JP2008232177A - Damper structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damper structure which reduces sliding resistance of a rod by a piezoelectric element, is simple in construction, and has the piezoelectric element disposed in a cylinder in isolation from oil in the cylinder. <P>SOLUTION: In the damper structure 11, the cylinder 12 receiving force such as vibrations and the rod 14 are combined through a piston 13, and a seal member 52 is arranged between a front end portion 16 of the cylinder 12 and the rod 14. The front end portion 16 is isolated from the oil 24 in the cylinder by an oil seal member 51, and the piezoelectric element 55 is disposed for applying drive force to the seal member 52. When the piezoelectric element 55 is energized, the piezoelectric element 55 is vibrated and vibrates the seal member 52. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a damper structure capable of adjusting sliding resistance in accordance with a force such as vibration.

Some damper structures generate vibration by a piezoelectric element in a sliding piston (see, for example, Patent Document 1).
JP-A-9-119469 (5th page, FIG. 2)

Next, Patent Document 1 will be briefly described.
FIG. 4 is an explanatory diagram of a conventional technique (Patent Document 1). In a conventional shock absorber 201, a piston 203 is slidably fitted to a piston rod 202, and a vibrator 204 is disposed therebetween. The sliding resistance is reduced by crimping and fixing by the crimping spring 205 and the fixing screw 206, and energizing the vibrator 204 to vibrate the piston 203 and the piston rod 202.

However, in the shock absorber 201 of Patent Document 1, the vibrator (piezoelectric element) 204 is immersed in the oil in the piston 203, so that there is a problem that it is necessary to take electrical oil countermeasures on the vibrator 204.
Further, since the piston 203 is slidably fitted to the piston rod 202 by the crimp spring 205 or the vibrator 204, there is a problem that the structure becomes complicated.

  It is an object of the present invention to provide a damper structure in which the sliding resistance of a rod can be reduced with a piezoelectric element, the structure is simple, and the piezoelectric element is disposed in the cylinder so as to be isolated from the oil in the cylinder. To do.

  The invention according to claim 1 is a damper structure in which a cylinder and a rod that receive a force such as vibration are combined via a piston, and a seal member is disposed between the front end of the cylinder and the rod. The inside fluid is isolated by an oil seal member, and a piezoelectric element for applying a driving force to the seal member is arranged.

  In the invention according to claim 1, the front end portion is isolated from the fluid in the cylinder by the oil seal member, and the piezoelectric element that applies driving force to the seal member is disposed. By vibrating, the seal member can be vibrated. As a result, the friction between the seal member and the rod changes from the static friction state to the dynamic friction state, and there is an advantage that the sliding resistance can be reduced.

  Further, since the seal member is vibrated by the piezoelectric element, there is an advantage that the structure is simplified.

  Furthermore, since the front end portion is isolated from the fluid in the cylinder by the oil seal member, and a piezoelectric element for applying a driving force to the seal member is disposed, the piezoelectric element is placed in the cylinder and outside the oil in the cylinder. There is an advantage that it can be arranged.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of the damper structure of the present invention.
2 is a cross-sectional view taken along line 2-2 of FIG.

The damper structure 11 includes a cylinder 12, a piston 13, a rod 14, a free piston 15, a rod cover 17 at the front end 16 of the cylinder 12, a front chamber 21 and a rear chamber 22 isolated by the piston 13, A fluid (oil) 24 filling the front chamber 21 and the rear chamber 22 and a gas 26 filling the gas chamber 25 are provided.
Further, the sealing mechanism 28 disposed on the rod cover 17 is controlled by the control device 31.

  The control device 31 controls, for example, the entire vehicle, and controls the damper structure 11 based on information from the vehicle state detection device 32 that detects the state of the vehicle.

  The free piston 15 is slidably fitted to the cylinder 12 to form a gas chamber 25 with the rear portion 34 of the cylinder 12, and between the gas 26 in the gas chamber 25 and the fluid (oil) 24 in the cylinder 12. Is intervening.

The piston 13 is slidably fitted to the cylinder 12 and attached to the rear end 36 of the rod 14 and has a valve mechanism 37.
When a compression load is applied to the damper structure 11 as indicated by an arrow a1, the valve mechanism 37 opens the compression valve body 38 as indicated by a two-dot chain line and causes the oil 24 to flow and move as indicated by an arrow a2. Conversely, when a tensile load is applied to the damper structure 11 as indicated by the arrow b1, the tension valve opening body 41 opens as indicated by a two-dot chain line, and the oil 24 is caused to flow and move as indicated by the arrow b2.

  The rod cover 17 includes a cover member 43 fitted to the front end portion 16 of the cylinder 12, an outer seal ring 45 fitted to the outer peripheral surface of the cover member 43, and a bearing 47 fitted to the inner peripheral surface of the cover member 43. And a seal mechanism 28 attached to the end of the cover member 43.

  The seal mechanism 28 includes an oil seal member 51 that prevents leakage of the oil 24 from the surface of the rod 14, a seal member 52 that continues to the oil seal member 51, a base ring board 53, and a piezoelectric element that is disposed on the base ring board 53. 55.

  The oil seal member 51 is formed with an outer peripheral sheet portion 58 that fits into the concave portion 57 of the cover member 43 to prevent leakage of the outer peripheral oil, and is connected to the outer peripheral sheet portion 58 so as to be in close contact with the rod 14 and slidable. An inner peripheral seat portion 61 for preventing leakage is formed, and a backup ring 62 is attached to the back portion of the inner peripheral seat portion 61. The inner peripheral sheet portion 61 is formed on the inner diameter portion 63 (see FIG. 2) of the base ring board 53, and the outer peripheral sheet portion 58 is formed on the outer diameter section 64 of the base ring board 53.

  The seal member 52 has a main body portion 65 formed on the base ring board 53, the main body portion 65 is in close contact with the end surface portion 66 of the cylinder 12 to form a piezoelectric element storage chamber 67, and is slid on the rod 14 along with the main body portion 65. A lip portion 71 that is movably adhered is formed. A seal member 52 is formed in the inner diameter portion 63 of the base ring board 53, and a relief recess 72 is formed between the seal member 52 and the oil seal member 51.

  The piezoelectric element storage chamber 67 includes an inner peripheral wall formed by the seal member 52, an outer peripheral wall formed by the concave portion 57 of the cover member 43, a front wall formed by the end surface portion 66, a rear wall formed by the base ring board 53 and the outer peripheral sheet portion 58. The piezoelectric element 55 is stored in a sealed space consisting of As a result, the piezoelectric element 55 is not immersed in the oil in the cylinder 12. Moreover, rainwater and dust are not applied to the piezoelectric element 55. Therefore, it is not necessary to take measures for waterproofing / dustproofing the piezoelectric element 55, and the trouble of measures for waterproofing / dustproofing can be saved.

  The piezoelectric element 55 has an existing configuration and is distorted when a voltage is applied. Four piezoelectric elements 55 are attached to the outer diameter portion 64 of the base ring board 53 at a central angle θ of an equal pitch, and the piezoelectric elements 55 are connected to the wire extraction portion 76 that penetrates from the concave portion 57 of the cover member 43 to the front end portion 16. Is taken out of the cylinder 12 through the electric wire.

The piezoelectric element 55 may cause the vibration wave to travel in the direction intersecting the axis Cr of the rod 14 (the direction of the arrow b3), or may proceed in the direction of the axis Cr of the rod 14 (the direction of the arrow b4). Also good.
Although four piezoelectric elements 55 are arranged, the number of piezoelectric elements 55 is arbitrary.

Next, the operation of the damper structure of the present invention will be described.
When the control device 31 energizes the piezoelectric element 55 of the damper structure 11 based on the vehicle information of the vehicle state detection device 32 shown in FIG. 1, the seal member 52 vibrates by the piezoelectric element 55. The sliding resistance between the two can be reduced.
Further, since the seal member 52 is vibrated by the piezoelectric element 55, the structure is simple.

Since the front end portion 16 of the cylinder 12 is partitioned without leakage by the oil seal member 51 and the piezoelectric element 55 is disposed at the front end portion 16, the piezoelectric element 55 is disposed within the cylinder 12 so as to be isolated from the oil 24 in the cylinder 12. be able to.
Specifically, the oil seal member 51, the cover member 43, and the outer seal ring 45 isolate the front end portion 16 of the cylinder 12, and the piezoelectric element 55 is disposed at the isolated front end portion 16. The piezoelectric element 55 can be disposed in the cylinder 12 so as to be isolated from the cylinder 12.

  FIG. 3 is a graph showing the relationship between the sliding resistance of the seal member and the vibration frequency, in which the horizontal axis represents the vibration frequency and the vertical axis represents the sliding resistance of the seal member.

A broken line is a characteristic of a general damper which employs a seal member in the comparative example.
A solid line is a characteristic of the embodiment.
In the damper of the embodiment, the sliding resistance is set higher as indicated by the arrow c1 than a general damper (broken line). As a result, in a non-energized state, the sliding resistance in the low frequency region near the frequency V1 can be increased, and the posture change (rolling or pitching) of the vehicle body can be suppressed.

  Further, when energized, the sliding resistance decreases as indicated by an arrow c2, so that the sliding resistance in the high frequency region near the frequency Vh can be lowered, and the vibration can be absorbed to improve the riding comfort.

In the damper structure of the present invention, the seal member 52 and the oil seal member 51 are integrally formed in the embodiment, but may be formed separately.
The form of the oil flow path and the form of the valve are arbitrary.
The traveling direction of the vibration wave of the piezoelectric element 55 is arbitrary.

  The form of the cylinder 12 is arbitrary, and the fitting form of the front end portion 16 of the cylinder 12 and the cover member 43 of the rod cover 17 is arbitrary. For example, the cylinder is formed of an outer cylinder and an inner cylinder arranged with a predetermined space between the outer cylinder, and the cover member 43 is attached to the inner cylinder and the outer cylinder.

  The damper structure of the present invention is suitable for an automobile suspension device.

It is sectional drawing of the damper structure of this invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is the graph which showed the relationship between the sliding resistance of a sealing member, and a vibration frequency. It is explanatory drawing of a prior art (patent document 1).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Damper structure, 12 ... Cylinder, 13 ... Piston, 14 ... Rod, 16 ... Front end part of cylinder, 24 ... Fluid (oil), 51 ... Oil seal member, 52 ... Seal member, 55 ... Piezoelectric element.

Claims (1)

In a damper structure in which a cylinder and a rod that receive a force such as vibration are combined via a piston, and a seal member is disposed between the front end of the cylinder and the rod,
The front end is isolated from the fluid in the cylinder by an oil seal member,
A damper structure in which a piezoelectric element for applying a driving force to the seal member is disposed.

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