 22, as shown in FIG. 4B, the piston rod 22 is pushed into the cylinder 10, and the opening 42 of the communication passage 40 is a spherical body. 44, the silicon oil is pushed by the piston ring 26 at the tip of the piston rod 22, and the pushed silicon oil flows backward through the gap between the piston ring 26 and the cylinder 10, and the silicon oil at this time The flow resistance absorbs the kinetic energy of the piston rod 22, the pushing of the piston rod 22 is gently decelerated, and the conveyance table stops at a desired position together with the parts.

  When the transfer table moves away from the end of the piston rod 22, the force for pushing the piston rod 22 into the cylinder 10 is released, and the piston rod 22 is moved to the cylinder by the biasing force of the coil spring 18 as shown in FIG. 10, the spherical body 44 is separated from the opening 42 of the communication path 40, the communication path 40 connecting the spaces before and after the piston ring 26 is opened as indicated by arrows, and the silicon outside the piston ring 26 is opened. Oil flows into the space inside the piston ring 26 through the communication passage 40 and moves until the piston 16 returns to the original position.

By the way, in recent years, in order to further improve the productivity, it is required to reduce the high tact and vibration of the transfer table, and further to reduce the impact of the transfer table due to the delicate work. For this reason, a shock absorber capable of minimizing an impact within a limited stroke and total length is preferable, and development of such a shock absorber is desired.
JP 2006-250309 A

  The problem to be solved is to provide a shock absorber capable of minimizing the impact within a limited stroke and total length.

  And in the study to minimize the impact within the limited stroke and overall length, during the stroke of the conventional shock absorber, the shock absorption is performed until the shock absorption starts from the moment when the transfer table collides with the piston rod. There was a problem that there was a part of play that was not used, and a part of the play that was not used to absorb this shock prevented the minimization of the stroke.

  For example, in FIG. 3 showing the prior art, silicon oil has a flow resistance in the gap between the piston ring 26 and the cylinder 10 due to the flange 20 and the piston ring 26 abutting and closely contacting each other from (a) before shock absorption. The flange 20 moves to the stopped piston ring 26 from the state until the state (b) in which it flows and begins to absorb kinetic energy, that is, from the state where there is a gap between the flange 20 and the piston ring 26. This is a portion of play that does not absorb impact until it reaches and abuts and comes into close contact.

  Also, in FIG. 4 showing the prior art, from (a) before shock absorption, the sphere 44 comes into contact with and closely contacts the opening 42, and the silicone oil has flow resistance in the gap between the piston ring 26 and the cylinder 10. The opening 42 moves and arrives at the stopped sphere 44 from the time when it flows to the state of (b) where it begins to absorb kinetic energy, that is, from the state where there is a gap between the opening 42 and the sphere 44. Until the contact / contact state, it is a portion of play that does not absorb impact.

  The main feature of the present invention is that an auxiliary spring for urging the valve in the direction of closing the valve is provided in the valve in the shock absorber so that the shock can be absorbed immediately from the moment when the transfer table collides with the piston rod. And

  Since the shock absorber of the present invention is provided with an auxiliary spring that biases the valve in the shock absorber in the direction of closing the valve, the shock is absorbed from the moment when the transfer table collides with the piston rod. The entire stroke of the shock absorber can be used to absorb the shock.

  In addition, since the entire stroke of the shock absorber can be used to absorb the shock, the peak of the deceleration acceleration can be kept low even if the piston stroke is shortened.

  The objective of providing a shock absorber that can minimize impact within a limited stroke and length is achieved with a simple configuration and without damaging the characteristics of the shock absorber.

  FIG. 1 is an explanatory view of a shock absorber according to an embodiment of the present invention. In FIG. 1A, reference numeral 10 denotes a substantially bottomed cylindrical cylinder, and the cylinder 10 is arranged on one side (lower side of the figure). Side) is open, and the other side (upper side of the figure: bottom side) is closed. A screw hole for filling silicon oil (fluid) into a sealed space 38, which will be described later, is coaxially formed at the end of the other side of the cylinder 10, and a small screw 12 is inserted through the O-ring 14 into the screw hole. Are screwed together. Further, a screw is engraved around the center of the cylinder 10, and a pair of hexagon nuts 48 and 48 are screwed together.

  The piston 16 is inserted into the inside of the cylinder 10 from one side of the cylinder 10, that is, from the opening side, and the piston 16 is inserted between one end of the piston 16 and the bottom of the cylinder 10, that is, the piston 16. A cylindrical coil spring 18 that is biased toward the base end side (the lower side in the figure) is inserted coaxially.

  The piston 16 includes a rod-shaped piston rod 22 provided with a flange 20 at a position that is a predetermined length away from the distal end, and a distal end side (the bottom of the cylinder 10) from the flange 20 of the piston rod 22. The E-ring 24, which is a spring receiving member that is coaxially fitted at a predetermined interval on the side), and a play between the flange portion 20 of the piston rod 22 and the E-ring 24 in the longitudinal direction coaxially. The piston ring 26 is slidably fitted in the holding state.

  The piston ring 26 has a flow path through which silicone oil can pass between the piston rod 22 and a valve is formed by the piston ring 26, the flange 20, and the E-ring 24. That is, when the piston 16 moves in the direction of the bottom of the cylinder 10 due to an external force, the piston ring 26 comes into close contact with the flange portion 20 to close the flow path, so that the external force acting on the piston 16 is eliminated. When the coil spring 18 moves toward the opening side of the cylinder 10 by the urging force, the flow path is opened away from the flange portion 20.

  An auxiliary spring 50 is provided between the piston ring 26 and the E-ring 24 to lightly bias the piston ring 26 toward the flange 20 side. The biasing force of the auxiliary spring 50 is such that there is no external force applied to the piston rod 22, and the piston ring 26 is brought into close contact with the flange portion 20 in a state where the piston rod 22 is fully extended from the opening side of the cylinder 10. When the external force applied to the piston 16 is released and the piston 16 is pushed by the coil spring 18 and returns to the base end side, the piston ring 26 is compressed by the pressure of the silicon oil flowing in from the flow path. The force is sufficient to leave the unit 20.

  The piston rod 22 is slidably surrounded by a sleeve 28 at a portion close to the piston ring 26, and a base end portion of the piston rod 22 protrudes from the opening of the cylinder 10 in a state where no external force is applied to the piston rod 22. Yes. A protective cap (not shown) is put on the end of the piston rod 22 on the base end side.

  An accumulator 30 and an O-ring 32 are inserted outside the sleeve 28, that is, between the sleeve 28 and the cylinder 10, and a rod packing 34 is inserted inside the sleeve 28, that is, between the sleeve 28 and the piston rod 22. ing. A ring-shaped gap between the opening of the cylinder 10 and the piston rod 22 is closed by a ring-shaped plug 36. A seal portion is formed by the sleeve 28, the accumulator 30, the O-ring 32, the rod packing 34, and the plug 36, and the space inside the cylinder 10 is a sealed space 38 on the bottom side of the seal portion. Filled with silicone oil.

  Next, the operation principle of shock absorption by this shock absorber will be described.

  The shock absorber is installed so that the end of the piston rod 22 collides with the table just before the stop position of the transfer table on which the parts are placed.

  When the conveying table carrying the components collides with the end of the piston rod 22, the piston rod 22 is pushed into the cylinder 10 together with the flange 20, and the piston ring 26 is moved to the bottom side of the cylinder 10 (the side where the coil spring 18 is present). The silicon oil in the sealed space 38 is pushed by the piston ring 26, and the silicone oil flows back through the gap between the piston ring 26 and the cylinder 10 to the back side (the side with the piston rod 22). The flow resistance of the fluid absorbs the kinetic energy of the piston rod 22, the pushing of the piston rod 22 is decelerated, and the piston rod 22 and the table stop at a desired position.

  Since the piston ring 26 of this shock absorber is always urged toward the flange 20 by the auxiliary spring 50, the piston ring 26 is always in close contact with the flange 20 and the transport table collides with the piston rod. The impact is absorbed from the moment, so the entire stroke of the shock absorber is utilized for absorbing the impact.

  When the transfer table moves away from the end of the piston rod 22, the force for pushing the piston rod 22 into the cylinder 10 is released, and the piston rod 22 is moved to the cylinder by the biasing force of the coil spring 18 as shown in FIG. 10, the piston ring 26 is separated from the flange portion 20, and a flow path connecting the spaces before and after the piston ring 26 is formed as indicated by arrows, and the silicon oil on the back side of the piston ring 26 flows through this flow. It flows into the sealed space 38 on the front side (the side where the coil spring is present) of the piston ring 26 through the path, and the piston 16 is pushed by the coil spring 18 and returns to the original position while moving to the base end side.

  FIG. 2 is an explanatory view of a shock absorber according to another embodiment of the present invention. In FIG. 2A, reference numeral 10 denotes a substantially bottomed cylindrical cylinder, and the cylinder 10 is open on one side and the other side. Side (bottom side) is closed. A screw hole for filling a later-described sealed space 38 with silicone oil is formed coaxially at the other end (bottom side) of the cylinder 10, and a small screw 12 is inserted through the O-ring 14 into the screw hole. Are screwed together. A screw is formed around the cylinder 10 and a pair of hexagon nuts (not shown) are screwed together.

  The piston 16 is inserted into the inside of the cylinder 10 from one side of the cylinder 10, that is, from the opening side, and the piston 16 is urged to the base end side between the distal end portion of the piston 16 and the bottom portion of the cylinder 10. A cylindrical coil spring 18 is inserted coaxially.

  The piston 16 includes a rod-shaped piston rod 22, a piston ring 26 that is integrally provided on the tip end side of the piston rod 22, one side of the piston ring 26 (tip end side of the piston rod 22), and the other side. The communication passage 40 communicating with the side (the base end portion side of the piston rod 22) and the opening 42 on one side of the communication passage 40 and closing the communication passage 40 when the piston 16 is compressed. It consists of a sphere 44 that opens the communication path 40 away from the opening 42, and a sphere holder 46 that holds the sphere 44. A valve is formed by the communication path 40, the sphere 44, and the sphere holder 46. Here, the sphere 44 may be made of synthetic resin, ceramic or metal (steel or other metal).

  The spherical body holding portion 46 is provided with an auxiliary spring 50 that urges the spherical body 44 lightly toward the opening portion 42 of the communication path 40. The urging force of the auxiliary spring 50 is such that there is no external force applied to the piston rod 22, and the sphere 44 is brought into close contact with the opening 42 in a state where the piston rod 22 extends outward from the opening side of the cylinder 10. When the external force applied to 16 is released and the piston 16 is pushed by the coil spring 18 and returns to the proximal end side, the sphere 44 is contracted by the pressure of the silicon oil flowing in from the flow path and the sphere 44 is opened. The power is enough to leave.

  The piston rod 22 is slidably surrounded by a sleeve 28 at a portion close to the piston ring 26, and a portion far from the piston ring 26 is opened from the opening of the cylinder 10 with no external force applied to the piston rod 22. A part protrudes and the end is covered with a protective cap (not shown).

  An accumulator 30 and an O-ring 32 are inserted outside the sleeve 28, that is, between the sleeve 28 and the cylinder 10, and a rod packing 34 is inserted inside the sleeve 28, that is, between the sleeve 28 and the piston rod 22. ing. A ring-shaped gap between the opening of the cylinder 10 and the piston rod 22 is closed by a ring-shaped plug 36. A seal portion is formed by the sleeve 28, the accumulator 30, the O-ring 32, the rod packing 34, and the plug 36, and the space inside the cylinder 10 is a sealed space 38 on the bottom side of the seal portion. Filled with silicone oil.

  Next, the operation principle of shock absorption by this shock absorber will be described.

  The shock absorber is installed so that the end of the piston rod 22 collides with the table just before the stop position of the transfer table on which the parts are placed.

  When the transfer table on which the parts are placed collides with the base end of the piston rod 22, as shown in FIG. 2A, the piston rod 22 is pushed into the cylinder 10, and the silicon oil in the sealed space 38 is moved into the piston. The silicon oil pushed by the piston ring 26 at the tip of the rod 22 passes through the gap between the piston ring 26 and the cylinder 10 as indicated by the arrow, and the back side of the piston ring 26 (the side where the piston rod 22 is located). The flow resistance of the silicone oil at this time absorbs the kinetic energy of the piston rod 22, the pushing of the piston rod 22 is gently decelerated, and the conveyance table stops at a desired position together with the parts.

  Since the opening 42 of the communication passage 40 of the piston rod 22 of the shock absorber is always closed by the sphere 44 urged by the auxiliary spring 50, the shock is absorbed from the moment when the transfer table collides with the piston rod. Therefore, the entire stroke of the shock absorber is used for absorbing the shock.

  When the transfer table moves away from the end of the piston rod 22, the force for pushing the piston rod 22 into the cylinder 10 is released, and the piston 16 is moved to the base end by the biasing force of the coil spring 18 as shown in FIG. The silicon oil on the back side of the piston ring 26 (the side on which the piston rod 22 is located) is pushed by the piston ring 26 and flows into the communication passage 40 as shown by the arrow. The spherical body 44 separates from the opening 42 of the communication passage 40 against the biasing force of the auxiliary spring 50 due to the pressure of the silicone oil flowing into the communication passage 40, and the silicon oil on the back side of the piston ring 26 passes through the communication passage 40. It flows into the sealed space 38 on the front side of the piston ring 26 (the side on which the coil spring 18 is present), and the piston 16 is pushed by the coil spring 18 to the base. While moving part side will return to its original position.

It is explanatory drawing of the shock absorber which concerns on Example 1 of this invention. It is explanatory drawing of the shock absorber which concerns on Example 2 of this invention. It is explanatory drawing which shows an example of the conventional shock absorber. It is explanatory drawing which shows the other example of the conventional shock absorber.

Explanation of symbols

10 cylinder 12 machine screw 14 O-ring 16 piston 18 coil spring 20 collar 22 piston rod 24 E-ring 26 piston ring 28 sleeve 30 accumulator 32 O-ring 34 rod packing 36 plug 38 sealed space 40 communication path 42 opening 44 sphere 46 Sphere holder 48 Hex nut 50 Auxiliary spring

Claims (3)

  A substantially bottomed cylindrical cylinder, a seal member that seals the opening side of the cylinder to form a sealed space in the cylinder, and a slidably penetrating through the seal member A piston provided in the sealed space; a coil spring that urges the piston toward the proximal end of the piston in the sealed space; and a fluid filled in the sealed space, the piston including the seal member A piston rod slidably penetrating therethrough, a piston ring connected to the piston rod and sliding in contact with the inner surface of the cylinder in the sealed space, and the two pistons partitioned by the piston ring A flow path communicating with the sealed space; and a valve for opening and closing the flow path. The valve is closed when the piston moves toward the bottom of the cylinder by an external force. Energizing Shock absorber, characterized in that features in shock absorbers which are adapted to open when moving to the side of the opening of the cylinder, the auxiliary spring for urging in a direction to close the valve the valve by.   The piston includes a rod-shaped piston rod having a flange portion provided at a position that is a predetermined length away from the distal end portion toward the proximal end portion, and a portion that is spaced a predetermined distance from the flange portion of the piston rod toward the distal end portion side. And a piston ring that is slidably fitted with a play in the longitudinal direction coaxially at a position between the flange portion of the piston rod and the spring receiving member. The piston ring has a flow path through which the fluid can pass between the piston rod, the valve is formed by the piston ring, the flange portion, and the spring receiving member, and the auxiliary spring has the The shock absorber according to claim 1, wherein the shock absorber is provided between the piston ring and the spring receiving member so as to bias the piston ring toward the flange portion.   The piston includes a rod-shaped piston rod, a piston ring integrally provided on the tip end side of the piston rod, one side of the piston ring (tip end side of the piston rod) and the other side ( A communication passage communicating with the base end side of the piston rod), the opening of the one side of the communication passage in contact with the opening on the one side, the communication passage being closed when the piston is compressed, and the opening when the piston is returned A sphere that opens the communication path away from the sphere, and a sphere holding portion that holds the sphere. The valve is formed by the communication path and the sphere, and the auxiliary spring connects the sphere to the communication path. The shock absorber according to claim 1, wherein the shock absorber is provided so as to be biased toward the opening.

Images