JP2006327296A - Air suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air suspension device capable of enhancing the ride comfort of a vehicle. <P>SOLUTION: The air suspension device is equipped with a shock absorber D furnished with an absorber body 1 and a piston rod 2 inserted into the absorber body 1 in such a way as able to emerge and retract and an air chamber A formed at the outer periphery of the shock absorber D, in which a seal part S to seal the gap between the absorber body 1 and the piston rod 2 is located outside the air chamber A, and it is arranged so that the pressure in the air chamber A does not act on the seal part S, which leads to enhancement of the ride comfort in the vehicle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement of an air suspension device.

  In the conventional air suspension device, for example, a shock absorber provided with a shock absorber main body and a piston rod inserted into the shock absorber main body so as to be able to protrude and retract, and an air chamber formed on the outer peripheral side of the shock absorber. It is prepared for.

  The air chamber is specifically composed of a cylindrical air chamber connected to the piston rod, a cylindrical air piston connected to the shock absorber body, and a diaphragm connecting the air chamber and the air piston. It is formed and covers the outer peripheral surface of the shock absorber (see, for example, Patent Document 1).

  The air chamber is filled with compressed air supplied from a compressor, and the air suspension device elastically supports the vehicle body weight of the vehicle by the air spring force of the compressed air in the air chamber and controls the pressure in the air chamber. The vehicle height can be adjusted by increasing or decreasing it.

That is, in this air suspension device, the compressed air filled in the air chamber functions as a suspension spring.
Japanese Patent Laid-Open No. 9-250587 (FIG. 1)

  By the way, in the above-described conventional air suspension device, as described above, since the air chamber covering the outer peripheral surface of the shock absorber is provided, the space between the shock absorber main body and the piston rod is sealed. The pressure of compressed air always acts on the seal portion.

  In the shock absorber applied to such an air suspension device, since it is necessary to prevent the compressed air from being mixed into the shock absorber body, the shock absorber used in the suspension device having a coil spring as a suspension spring. Compared to the above, the contact surface pressure of the seal portion to the piston rod is increased.

  Therefore, in the shock absorber applied to the air suspension device, the sliding resistance at the seal portion when the piston rod protrudes and retracts with respect to the shock absorber body during expansion and contraction is used for the suspension device using the coil spring as a suspension spring. The sliding resistance of the shock absorber becomes awkward due to the sliding resistance, which may impair the riding comfort of the vehicle.

Accordingly, the present invention has been made to improve the above-mentioned problems, and an object of the present invention is to provide an air suspension device that improves the riding comfort in a vehicle.

  The present invention relates to a shock absorber provided with a shock absorber body and a piston rod inserted into the shock absorber body so as to be retractable and an air chamber formed on the outer peripheral side of the shock absorber. The seal portion that seals between the container main body and the piston rod is arranged outside the air chamber to solve the problem.

  According to the present invention, the air in the air chamber does not act on the seal portion because the seal portion is disposed outside the air chamber. That is, no matter what the pressure in the air chamber becomes, the seal portion is not affected at all.

  That is, since the compressed air in the air chamber does not enter the shock absorber body, there is no need to increase the contact surface pressure of the seal portion to the piston rod, and the suspension device uses the coil spring as a suspension spring. It can be made to be equivalent to the seal part of the shock absorber used.

  Therefore, even in the shock absorber applied to the air suspension device, the sliding resistance at the seal portion when the piston rod protrudes and retracts with respect to the shock absorber body during expansion and contraction is reduced as compared with that of the conventional air suspension device. Therefore, the problem that the expansion / contraction operation of the shock absorber becomes awkward and the riding comfort in the vehicle is impaired is solved.

  The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view of an air suspension device according to an embodiment. FIG. 2 is a longitudinal sectional view of an air suspension device according to another embodiment.

  As shown in FIG. 1, an air suspension device according to an embodiment includes a shock absorber D including a shock absorber main body 1 and a piston rod 2 that is inserted into and retracted from the shock absorber main body 1. And an air chamber A formed on the outer peripheral side.

  More specifically, the shock absorber body 1 includes a cylinder 1a and a piston (not shown) that is slidably inserted into the cylinder 1a. The piston rod 2 is connected to the piston at one end. 1a is movably inserted, and between the piston rod 2 and the cylinder 1a is provided by a seal portion S provided with a seal member such as a U-packing and a dust seal for preventing entry of dust and the like into the shock absorber body 1. It is sealed.

  The cylinder 1a has two pressure chambers separated by a piston (not shown), and the two pressure chambers are filled with a liquid such as hydraulic oil.

  In the case of the shock absorber D, although not specifically shown, a free piston (not shown) is inserted into the cylinder 1a to partition the pressure chamber and the air chamber (not shown), and the pressure when the shock absorber D expands and contracts. The change in the volume of the chamber is compensated by the movement of the free piston in the axial direction with respect to the cylinder 1a.

  The piston is provided with a passage communicating with each of the pressure chambers. A damping force generating element (not shown) is provided in the middle of the passage, and the shock absorber D is connected to the shock absorber main body 1 by a piston. When the rod 2 appears and disappears, the damping force generating element gives resistance to the flow of liquid passing through the passage so that a predetermined damping force can be generated.

  As described above, the shock absorber D is configured as a so-called single-tube shock absorber, but may be configured as a so-called double-tube shock absorber provided with a reservoir chamber on the outer periphery of the cylinder 1a. .

  Subsequently, the air chamber A connects the cylindrical air chamber 3 connected to the piston rod 2, the cylindrical air piston 4 connected to the shock absorber body 1, and the air chamber 3 and the air piston 4. A diaphragm 5 that is a partition wall that allows the axial movement of the air chamber 3 and the air piston 4, and a cylinder that is connected to the piston rod 2 and is smaller in diameter than the air piston 4 and adjacent to the outer periphery of the shock absorber body 1. The body 6 and the diaphragm 7 which is an elastic partition connected to the cylinder 6 and the air piston 4 are separated.

  More specifically, the cylindrical body 6 has an inner periphery at its upper end in the drawing connected to the upper end in the drawing of the piston rod 2, and its inner peripheral diameter is such that the shock absorber main body 1 can be inserted. 1 is set to be larger than the outer peripheral diameter of 1, and a flange 61 is provided on the outer periphery. In addition, a communication hole 62 is provided at the upper end of the cylindrical body 6 to communicate the inside and the outside.

  The air chamber 3 is formed in a bottomed cylindrical shape, and a hole 32 is opened in the bottom 31, and the upper end of the cylinder 6 is inserted into the hole 32, and further, the bottom 31 and the cylinder 6 The flange portion 61 is connected by an annular vibration-proof rubber 8.

  The air chamber 3 is connected to a plate 10 that is annular and is coupled to the vehicle body of the vehicle via an anti-vibration rubber 9 that is welded to the upper surface of the bottom 31. The upper end of the piston rod 2 is described above. The cylinder 6 and the air chamber 3 can be connected to the vehicle body.

  In this embodiment, the anti-vibration rubbers 8 and 9 are arranged on the mount portion where the air suspension device is attached to the vehicle body. However, the anti-vibration rubber 9 is eliminated and the air chamber 3 is directly attached to the vehicle body. You may make it connect. However, since the anti-vibration rubber 9 is also interposed between the air chamber 3 and the vehicle body as described above, it is possible to suppress vibrations such that the wheels get over the unevenness of the road surface as they are to the vehicle body side. It is possible.

  On the other hand, the air piston 4 includes a cylindrical portion 41 having a diameter larger than that of the cylindrical body 6, an annular plate portion 42 extending from the lower end of the cylindrical portion 41, and a cylindrical fixing portion 43 suspended from the annular plate portion 42. The air piston 4 is connected to the shock absorber body 1 by welding the lower end of the fixed portion 43 to the lower end of the cylinder 1a.

  Here, it is assumed that the lower end of the fixed portion 43 is welded to the cylinder 1a. In this case, the shock absorber D is formed in a single cylinder type, so that welding distortion is not generated in the side portion of the cylinder 1a. In this way, smooth movement of the piston is guaranteed. When the shock absorber D is configured as a double-tube shock absorber, the fixing portion 43 is omitted and the inner periphery of the annular plate portion 42 is directly welded to the side portion of the shock absorber body 1. Also good.

  As described above, since the diameter of the cylindrical body 6 is smaller than that of the cylindrical portion 41 of the air piston 4, the cylindrical body 6 enters the cylindrical portion 41 when the shock absorber D contracts. However, the annular plate portion 42 is attached at a position so that the lower end of the cylindrical body 6 does not contact the cylinder 1a during the full stroke of the shock absorber D.

  The inner periphery of the diaphragm 7 is attached to the outer periphery of the lower end of the cylindrical body 6 by being pressed by a ring 15, and the outer periphery of the diaphragm 7 is attached to the inner periphery of the upper end of the cylindrical portion 41 of the air piston 4. The cylinder 6 and the air piston 4 are connected by a diaphragm 7, and the outer periphery of the diaphragm 5 is attached to the outer periphery of the lower end of the air chamber 3 by a ring 17. The inner periphery of the diaphragm 5 is attached to the outer periphery of the upper end of the cylinder portion 41 of the piston 4 by being pressed by a ring 18, and the air chamber 3 and the air piston 4 are connected by the diaphragm 5.

  A guide cylinder 11 extends from the lower end of the air chamber 3, and the diaphragm 5 is provided between the guide cylinder 11 and the cylinder portion 41 of the air piston 4.

  That is, the air chamber A is annularly separated on the outer peripheral side of the shock absorber D by the air chamber 3, the air piston 4, the cylindrical body 6, and the diaphragms 5 and 7, and the shock absorber body 1 and the piston rod 2 are separated from each other. The seal portion S that seals the gap is arranged outside the air chamber A.

  Although not shown, a valve for adjusting the pressure of the compressed air in the air chamber A is provided on the side portion of the air chamber 3 or the like, and the compressed air is supplied from the compressor (not shown) through the valve. It is supplied into the chamber A.

  Now, the air suspension device is configured as described above, and the operation thereof will be described.

  When the shock absorber D contracts, that is, when the piston rod 2 enters the shock absorber main body 1, the air piston 4 enters the space formed by the air chamber 3 and the cylindrical body 6. Compress A.

  Then, the air in the air chamber A is compressed, an air spring reaction force corresponding to the degree of the compression is generated, and the shrinkage of the shock absorber D is suppressed. Since the seal portion S is outside the air chamber A, no pressure is applied to the seal portion S. That is, no matter what the pressure in the air chamber A becomes, the seal portion S is not affected at all.

  That is, since the compressed air in the air chamber A is not mixed into the shock absorber main body 1, there is no need to increase the contact surface pressure of the seal portion S to the piston rod 2, and the contact surface pressure is suspended by the coil spring. It can be made equivalent to the seal part of the shock absorber used in the suspension device as a spring.

  Therefore, even in the shock absorber D applied to the air suspension device, the sliding resistance in the seal portion S when the piston rod 2 protrudes and retracts with respect to the shock absorber main body during expansion and contraction is higher than that of the conventional air suspension device. Since it can reduce, the expansion-contraction operation | movement of the buffer D becomes awkward and the malfunction of impairing the riding comfort in a vehicle is eliminated.

  Further, in the present embodiment, the communication hole 62 is provided in the cylindrical body 6, and the space R formed by the cylindrical body 6, the diaphragm 7, and the air piston 4 when the shock absorber D is contracted is the above-described communication hole. Since the open space is opened to the outside at 62, it is also possible to prevent the pressure in the seal portion S from being compressed by the gas in the space R being compressed. The contact surface pressure of S can be reduced, and the riding comfort improvement effect is enhanced.

  Although the communication hole 62 is not provided in the upper part of the cylindrical body 6, for example, it can be provided in the annular plate portion 42 of the air piston 4, the riding comfort improvement effect can be enhanced as described above. Since the space R communicates with the inside of the vehicle body by being provided at the top of the vehicle body, there is an advantage that rain water, dust, dust, and the like can be prevented from entering the space R. It is possible to omit the dust seal provided in the seal portion S.

  Further, as described above, the diaphragm 5 is disposed between the guide cylinder 11 and the air piston 4, and the diaphragm 7 is disposed between the air piston 4 and the shock absorber body 1 adjacent to the tubular body 6. The deformation of the diaphragms 5 and 7 in the left-right direction in the drawing when the air piston 4 advances and retreats with respect to the space formed by the air chamber 3 and the cylinder 6 due to the expansion and contraction of D is the guide cylinder 11, the air piston 4 and the buffer Since the pressure receiving area of each of the diaphragms 5 and 7 is kept substantially constant, the air spring force acting on the piston rod 2 and the shock absorber main body 1 does not change abruptly. Does not perceive a sense of incongruity.

  Next, an air suspension device according to another embodiment will be described. In the description of the air suspension device in the other embodiments, the same parts as those in the air suspension device in the embodiment are given the same reference numerals, and detailed description thereof is omitted, and the air suspension in the embodiment is omitted. The parts different from the suspension apparatus will be described.

  As shown in FIG. 2, the air suspension device in this other embodiment eliminates the guide cylinder 11 and the diaphragm 5 of the air suspension device in one embodiment, and replaces the air chamber 3 and the air piston 4 with a bellows 19. It is connected with.

  As described above, in the air suspension device according to the other embodiment, since the bellows 19 is employed, the guide at the time of expansion / contraction of the shock absorber D generated in the air suspension device according to the one embodiment is used. Friction between the cylinder 11 and the air piston 4 and the diaphragm 5 does not occur.

  Therefore, in the air suspension device according to the other embodiment, in addition to the function and effect of the air suspension device according to the above-described one embodiment, there is no generation of the friction. There is an advantage that the ride comfort in the vehicle can be further improved.

  This is the end of the description of the present invention, but it goes without saying that the scope of the present invention is not limited to the details shown or described.

It is a longitudinal cross-sectional view of the air suspension apparatus in one embodiment. It is a longitudinal cross-sectional view of the air suspension apparatus in other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shock absorber main body 1a Cylinder 2 Piston rod 3 Air chamber 31 Bottom part 32 Hole 4 Air piston 41 Cylindrical part 42 Annular plate part 43 Fixing part 5, 7 Diaphragm 6 Cylindrical body 61 Gutter part 62 Communication hole 8, 9 Anti-vibration rubber 10 Plate 11 Guide cylinder 15, 16, 17, 18 Ring 19 Bellows A Air chamber D Buffer R Space S Seal part

Claims (5)

In an air suspension device comprising a shock absorber provided with a shock absorber main body and a piston rod inserted into the shock absorber main body so as to be retractable, and an air chamber formed on the outer peripheral side of the shock absorber, the shock absorber main body and the piston An air suspension device, wherein a seal portion for sealing between the rod and the rod is disposed outside the air chamber. The air chamber connects the cylindrical air chamber connected to the piston rod, the cylindrical air piston connected to the shock absorber body, the air chamber and the air piston, and in the axial direction of the air chamber and the air piston. A partition body that allows relative movement, a cylindrical body that is connected to the piston rod and has a smaller diameter than the air piston, and an elastic partition wall that is connected to the cylindrical body and the air piston. Item 2. The air suspension device according to Item 1. The air suspension device according to claim 2, wherein the partition wall is a bellows. The guide cylinder extended in the edge part of an air chamber is provided, The said partition body is a diaphragm provided between the outer periphery of an air piston, and the inner periphery of a guide cylinder, The Claim 2 characterized by the above-mentioned. Air suspension device. The air suspension device according to any one of claims 2 to 4, wherein a space formed by the air piston, the cylindrical body, and the elastic partition wall is an open space.

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