JP3653642B2 - Backrest angle adjustment device - Google Patents

Description

[0001]
[Industrial application fields]
  This invention is a reclinable reclining seat used in Shinkansen, conventional express railcars and recreational automobiles, etc., or arranged in multiple rows regardless of the turning type The present invention relates to a cylinder-type backrest angle adjustment device suitable for adjusting the backrest angle of the reclining seat.
[0002]
[Prior art]
  A cylinder-type backrest angle adjusting device that has been generally used in the past is a rod side chamber and a head side chamber in which a piston bearing a piston rod is slidably inserted into the cylinder, and the inside of the cylinder is filled with hydraulic oil by the piston. Are divided into two working chambers.
[0003]
  On the other hand, a free piston is slidably arranged inside the working chamber located on the head side, and a part of the working chamber on the head side is defined as a gas chamber by the free piston, and the rod side chamber is separated from the piston. An open / close valve is provided to intermittently connect the two working chambers in the head side chamber.
[0004]
  And the backrest angle adjusting device comprised as mentioned above is interposed between a seat and a backrest using the attachment member provided in the base end of a cylinder, and the external protrusion end of a piston rod, respectively.
[0005]
  Thus, by opening and closing the open / close valve provided on the piston with the operation rod inserted from the outside through the piston rod, the relative position between the cylinder and the piston can be changed, and the backrest angle adjusting device is expanded and contracted, and A type in which the angle of the backrest is adjusted by locking at a desired expansion / contraction position is used.
[0006]
  That is, according to this, if the open / close valve is opened by operating the operating rod while pushing the backrest with the back while seated on the seat, the backrest angle adjusting device operates on the compression side and the backrest is moved. Falls backwards.
[0007]
  Then, when the backrest is tilted to the desired angle, if the operation rod is released and the open / close valve is closed, the backrest angle adjusting device is locked and the backrest is adjusted to the desired angle. Keep and stop.
[0008]
  On the other hand, when the backrest is raised forward, if the open / close valve is opened by the operating rod with the back away from the backrest, the backrest angle adjustment device automatically adjusts with the gas pressure in the gas chamber. It moves to the extension side and the backrest occurs.
[0009]
  Moreover, even in this case, if the operation rod is released and the open / close valve is closed when the backrest occurs to a desired angle, the backrest angle adjustment device is locked and the desired backrest The backrest stops at an angle.
[0010]
  However, when adjusting the backrest angle as described above, if the operating resistance when tilting or standing up against the gas pressure in the gas chamber or tilting due to the gas pressure as the open / close valve is opened is low, The tilting and standing up speeds become too fast, making it difficult to adjust the fine backrest angle.
[0011]
  Therefore, an orifice is installed in the middle of the passage through the opening / closing valve of the backrest angle adjusting device, and this orifice adds flow resistance to the flow of hydraulic fluid through the opening / closing valve, thereby extending and compressing the backrest angle adjusting device. Usually, the resistance is kept large to limit the tilt of the backrest and the speed of standing up.
[0012]
[Problems to be solved by the invention]
  Therefore, when such a backrest angle adjusting device is used for a revolving reclining seat or a reclining seat arranged in a plurality of rows, the following disadvantages occur.
[0013]
  That is, in a swing type reclining seat that uses this type of cylinder-type backrest angle adjustment device, the backrest is raised further from the preferred angular position at the most upright position of the normal backrest angle adjustment range. In general, the lock for turning the seat is released, and the seat is turned in the horizontal direction to change the direction.
[0014]
  In addition, even when reclining seats are used in a plurality of rows regardless of the presence or absence of the swivel type as described above, the backrest is further upright from the preferred angle position at the most upright position of the normal backrest angle adjustment range. It is desired to increase the width of the passage between the rear seat and the rear seat, thereby facilitating the cleaning of the passage between seats.
[0015]
  Therefore, in these swivel type and multiple row type reclining seats, it is necessary to increase the angle of the backrest to the standing side as compared with a normal reclining seat.
[0016]
  As a result, if the conventional cylinder-type backrest angle adjusting device described above is used for such a revolving seat or a plurality of rows of reclining seats, the backrest that is restricted by the standing speed is set to a preferred angular position at the time of the most upright. However, it takes too much time to wake up to the standing end position, and there is a problem that the efficiency of the turning operation and the cleaning work is not improved.
[0017]
  Therefore, the object of the present invention is to quickly increase the standing speed when raising the back and moving forward beyond the preferred angular position at the most standing, regardless of the tilt of the back and the restriction of the standing speed. To provide a cylinder-type backrest angle adjustment device that can be raised to a standing end position.
[0018]
[Means for Solving the Problems]
  The object of the present invention described above isIn the cylinder type seat back angle adjusting device, the backrest angle adjusting device is provided with two one-way sealing members having a sealing function from the outside to the inside on the outer peripheral surface of the piston with a gap therebetween. An enlarged diameter portion is formed in the inner wall portion of the cylinder facing the seal member located on the rod side of these two seal members in the vicinity of the extended end of the cylinder, and the enlarged diameter portion on the cylinder side faces the rod side seal member of the piston. A bypass passage is formed between the inner wall of the cylinder and the rod-side seal member of the piston from that point in time, and the rod-side chamber in the cylinder defined by the piston passes through the head-side seal member of the piston from the bypass passage. This is achieved by the first invention which communicates with the side chamber.
[0019]
  Also,A seal member and an intermediate chamber are arranged side by side from the rod side to the head side on the outer periphery of the piston, and this intermediate chamber communicates with the head side chamber in the cylinder defined by the piston through a restriction orifice provided in the piston, while adjusting the backrest angle An enlarged diameter portion is formed in the inner wall portion of the cylinder facing the piston seal member in the vicinity of the extended end of the device, and the inner wall of the cylinder and the piston seal member from the time when the enlarged diameter portion on the cylinder side faces the piston seal member. A bypass passage is formed between the rod side chamber and the head side chamber in the cylinder defined by the piston and communicates with each other through the bypass passage, the intermediate chamber of the piston and the restriction orifice.Is achieved more effectively.
[0020]
  Still further preferably, in these inventions described above, when forming the enlarged-diameter portion in the inner wall portion in the vicinity of the extended end of the cylinder, the portion of the cylinder is extended over the entire circumference or partially outward. I'll make it inflated.
[0021]
[Action]
  Thus, in any of the above-described inventions, in the normal backrest angle adjustment range in which the portion other than the diameter-expanded portion of the cylinder extends and contracts while sliding on the piston, the rod side chamber in the cylinder The head side chamber is in a state defined by the piston.
[0022]
  Therefore, by opening and closing the open / close valve provided on the piston through the operating rod from the outside, the tilting and standing up speed is limited by the orifice interposed in the passage passing through the open / close valve as in the conventional backrest angle adjusting device. The angle of the backrest is adjusted.
[0023]
  On the other hand, in the case where the backrest is raised or tilted between the preferred angular position and the standing end position at the most upright position of the normal backrest angle adjustment range, the portion of the enlarged diameter portion formed in the cylinder is in the meantime. The backrest angle adjustment device expands and contracts while facing the piston.
[0024]
  Therefore, in the first invention, a bypass passage is formed between the piston and the cylinder by the diameter-enlarged portion on the cylinder side so that the rod side chamber and the head side chamber communicate with each other. Rather, the hydraulic oil goes back and forth between the rod side chamber and the head side chamber through the bypass passage.
[0025]
  As a result, within this range, even if the on-off valve is kept closed, the backrest automatically stands up at a faster speed than in the normal normal backrest angle adjustment range, or By applying an external force to the backrest, the seat is easily tilted, and the seat can be quickly unlocked or the passage between the seats can be widened.
[0026]
  In addition, when the backrest is returned to the tilting direction, the bypass passage is closed when the backrest returns to the preferred angle position at the most upright position of the normal backrest angle adjustment range. The backrest will automatically stop.
[0027]
  Further, with the formation of the bypass passage described above, the flow of hydraulic oil from the rod side chamber toward the head side chamber is allowed while pushing and opening a one-way seal member provided on the piston head side through the bypass passage.
[0028]
  When the backrest is returned to the tilt side, the head-side seal member provided on the piston prevents the flow of hydraulic oil from the head-side chamber toward the rod-side chamber.
[0029]
  Therefore, even if the backrest is within the operation range for returning the backrest to the preferred angle position at the time of standing up in the normal backrest angle adjustment range, the backrest angle can be adjusted by opening / closing the open / close valve provided on the piston from the outside. Can be adjusted.
[0030]
  In addition, when returning this backrest, the cylinder part other than the enlarged diameter part enters the original cylinder part from the back side with respect to the rod side seal member of the piston. Prolong the life of the members.
[0031]
  further,secondIn this invention, when a bypass passage is formed between the enlarged diameter portion of the cylinder and the rod-side seal member of the piston, the rod-side chamber in the cylinder passes through a restriction orifice provided in the intermediate chamber and the piston from the bypass passage. And the head side chamber communicate with each other.
[0032]
  in this way,secondIn the first aspect of the invention, the rod side chamber and the head side chamber are not communicated with each other only by the bypass passage as in the first aspect of the invention, but through the restriction orifice provided in the piston from the intermediate chamber connected in series with the bypass passage. Will be communicated to.
[0033]
  For this purpose, the backrest is raised by the restriction resistance of the restriction orifice.The tilting speed is controlled to a desired value..
[0034]
  Furthermore, in constructing the enlarged diameter portion in the inner wall portion in the vicinity of the extended end of the cylinder, the inner wall portion of the cylinder is configured to be expanded over the entire circumference or partially outward.First and secondThe diameter-expanded portion in the invention can be easily made using means such as bulging.
[0035]
【Example】
  Hereinafter, using the attached drawingsFirst, the backrest angle adjustment device in the reference example will be described, and thenA preferred embodiment of the invention will be described.
[0036]
  As shown in FIG.In the reference exampleThe cylinder-type seat back angle adjusting device 1 includes mounting members 4 and 5 at the base end of a cylinder 2 and the tip of a piston rod 3 that is detachably inserted into the cylinder 2.
[0037]
  The attachment member 4 on the cylinder 2 side is connected to the tip of an arm 9 extending from the hinge 8 of the backrest 7 of the seat 6.
[0038]
  On the other hand, the mounting member 5 on the piston rod 3 side is connected to a bracket 10 that hangs down from the seat 6.
[0039]
  Thus, the backrest angle adjusting device 1 is attached between the seat 6 and the backrest 7 through the attachment members 4 and 5.
[0040]
  As shown in FIG. 2, the base end of the cylinder 2 is closed by attaching a bottom cap 11 having an attachment member 4 by welding.
[0041]
  The tip is oil-tightly closed by attaching a rod guide 13 having a dust seal 12 on the outer surface side with a roll caulking 14 and disposing a seal 15 on the inner surface side.
[0042]
  The piston rod 3 is inserted into the cylinder 2 through the dust seal 12, the rod guide 13, and the seal 15 on the tip side from the outside so as to be freely inserted and removed.
[0043]
  A piston 16 is integrally connected to the base end of the piston rod 3 by a caulking 17 located in the cylinder 2.
[0044]
  The piston 16 is positioned to the right of the position shown in FIG. 2 in a normal state, whereby the seal member 18 fitted on the outer periphery is in sliding contact with the original inner wall portion of the cylinder 2, and the piston 16 The interior is partitioned into a rod side chamber R and a head side chamber H.
[0045]
  On the other hand, in the rod side chamber R, a stopper 20 is provided with its position regulated by a roll caulking 19 formed in the cylinder 2.
[0046]
  The stopper 20 collides with the piston 16 at the maximum extension position of the backrest angle adjusting device 1 (the state shown in FIG. 2), prevents further extension operation, and minimizes the minimum fitting length between the cylinder 2 and the piston rod 3. To ensure.
[0047]
  In the head side chamber H, a free piston 22 having a seal member 21 fitted on its outer periphery is slidably disposed in sliding contact with the inner wall of the cylinder 2.
[0048]
  The free piston 22 partitions the gas chamber G on the base end side of the head side chamber H in the cylinder 2 by the sealing action of the seal member 21 fitted on the outer periphery.
[0049]
  In order to fill the gas chamber G with pressure gas, a gas injection hole 23 is formed in the bottom cap 11 that closes the base end side of the cylinder 2.
[0050]
  When the attachment member 4 is welded to the bottom cap 11 after the pressure gas is injected into the gas chamber G, the gas injection hole 23 is permanently blocked by the plug 24 provided in the attachment member 4.
[0051]
  In this manner, the attachment member 4 is attached to the bottom cap 11 that closes the base end of the cylinder 2 by welding, whereas the attachment member 5 is attached by being screwed to the tip of the piston rod 3 and then being fixed by the lock nut 25. It is done.
[0052]
  As shown in detail in FIG. 3, the piston 16 is provided with a passage 27 having an orifice 26 extending through the piston 16.
[0053]
  The passage 27 communicates the rod side chamber R and the head side chamber H in the cylinder 2 with each other through the orifice 26.
[0054]
  A valve seat 28 made of rubber or plastic is fixed to the opening portion of the passage 27 to the head side chamber H by a holding plate 29 press-fitted into the piston 16.
[0055]
  An opening / closing valve 30 that opens and closes the opening end of the passage 27 to the head side chamber H is provided in the piston 16 so as to face the valve seat 28.
[0056]
  The on-off valve 30 includes a rod 31 extending toward the passage 27, and the rod 31 extends through the seal 32 provided on the piston rod 3 into the hollow portion of the piston rod 3.
[0057]
  Thus, in the opening / closing valve 30, the pressure receiving area on the rod 31 side is smaller by the cross-sectional integral of the rod 31 than the pressure receiving area on the opposite side.
[0058]
  Accordingly, the rod side chamber R and the head side chamber H pressurized by the gas pressure in the gas chamber G through the free piston 22 (see FIG. 2) are pressed against the valve seat 28 by the hydraulic oil pressure to maintain the closed state.
[0059]
  Returning to FIG. 2, the operation rod 33 is slidably inserted into the hollow portion of the piston rod 3 from the outside over the tip of the rod 31 of the opening / closing valve 30.
[0060]
  The projecting end of the operation rod 33 to the outside is in contact with a contact plate 36 provided on the side surface of the operation lever 35 that is pivotally supported by the mounting member 5 by using the shaft 34, and the operation lever 35 is operated from outside to open and close the valve. 30 can be opened and closed.
[0061]
  In addition, theReference exampleIn this case, in the vicinity of the extended end of the backrest angle adjusting device 1, the inner wall portion of the cylinder 2 facing the piston 16 is inflated outward over the entire circumference to form an enlarged diameter portion 37 in that portion.
[0062]
  In addition, you may make it this diameter enlarged part 37 cut off the inner wall of the said part of the cylinder 2, for example directly.
[0063]
  As shown in FIG. 3, the enlarged diameter portion 37 is located between the inner wall of the cylinder 2 when the sealing member 18 fitted on the outer periphery of the piston 16 is positioned at the enlarged diameter portion 37 on the cylinder 2 side. A bypass passage 38 is formed.
[0064]
  Thus, the configuration configured as aboveReference exampleThe backrest angle adjustment device 1 performs the following operations to adjust the angle of the backrest 7 in the seat 6.
[0065]
  1 to 3, the piston 16 is now in a position (for example, the position of the chain line in FIG. 3) that is out of the enlarged diameter portion 37 on the cylinder 2 side. In this state, the opening / closing valve 30 is kept closed. Assume that the backrest 7 is locked at a desired angle by the backrest angle adjustment device 1.
[0066]
  In this state, when the backrest 7 is tilted backward, the user rests on the seat 6 and operates the operation lever 35 to push the backrest 7 with the back while opening the opening / closing valve 30.
[0067]
  The backrest 7 pushed by the back exerts a force in the compression direction on the cylinder 2 of the backrest angle adjusting device 1 through the arm 9.
[0068]
  With this force, the cylinder 2 pushes the hydraulic oil in the head side chamber H from the passage 27 of the piston 16 to the rod side chamber R while applying flow resistance through the orifice 26, and slowly moves in the compression direction at a predetermined speed.
[0069]
  At this time, the free piston 22 also operates simultaneously while compressing the pressure gas in the gas chamber G, and compensates for an excess amount of hydraulic oil corresponding to the intrusion volume of the piston rod 3 with respect to the cylinder 2.
[0070]
  Thereby, the backrest angle adjusting device 1 performs a compression operation, and accordingly, the backrest 7 falls backward.
[0071]
  If the operation lever 35 is released when the backrest 7 is tilted to a desired angle, the opening / closing valve 30 is automatically closed by the hydraulic oil pressure in the cylinder 2 caused by the gas pressure in the gas chamber G. It is done.
[0072]
  Thus, the backrest angle adjusting device 1 returns to the locked state, and the backrest 7 stops while maintaining a desired tilt angle.
[0073]
  On the other hand, when the backrest 7 is raised forward, the operation lever 35 is operated with the back away from the backrest 7 to open the opening / closing valve 30.
[0074]
  Then, this time, the cylinder 2 is pushed by the gas pressure in the gas chamber G, and the hydraulic oil in the rod side chamber R is pushed out from the passage 27 of the piston 16 to the head side chamber H while applying a flow resistance through the orifice 26. Slowly moves in the direction of extension.
[0075]
  In addition, at this time, the free piston 22 is operated by the pressure gas in the gas chamber G to expand the gas chamber G at the same time, and the operation corresponding to the withdrawal volume of the piston rod 3 with respect to the cylinder 2 is performed. Compensate for oil shortages.
[0076]
  As a result, the backrest angle adjusting device 1 extends and raises the backrest 7 forward through the arm 9.
[0077]
  If the operation lever 35 is released when the backrest 7 is raised to a desired angle, the opening / closing valve 30 is caused by the gas pressure in the gas chamber G as in the case of the tilting operation of the previous backrest 7. It is automatically closed by the hydraulic oil pressure in the cylinder 2.
[0078]
  Thus, the backrest angle adjusting device 1 returns to the locked state, and the backrest 7 stops while maintaining its desired standing angle.
[0079]
  On the other hand, during the standing operation of the backrest 7, the backrest 7 is moved to a position where the enlarged diameter portion 37 of the cylinder 2 in the backrest angle adjusting device 1 faces the seal member 18 fitted to the outer periphery of the piston 16. Suppose you wake up.
[0080]
  In this case, the bypass passage 38 is formed between the inner wall of the cylinder 2 and the outer periphery of the seal member 18 on the piston 16 side when the enlarged diameter portion 37 of the cylinder 2 faces the seal member 18 on the outer periphery of the piston 16. It is formed.
[0081]
  Thereby, from the time point, the rod side chamber R and the head side chamber H are communicated through the bypass passage 38.
[0082]
  For this reason, within this range, the backrest angle adjusting device 1 is relatively in comparison with the conventional normal backrest angle adjustment regardless of the opening / closing operation of the opening / closing valve 30, that is, regardless of the flow resistance by the orifice 26. It freely expands and contracts at a high speed, and the backrest 7 stands and tilts.
[0083]
  Like thisReference exampleIn the case where the backrest 7 is adjusted within the normal backrest angle adjustment range θ shown in FIG. The inner wall portion of the piston 16 is in sliding contact with the seal member 18 of the piston 16 to expand and contract.
[0084]
  Therefore, within the range of the normal backrest angle adjustment range θ, the opening / closing valve 30 of the piston 16 is opened / closed through the operation lever 35, so that the tilting and standing up speed by the orifice 26 is the same as in the conventional backrest angle adjustment device. The angle of the backrest 7 is adjusted steplessly while restricting.
[0085]
  On the other hand, when the backrest 7 is lifted forward toward the standing end position B beyond the preferred angular position A at the most upright position of the normal backrest angle adjustment range, the diameter of the cylinder 2 is increased. The portion 37 faces the seal member 18 of the piston 16 and forms a bypass passage 38 therebetween.
[0086]
  As a result, within the angle adjustment range α in FIG. 1, the backrest 7 rises at a higher speed than the normal backrest angle adjustment range θ regardless of the opening / closing operation of the opening / closing valve 30. It operates to the position B, and the lock for turning the seat 6 is quickly released or the passage width between the seat 6 and the rear seat 6 is widened.
[0087]
  Further, when the backrest 7 is returned from the standing end position B, the bypass passage 38 is operated while the backrest 7 is inclined to the preferred angular position A at the most upright position in the normal backrest angle adjustment range. Drowning 7 operates lightly and quickly.
[0088]
  When the angle position A is reached, the bypass passage 38 is closed by the seal member 18 of the piston 16 and the backrest 7 is automatically stopped.
[0089]
  FIG. 4 shows an embodiment in which only the main part of the present invention is taken out and shown in detail, like FIG.
[0090]
  This FIG. 4First embodimentHas been described so farReference exampleOnly the configuration of the seal member fitted to the outer periphery of the piston 16 and the configuration of the enlarged diameter portion of the cylinder 2 are different, and the other configurations are not different at all.
[0091]
  Therefore, here, only the above-described differences will be described with reference to FIG.
[0092]
  That is, in the embodiment of FIG. 4, two U-shaped seal members 18a and 18b having insert metals 39a and 39b are arranged on the outer periphery of the piston 16 with their lip portions 18c and 18d facing outward. It is.
[0093]
  The reason why the seal members 18a and 18b are made of a seal with an insert metal is to facilitate the mounting to the piston 16, and a normal U-shaped seal having no insert metal is provided on the outer periphery of the piston 16. It may be used by being fitted in the annular groove.
[0094]
  Thus, each of the seal members 18a and 18b blocks only the flow of the hydraulic oil that tries to flow through the seal members 18a and 18b from the side facing the lip portions 18c and 18d, and prevents the flow of hydraulic oil in the opposite direction. The lip portions 18c and 18d are reduced in diameter to allow the flow.
[0095]
  In this way, the seal members 18a and 18b function as a one-way seal having a seal function only in one direction, and the two seal members 18a and 18b cooperate with each other to serve as a piston seal. .
[0096]
  On the other hand, on the inner wall portion of the cylinder 2 facing the rod-side seal member 18a of the piston 16 in the vicinity of the extended end, the inner wall is inflated outward in the axial direction, and an appropriate number of enlarged diameter portions 37a (in FIG. 4). One).
[0097]
  The enlarged diameter portion 37a is positioned so that the enlarged diameter portion 37a faces only the rod-side seal member 18a when the enlarged diameter portion 37a is positioned at the piston 16 portion, whereby the seal member 18a and the inner wall of the cylinder 2 A bypass passage 38 is formed between them.
[0098]
  Thereby, even in the case of the embodiment shown in FIG. 4, the normal backrest angle adjustment range in which the original inner wall portion of the cylinder 2 that is out of the enlarged diameter portion 37 a is in sliding contact with the seal members 18 a and 18 b of the piston 16. In this case, the seal members 18a and 18b cooperate with each other without opening the on-off valve 30.Reference exampleAs in the case of, the angle of the backrest 7 is adjusted steplessly while restricting the tilting and standing up speed at the orifice 26.
[0099]
  Further, when the backrest 7 is raised further forward from the preferred angular position A at the most upright position of the normal backrest angle adjustment range, the diameter-enlarged portion 37a of the cylinder 2 is the rod-side seal member 18a of the piston 16. A bypass passage 38 is formed to face this portion.
[0100]
  As a result, even in this case,Reference exampleAs in the case of the above, the backrest 7 moves to the standing end position B at a relatively high speed compared with the normal backrest angle adjustment regardless of the opening / closing operation of the opening / closing valve 30, and quickly locks the seat 6 for turning. The width of the passage between the rear seat 6 and the rear seat 6 is increased.
[0101]
  Moreover, according to the embodiment of FIG. 4, when the backrest 7 is returned from the above state,Reference exampleUnlike the case, the flow of hydraulic fluid from the head side chamber H to the rod side chamber R is blocked by the lip portion 18d of the head side seal member 18b.
[0102]
  Therefore, even within this range, the angle of the backrest 7 can be adjusted by opening / closing the opening / closing valve 30 through the operation lever 35.
[0103]
  So farFirst embodimentAccording to the above, on the extended end side of the backrest angle adjusting device 1, the operation lever 35 is not operated to open the opening / closing valve 30, and the external force is applied to the backrest 7 at a high speed quickly without being opened. can do.
[0104]
  Also,firstAccording to this embodiment, even when the backrest 7 is returned on the extended end side of the backrest angle adjusting device 1, the angle can be adjusted using the operation lever 35.
[0105]
  However, if the extension speed on the extension end side of the backrest angle adjusting device 1 is too high, a severe impact is generated at the extension end.
[0106]
  Therefore, in order to prevent this shock from occurring,firstIn this embodiment, the flow of the bypass passage 38 is determined by appropriately determining the passage area of the bypass passage 38 formed by the enlarged diameter portions 37, 37a of the cylinder 2 and the seal members 18, 18a provided on the piston 16. The flow resistance of the oil is selected, and the extension speed on the extension end side of the backrest angle adjusting device 1 is appropriately controlled.
[0107]
  As a result, it is possible to control the extension speed on the extension end side of the backrest angle adjusting device 1 to some extent to suppress the occurrence of impact, but such impact prevention means alone is still insufficient depending on the application. The case occurs.
[0108]
  FIG. 5 shows another embodiment of the present invention having a configuration adapted for use in such a case.
[0109]
  That is, as shown in FIG.secondIn the embodiment of FIG.firstAs in the first embodiment, two seal members 18e and 18f are arranged on the outer periphery of the piston 16.
[0110]
  However, the two sealing members 18e and 18f described above arefirstUnlike the case of this embodiment, it does not have a sealing function only in one direction, but is composed of a normal piston seal having a sealing function in both directions, and these two sealing members 18e and 18f An intermediate chamber 40 is formed.
[0111]
  The intermediate chamber 40 is always in communication with the head side chamber H in the cylinder 2 through a restriction orifice 41 provided in the piston 16.
[0112]
  On the other hand, the enlarged diameter portion 37 on the cylinder 2 side is positioned so that the enlarged diameter portion 37 faces only the seal member 18e on the rod side when positioned at the piston 16 portion.
[0113]
  Thus, the enlarged diameter portion 37 and the seal member 18e form a bypass passage 38 between the inner wall of the cylinder 2 and the seal member 18e, and the cylinder is passed through the bypass orifice 38 and the restriction orifice 41 provided in the piston 16. The rod side chamber R and the head side chamber H in 2 are communicated with each other.
[0114]
  Thus, as shown in FIG.secondEven in the case of this embodiment, when the original inner wall portion of the cylinder 2 out of the expanded diameter portion 37 is in the normal backrest angle adjustment range θ in which it is in sliding contact with the seal members 18e, 18f of the piston 16, As the valve 30 is opened and closed, the angle of the backrest 7 is adjusted steplessly while restricting the tilting and rising speed at the orifice 26.
[0115]
  Further, in the angle adjustment range α between the preferred angle position A and the standing end position B at the most standing time of the normal backrest angle adjustment range, the diameter-expanded portion 37 of the cylinder 2 is the rod side seal member 18e in the piston 16. And a bypass passage 38 is formed between the enlarged diameter portion 37 and the rod side seal member 18e.
[0116]
  As a result, the rod side chamber R and the head side chamber H are communicated with each other through the bypass passage 38, the intermediate chamber 40, and the restriction orifice 41.
[0117]
  Therefore, within this angle adjustment range α, the backrest 7 stands up and tilts at a predetermined high speed controlled by the restriction orifice 41, regardless of the opening / closing operation of the opening / closing valve 30, and compared with the normal backrest angle adjustment. Operate.
[0118]
  As a result, the backrest 7 quickly operates to release the turning lock of the seat 6, or the passage width between the seat 6 and the rear seat 6 can be increased.
[0119]
  FIG. 6 shows a modification of the embodiment of FIG. 5 described above. In this embodiment, the piston is composed of two parts, that is, a piston 16 as a main body part and a guide member 16a as an extension part. ing.
[0120]
  The guide member 16a is oil-tightly coupled to the piston 16 by means such as press fitting, and a seal member 18f and a restriction orifice 41 are provided on the guide member 16a side.
[0121]
  According to this, it is possible to use the piston 16 that is a standard part without making the piston 16 into a special shape as in the embodiment of FIG.
[0122]
  5 and 6, the two seal members 18e and 18f are used on the piston 16 side. However, the expansion / contraction speed in the vicinity of the extension end of the backrest angle adjusting device 1 is somewhat high. If variation is permitted, the seal member 18f may be omitted to allow some hydraulic oil leakage therefrom.
[0123]
  Further, as a means for preventing the impact at the extended end of the backrest angle adjusting device 1, the rod side of the piston 16 on the extended end side without using the bypass passage 38 and the restriction orifice 41 by the enlarged diameter portions 37 and 37 a described so far. So that the outer peripheral portion passes through the enlarged diameter portions 37 and 37a and is fitted into the cylindrical portion of the cylinder 2, thereby using a so-called oil lock means for flowing the hydraulic oil in the rod side chamber R from the fitting gap between them. Or they may be used in combination.
[0124]
  Although not shown in particular, FIG.firstThe partial enlarged diameter portion 37a used in the embodiment isSecondNeedless to say, it may be used for the cylinder 2 in the embodiment and the modified example, or conversely, the circumferential enlarged diameter portion 37 may be used for the cylinder 2 of FIG.
[0125]
【The invention's effect】
  As aboveAccording to the inventions of claim 1 and claim 2,Regardless of the normal inclination of the backrest and the limitation of the operation speed at the time of standing, the standing speed when raising further forward from the preferred angle position at the most standing position of the backrest angle adjustment range is adjusted during these normal backrest angle adjustments. The backrest can be quickly raised to the standing end position.
[0126]
  In addition, even when tilting the backrest from the standing end position, simply sitting on the seat and leaning the back against the backrest, the preferred angle at the most standing position without operating the operation lever It can be quickly returned to the position.
[0127]
  Moreover,According to the invention of claim 1Even if it is within the operating range to return the backrest at the standing end position to the preferred angle position at the most upright position of the backrest angle adjustment range, it is possible to adjust the backrest angle steplessly using the operation lever become.
[0128]
  In addition, when the cylinder expands from the piston and the normal part enters the piston as the cylinder is compressed, the normal part of the cylinder enters from the back side of the rod-side seal member of the piston. The resistance at the time of penetration is reduced, and therefore the durability of the piston seal is significantly improved.
[0129]
  on the other hand,According to the invention of claim 2The operating speed when the backrest is raised and tilted beyond the normal backrest angle adjustment range can be appropriately controlled by selecting the hole diameter of the limiting orifice provided in the piston.
[0130]
  further,According to invention of Claim 3 and 4,In addition to the above, the enlarged diameter portion for the bypass passage formed in the cylinder of the backrest angle adjusting device can be easily made by using a drawing means such as a bulge.
[Brief description of the drawings]
FIG. 1 is a view showing an example of mounting a backrest angle adjusting device according to the present invention on a seat.
[Fig. 2] Same as above, of the backrest angle adjustment deviceReference exampleFIG.
[Figure 3]In the reference exampleIt is a partial vertical front view which shows only the principal part of a backrest angle adjusting device longitudinally and shows in detail.
[Fig. 4]FirstIt is the fragmentary longitudinal cross-sectional front view which shows only the principal part of the backrest angle adjusting device which concerns on an Example, and shows in detail.
[Figure 5]SecondIt is the fragmentary longitudinal cross-sectional front view which shows only the principal part of the backrest angle adjusting device which concerns on an Example, and shows in detail.
FIG. 6 is a partially longitudinal front view showing a modified example of the above.
[Explanation of symbols]
  1 Backrest angle adjustment device
  2 cylinders
  3 Piston rod
  6 sheets
  7 Backrest
  16 piston
  18 Piston seal member
  18a One-way piston seal member on rod side
  18b One-way piston seal member on the head side
  18c, 18d Lip part
  18e, 18f Piston seal member
  26 Orifice
  27 passage
  28 Valve seat
  30 Open / close valve
  31 Rod
  32 seals
  33 Operating rod
  35 Control lever
  37, 37a Expanded part
  38 Bypass passage
  40 Intermediate room
  41 Restriction orifice
  G gas chamber
  H Head side chamber
  R Rod side chamber

Claims (4)

In a cylinder-type seat back angle adjusting device, two one-way seal members having a sealing function are arranged on the outer peripheral surface of the piston from the outside to the inside, with a gap therebetween, while the back angle adjusting device An enlarged diameter portion is formed in the inner wall portion of the cylinder facing the seal member located on the rod side of these two seal members in the vicinity of the extended end of the cylinder, and the enlarged diameter portion on the cylinder side faces the rod side seal member of the piston. A bypass passage is formed between the inner wall of the cylinder and the rod-side seal member of the piston from that point in time, and the rod-side chamber in the cylinder defined by the piston passes through the head-side seal member of the piston from the bypass passage. A backrest angle adjusting device characterized in that it communicates with a side chamber. In a cylinder-type seat back angle adjustment device, a seal member and an intermediate chamber are arranged side by side from the rod side to the head side on the outer periphery of the piston, and this intermediate chamber is located in a cylinder defined by the piston through a restriction orifice provided in the piston. An enlarged diameter portion is formed in the inner wall portion of the cylinder facing the piston seal member in the vicinity of the extended end of the backrest angle adjustment device, and the enlarged diameter portion on the cylinder side is connected to the piston seal member. A bypass passage is formed between the inner wall of the cylinder and the seal member of the piston from the point of opposition, and the rod side chamber and head side chamber in the cylinder defined by the piston are connected to the bypass passage, the intermediate chamber of the piston, and the restriction orifice. A backrest angle adjustment device characterized in that it communicates with each other through the backrest. The backrest angle adjusting device according to claim 1 or 2, wherein a portion in the vicinity of the extended end of the cylinder is inflated outward over the entire circumference to constitute an enlarged diameter portion. The backrest angle adjusting device according to claim 1 or 2, wherein a portion in the vicinity of the extended end of the cylinder is partially inflated outward to form an enlarged diameter portion.

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