JPH0569426U - Prop device - Google Patents

Abstract

(57) [Summary] [Purpose] It should also be used for materials that require high holding power without increasing the gas pressure or increasing the cylinder outer diameter. [Structure] Piston rods 1 and 2 are movably inserted into a cylinder 3 via a piston 5, and the piston defines two upper and lower oil chambers A and B in the cylinder, and a guide 30 is provided below the lower oil chamber. A gas chamber partitioned by is provided, and the piston rod penetrating the guide is constantly energized in the extending direction by gas pressure, and the upper and lower two oil chambers are provided in the passages 19a, 19b, 19c and the passage provided in the piston rod Open / close valve 1
In a strut device which is opened and closed at 0, free pistons 37, 37a having a small pressure receiving surface facing the lower oil chamber side and a large pressure receiving surface facing the gas chamber side are slidably fitted to the guide. And

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention is suitable for use in a seat lock mechanism for arbitrarily adjusting the angle of the backrest seat portion of a reclining seat for vehicles, trains, aircrafts, or households, and for adjusting the height of the seat of a chair. The present invention relates to a strut device that is telescopic and can be locked at any position.

[0002]

[Prior Art]

 As this type of strut device, for example, one shown in FIG. 6 has been developed (Japanese Patent Application No. 3-110561).

In this strut device, a first piston rod 1 and a second piston rod 2 on both sides of the piston are movably inserted into a cylinder 3 via a piston 5, and the piston 5 is inserted into the cylinder 3 at a first position. First and second two oil chambers A and B are divided, and the two oil chambers A and B are formed in the passages as formed in the first and second piston rods 1 and 2 and are closed in the passage a. An operation rod 4 for opening and closing the on-off valve 10 is provided in the first piston rod 1 so as to communicate with each other via an on-off valve 10 which is energized and is openable and closable. A gas chamber C is defined by a partition member 20 that can move up and down, and a lower end of the second piston rod 2 slidably penetrates the partition member 20 and faces the lower gas chamber C. is there.

The partition wall member 20 serving as a guide is caulked to the cylinder 3 at the caulking portion b, but the groove on the outer periphery of the partition wall member 20 is slightly wide, and when the cylinder 3 is caulked at the caulking portion b, the gap L is formed. To be formed.

Therefore, the partition wall member 20 can move downward by the gap L against the gas pressure in the gas chamber C when the oil temperature rises at high temperature and the oil inside expands.

[0006]

[Problems to be Solved by the Invention]

 In the above-mentioned strut device, when locked, it is not normally compressed even if pressed from the reclining side.

However, when there is a sudden shock and the internal pressure of the lower oil chamber B rises above the gas pressure of the gas chamber C, even if there is a holding force of the caulking portion b and friction, these holding forces are small and the partition member 20 There is a danger that the piston rod 2 and the piston 5 move down in the compression direction.

That is, when it is used as a supporting device for a reclining seat of a vehicle such as a bus or a train, it is set so as not to be compressed even if a pressing force of about 200 kgf acts, but it has the same structure. If the product is used as it is for reclining seats for airplanes, the strut device may be compressed if the pressing force due to the shock is large and a sudden shock occurs.

If the outer diameter of the cylinder 3 is increased and the enclosed gas pressure is increased, the holding force is increased, and it can be applied to a prop device of a reclining seat for an aircraft. As described above, the prop device used for a vehicle is used. However, the outer diameter of the cylinder and the pressure of the enclosed gas are limited by the installation space and other factors, and cannot be used as is for aircraft.

Therefore, an object of the present invention is to provide a strut device that can be used even for a reclining seat for aircraft that requires high holding force without increasing the gas pressure or increasing the outer diameter of the cylinder. That is.

[0011]

[Means for Solving the Problems]

 In order to achieve the above object, the structure of the present invention is such that a piston rod is movably inserted into a cylinder via a piston, and the piston defines two upper and lower oil chambers in the cylinder, and a piston is arranged below Is provided with a gas chamber divided by a guide, the piston rod penetrating the guide is constantly energized in the extending direction by gas pressure, and the upper and lower two oil chambers are provided in the passage provided in the piston rod and in this passage. A free piston having a small pressure receiving surface facing the lower oil chamber side and a large pressure receiving surface facing the gas chamber side was slidably fitted into the guide in the strut device that is opened and closed by the open / close valve. It is characterized by

[0012]

[Action]

 When the oil temperature in the lower oil chamber rises and the oil expands, or when there is a sudden shock and the internal pressure in the lower oil chamber rises, the free piston moves down against the gas pressure.

However, since the pressure receiving surface of the free piston is small on the lower oil chamber side and large on the gas chamber side, the free piston does not descend unless the internal pressure on the lower oil chamber side becomes considerably higher than the gas pressure in the gas chamber, and the holding force is reduced. Can be set large.

[0014]

【Example】

 Hereinafter, one embodiment of the present invention will be described with reference to FIG.

The first piston rod 1 and the second piston rod 2 on both sides of the piston 5 are movably inserted into the cylinder 3 via the piston 5, and the piston 5 is inserted into the cylinder 3 in the upper first oil chamber A and the lower portion. It is partitioned from the second oil chamber B and is sealed by the seal 13 and the backup 12.

A partition member 30 that guides to one side of the cylinder 3, that is, the second piston rod 2 side is fixed by caulking, and the partition member 30 defines a gas chamber C in which gas is sealed in the cylinder 3. Then, the gas chamber C is cut off from the second oil chamber B, and the gas pressure does not act on the second oil chamber B.

The tip of the second piston rod 2 slidably penetrates the partition member 30 and faces the gas chamber C 1.

An O-ring 31 as a seal and a backup 32 are provided on the outer circumference of the partition wall member 30 as a guide, and a seal 33 is provided on the inner circumference.

A free piston 37 is arranged below the partition member 30 so as to be vertically movable, and an upper sleeve 41 of the free piston 37 is vertically movably fitted to the inner periphery of the partition member 30.

Therefore, the repulsive force that pushes up the piston rods 1 and 2 is represented by the formula: repulsive force = second piston rod cross-sectional area × enclosed gas pressure.

Although the first and second piston rods 1 and 2 are integrally connected to the piston 5 by a joint 40 which is integral with the piston 5, the first and second piston rods 1 and 2 are connected to each other. May be molded in one piece.

The first and second piston rods 1 and 2 are formed with passages 19a, 19b, and 19c for communicating the first and second oil chambers A and B, respectively, and openable and closable balls are provided in the passage 19c. The on-off valve 10 and the spring 11 are built in, and the on-off valve 10 is biased by the spring 11 in the closing direction.

An operation rod 4 for opening and closing the on-off valve 10 is inserted into the first piston rod 1 from the outside so as to be vertically movable, and an inner end of the operation rod 4 is connected to the on-off valve 10 via a push rod tip 6. Facing each other.

The push rod tip 6 moves vertically while being sealed by the seal 8, the backup 7, and the guide 9.

The operation rod 4 may integrally face the on-off valve 10 directly.

A guide 15, a packing 16, a stopper 17, a collar 18 and a stop rubber 14 are provided on the upper portion of the cylinder 3.

A backrest seat portion of a reclining seat, a seat of a chair, and the like are connected to the outside of the first piston rod 1, and the angle of these seat portions and the height of the seat are adjusted by expanding and contracting the piston rod. Is becoming

The piston of the free piston 37 is slidably fitted into the cylinder 3 in the gas chamber C via the seal 36 and the backup 35, and the sleeve 41 has the inner peripheral seal 33 inside the partition wall member 30. It is fitted so that it can move up and down.

The second piston rod 2 penetrates the inner circumference of the free piston 37 through a seal composed of an O-ring 38 and a backup 39 so as to be vertically movable.

The free piston 37 has a large pressure receiving surface which is the lower surface of the piston portion, and a small pressure receiving surface which is the upper surface of the sleeve 41, so that there is a difference in size between the two pressure receiving surfaces.

The free piston 37 is constantly urged upward by the gas pressure in the gas chamber C and is locked by the gas pressure. Therefore, when a pressing force larger than the product of the gas pressure and the sectional area of the piston portion acts on the pressure receiving surface of the sleeve 41, the free piston moves down.

An air vent hole 3 A is formed in the upper part of the cylinder 3 in the radial direction.

When the operating rod 4 is pushed in, the opening / closing valve 10 is opened against the spring 11, and at this time, the first and second oil chambers A and B are in communication.

In this state, if an external force is not applied to the first piston rod 1 from the seat side, the entire piston rod and piston 5 will move in FIG. 1 by the gas pressure acting on the tip of the second piston rod 2. When moving upward, the oil in the first oil chamber A flows out from the passages 19a, 19b, 19c and the opening / closing valve 10 into the second oil chamber B, and the angle of the seat portion of the reclining seat changes in accordance with the movement of the piston rod. It changes to the front side or the height of the chair changes to the upper side.

On the contrary, when an external force is applied to the first piston rod 1 to push it in the above-mentioned state, the first piston rod 1 is compressed against the gas pressure, and the angle of the seat portion is changed to the rear side by the compressed amount, or the height of the chair is increased. Becomes lower.

When the piston rod expands and contracts and the seat portion or the like reaches a desired arbitrary angle or height, when the pressing force of the operating rod 4 is stopped, the opening / closing valve 10 automatically returns to the closing direction by the spring force of the spelling 11. , The passages 19a, 19b, 19c are closed so that the seat angle and seat height are set and maintained in place.

The locking force in this case is that there is no escape of oil in the first and second oil chambers A and B, and the second oil chamber B is separated from the gas chamber C by the fixed partition member 30. Occurs regardless of gas pressure, and its size is infinite unless there is a leak from the seal.

Further, the gas pressure does not act on the on-off valve 10, and the opening operation force of the operation rod 4 can be made small by only resisting the spring force of the spring 23.

A stop groove 18A is formed on the outer periphery of the collar 18 and annular seals 19 and 19 are fitted vertically, and the seals 19 and 19 communicate the air vent hole 3A with the upper first oil chamber A. Is shut off.

The operation of enclosing the working oil and gas in the above-mentioned strut device is performed as follows.

The partition member 30 and the free piston 37 are assembled and fixed to the cylinder 3, and the driving hole 42A of the gas charging plug 42 is temporarily sealed with a tape or the like in a pair. The hydraulic oil is filled up to the air vent hole 3A.

Next, the piston 5 and the piston rod assembly are inserted into the cylinder 3.

When the piston 5 is inserted into the cylinder 3, a part of the hydraulic oil corresponding to the volume of the second piston rod 2 in the upper portion of the cylinder 3 is pushed out from the air vent hole 3 A and the oil in the lower portion of the cylinder 3 is pushed out. Is pushed out from the hole 42A by pushing open the temporary sealing such as tape.

When the piston 5 passes through the air vent hole 3A, the second piston rod 2 is fitted into the partition wall member 30, and the seals 21 and 22 start to work, the lower portion between the piston 5 and the partition member 30 is started. The hydraulic oil sealed in the second oil chamber B loses its place of departure and is locked.

After that, the operating rod 4 is pushed to open the on-off valve 10, the passage between the two oil chambers A and B is secured, and the piston rod assembly is pushed down to the stroke end.

In this state, the filling of the lower second oil chamber is guaranteed.

Next, the stop rubber 14 and the collar 18 are mounted in the cylinder 3, and the upper end of the collar 18 is positioned below the air vent hole 3A.

Further, a stopper 17 is attached, the air vent hole 3 A is directed upward, and temporary sealing is performed with tape or the like, and the upper portion of the cylinder 3 is further filled with hydraulic oil.

When the packing 16 is further fitted and the guide 15 is pushed in and temporarily fixed, the oil of the invading volume of these members becomes together with the air slightly left in the upper second oil chamber A. The tape or the like in the air vent hole 3A that is temporarily sealed is pushed open and pushed out to the outside, and a predetermined hydraulic oil is filled.

After that, the air vent hole 3 A is held, and the piston 5 is pulled up while the on-off valve 10 is opened. This piston 5 pushes up the stop rubber 14 and the collar 18 until they hit the stopper 17.

At this time, the air vent hole 3A is located between the upper and lower seals 19 and 19 to cut off communication with the first oil chamber A.

Furthermore, a stop ball 26 is driven into the air vent hole 3A from the outside and is fitted between the stop ball 26 and the stop groove 18A of the collar 18 to achieve sealing and prevention of vertical movement of the collar 18.

The piston rod assembly, especially the second piston rod 2 is fully stroked up and down several times to push out the hydraulic oil remaining in the gas chamber C in the same manner as a water gun, and then to fill the gas through the hole 42A, The sealing plug 42 is driven in for gas sealing, and then the bracket 25 is joined by welding.

Since a part of the upper end surface of the free piston 37 is cut off from the lower oil chamber B by the partition member 30, the pressure receiving area where the pressure P1 of the lower oil chamber B acts on the free piston 37 is the disconnection of the sleeve 41. The area A is obtained by subtracting the cross-sectional area of the second piston 2 from the area, and the force F1 that the free piston 37 receives from the lower oil chamber B is F1 = A1 × P1.

Further, the pressure receiving area where the gas pressure P2 of the gas chamber C acts on the free piston 37 becomes an area A2 obtained by subtracting the cross-sectional area of the second piston rod 2 from the inner diameter of the cylinder 3, and the free piston 37 moves to the gas chamber C. The force F2 received from is F2 = A2 × P2.

When the oil temperature rises, the oil expands, the pressure P1 in the lower oil chamber B rises, and when the force F1 received from the lower oil chamber B becomes larger than F2, the free piston 37 descends.

Similarly, due to a sudden shock or the like, a pressing force is generated from the reclining seat to exert a downward force on the piston 5, and when F1 becomes larger than F2, the free piston 37 descends.

When the free piston 37 moves slightly downward in FIG. 1, the free piston 37 is balanced at a position satisfying F1 = F2.

From the above equation, A1 × P1 = A2 × P2 and P1 = (A2 ÷ A1) × P2, and the pressure P1 in the lower oil chamber B is not increased as long as the ratio of the upper and lower pressure receiving areas A1 and A2 of the free piston Since the free piston 37 does not move downward, it can be used even for a strut device that receives a large pressing force such as a reclining seat for an aircraft without changing the gas pressure or the cylinder diameter as long as it is below the withstand pressure limit of the cylinder 3. become.

A space E may be provided between the lower surface of the partition member 30 and the upper surface of the piston portion of the free piston 37. In this case, negative pressure is generated when the free piston 37 descends, but it is an independent space. It does not affect the seat lock function.

If a small hole 3 B is provided in the cylinder 3 at a position corresponding to this space E, it is possible to crimp the partition member 30 into the cylinder 3 and then insert only the free piston 37 independently from below the cylinder 3. I can.

That is, like the other embodiment shown in FIG. 3, the free piston 37 is inserted from below before welding the lower cap to the cylinder 3, and positioning and mounting can be performed while pushing up with the jig J.

Even when the free piston 37 is assembled and attached to the partition wall member 30, the free piston 37 can be suppressed by the jig J.

FIG. 4 shows another embodiment of the present invention.

In this, a skirt 30a is vertically provided under the partition member 30, and a piston portion of a free piston 37 is vertically slidably inserted into the skirt 30a so that the free piston 37 and the partition member 30 have the same concentricity. Is improved.

Other structures, actions and effects are the same as those of the embodiment shown in FIG.

FIG. 5 shows another embodiment of the present invention.

This is one in which the free piston 37a is vertically movably fitted in the lower skirt 30a of the partition member 30 via an elastic member 30b such as rubber.

The free piston 37a may be coupled to the skirt 30a of the partition member 30 via the elastic member 30b, or may be simply fitted movably.

In the case of this integral connection, the jig J is unnecessary, and the jig J can be sufficiently used for a column device with a small amount of hydraulic oil and a small expansion / contraction amount.

[0071]

【The invention's effect】

 According to the present invention, since the guide is fitted with the free piston having the small upper pressure receiving surface and the larger lower pressure receiving surface, the pressure in the lower oil chamber is equal to the ratio of the pressure receiving surfaces of the free piston. The free piston does not descend unless it becomes higher than the gas pressure in the gas chamber. For this reason, the locking force can be increased without increasing the gas pressure or the cylinder diameter, and it can also be used for aircraft reclining seats that receive a sudden and large pressing force.

[Submission date] November 25, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content] [Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention is suitable for use in a seat lock mechanism for arbitrarily adjusting the angle of the backrest seat portion of a reclining seat for vehicles, trains, aircrafts, or households, or for adjusting the height of a seat of a chair. The present invention relates to a strut device that is extendable and can be locked in any position.

[0002]

[Prior Art]

 As this type of strut device, for example, one shown in FIG. 6 has been developed (Japanese Patent Application No. 3-110561).

In this strut device, a first piston rod 1 and a second piston rod 2 on both sides of the piston are movably inserted into a cylinder 3 via a piston 5, and the piston 5 is inserted into the cylinder 3 at a first position. First and second two oil chambers A and B are divided, and the two oil chambers A and B are formed in the passages as formed in the first and second piston rods 1 and 2 and are closed in the passage a. An operation rod 4 for opening and closing the on-off valve 10 is provided in the first piston rod 1 so as to communicate with each other via an on-off valve 10 which is energized and is openable and closable. A gas chamber C is defined by a partition member 20 that can move up and down, and a lower end of the second piston rod 2 slidably penetrates the partition member 20 and faces the lower gas chamber C. is there.

The partition wall member 20 serving as a guide is crimped to the cylinder 3 at the crimp portion b. However, the groove on the outer periphery of the partition wall member 20 is slightly wide, and when the cylinder 3 is crimped at the crimp portion b, the gap L To be formed.

Therefore, the partition wall member 20 can move downward by the gap L against the gas pressure in the gas chamber C when the oil temperature rises at high temperature and the oil inside expands.

[0006]

[Problems to be solved by the device]

 In the above-mentioned strut device, when locked, it is not normally compressed even if pressed from the reclining side.

However, when there is a sudden shock and the internal pressure of the lower oil chamber B rises above the gas pressure of the gas chamber C, even if there is a holding force of the caulking portion b and friction, these holding forces are small and the partition member 20 There is a risk that the piston rod 2 and piston 5 will move down in the compression direction as they descend.

That is, when it is used as a supporting device for a reclining seat of a vehicle such as a bus or a train, it is set so as not to be compressed even if a pressing force of about 200 kgf acts, but it has the same structure. If the product is used as it is for reclining seats for airplanes, the strut device may be compressed if the pressing force due to the shock is large and a sudden shock occurs.

If the outer diameter of the cylinder 3 is increased and the enclosed gas pressure is increased, the holding force is increased, and it can be applied to a prop device of a reclining seat for an aircraft. As described above, the prop device used for a vehicle is used. However, the outer diameter of the cylinder and the pressure of the enclosed gas are limited by the installation space and other factors, and cannot be used as is for aircraft.

Therefore, an object of the present invention is to provide a strut device that can be used for a reclining seat for aircraft that requires high holding force without increasing the gas pressure or increasing the outer diameter of the cylinder. That is.

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in the structure of the present invention, a piston rod is movably inserted into a cylinder through a piston, and the piston divides the upper and lower oil chambers into the cylinder, and the piston chamber is located below the lower oil chamber. Is provided with a gas chamber divided by a guide, the piston rod penetrating the guide is constantly energized in the extending direction by gas pressure, and the upper and lower two oil chambers are provided in the passage provided in the piston rod and in this passage. A free piston having a small pressure receiving surface facing the lower oil chamber side and a large pressure receiving surface facing the gas chamber side was slidably fitted into the guide in the strut device that is opened and closed by the open / close valve. It is characterized by

[0012]

[Action]

 When the oil temperature in the lower oil chamber rises and the oil expands, or when there is a sudden shock and the internal pressure in the lower oil chamber rises, the free piston moves down against the gas pressure.

However, since the pressure receiving surface of the free piston is small on the lower oil chamber side and large on the gas chamber side, the free piston does not descend unless the internal pressure on the lower oil chamber side becomes considerably higher than the gas pressure in the gas chamber, and the holding force is reduced. Can be set large.

[0014]

【Example】

 An embodiment of the present invention will be described below with reference to FIG.

The first piston rod 1 and the second piston rod 2 on both sides of the piston 5 are movably inserted into the cylinder 3 via the piston 5, and the piston 5 is inserted into the cylinder 3 in the upper first oil chamber A and the lower portion. It is partitioned from the second oil chamber B and is sealed by the seal 13 and the backup 12.

A partition member 30 that guides to one side of the cylinder 3, that is, the second piston rod 2 side is fixed by caulking, and the partition member 30 defines a gas chamber C in which gas is sealed in the cylinder 3. Then, the gas chamber C is cut off from the second oil chamber B, and the gas pressure does not act on the second oil chamber B.

The tip of the second piston rod 2 slidably penetrates the partition member 30 and faces the gas chamber C 1.

An O-ring 31 as a seal and a backup 32 are provided on the outer circumference of the partition wall member 30 as a guide, and a seal 33 is provided on the inner circumference.

A free piston 37 is arranged below the partition member 30 so as to be vertically movable, and an upper sleeve 41 of the free piston 37 is vertically movably fitted to the inner periphery of the partition member 30.

Therefore, the repulsive force that pushes up the piston rods 1 and 2 is represented by the formula: repulsive force = second piston rod cross-sectional area × enclosed gas pressure.

Although the first and second piston rods 1 and 2 are integrally connected to the piston 5 by a joint 40 which is integral with the piston 5, the first and second piston rods 1 and 2 are connected to each other. May be molded in one piece.

The first and second piston rods 1 and 2 are formed with passages 19a, 19b and 19c for communicating the first and second oil chambers A and B, respectively, and openable and closable balls are provided in the passage 19c. The on-off valve 10 and the spring 11 are built in, and the on-off valve 10 is biased by the spring 11 in the closing direction.

An operation rod 4 for opening and closing the on-off valve 10 is inserted into the first piston rod 1 from the outside so as to be vertically movable, and an inner end of the operation rod 4 is connected to the on-off valve 10 via a push rod tip 6. Facing each other.

The push rod tip 6 moves vertically while being sealed by the seal 8, the backup 7, and the guide 9.

The operation rod 4 may integrally face the on-off valve 10 directly.

A guide 15, a packing 16, a stopper 17, a collar 18 and a stop rubber 14 are provided on the upper portion of the cylinder 3.

A backrest seat portion of a reclining seat, a seat of a chair, and the like are connected to the outside of the first piston rod 1, and the angle of these seat portions and the height of the seat are adjusted by expanding and contracting the piston rod. Is becoming

The piston of the free piston 37 is slidably fitted into the cylinder 3 in the gas chamber C via the seal 36 and the backup 35, and the sleeve 41 has the inner peripheral seal 33 inside the partition wall member 30. It is fitted so that it can move up and down.

The second piston rod 2 penetrates the inner circumference of the free piston 37 through a seal composed of an O-ring 38 and a backup 39 so as to be vertically movable.

The free piston 37 has a large pressure receiving surface which is the lower surface of the piston portion, and a small pressure receiving surface which is the upper surface of the sleeve 41, so that there is a difference in size between the two pressure receiving surfaces.

The free piston 37 is constantly urged upward by the gas pressure in the gas chamber C and is locked by the gas pressure. Therefore, when a pressing force larger than the product of the gas pressure and the sectional area of the piston portion acts on the pressure receiving surface of the sleeve 41, the free piston moves down.

An air vent hole 3 A is formed in the upper part of the cylinder 3 in the radial direction.

When the operating rod 4 is pushed in, the opening / closing valve 10 is opened against the spring 11, and at this time, the first and second oil chambers A and B are in communication.

In this state, if an external force is not applied to the first piston rod 1 from the seat side, the entire piston rod and piston 5 will move in FIG. 1 by the gas pressure acting on the tip of the second piston rod 2. When moving upward, the oil in the first oil chamber A flows out from the passages 19a, 19b, 19c and the opening / closing valve 10 into the second oil chamber B, and the angle of the seat portion of the reclining seat changes in accordance with the movement of the piston rod. It changes to the front side or the height of the chair changes to the upper side.

On the contrary, when an external force is applied to the first piston rod 1 to push it in the above-mentioned state, the first piston rod 1 is compressed against the gas pressure, and the angle of the seat portion is changed to the rear side by the compressed amount, or the height of the chair is increased. Becomes lower.

When the piston rod expands and contracts and the seat portion or the like reaches a desired arbitrary angle or height, when the pressing force of the operating rod 4 is stopped, the opening / closing valve 10 automatically returns to the closing direction by the spring force of the spelling 11. , The passages 19a, 19b, 19c are closed so that the seat angle and seat height are set and maintained in place.

The locking force in this case is that there is no escape of oil in the first and second oil chambers A and B, and the second oil chamber B is separated from the gas chamber C by the fixed partition member 30. Occurs regardless of gas pressure, and its size is infinite unless there is a leak from the seal.

Further, the gas pressure does not act on the on-off valve 10, and the opening operation force of the operation rod 4 can be made small by only resisting the spring force of the spring 23.

A stop groove 18A is formed on the outer periphery of the collar 18 and annular seals 19 and 19 are fitted vertically, and the seals 19 and 19 communicate the air vent hole 3A with the upper first oil chamber A. Is shut off.

The operation of enclosing the working oil and gas in the above-mentioned strut device is performed as follows.

The partition member 30 and the free piston 37 are assembled and fixed to the cylinder 3, and the driving hole 42A of the gas charging plug 42 is temporarily sealed with a tape or the like in a pair. The hydraulic oil is filled up to the air vent hole 3A.

Next, the piston 5 and the piston rod assembly are inserted into the cylinder 3.

When the piston 5 is inserted into the cylinder 3, a part of the hydraulic oil corresponding to the volume of the second piston rod 2 in the upper portion of the cylinder 3 is pushed out from the air vent hole 3 A and the oil in the lower portion of the cylinder 3 is pushed out. Is pushed out from the hole 42A by pushing open the temporary sealing such as tape.

When the piston 5 passes through the air vent hole 3A, the second piston rod 2 is fitted into the partition wall member 30, and the seals 21 and 22 start to work, the lower portion between the piston 5 and the partition member 30 is started. The hydraulic oil sealed in the second oil chamber B loses its place of departure and is locked.

After that, the operating rod 4 is pushed to open the on-off valve 10, the passage between the two oil chambers A and B is secured, and the piston rod assembly is pushed down to the stroke end.

In this state, the filling of the lower second oil chamber is guaranteed.

Next, the stop rubber 14 and the collar 18 are mounted in the cylinder 3, and the upper end of the collar 18 is positioned below the air vent hole 3A.

Further, a stopper 17 is attached, the air vent hole 3 A is directed upward, and temporary sealing is performed with tape or the like, and the upper portion of the cylinder 3 is further filled with hydraulic oil.

When the packing 16 is further fitted and the guide 15 is pushed in and temporarily fixed, the oil of the invading volume of these members becomes together with the air slightly left in the upper second oil chamber A. The tape or the like in the air vent hole 3A that is temporarily sealed is pushed open and pushed out to the outside, and a predetermined hydraulic oil is filled.

After that, the air vent hole 3 A is held, and the piston 5 is pulled up while the on-off valve 10 is opened. This piston 5 pushes up the stop rubber 14 and the collar 18 until they hit the stopper 17.

At this time, the air vent hole 3A is located between the upper and lower seals 19 and 19 to cut off communication with the first oil chamber A.

Furthermore, a stop ball 26 is driven into the air vent hole 3A from the outside and is fitted between the stop ball 26 and the stop groove 18A of the collar 18 to achieve sealing and prevention of vertical movement of the collar 18.

The piston rod assembly, especially the second piston rod 2 is fully stroked up and down several times to push out the hydraulic oil remaining in the gas chamber C in the same manner as a water gun, and then to fill the gas through the hole 42A, The sealing plug 42 is driven in for gas sealing, and then the bracket 25 is joined by welding.

Since a part of the upper end surface of the free piston 37 is cut off from the lower oil chamber B by the partition member 30, the pressure receiving area where the pressure P1 of the lower oil chamber B acts on the free piston 37 is the disconnection of the sleeve 41. The area A is obtained by subtracting the cross-sectional area of the second piston 2 from the area, and the force F1 that the free piston 37 receives from the lower oil chamber B is F1 = A1 × P1.

Further, the pressure receiving area where the gas pressure P2 of the gas chamber C acts on the free piston 37 becomes an area A2 obtained by subtracting the cross-sectional area of the second piston rod 2 from the inner diameter of the cylinder 3, and the free piston 37 moves to the gas chamber C. The force F2 received from is F2 = A2 × P2.

When the oil temperature rises, the oil expands, the pressure P1 in the lower oil chamber B rises, and when the force F1 received from the lower oil chamber B becomes larger than F2, the free piston 37 descends.

Similarly, due to a sudden shock or the like, a pressing force is generated from the reclining seat to exert a downward force on the piston 5, and when F1 becomes larger than F2, the free piston 37 descends.

When the free piston 37 moves slightly downward in FIG. 1, the free piston 37 is balanced at a position satisfying F1 = F2.

From the above equation, A1 × P1 = A2 × P2 and P1 = (A2 ÷ A1) × P2, and the pressure P1 in the lower oil chamber B is not increased as long as the ratio of the upper and lower pressure receiving areas A1 and A2 of the free piston Since the free piston 37 does not move downward, it can be used even for a strut device that receives a large pressing force such as a reclining seat for an aircraft without changing the gas pressure or the cylinder diameter as long as it is below the withstand pressure limit of the cylinder 3. become.

A space E may be provided between the lower surface of the partition member 30 and the upper surface of the piston portion of the free piston 37. In this case, negative pressure is generated when the free piston 37 descends, but it is an independent space. It does not affect the seat lock function.

If a small hole 3 B is provided in the cylinder 3 at a position corresponding to this space E, it is possible to crimp the partition member 30 into the cylinder 3 and then insert only the free piston 37 independently from below the cylinder 3. I can.

That is, like the other embodiment shown in FIG. 3, the free piston 37 is inserted from below before welding the lower cap to the cylinder 3, and positioning and mounting can be performed while pushing up with the jig J.

Even when the free piston 37 is assembled and attached to the partition wall member 30, the free piston 37 can be suppressed by the jig J.

FIG. 4 shows another embodiment of the present invention.

In this, a skirt 30a is vertically provided under the partition member 30, and a piston portion of a free piston 37 is vertically slidably inserted into the skirt 30a so that the free piston 37 and the partition member 30 have the same concentricity. Is improved.

Other structures, actions and effects are the same as those of the embodiment shown in FIG.

FIG. 5 shows another embodiment of the present invention.

This is one in which the free piston 37a is vertically movably fitted in the lower skirt 30a of the partition member 30 via an elastic member 30b such as rubber.

The free piston 37a may be coupled to the skirt 30a of the partition member 30 via the elastic member 30b, or may be simply fitted movably.

In the case of this integral connection, the jig J is unnecessary, and the jig J can be sufficiently used for a column device with a small amount of hydraulic oil and a small expansion / contraction amount.

[0071]

[Effect of the device]

 According to the present invention, since the free piston having the smaller upper pressure receiving surface and the larger lower pressure receiving surface is fitted to the guide, the pressure in the lower oil chamber is equal to the ratio of each pressure receiving surface of the free piston. The free piston does not descend unless it becomes higher than the gas pressure in the gas chamber. For this reason, the locking force can be increased without increasing the gas pressure or the cylinder diameter, and it can also be used for aircraft reclining seats that receive a sudden and large pressing force.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a column device according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of FIG.

FIG. 3 is a partially longitudinal front view of a strut apparatus according to another embodiment when a free piston is attached.

FIG. 4 is a vertical cross-sectional front view of a column device according to another embodiment.

FIG. 5 is a partially longitudinal front view of a column device according to another embodiment.

FIG. 6 is a vertical sectional front view of a conventional strut device.

[Explanation of symbols]

 1, 2 Piston rod 3 Cylinder 5 Piston 10 Open / close valve 19b, 19b, 19c Passage 30 Partition wall member 37, 37a serving as a guide Free piston A. B oil chamber

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[Procedure amendment]

[Submission date] November 25, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

[Title of device] Support device

[Scope of utility model registration request]

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view of a column device according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of FIG.

FIG. 3 is a partially longitudinal front view of a strut apparatus according to another embodiment when a free piston is attached.

FIG. 4 is a vertical cross-sectional front view of a column device according to another embodiment.

FIG. 5 is a partially longitudinal front view of a column device according to another embodiment.

FIG. 6 is a vertical sectional front view of a conventional strut device.

[Explanation of Codes] 1, 2 Piston rod 3 Cylinder 5 Piston 10 Open / close valve 19b, 19b, 19c Passage 30 Partition wall member 37, 37a Free piston A. B oil chamber

Claims (1)

[Scope of utility model registration request] 1. A piston rod is movably inserted into a cylinder via a piston, the piston defines two upper and lower oil chambers in the cylinder, and a gas chamber defined by a guide is formed below the lower oil chamber. A piston rod that is provided and penetrates the guide is always urged in the extending direction by gas pressure, and two upper and lower oil chambers are opened and closed by a passage provided in the piston rod and an opening / closing valve provided in this passage. A free-standing piston having a small pressure receiving surface facing the lower oil chamber side and a large pressure receiving surface facing the gas chamber side is slidably fitted to the guide.