JP2013166470A - Damper stay structure - Google Patents

Abstract

Disclosed is a damper stage that can be reduced in size in a pressure gas-filled damper stage.
A cylinder 26 is movable along the axial direction of the cylinder 24. For this reason, when the pressure in the gas chamber 36 increases in summer or the like, the cylinder 26 moves in the direction of the arrow A along the axial direction of the outer cylinder 18 against the urging force of the coil spring 28, and the volume in the gas chamber 36. Increases and decreases pressure. Further, when the pressure in the gas chamber 36 becomes low in winter or the like, the cylinder 26 moves in the direction opposite to the arrow A along the axial direction of the outer cylinder 18 to reduce the volume in the gas chamber 36 and increase the pressure. That is, in accordance with the gas pressure in the gas chamber 36, the cylinder 26 moves along the axial direction of the cylinder 24 to a position that balances the urging load of the coil spring 28. Thereby, the volume of the gas chamber 36 increases / decreases, the amount of change in the gas pressure due to temperature in the gas chamber 36 can be reduced, and the size can be reduced as compared with the conventional damper stage.
[Selection] Figure 3

Description

  The present invention relates to a damper stay structure used for a vehicle back door.

  For example, in the invention described in Patent Document 1, an inner cylinder is provided in an outer cylinder (cylinder), and a spring (coil spring) is disposed between the inner cylinder and the outer cylinder. ing. The piston is slidable by the spring, and the pressure in the cylinder is adjusted. In addition, Patent Documents 2 to 6 disclose a damper stay structure.

Japanese Utility Model Publication No. 50-026967 Japanese Utility Model Publication No. 56-087914 JP 05-280242 A JP 05-155253 A Japanese Patent Laid-Open No. 02-102940 Japanese Utility Model Publication No. 58-187637

  However, in the invention described in Patent Document 1, since the spring is disposed between the inner cylinder and the outer cylinder, the coil average diameter and wire diameter of the spring are regulated by the inner cylinder and the outer cylinder. End up. For this reason, in order to ensure the rigidity of a spring, the outer diameter of an outer cylinder may become large. In another embodiment in the document, since a compression spring is disposed between the cylinder and the piston at the axial end of the cylinder, a stroke for the compression spring is required. For this reason, in order to ensure the stroke allowance of a compression spring, a damper stage may become long. That is, these prior arts have room for improvement from the viewpoint of reducing the size of the damper stay.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a damper stage structure that can be miniaturized in a pressure gas-filled type damper stage.

  According to a first aspect of the present invention, a damper stay structure includes an outer cylinder attached to either one of both sides of an opening provided at a rear portion of the vehicle and a back door that opens and closes the opening, and the outer cylinder. A first cylinder that is fixed and formed shorter than the outer cylinder and penetrates the inside thereof, and a first piston that reciprocally slides along the inner peripheral surface of the first cylinder along the axial direction of the first cylinder are arranged at one end. The other end of the piston rod is attached to either side of the opening and the other of the back doors, and is provided on the radially inner side of the first cylinder. A sealing member to be sealed and a gas chamber which is accommodated in the outer cylinder in a state where the first cylinder is inserted therein and in which gas is sealed between the sealing member and the shaft of the first cylinder Along the direction A second cylinder capable of reciprocating, and a coil spring provided in the outer cylinder and disposed radially outside the second cylinder to urge the second cylinder in a direction of compressing the gas in the gas chamber; ,have.

  In the damper stay structure according to the first aspect of the present invention, the outer cylinder is attached to either one of the both sides of the opening provided in the rear part of the vehicle and the back door that opens and closes the opening. The 1st cylinder and the 2nd cylinder are accommodated in. The first cylinder is formed shorter than the outer cylinder, penetrates the inside thereof, and is fixed to the outer cylinder.

  The first piston reciprocally slides on the inner peripheral surface of the first cylinder along the axial direction of the first cylinder. One end of a piston rod is fixed to the first piston, and the other end of the piston rod is attached to either side of the opening and the other of the back doors. Thereby, when the back door is opened and closed, the first piston reciprocates in the first cylinder via the piston rod.

  On the other hand, a seal member is provided on the inner side in the radial direction of the first cylinder to seal between the piston rod. The first cylinder is inserted into the second cylinder. The second cylinder constitutes a gas chamber in which gas is sealed between the first cylinder and the axial direction of the first cylinder. It can move back and forth. That is, the volume in the gas chamber can be changed by the reciprocating movement of the second cylinder.

  A coil spring is provided in the outer cylinder. The coil spring is arranged on the outer side in the radial direction of the second cylinder, and urges the second cylinder in a direction in which the gas in the gas chamber is compressed. When the temperature changes, the gas pressure (gas pressure) in the gas chamber changes, but the second cylinder moves along the axial direction of the first cylinder in accordance with the gas pressure. Then, the first cylinder stops moving at a position where the gas pressure in the gas chamber and the biasing load (biasing force) by the coil spring balance.

  With such a configuration, the volume of the gas chamber can be increased or decreased, and the amount of change in pressure due to temperature in the gas chamber can be reduced. Therefore, according to the present invention, compared with the conventional damper stay, the reaction force (stay reaction force) when the back door is fully closed particularly at a high temperature is reduced, and the operation force of the back door is reduced.

  Moreover, since the change of the gas pressure in the gas chamber due to the stroke of the first piston when the back door is opened and closed can be reduced, the peak load due to the gas pressure can be suppressed. Therefore, the length of the outer cylinder can be shortened, and the required space can be reduced.

  Moreover, since the change in the gas pressure in the gas chamber due to the stroke of the first piston can be reduced, the rod diameter of the piston rod can be increased, and the rigidity of the damper stay itself can be increased.

  The coil spring is disposed on the outer side in the radial direction of the second cylinder. For this reason, compared with the case where a coil spring is arrange | positioned in a 2nd cylinder, the coil effective diameter and wire diameter of the said coil spring can be set freely. Thereby, the freedom degree of design of a coil spring improves and the rigidity of a coil spring can be improved. In other words, the damper stay can be reduced in size while ensuring the rigidity of the coil spring. Further, when the back door is fully opened, it is possible to deal with a heavy back door, and the operating force of the back door can be reduced.

  A damper stay structure according to a second aspect of the present invention is the damper stay structure according to the first aspect, wherein the gas chamber is formed between the seal member by reciprocatingly sliding on the inner peripheral surface of the first cylinder. Two pistons are provided in the second cylinder.

  In the damper stay structure according to the second aspect of the present invention, the second piston is provided in the second cylinder, and the gas chamber is configured between the seal member by reciprocatingly sliding on the inner peripheral surface of the first cylinder. It has become. For this reason, the accuracy in the outer diameter dimension of the first cylinder and the inner diameter dimension of the second cylinder can be roughened, and productivity is increased accordingly.

  As described above, the damper stay structure according to the first aspect of the present invention has an excellent effect that it can be miniaturized in a pressure gas-filled damper stay.

  The damper stay structure according to the second aspect of the present invention has an excellent effect that the design becomes easy.

1 is a perspective view of a vehicle to which a damper stay to which a damper stay structure according to the present embodiment is applied is attached. It is a disassembled perspective view which shows the structure of the damper stay to which the damper stay structure which concerns on this Embodiment was applied. It is sectional drawing which shows the state by which the back door was fully closed in the damper stay to which the damper stay structure which concerns on this Embodiment was applied. It is sectional drawing which shows the state by which the back door was half-opened in the damper stay to which the damper stay structure which concerns on this Embodiment was applied. It is sectional drawing which shows the state by which the back door was fully opened in the damper stay to which the damper stay structure which concerns on this Embodiment was applied. 4A and 4B are cross-sectional views corresponding to FIG. 3, and FIG. It is sectional drawing corresponding to FIG. 4, (A), (B) is sectional drawing which shows the state of the damper stage by a temperature change. FIGS. 6A and 6B are cross-sectional views corresponding to FIG. 5, and FIGS.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that an arrow FR appropriately shown in the drawing indicates a forward direction in the vehicle longitudinal direction, and an arrow UP indicates an upward direction in the vehicle vertical direction.

(Structure of damper stay structure)
First, the structure of the damper stay structure according to the present embodiment will be described. Here, FIG. 1 shows a perspective view of the vehicle 12 to which the damper stay 10 to which the damper stay structure according to the present embodiment is applied is attached as viewed from the rear side of the vehicle. FIG. An exploded perspective view showing the configuration is shown.

  As shown in FIG. 1, an opening 14 is provided at the rear of the vehicle 12 and can be opened and closed by a back door 16. Outer cylinders 18 constituting a part of the damper stay 10 are respectively attached to both sides in the vehicle width direction of the upper periphery of the opening 14. As shown in FIG. 2, the outer cylinder 18 has a bottomed cylindrical shape, and a mounting rod 20 protrudes from the center of the outer surface of the bottom wall 18A.

  A substantially hollow hemispherical support portion 22 that engages with a ball joint (not shown) provided on both sides of the opening 14 is provided integrally with the mounting rod 20 at the distal end portion of the mounting rod 20. And the outer cylinder 18 can rotate along a vehicle up-down direction via the support part 22 centering | focusing on a ball joint in the state in which the said support part 22 was engaged with the ball joint.

  Here, FIG. 3 is a sectional view showing a state in which the back door 16 (see FIG. 1) is fully closed in the damper stay 10 to which the damper stay structure according to the present embodiment is applied. As shown in FIG. 3, a cylinder 24 as a first cylinder and a cylinder 26 as a second cylinder are accommodated in a concentric circle of the outer cylinder 18 in the outer cylinder 18. The cylinder 24 is inserted into the cylinder 26, and the cylinder 26 is disposed outside the cylinder 24.

  Further, the inside of the cylinder 24 penetrates, and a flange portion 24 </ b> A projects from one end portion of the cylinder 24 toward the outside of the cylinder 24. The peripheral edge portion of the flange portion 24A is fixed to the open end portion 18B of the outer cylinder 18, and the cylinder 24 is fixed to the outer cylinder 18 via the flange portion 24A. The cylinders 24 and 26 are set to be shorter than the outer cylinder 18, and the cylinder 26 is movable along the axial direction of the cylinder 24.

  Further, a flange portion 26A projects from one end portion of the cylinder 26 toward the outside of the cylinder 26, and a coil spring 28 is disposed between the flange portion 26A and the bottom wall 18A of the outer cylinder 18. ing. That is, the coil spring 28 is disposed on the radially outer side of the cylinder 26, one end of the coil spring 28 is in contact with the flange portion 26 </ b> A, and the other end of the coil spring 28 is in contact with the bottom wall 18 </ b> A of the outer cylinder 18. . The coil spring 28 urges the cylinder 26 in a direction away from the bottom wall 18A of the outer cylinder 18 (arrow A direction) via the flange portion 26A.

  A rod 30 extends from the center of the inner surface of the bottom wall 26 </ b> B of the cylinder 26 along the axial direction of the cylinder 26. A cylindrical piston 32 as a second piston is provided at the tip of the rod 30. The piston 32 is slidable along the inner peripheral surface 24 </ b> B of the cylinder 24 in a state where the cylinder 24 is inserted into the cylinder 26.

  On the other hand, a cylindrical piston 34 as a first piston is accommodated in the cylinder 24. An orifice 34 </ b> A penetrates along the axial direction of the piston 34 on the outer peripheral side of the piston 34, and the piston 34 is slidable along the inner peripheral surface 24 </ b> B of the cylinder 24. The cylinder 24 is filled with gas, and a gas chamber 36 is formed between the piston 34 and the piston 32.

  Here, one end of a piston rod 38 is fixed to the piston 34, and a gas chamber 37 is formed between the piston 34 and the piston rod 38 on the radially inner side of the cylinder 24. The gas chamber 37 communicates with the gas chamber 36 through an orifice 34 </ b> A that penetrates the piston 34. An annular seal member 42 that fills the gap with the piston rod 38 is fixed on the radially inner side of the cylinder 24 located at one end of the cylinder 24 so that the gas in the gas chamber 37 does not leak. Is set. Further, an annular retaining member 40 that restricts the movement of the piston 34 is fixed to one end side of the cylinder 24, and is set so that the piston 34 does not come off.

  A substantially hollow hemispherical support portion 38A is provided at the other end of the piston rod 38, and can be attached to the back door 16 (see FIG. 1) side. Thus, when the back door 16 is opened and closed, the piston 34 reciprocates in the cylinder 24 via the piston rod 38, and the damper stage 10 expands and contracts.

  Although not shown, the back door 16 is locked by a door lock provided on the back door 16 side and a striker provided on the vehicle 12 side, for example, and is maintained in a fully closed state. The The gas in the gas chamber 36 is set to be in a compressed state when the back door 16 is fully closed.

(Operation and effect of damper stay structure)
Next, functions and effects of the damper stay structure according to the present embodiment will be described. Here, as described above, FIG. 3 is a sectional view showing a state where the back door 16 (see FIG. 1) is fully closed in the damper stay 10 to which the damper stay structure according to the present embodiment is applied. ing. 4 is a cross-sectional view showing the state where the back door 16 is half-opened, and FIG. 5 is a cross-sectional view showing the damper stage 10 with the back door 16 fully opened.

  As shown in FIG. 3, in a state where the back door 16 is fully closed, the piston 34 is located at a substantially central portion in the longitudinal direction of the outer cylinder 18. As described above, when the back door 16 is fully closed, the gas in the gas chamber 36 formed between the piston 32 and the piston 34 is set to be in a compressed state. The cylinder 26 is urged by a coil spring 28 in a direction away from the bottom wall 18 </ b> A of the outer cylinder 18 (arrow A direction). Further, the pressure receiving area received by the piston 34 is larger in the gas chamber 36 than in the gas chamber 37, so that a pressing force directed in the direction of arrow A acts on the piston 34 by the gas pressure in the cylinder 24. Yes.

  When the locked state of the back door 16 is released in this state, the piston 34 is pressed away from the piston 32 by the gas pressure in the gas chamber 36 and the urging force of the coil spring 28 as shown in FIG. The piston rod 38 is pushed out from the outer cylinder 18 through the piston 34.

  The cylinder 26 moves to a position where the gas pressure in the gas chamber 36 and the biasing load (biasing force) by the coil spring 28 are balanced. That is, in this state, the gas pressure is set to be lower than the gas pressure in the gas chamber 36 when fully closed.

  As shown in FIG. 5, when the damper stage 10 is fully opened, the volume in the gas chamber 36 is further increased and the gas pressure is further decreased. However, the cylinder 26 is adjusted in accordance with the gas pressure in the gas chamber 36. It moves along the axial direction of the cylinder 24. The cylinder 26 stops moving at a position where the gas pressure in the gas chamber 36 and the biasing load (biasing force) by the coil spring 28 are balanced. That is, since the change in stay reaction force when the back door 16 is opened and closed is reduced, the load during operation is reduced.

  By the way, when the back door 16 is heavy, it is necessary to increase the gas pressure in the gas chamber 36 in order to hold it fully open. However, when the back door 16 is heavy, the amount of change in the gas pressure due to temperature change is Is larger than when it is light. For this reason, when the back door 16 is fully closed, the stay reaction force increases even at room temperature, and the operating force of the back door 16 increases. On the other hand, when the volume of the gas chamber 36 is constant, the gas pressure changes in proportion to the temperature according to Boyle-Charles' law.

  For this reason, in this embodiment, the cylinder 26 is movable along the axial direction of the cylinder 24. 6A and 6B are cross-sectional views showing the state of the damper stage 10 due to temperature change in the state where the back door 16 (see FIG. 1) is fully closed. The positions indicated by the imaginary lines in FIGS. 6A and 6B are the positions of the cylinder 26 and the piston 32 at normal temperature, and are sectional views corresponding to FIG. 6A is the position of the cylinder 26 and the piston 32 at a high temperature, and the position shown by the solid line in FIG. 6B is a position of the cylinder 26 and the piston 32 at a low temperature.

  7A and 7B are cross-sectional views showing the state of the damper stay 10 due to a temperature change in a state where the back door 16 is half opened. The positions indicated by the imaginary lines in FIGS. 7A and 7B are the positions of the cylinder 26 and the piston 32 at room temperature, and are sectional views corresponding to FIG. 7A is the position of the cylinder 26 and the piston 32 at a high temperature, and the position shown by the solid line in FIG. 7B is a position of the cylinder 26 and the piston 32 at a low temperature.

  Further, FIGS. 8A and 8B are cross-sectional views showing the state of the damper stay 10 due to temperature change in a state where the back door 16 is fully opened. The positions indicated by the imaginary lines in FIGS. 8A and 8B are the positions of the cylinder 26 and the piston 32 at the normal temperature, and are sectional views corresponding to FIG. The position indicated by the solid line in FIG. 8A is the position of the cylinder 26 and the piston 32 at a high temperature, and the position indicated by the solid line in FIG. 8B is the position of the cylinder 26 and the piston 32 at a low temperature.

  That is, according to the present embodiment, when the gas pressure in the gas chamber 36 increases at a high temperature such as summer, as shown in FIGS. 6 (A), 7 (A), and 8 (A), the cylinder 26 Moves in the direction of arrow B along the axial direction of the outer cylinder 18 against the urging force of the coil spring 28. Thereby, the piston 32 moves in the direction away from the piston 34, the volume in the gas chamber 36 increases, and the gas pressure can be lowered. Therefore, in FIG. 8A, the stay reaction force at normal temperature and high temperature when the back door 16 is fully opened is reduced, and the operating force of the back door 16 can be reduced.

  Further, when the gas pressure in the gas chamber 36 becomes low at a low temperature such as in winter, the cylinder 26 is moved by the urging force of the coil spring 28 as shown in FIGS. 6 (B), 7 (B) and 8 (B). Then, it moves in the direction opposite to the arrow B along the axial direction of the outer cylinder 18. Thereby, the volume in the gas chamber 36 can be reduced and the gas pressure can be increased. Therefore, in FIG. 8B, the back door 16 can be held in a fully opened state even at a low temperature.

  That is, according to the present embodiment, in accordance with the gas pressure in the gas chamber 36, the cylinder 26 moves along the axial direction of the cylinder 24 to a position that balances the urging load by the coil spring 28. As a result, the volume of the gas chamber 36 increases or decreases, and the amount of change in gas pressure due to temperature in the gas chamber 36 can be reduced.

  Further, since the change in the gas pressure in the gas chamber 36 due to the stroke of the piston 34 when the back door 16 is opened and closed can be reduced, the peak load due to the gas pressure can be suppressed. Therefore, the length of the outer cylinder 18 can be shortened, and the required space can be reduced. Thereby, the damper stay 10 can be reduced in size.

  Further, since the change in the gas pressure in the gas chamber 36 due to the stroke of the piston 34 can be reduced, the rod diameter of the piston rod 38 can be increased, and the rigidity of the damper stay 10 itself can be increased.

  The coil spring 28 is disposed on the radially outer side of the cylinder 26. For this reason, compared with the case where the coil spring 28 is arrange | positioned in the cylinder 26, the coil effective diameter and wire diameter of the said coil spring 28 can be set freely. Thereby, the design freedom of the coil spring 28 improves, and the rigidity of the coil spring 28 can be improved. In other words, the damper stage 10 can be downsized while the rigidity of the coil spring 28 is ensured. Further, when the back door 16 is fully opened, it is possible to deal with a heavy back door 16 and to reduce the operating force of the back door 16.

  Although not shown, for example, when a coil spring is disposed in the cylinder of the damper stage, it is necessary to bend the coil spring in accordance with the position of the piston, and the cylinder must be lengthened. growing. However, in this embodiment, as shown in FIG. 3, since the coil spring 28 is disposed on the radially outer side of the cylinder 26, the coil spring 28 can be set regardless of the position of the piston 34.

  In this embodiment, the cylinder 26 is provided with a flange portion 26A, and the coil spring 28 is disposed between the flange portion 26A and the bottom wall 18A of the outer cylinder 18, so that the space in the longitudinal direction of the cylinder 26 is effective. Can be used for For this reason, the damper stage 10 can be made small and it can respond also to a small vehicle.

  Here, in the present embodiment, a piston 32 is provided in the cylinder 26, the piston 32 is slidable along the inner peripheral surface 24 </ b> B of the cylinder 24, and the piston 32 and the piston 34 accommodated in the cylinder 24 are A gas chamber 36 is formed between them. Thereby, the precision in the outer diameter size of the cylinder 24 and the inner diameter size of the cylinder 26 can be roughened, and the productivity is increased accordingly. Also, the design becomes easy.

  In addition, since the gas chamber 36 should just be formed between the piston 34 and the cylinder 26, the piston 32 is not necessarily required. However, in this case, it is necessary to insert the cylinder 26 tightly into the cylinder 24. In addition, in this “tightness”, a tight state is formed between the outer diameter of the cylinder 24 and the inner diameter of the cylinder 26, and a seal member having high slidability is provided between the cylinder 24 and the cylinder 26. The case where it is installed is also included. In this embodiment, the orifice 34A is formed in the piston 34, but the orifice may be formed on the cylinder 24 side.

  Further, in the present embodiment, as shown in FIG. 1, outer cylinders 18 constituting a part of the damper stage 10 are respectively attached to both side portions of the opening portion 14 provided at the rear portion of the vehicle 12, and the piston rod 38 is It is attached to the back door 16 side. However, the piston rod 38 may be attached to both sides of the opening 14 and the outer cylinder 18 may be attached to the back door 16 side.

  As described above, the present invention has been described with reference to one embodiment. However, the present invention is not limited to the embodiment, and the above-described embodiments are within the scope of the present invention. Various modifications and substitutions can be made to the embodiment.

DESCRIPTION OF SYMBOLS 10 Damper stage 12 Vehicle 14 Opening part 16 Back door 18 Outer cylinder 24 Cylinder (1st cylinder)
26 Cylinder (2nd cylinder)
28 Coil spring 32 Piston (second piston)
34 Piston (first piston)
36 Gas chamber 37 Gas chamber 38 Piston rod 42 Seal member

Claims (2)

An outer cylinder attached to either one of both sides of the opening provided at the rear of the vehicle and a back door that opens and closes the opening;
A first cylinder fixed in the outer cylinder, formed shorter than the outer cylinder and penetrating through the inside;
A first piston that reciprocally slides along an inner circumferential surface of the first cylinder along the axial direction of the first cylinder is fixed to one end, and the other end is either one of the side portions of the opening or the back door. Or a piston rod attached to the other,
A seal member provided radially inward of the first cylinder and sealing between the piston rod;
The first cylinder is housed in the outer cylinder with the first cylinder inserted therein, and forms a gas chamber filled with gas between the first cylinder and the reciprocating movement along the axial direction of the first cylinder. A possible second cylinder;
A coil spring provided in the outer cylinder, disposed on the radially outer side of the second cylinder, and biasing the second cylinder in a direction of compressing the gas in the gas chamber;
Damper pasture structure having.   2. The damper stay structure according to claim 1, wherein a second piston that constitutes the gas chamber with the seal member by reciprocatingly sliding on an inner peripheral surface of the first cylinder is provided in the second cylinder.