JP2888018B2 - Damper stay - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper stay,
In particular, the present invention relates to a damper stay used for a back door opening / closing device of a vehicle.

[0002]

2. Description of the Related Art Conventionally, a back door of an automobile is provided with a damper stay, and the back door is opened by a repulsive force of the damper stay.

As shown in FIG. 9, a damper stay 17 is provided.
The high pressure gas 174 is sealed in the zero cylinder 172, and a repulsive force is generated in the left direction of FIG. 9 (the direction of arrow K in FIG. 9) by the difference S1-S2 in the pressure receiving area of the piston 176. Has become. That is, the piston 176 moves in the direction of arrow K in FIG. 9 due to the pressure of the high-pressure gas 174, and the piston rod 180 is pushed out of the cylinder 172 integrally therewith. (Omitted) is opened.

[0004]

However, in this damper stay 170, the high pressure gas chamber 177 and the high pressure gas chamber 17
The high-pressure gas 174 is sealed in these high-pressure gas chambers 177 and 178 each having a fixed volume V. Therefore, when the temperature of the high-pressure gas 174 increases, the gas pressure of the high-pressure gas 174 increases according to Boyle's law, and the repulsive force of the damper stay 170 increases. For this reason, when the temperature is high in summer or the like, a large force is required to push the piston rod 180 and contract the damper stay 170, and it becomes difficult to close the back door.

On the other hand, when the temperature is low in winter or the like, the temperature of the high-pressure gas 174 decreases and the gas pressure in the high-pressure gas chamber 178 decreases, so that the repulsive force of the damper stay 170 decreases. Therefore, if the repulsive force of the damper stay 170 becomes too weak, it becomes difficult to hold the back door in an open state.

The present invention has been made in view of the above circumstances, and has as its object to obtain a damper stay that has a small change in repulsion force for pushing a piston rod due to a temperature change.

[0007]

According to the present invention, there is provided a cylinder filled with a high-pressure gas, a piston which divides the inside of the cylinder into two high-pressure gas chambers and slides inside the cylinder, A piston rod connected to the piston, and an orifice provided in the piston for communicating the two high-pressure gas chambers, and a valve provided on the piston movably in a direction to open and close the orifice. A pressure that reduces the volume when the valve body provided in the piston moves in a direction to open the orifice and the valve body moves in a direction to close the orifice. Chamber, which is sealed in the pressure chamber and expands and contracts depending on the outside air temperature,
A gas body for moving the valve body in the opening direction of the orifice during expansion and moving the valve body in the closing direction of the orifice when contracted.

[0008]

According to the damper stay of the present invention described in claim 1,
When pulling out the piston rod, the valve element moves due to the pressure difference between the two high-pressure gas chambers in the cylinder, and the orifice is opened. Therefore, the high-pressure gas can move between the two high-pressure gas chambers. On the other hand, when the piston rod is pushed in, the valve element moves due to the pressure difference between the two high-pressure gas chambers and tends to move in a direction to close the orifice.

In this case, when the temperature rises and the gas body sealed in the pressure chamber expands and the gas pressure exceeds a predetermined value,
Even when pushing the piston rod, depending on the gas pressure,
The valve moves in the orifice opening direction, and the orifice is opened. This allows the high pressure gas to move between the two high pressure gas chambers and does not require a large force to push the piston rod. For example, when this damper stay is used for a back door, a large force is not required to contract the damper stay even at a high temperature such as in summer, and the back door is easily closed.

On the other hand, when the temperature drops and the gas filled in the pressure chamber contracts, the valve moves in the orifice closing direction, and the orifice is closed. This makes it impossible for the high-pressure gas to move between the two high-pressure gas chambers, and the movement of the high-pressure gas does not reduce the repulsive force for pushing the piston rod.

For this reason, for example, when this damper stay is used for a back door, the back door can be reliably held in an open state even at a low temperature such as winter.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a damper stay according to the present invention will be described with reference to FIGS.

As shown in FIG. 4, a back door 5 of the vehicle is provided.
6 is a roof part 5 of the body 54 by a pair of hinges 57.
Attached to the rear end of the rear door 4A is a mounting portion 10A provided at one end of the damper stay 10 near both ends of the back door 56 in the vehicle width direction. A mounting portion 10 </ b> B provided at the other end of the damper stay 10 is mounted on an opening edge of the body 54.

As shown in FIG. 3, the damper stay 10
Cylinder 12 is cylindrical, and contains a high-pressure gas 14
Is enclosed. Inside the cylinder 12, a piston rod 20 is inserted.
A piston 18 is slidably fitted to the cylinder 12 at the end of the cylinder.

The piston rod 20 is moved from one end 12A of the cylinder 12 to the left in FIG.
(In the direction of arrow A). Sealing portions 30, 32, 34, 3 are provided between the cylinder 12 and the piston rod 20 to prevent the high-pressure gas 14 from leaking outside.
6 are provided. The other end 12B of the cylinder 12 is provided with a spring 38 for reducing the impact when the piston rod 20 is pushed into the cylinder 12.

The wire 42 is connected to the other end 12 B of the cylinder 12.
The end of the wire 42 is fixed to the innermost portion 46 of the hollow portion 44 provided at the center of the cross section of the piston 18 and the piston rod 20.

Since it is necessary to seal the high-pressure gas 14 sealed in the cylinder 12 so as not to leak, the wire 42 is inserted into the damper stay via a cylindrical wire guide 48. This wire guide 48
Inside is open to the atmosphere, and outside is
And is slidable with the seal portion 50 provided in the first portion.

That is, the wire guide 48 is fixed inside the other end portion 12B of the cylinder 12 in a state sealed by the seal portion 52, fitted into the cavity portion 44 with a margin, and has a seal portion between the wire portion 48 and the cavity portion 44. Sealed at 50. Therefore, the space from the inside of the wire guide 48 to the seal portion 50 of the hollow portion 44 is the air space, and the wire 42 exists only in the air space.

The interior of the cylinder 12 is divided by a piston 18 into a high-pressure gas chamber 22 on the end 12A side and a high-pressure gas chamber 24 on the other end 12B side.

As shown in FIG. 1, inside the piston 18, a ring-shaped cavity 21 extending in the axial direction of the piston 18 (the left-right direction in FIG. 1) is formed.
1 is communicated with the high-pressure gas chamber 24 by a through hole 19 formed in the center of the wall 18A of the piston 18. The cylinder 21 includes the hollow 21 and the high-pressure gas chamber 22.
An orifice 26 is formed to communicate the two.

In the cavity 21, a small piston 27 as a valve is provided so as to be movable in the direction of the orifice 26 (direction of arrow A in FIG. 1) and in the direction of the wall 18A (direction of arrow B in FIG. 1). . A gap 28 through which the high-pressure gas 14 can move is formed between the outer periphery of the small piston 27 and the cavity 21, and a seal rubber 29 is bonded to a portion of the small piston 27 facing the orifice 26. ing. Therefore,
When the seal rubber 29 is in contact with the orifice 26 (the state shown in FIG. 1), the orifice 26 is closed, and the high-pressure gas chamber 22 and the high-pressure gas chamber 24 are shut off. On the other hand, when the seal rubber 29 is separated from the orifice 26 (the state shown in FIG. 2), the orifice 26 is open, and the high-pressure gas chamber 22 and the high-pressure gas chamber 24 are communicated.

On the high-pressure gas chamber 22 side of the cavity 21, a ring-shaped small-diameter portion 21A is formed.
The ring-shaped small diameter portion 2 protruding from the small piston 27
7A is inserted. Small diameter part 27A of small piston 27
Is in an airtight state with the inner periphery of the small-diameter portion 21A of the cavity 21, and the end of the small-diameter portion 21A of the cavity 21 on the side of the high-pressure gas chamber 22 is a pressure at which the volume changes due to the movement of the small piston 27. A room 31 is provided.

A gas body 33 is sealed in the pressure chamber 31. When the gas chamber 33 is expanded, the small piston 27 is connected to the orifice 26.
The small piston 27 is moved in the opening direction (arrow B direction) and the small piston 27 is moved in the closing direction of the orifice 26 (arrow A direction) during contraction. Also, piston 1
8, a coil spring 35 is inserted between the small piston 27 and the wall portion 18A.
Is set to balance with the gas pressure P of the pressure chamber 31 at a predetermined temperature T (for example, 0 ° C.).

As shown in FIG. 5, a wire 42 having one end fixed to the piston rod 20 passes through a wire guide tube 43 extending to the lower back 64 along the roof side inner 58, the suspension tower 60, and the floor 62. Further, it is connected to a wire driving device 66 provided in the lower bag 64.

As shown in FIG. 6, the wire driving device 66
A motor 68 fixed to a bracket 69 fixed to a lower bag 64 by screws 67;
A pulley 74 is fixed to a drive shaft 72A of a drive gear 72 which is a final deceleration output section of the gear group 70. The other end of the wire 42 is fixed to the outer periphery of the pulley 74, and the left and right wires 42 extending from the damper stays 10 (see FIG. 4) provided on the left and right of the body 54 are simultaneously wound. You can take it and send it out. The end 43A of the wire guide tube 43 is fixed to wire guide tube support brackets 73 and 75 welded to the bracket 69.

Therefore, when the pulley 74 is rotated in the counterclockwise direction of FIG. 6 (the direction of arrow C in FIG. 6), the left and right wires 42 can be simultaneously sent out, whereby the piston rod 20 is pushed out of the cylinder 12. Then, the back door 56 is opened. Conversely, when the pulley 74 is rotated in the clockwise direction in FIG. 6 (the direction of arrow D in FIG. 6), the left and right wires 42 can be wound simultaneously, whereby the piston rod 20
And the back door 56 is closed.

Next, the operation of this embodiment will be described. In this embodiment, when opening the back door 56, the occupant presses, for example, a back door open switch provided in the vehicle interior. As a result, the motor 68 operates and the pulley 74 rotates in the direction of arrow C in FIG.
Send out. When the wire 42 is sent out, the back door 56 starts the opening operation due to the repulsive force of the damper stay 10 and enters the open state.

In the damper stay 10 of the present embodiment, the force F of the coil spring 35 inserted between the wall 18A of the piston 18 and the small piston 27 increases the pressure F at a set temperature T (for example, 0 ° C.). It is set so as to balance with the gas pressure P of the chamber 31. For this reason, when the temperature T is lower than 0 ° C., the gas pressure P in the pressure chamber 31 is determined by Boyle's law.
Is smaller than the force F of the coil spring 35, the piston 18 moves in the direction of arrow A in FIG. Due to this movement, the gas pressure P in the pressure chamber 31 increases, so that the piston 1
8 stands still when the gas pressure P + ΔP in the pressure chamber 31 and the force F of the coil spring 35 are balanced. Here, when the seal rubber 29 adhered to the piston 18 closes the orifice 26 by this movement, the high-pressure gas chamber 22 and the high-pressure gas chamber 24 are shut off.

If the blockage of the orifice 26 occurs when the damper stay 10 is fully extended, the damper stay 10
Is reduced, the pressure in the high-pressure gas chamber 24 increases and the pressure in the high-pressure gas chamber 22 decreases according to Boyle's law. Therefore, the small piston 27 further moves in the direction of arrow A in FIG. 1, so that the sealing rubber 29 continues to close the orifice 26, and this closing increases the repulsive force of the damper stay, thereby causing the damper stay 10 to contract. Is more difficult to contract than when there is no obstruction.

Therefore, even at a low temperature such as winter, the back door 56 can be reliably held in the open state.

Next, when the orifice 26 is closed when the damper stay 10 is fully retracted, the damper stay 1
When the damper stay 10 is extended from the minimum contraction state of 0, that is, when the piston 18 is moved in the direction of arrow A in FIG. 3, the pressure in the high-pressure gas chamber 22 increases, and the pressure in the high-pressure gas chamber 24 decreases. As a result, a force W is generated to move the small piston 27 in the direction of arrow B in FIG.
Is generated by the sum (P + ΔP) of the gas pressure P of the pressure chamber 31 and the pressure difference ΔP between the high-pressure gas chamber 22 and the high-pressure gas chamber 24. When this force W overcomes the force F of the coil spring 35, the small piston 27 moves in the direction of arrow B in FIG. 1, and the orifice 26 is opened.

When the orifice 26 is opened, the high-pressure gas chamber 22 and the high-pressure gas chamber 24 have the same pressure, and the small piston 27 moves in the direction of arrow A in FIG.
Is closed. Further, when the damper stay 10 is extended, the pressure in the high-pressure gas chamber 22 becomes higher than the pressure in the high-pressure gas chamber 24, the small piston 27 moves in the direction of arrow B in FIG. 1, and the orifice 26 is opened.

As described above, the orifice 26 is repeatedly closed and opened, and the damper stay 10 is fully extended. At this time, the pressure of the high-pressure gas chamber 22 and the high-pressure gas chamber 2
The pressure of No. 4 is substantially equal.

When the damper stay 10 is contracted while the damper stay 10 is between the most extended state and the most contracted state, the pressure of the high-pressure gas chamber 24 increases according to Boyle's law, and The pressure at 22 drops. Accordingly, since the small piston 27 tends to move in the direction of arrow A in FIG. 1, the closing of the orifice 26 by the sealing rubber 29 is continued, and the closing force increases the repulsive force of the damper stay, and the contraction of the damper stay 10 is closed. It becomes harder to shrink than when there is no. After that, damper stay 1
When 0 is extended, the closing and opening of the orifice 26 are repeated, and the damper stay 10 is extended.

As described above, the damper stay 1 of this embodiment is
In the case of 0, when the temperature falls below the set temperature T, the repulsive force of the damper stay 10 increases, and it is possible to prevent the repulsive force of the damper stay 10 from decreasing even at a low temperature such as winter.

As a result, as shown in FIG. 7, in the damper stay having the conventional structure, the repulsive force characteristic H at a high temperature such as in the summertime is obtained.
1 and the difference between the repulsion force characteristics H2 at low temperatures in winter and the like become large, whereas the damper stay 10 of this embodiment sets the gas pressure P of the pressure chamber 31 and the force F of the coil spring 35. As a result, the resilience characteristics at a low temperature in winter or the like become higher than the resilience characteristics H2 of the damper stay having the conventional structure, as indicated by H3 or H4 in FIG. As a result, the difference from the repulsion force characteristic H1 at a high temperature such as in the summer is reduced.

Accordingly, it is not necessary to set the repulsion at high temperatures in summer or the like more than necessary in consideration of the decrease in resilience at low temperatures in winter or the like. The repulsive force H1 of the damper stay can be set lower. As a result, the difference between the back door opening / closing force in summer and winter can be reduced.

When the temperature is high in summer or the like, the temperature of the gas body 33 in the pressure chamber 31 increases, and the gas pressure P increases. When the force S due to the gas pressure P overcomes the force F of the coil spring 35, the small piston 27 moves in the direction of arrow B in FIG. 1, the orifice 26 is opened, and the repulsive force when the damper stay contracts decreases. As a result, the difference in force required to shrink the damper stay 10 due to the temperature difference is reduced, so that the force for pulling the wire 42 can be reduced,
The motor 68 can be made smaller and smaller, and the cost can be reduced.

The pressure chamber 31 contains R ₁₁ CCl ₃ F
(Boiling point is 297.0K in absolute temperature) or R ₁₂ CCl
_When a refrigerant vapor such as ₂ F ₂ (boiling point is 243.5K in absolute temperature) is introduced, the pressure rise in the pressure chamber 31 due to the temperature rise exceeds the pressure rise in the high pressure gas chamber 24, The above operation is performed more smoothly.

In the above embodiment, the damper stay 10 in which the wire 42 is inserted has been described.
The damper stay is not limited to this, and as shown in FIG.
The same configuration can be applied to 0.

In the above embodiment, the opening and closing of the orifice 26 is performed by a mechanism using the small piston 27. However, the opening and closing mechanism of the orifice 26 is not limited to this, and the valve body is formed of a shape memory alloy. Alternatively, the valve body having a shape that closes the orifice 26 at a low temperature in winter or the like may have a shape that opens the orifice 26 at a high temperature in summer or the like.

[0042]

The damper stay according to the present invention has an orifice formed in the piston so as to communicate with two high-pressure gas chambers defined by the piston, and a valve provided in the piston so as to be movable in the direction of opening and closing the orifice. A pressure chamber provided in the piston such that the volume increases when the valve element moves in a direction to open the orifice, and the volume decreases when the valve element moves in a direction to close the orifice. , Which expands and recovers depending on the outside air temperature
Contraction, and a body of gas which moves the orifice closing direction the valve element the valve element upon contraction is moved into the orifice opening direction when inflated, since a configuration with a change in repulsive force to push the piston rod due to temperature change It has an excellent effect of being small.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a half of a piston portion of a damper stay according to an embodiment of the present invention in an orifice closed state.

FIG. 2 is an enlarged sectional view showing a half of a piston portion of the damper stay according to the embodiment of the present invention in an orifice opened state.

FIG. 3 is a sectional view showing a damper stay according to one embodiment of the present invention.

FIG. 4 is a perspective view showing a back door of the vehicle to which the damper stay of one embodiment of the present invention is applied, as viewed from the rear of the vehicle body.

FIG. 5 is a perspective view showing the rear portion of the vehicle to which the damper stay according to the embodiment of the present invention is applied, as viewed from the front inside of the vehicle body.

FIG. 6 is a schematic explanatory view showing a back door opening / closing device of a vehicle to which a damper stay according to an embodiment of the present invention is applied.

FIG. 7 is a graph showing a relationship between a damper stroke and a damper stay repulsion.

FIG. 8 is an enlarged sectional view showing a piston portion of a damper stay according to another embodiment of the present invention.

FIG. 9 is a schematic sectional view showing a conventional damper stay.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Damper stay 12 Cylinder 14 High pressure gas 18 Piston 20 Piston rod 22 High pressure gas chamber 24 High pressure gas chamber 26 Orifice 27 Small piston (valve element) 29 Seal rubber 31 Pressure chamber 33 Gas body

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Matsumoto 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References Japanese Utility Model No. 3-75327 (JP, U) (58) Fields surveyed (Int.Cl. ⁶ , DB name) B62D 25/12 B60J 5/10 F16F 9/00 F16F 9/52

Claims (1)

(57) [Claims] 1. A damper stay having a cylinder filled with high-pressure gas, a piston which divides the inside of the cylinder into two high-pressure gas chambers and slides in the cylinder, and a piston rod connected to the piston. An orifice provided in the piston for communicating the two high-pressure gas chambers; a valve body provided in the piston so as to be movable in a direction to open and close the orifice; A pressure chamber whose volume increases when moving in the direction of opening the orifice and whose volume decreases when the valve moves in the direction of closing the orifice; and a pressure chamber which is sealed in the pressure chamber and expanded by the outside air temperature. And shrinkage
Damper stay, and is characterized in that and a body of gas for moving the valve body to the orifice closing direction during contraction is moved into the orifice opening direction of the valve body when inflated.