JPH08205952A - Backrest angle adjustment device - Google Patents

Abstract

PURPOSE: To easily operate a backrest only by applying a force without operating a control lever when the erecting and tilting operation of the backrest of a seat are performed between a desirable angle position when it is erected to the highest position and the highest erected position. CONSTITUTION: In this backrest angle adjusting device A for seat of cylinder type, a slide pin 15 provided with a head part 18 of thick diameter is inserted by fitting in a free piston 4 freely slidably, and a spring receiver 19 is disposed at the tip side of the slide pin 15, and a spring 20 with spring force overcoming the closing power of an opening/closing valve 8 on a piston 3 side is interposed between the free piston 4. The opening/closing valve 8 is connected to the slide pin 15 with rigging 24a which applies a compression force to the spring 20 by making stretch fully when the piston 3 and the free piston 4 reach a set interval according to the erecting operation of the backrest B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reclinable seat that can be turned around (swinging type) used in Shinkansen, conventional limited express railway vehicles and recreational automobiles, and how to use it. The present invention relates to a cylinder-type backrest angle adjusting device suitable for adjusting an angle of a backrest in a seat (seat) in reclining seats arranged in a plurality of rows regardless of each other.

[0002]

2. Description of the Related Art As shown in FIG. 7, a cylinder type backrest angle adjusting device that has been generally used in the past inserts a piston 3 bearing a piston rod 2 into a cylinder 1 so that the piston 3 can slide freely. The two working chambers R on the rod side and the head side where the inside of the cylinder 1 is filled with hydraulic oil at 3
It is divided into H.

The inside of the working chamber H located on the head side is further divided into two chambers by the free piston 4, thereby defining a gas chamber G in the portion opposite to the piston 3.

The piston 3 is provided with an oil passage 6 having an orifice 5 for communicating the two working chambers R and H on the rod side and the head side, and the outlet portion of this oil passage 6 on the working chamber H side. An opening / closing valve 8 is provided by slidably inserting the tip of the guide rod 7 into the piston 3.

This on-off valve 8 is provided with the guide rod 7 and the difference between the pressure receiving areas on both sides and the hydraulic oil pressures in the working chambers R and H based on the gas pressure in the gas chamber G synergistically actuate the oil passage 6 side. Is pressed to close the oil passage 6 in a normal state.

In order to open / close the open / close valve 8 from the outside, an operation rod 9 is slidably inserted through the axial center portion of the piston rod 2, and the external protruding end of the operation rod 9 is operated. By pushing with the lever 10, the opening / closing valve 8 can be pushed open by overcoming the closing force by the internal hydraulic pressure.

Inside the rod-side working chamber R, a stopper 12 is provided whose position is regulated by roll crimping 11 provided on the cylinder 1, and the most extended position of the piston 3 is limited by the stopper 12. Ensures a minimum fitting length between the cylinder 1 and the piston 3.

As shown in FIG. 8, the seat backrest angle adjusting device constructed as described above is attached to the base end of the cylinder 1 and the external projecting end of the piston rod 2, respectively. Is used to interpose between the seat S and the backrest B.

Thus, when the backrest B is tilted down, the operation lever 10 of the backrest angle adjusting device is operated while pushing the backrest B with the back while seated on the seat S.

As a result, the opening / closing valve 8 in the piston 3 is pushed through the operating rod 9 to overcome the closing force due to the hydraulic oil pressure, and is opened, whereby the rod-side and head-side operating chambers R and H are opened.
Communicate with each other through the oil passage 6 of the piston 3.

Therefore, the cylinder 1 of the backrest angle adjusting device, which is pushed in the contraction direction through the backrest B, pushes the hydraulic oil in the working chamber H into the working chamber R from the oil passage 6 under the regulation of the orifice 5. While moving in the contraction direction, the backrest B falls down at a predetermined speed while contracting the backrest angle adjusting device.

At the same time, the free piston 4 is slower than the contraction speed of the cylinder 1 according to the difference in sectional area between the piston rod 2 and the piston 3 in the gas chamber G.
It operates in the contracting direction while compressing the gas inside, thus,
Backrest B falls backwards.

If the operation lever 10 is released when the backrest B is tilted to a desired angle, the opening / closing valve 8 automatically closes the oil passage 6 of the piston 3 due to the pressure-receiving area difference between the two surfaces. The leaning angle adjusting device returns to the original locked state, and the backrest B is held at the desired angle and stopped.

On the other hand, when raising the backrest B toward the front, the operating lever 10 is operated while the back is separated from the backrest B, and the open / close valve 8 is passed through the operating rod 9.
I'll open it.

Then, this time, the cylinder 1 causes the synergistic action of the difference in sectional area between the working chambers R and H due to the existence of the piston rod 2 and the hydraulic oil pressure in the working chambers R and H based on the gas pressure in the gas chamber G. Then, the hydraulic oil in the working chamber R is pushed in the working chamber H from the oil passage 6 under the restriction of the orifice 5 and operates in the extending direction.

In addition to the above, the free piston 4
However, for the extension speed of the cylinder 1, the piston rod 2
And the piston 3 is pushed by the gas pressure in the gas chamber G at a slower speed according to the difference in cross-sectional area of the piston 3 and moves toward the extension side.

As a result, the backrest angle adjusting device is pushed by the gas pressure in the gas chamber G and automatically operates in the extension direction to raise the backrest B forward.

Moreover, even in this case, if the backrest B is raised to a desired angle and the operation lever 10 is released and the opening / closing valve 8 is closed, the desired angle is maintained. Leaning B will stop.

[0019]

Thus, when the above-mentioned backrest angle adjusting device is used for a swivel type reclining seat or a reclining seat arranged side by side in a plurality of rows, the following inconvenience occurs.

That is, in the revolving type reclining seat, the backrest B is raised from the preferable angular position X at the time of the most upright position in FIG. In this state, the sheet S is generally rotated in the horizontal direction to change the direction.

Further, even when the reclining seats are arranged in a plurality of rows regardless of the presence or absence of the swivel type as described above, the backrest B is desired to be in the most preferable angular position X when standing upright.
It is desired to raise the width from the above to the standing end position Z to increase the width of the passage to the rear seat, thereby facilitating the cleaning of the inter-seat passage.

For this reason, in these swivel type and multi-row type reclining seats, the operating angle of the backrest B must be necessarily larger than that of a normal reclining seat.

As a result, if the conventional cylinder-type backrest angle adjusting device described above is used for such a swivel type or multiple-row type reclining seat, the backrest B is set to the most preferable angular position X at the most upright position. In order to operate over the upright position Z, it is necessary to manually operate the operating lever 10 for each operation.

As a result, there is a problem in that it takes too much time to raise and tilt the backrest B beyond the preferable angular position X at the most upright position, and the efficiency of the turning operation and the cleaning work cannot be improved.

Accordingly, an object of the present invention is to prevent the backrest of the seat from leaning back and forth without operating the operating lever when the seatback is raised and tilted between the most preferable position when the seat is raised and the most raised position. It is to provide a cylinder type backrest angle adjusting device which can be easily operated by applying a force.

[0026]

SUMMARY OF THE INVENTION In the present invention, the above-mentioned object is to provide a piston-side opening / closing valve for connecting / disconnecting communication between the free piston and the rod-side and head-side working chambers in a cylinder type seat back angle adjusting device. And a compression spring member having a spring force of a magnitude that resists the closing force of the on-off valve, and a compression spring member that is fully extended when the free piston and the piston reach a set interval in accordance with the backrest rising operation. It is achieved by connecting the elastic member through a connecting mechanism composed of an elastic member that applies a compressive force.

Further, the free piston and the on-off valve have a spring characteristic in which the compressive force that tries to return to the original position when the piston and the free piston reach a set interval due to the upright operation of the backrest overcomes the closing force of the on-off valve. It can also be achieved by connecting them with tension springs having

[0028]

That is, in the cylinder type seat back angle adjusting device, the free piston moves in the same direction at a slower speed than the cylinder due to the movement of the piston rod into and out of the cylinder due to the expansion and contraction operation, and at the time of extension. If so, the distance between the piston and the free piston increases, and conversely decreases when contracting.

Utilizing this point, the former means allows the elastic member to be in a stretched state at the time when the backrest reaches the preferable angular position when the backrest is raised, and the latter means,
Set so that the spring force of the tension spring is equal to the closing force of the on-off valve.

Accordingly, the expansion / contraction member or the tension spring does not pull and open the on-off valve provided on the piston until the backrest reaches the preferable angular position when the backrest is in the most upright position.

Therefore, in the normal backrest angle adjusting range, the opening / closing valve is opened / closed by the operation lever as in the conventional backrest angle adjusting device, thereby restricting the tilting and standing speed by the orifice. The backrest angle is adjusted.

On the other hand, if the backrest is raised forward as much as possible beyond the preferred angular position when standing upright, in the former means, the expandable member is fully extended and a compressive force is applied to the compression spring member. The expansion / contraction member pulls the open / close valve automatically by the extension force of the compression spring member to return to its original position regardless of the operating lever.

In the latter means, the spring force of the tension spring overcomes the closing force of the on-off valve and pulls, and the on-off valve is pulled and automatically opened regardless of the operating lever.

As a result, even if the opening operation of the on-off valve by the operation lever is released, the backrest angle adjusting device automatically extends to raise the backrest to the standing end position, and the seat turning lock is released. Extend the width of the passage between the seat and the seat behind.

When returning the backrest from this state,
The open / close valve is kept open by the spring force of the compression spring member or the tension spring until the backrest reaches a preferable angular position when the backrest is upright.

Therefore, the backrest can be returned to the preferable angular position at the time of the most standing up while the backrest angle adjusting device is contracted by simply applying a force in the tilting direction to the backrest, and at this time, opening and closing. The valve will be closed and the backrest will stop automatically.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to FIGS. 1 and 2, but the other structures and usages except for the piston and the free piston are the cylinders of the conventional example described above. Since there is no difference from a backrest angle adjusting device of a type, here, only different parts will be mainly illustrated and described.

Referring to FIG. 1, the free piston 4 of the seat type backrest angle adjusting device A of the cylinder type according to this embodiment is provided with a slide pin 15 penetrating the central portion and slidably inserted in the axial direction. .

A seal 16 is interposed between the free piston 4 and the slide pin 15, and the seal 16 is interposed between the cylinder 1 and the free piston 4.
In cooperation with the above, the gas chamber G in the cylinder 1 is kept airtight with respect to the working chamber H on the head side.

The end portion of the slide pin 15 on the working chamber H side engages with the free piston 4 to prevent further movement of the slide pin 15 toward the gas chamber G side. Is configured as.

A spring receiver 19 is provided at the tip of the slide pin 15 on the gas chamber G side so as to face the free piston 4, and a compression spring member is provided between the spring receiver 19 and the free piston 4. Spring 2
0 is inserted.

As a result, normally, the slide pin 15
Is urged toward the gas chamber G by the spring force of the spring 20 with respect to the free piston 4, and the head portion 18 is held at the predetermined position locked by the free piston 4.

On the other hand, at the end of the piston 3 on the working chamber H side, the base of the opening / closing valve 8 on the piston 3 side that connects and disconnects the oil passage 6 that connects the rod-side and head-side working chambers R and H through the orifice 5. A stopper 21 is provided so as to face the end.

The stopper 21 not only serves to regulate the movement of the opening / closing valve 8 at a fixed position when the opening / closing valve 8 is opened, but also an oil hole for ensuring the flow of the working oil flowing through the orifice 5 and the oil passage 6 at the time of the regulation. It also has 22.

In the case of this embodiment, a rod 24 which extends from the open / close valve 8 and which constitutes the elastic member 23 through the slide pin 15 on the free piston 4 side extends toward the gas chamber G.

The rod 24 extends to a position at a predetermined distance from the base end of the slide pin 15 in the gas chamber G, and an engaging element 25 capable of contacting the base end of the slide pin 15 is provided at the tip of the rod 24. .

A seal 26 is interposed between the slide pin 15 and the rod 24, and the seal 26 ensures the airtightness of the gas chamber G.

Thus, the seat backrest angle adjusting device A according to the present invention, which is constructed by changing the piston portion of the conventional cylinder type seatback angle adjusting device as described above, operates as described below. Then, the angle of the backrest B of the seat S is adjusted.

That is, in the cylinder type seat back angle adjusting device, the total volume of the rod-side and head-side working chambers R and H filled with hydraulic oil at the time of expansion and contraction is the piston rod relative to the cylinder 1. As the piston rod 2 moves forward and backward, the volume of the piston rod 2 entering and leaving changes constantly.

As a result, the free piston 4 operates in the cylinder 1 while expanding or contracting the gas chamber G in an attempt to compensate for the volume change of the working chambers R and H.

As a result, the free piston 4 operates in the same direction at a speed lower than the operating speed of the cylinder 1 according to the sectional area ratio of the cylinder 1 and the piston rod 2.

For example, if the cross-sectional area ratio between the cylinder 1 and the piston rod 2 is 2: 1, the free piston 4 moves in the same direction at a speed half that of the cylinder 1, and the piston 3 moves at the time of extension. And the distance between the free pistons 4 increases, and conversely decreases when contracting.

Taking advantage of this point, in this embodiment, when the backrest B reaches the preferable angular position X at the time of the most upright position in FIG. 8, as shown in FIG.
The rod 24, which is shown in FIG.
The length of the rod 24 is set in advance so that 5 engages with the base end of the slide pin 15 of the free piston 4.

As a result, when the angle of the backrest B is between the preferable angle position X at the most upright position and the most tilted position Z in FIG. 8, the engaging element 25 of the rod 24 causes the free piston 4 to move.
It does not engage the side slide pin 15.

Moreover, unless the opening / closing valve 8 on the piston 3 side is forcedly opened by the operating lever 10, the opening / closing valve 8 is operated by the operating chambers R, H based on the pressure difference between the pressure receiving areas on both sides and the gas pressure of the gas chamber G. It is kept closed due to the synergistic effect with the hydraulic oil pressure inside.

Therefore, when the backrest B is tilted backward within the adjustment range of the angular position X and the angle position Z of the backrest B, which is the above-mentioned normal backrest angle adjustment range, as in the conventional case. The operator sits on the seat S, operates the operation lever 10, and pushes the backrest B with his back while opening the opening / closing valve 8 through the operation rod 9.

As a result, the backrest B pushed by the back is
A force in the contracting direction is applied to the cylinder 1 of the backrest angle adjusting device A.

By this force, the cylinder 1 pushes the working oil in the working chamber H on the head side into the working chamber R on the rod side while applying flow resistance from the oil passage 6 of the piston 3 by the orifice 5, and slowly at a predetermined speed. And work in the contraction direction

At this time, the free piston 4 also operates in the same direction while compressing the pressure gas in the gas chamber G, so that the excess amount of hydraulic oil corresponding to the intrusion volume of the piston rod 2 into the cylinder 1 is released. Absorb.

As a result, the backrest angle adjusting device A contracts, and accordingly, the backrest B tilts backward.

If the operating force of the operating lever 10 is released when the backrest B is tilted to a desired angle, the opening / closing valve 8 causes the gas pressure in the gas chamber G due to the difference in pressure receiving area between the two surfaces of the cylinder 1. It is automatically closed by the hydraulic pressure inside.

As a result, the backrest angle adjusting device A returns to the locked state, and the backrest B stops at the desired tilt angle.

On the other hand, when raising the backrest B toward the front, the operation lever 1 is moved with the back away from the backrest B.
Operate 0 to open the open / close valve 8.

Then, this time, the cylinder 1 is pushed by the gas pressure in the gas chamber G and the hydraulic oil in the rod-side working chamber R is added from the oil passage 6 of the piston 3 by the orifice 5 to the flow resistance to the head side. It is pushed out into the working chamber H and is slowly moved in the extension direction at a predetermined speed.

Moreover, even at this time, the free piston 4
Is pushed by the pressure gas in the gas chamber G to operate, and the cylinder 1
Compensate for a shortage of hydraulic oil in an amount corresponding to the exit volume of the piston rod 2 with respect to.

As a result, the backrest angle adjusting device A extends, and the backrest B rises forward with it.

If the operating force of the operating lever 10 is released when the backrest B has risen to a desired angle, the opening / closing valve 8 is set in the gas chamber G in the same manner as the previous tilting operation of the backrest B. It is automatically closed by the hydraulic oil pressure in the cylinder 1 caused by the gas pressure.

In this way, the backrest angle adjusting device A returns to the locked state, and the backrest B stops while maintaining its desired standing angle.

As described above, when the backrest B is within the normal backrest angle adjustment range which is adjusted within the range α from the preferable angle position X at the most upright position to the most tilted position Y in FIG.
By opening and closing the on-off valve 8 from the outside with the operation lever 10, the angle of the backrest B is adjusted while limiting the tilting and standing speeds by the orifice 5 as in the conventional backrest angle adjusting device. .

On the other hand, when the backrest B stands up to the preferable angular position X when the backrest is raised at the time of adjusting the backrest angle, as shown in FIG.
The engaging element 25 at the tip of the rod 24 extending from the abutment contacts the end surface of the slide pin 15 on the free piston 4 side.

Therefore, assuming that the backrest B is raised forward as much as possible beyond the preferable angular position X at the time of standing upright, the rod 24 passes through the engaging element 25 and the spring 20.
The slide pin 15 is pulled out from the free piston 4 while compressing, and the opening / closing valve 8 is automatically opened through the rod 24 by the extension force that tries to return the spring 20 regardless of the operation of the operation lever 10.

As a result, even if the opening operation of the opening / closing valve 8 by the operating lever 10 is released, the backrest angle is reached to the position where the cylinder 1 is locked by the piston 3 through the stopper 12 by holding the opening / closing valve 8 open by the spring 20. The adjusting device A automatically extends and raises the backrest B to the standing end position Z to release the turning lock of the seat S or widens the passage width between the seat S and the rear seat S.

Further, when the backrest B is returned from this state, the opening / closing valve 8 is extended by the extension force of the spring 20 until the backrest B reaches the preferable angular position X when the backrest B stands up.
Keeps open.

Therefore, by merely applying a force in the tilting direction to the backrest B, the backrest B returns to the preferable angular position X at the most upright position while causing the backrest angle adjusting device A to contract, and At this point, the opening / closing valve 8 is closed and the backrest B is automatically stopped.

After that, the opening / closing valve 8 is opened / closed by the operating lever 10, and the angle of the backrest B is adjusted as described above.

As described above, when the backrest B is within the normal backrest angle adjustment range which is adjusted within the range α from the preferable angle position X at the most upright position to the most tilted angle position Y in FIG. By opening and closing the open / close valve 8 with the operation lever 10, the angle of the backrest B is adjusted while limiting the tilting and standing speeds by the orifice 5 as in the conventional backrest angle adjusting device.

In addition to this, within the range θ from the preferable angular position X at the most upright position to the standing end position Z, the rod 2 is
4, the spring 20 is compressed to forcibly open the open / close valve 8, and the angular position X is set regardless of the operation of the operation lever 10.
The backrest B can be tilted or raised between the upright position Z and the upright end position Z to release the turning lock of the seat S or widen the passage width between the seat S and the rear seat S.

FIG. 3 shows another embodiment of the present invention. In the second embodiment, a cord-shaped elastic member 23 is used instead of the rod 24 in the previous embodiment of FIG. The cord 24a is used.

Then, one end of the rigging 24a is used as the opening / closing valve 8 on the piston 3 side, and the other end is used as the free piston 4
The on-off valve 8 and the slide pin 15 are connected through the cord 24a by being attached to the slide pins 15 on the side by means such as welding or brazing.

Therefore, if the length of the rigging 24a is set in advance so that the rigging 24a extends straight in a straight line when the backrest B reaches the preferable angular position X when the backrest is upright, When the lean B is within the normal backrest angle adjustment range in which the rigging 24a is adjusted within the angle range α in FIG. 8, the rigging 24a remains in a loose state, and in the angle range θ, the rigging 24a is maintained.
Is fully extended and the opening / closing valve 8 is forcibly opened by the extension force of the spring 20.

Therefore, it can be easily understood from the above first explanation that the same operation as that of the first embodiment can be performed by the second embodiment.

Moreover, according to the second embodiment, since it is not necessary to provide the rigging 24a penetrating the slide pin 15, the friction of the rod 24 is different from that of the first embodiment described above. It is possible to prevent deterioration of operability due to the above and prevention of deterioration of air tightness of the gas chamber G due to the free piston 4.

Further, in the above, as in the third embodiment shown in FIG. 4, the base end of the guide case 27 is attached to the surface of the free piston 4 facing the on-off valve 8 by means such as caulking, and this guide is attached. A compression spring member including the slide pin 15 and the spring 20 may be arranged in the case 27.

By doing so, it is not necessary to provide the slide pin 15 penetrating the free piston 4, and further, in addition to preventing the airtightness of the gas chamber G from being lowered, the operability by the friction of the slide pin 15 is also provided. Can be prevented.

Further, the open / close valve 8 in the free length state
By using the tension spring 20a having an initial spring load that overcomes the closing force of the above, the fourth embodiment shown in FIG. 5 can also be used.

That is, the tension spring 20a described above.
One end is directly fixed to the surface of the free piston 4 facing the piston 3, and the other end of the tension spring 20a is connected to the opening / closing valve 8 on the piston 3 side by using the cord 24a having a predetermined length.

Also by this, the rigging 24a remains slack within the normal backrest angle adjustment range in which the backrest B is adjusted within the angle range α in FIG. 8, and the angle range θ
Then, since the opening / closing valve 8 is forcibly opened by the compression force that the cord 24a is fully extended to return to the original position of the tension spring 20a, the backrest angle adjusting device A can be caused to perform the same operation. .

FIG. 6 shows still another embodiment of the present invention. In the fifth embodiment, the slide pin 15 and the rod which have been used in the first to fourth embodiments so far are shown. 24 and rigging 24a have been abolished.

Instead of these, when the backrest B is erected and the piston 3 and the free piston 4 reach the set distance, the compression force that tries to return to the original state is a spring that overcomes the closing force of the opening / closing valve 8. The tension spring 20b having the characteristics is used, and the free piston 4 and the opening / closing valve 8 are directly connected by the tension spring 20b.

Even with this structure, the compression force that tries to return to the original position of the tension spring 20b overcomes the closing force of the opening / closing valve 8 until the backrest B rises forward beyond the preferable angular position X at the most upright position. None, the tension spring 20b simply expands and contracts, and the on-off valve 8 is not forcibly opened.

Therefore, the backrest B is the angular range α in FIG.
Within the normal backrest angle adjustment range that is adjusted within, the operating lever 10 is the same as in the conventional backrest angle adjustment device.
The angle of the backrest B is adjusted by.

On the other hand, when the backrest B is raised forward beyond the angular position X, the compressive force that tries to return to the original position of the tension spring 20b overcomes the closing force of the opening / closing valve 8 to open the opening / closing valve 8. Forced to open.

Therefore, in the angle range θ shown in FIG. 8, the backrest angle adjusting device A extends and automatically raises the backrest B to the standing end position Z regardless of the operation of the operating lever 10. The same operation as in the first to fourth embodiments is performed.

[0094]

As described above, according to the first aspect of the present invention, when the seat backrest is moved beyond the preferable angular position at the time of standing upright, the seatback stands upright without operating the operating lever. It can be automatically raised to the standing end position only by applying a directional force.

Also, when returning the backrest from the above-mentioned standing end position, it is possible to easily return the backrest to the preferable angular position at the time of standing up by only applying a force in the tilting direction to the backrest. You can

According to the second aspect of the present invention, the free piston is provided with the compression spring member including the slide pin and the spring, and the rod is extended from the opening / closing valve on the piston side through the slide pin, and the tip of the rod is provided. The above effect can be achieved by providing an engaging element that abuts the slide pin.

According to the invention of claim 3, instead of the rod, a cord-like cord having a predetermined length is used.
It is possible to achieve the above-described effect by reducing the friction at the time of operation while achieving the airtightness of the gas chamber.

According to the invention of claim 4, it is possible to further improve the airtightness of the gas chamber and reduce the friction at the time of operation to achieve the above effect.

According to the invention of claim 5, it becomes possible to eliminate the slide pin provided on the free piston side and achieve the above effect.

Further, according to the invention of claim 6, the above effect can be achieved without using a slide pin or a cord.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an essential part showing an embodiment of a seat backrest angle adjusting device according to the present invention.

FIG. 2 is a vertical sectional front view of a main portion showing a state of the backrest angle adjusting device when the backrest is operated to a preferable angular position in the most upright position.

FIG. 3 is also a vertical sectional front view of a main part of another embodiment of the seat backrest angle adjusting device according to the present invention.

FIG. 4 is a vertical sectional front view of a main part showing a modified example of the above.

FIG. 5 is likewise a vertical cross-sectional front view of essential parts of another embodiment of the present invention.

FIG. 6 is a vertical sectional front view of a main portion showing another embodiment of the present invention.

FIG. 7 is a vertical cross-sectional front view showing a conventional backrest angle adjusting device for a seat.

FIG. 8 is a diagram showing an example of mounting a backrest angle adjusting device on a seat and an adjustment range of the backrest angle.

[Explanation of symbols]

 A Backrest angle adjustment device B Backrest G Gas chamber H Head side working chamber R Rod side working chamber S Seat 1 Cylinder 2 Piston rod 3 Piston 4 Free piston 5 Orifice 6 Oil passage 8 Open / close valve 9 Operating rod 10 Operating lever 15 slide pin 20 springs 20a, 20b tension spring 23 elastic member 24 rod 24a cordage 25 engaging element 27 guide case

Claims (6)

[Claims] 1. In a cylinder type seat back angle adjusting device, a piston-side on-off valve that connects and disconnects communication between a free piston that defines a gas chamber and a rod-side and head-side working chamber is closed. A compression spring member having a spring force of a magnitude that resists the force, and a free piston and an expansion / contraction member that applies a compressive force to the compression spring member when the free piston and the piston reach a set distance with the standing motion of the backrest. A backrest angle adjusting device characterized in that the backrest angle adjusting device is connected through a connecting mechanism consisting of. 2. The compression spring member is composed of a slide pin that is axially movable with respect to the free piston and a spring that biases the slide pin toward the gas chamber, and the expansion and contraction member is 2. The backrest angle adjusting device according to claim 1, comprising a rod extending from the on-off valve through the slide pin and an engaging element provided at the tip of the rod. 3. The compression spring member is composed of a slide pin movably arranged in the axial direction with respect to the free piston and a spring urging the slide pin toward the gas chamber side, and the expansion / contraction member is 2. The backrest angle adjusting device according to claim 1, wherein the backrest angle adjusting device comprises a cord connecting the on-off valve and the slide pin on the compression spring member side. 4. The backrest angle adjusting device according to claim 3, wherein a guide case is fixed to a surface of the free piston facing the on-off valve, and a compression spring member including a slide pin and a spring is arranged in the guide case. 5. In a cylinder type seat back angle adjusting device, one end is fixed to a surface of a free piston that defines a gas chamber and faces the piston, and a tension spring is axially arranged, and the other end of the spring is arranged. Is connected to the on-off valve on the piston side by using a rigging of a predetermined length that will be in a straight stretched state when the piston and the free piston reach the set interval with the backrest standing operation. Backrest angle adjustment device. 6. In a cylinder type seat back angle adjusting device, a backrest standing operation is performed by using a piston-side on-off valve that connects and disconnects communication between a free piston that defines a gas chamber and a rod-side and head-side working chamber. With this, the backrest angle adjustment is characterized in that the compression force that tries to return to the original position when the piston and the free piston reach the set interval overcomes the closing force of the on-off valve and is connected to each other by a tension spring with a spring characteristic. apparatus.