JP2009293698A - Shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent reduction in a mounting characteristic on a vehicle, without enlarging the whole device, when increasing damping force generated when a piston speed of a shock absorber is in an extremely low speed area of 0.05 m/sec or less. <P>SOLUTION: This shock absorber has a cylinder body 1 and a rod body 2 linked with this cylinder body 1 so as to be capable of protruding and retreating, and has a detection means S arranged between the cylinder body 1 side and the rod body 2 side and detecting a retractive position of the rod body 2 to the cylinder body 1 in expansion operation when the rod body 2 retracting to the cylinder body 1. This detection means S changes capacitance in response to the external force action. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shock absorber, and more particularly to an improvement of a shock absorber having a detection means that enables detection of a protruding position of a rod body with respect to a cylinder body.

  For example, in a shock absorber constituting a suspension device in a four-wheel vehicle, it is preferable to practice vehicle height adjustment and damping force adjustment according to the road surface condition on which the vehicle travels. It is best to detect the situation, i.e. the position of the rod body relative to the cylinder body.

  Thus, there have been various proposals so far for detecting the position of the rod body relative to the cylinder body in the shock absorber. For example, in the proposal disclosed in Patent Document 1, a stroke sensor serving as a detecting means is used. Have.

  That is, in the proposal of the above-mentioned literature disclosure, while the rod body which is inserted into the cylinder body constituting the shock absorber so as to be able to appear and retract and also constitutes the shock absorber has a magnet, a hole is formed in the head end portion of the cylinder body. It has a sensor.

  Therefore, in this shock absorber, the stroke state of the shock absorber, that is, the rod with respect to the cylinder body, is detected by detecting the magnetic flux emitted from the rod body when the rod body is projected and retracted with respect to the cylinder body. It is possible to detect the appearance position of the body.

And in the case of this measure, compared with the case where the conventional potentiometer is used as the detection means, the magnet constituting the detection means is built in the shock absorber. Does not cause sexual deterioration
JP-A-7-98036 (abstract, paragraphs 0008, 0014, 0016 to 0020 in the specification, see FIGS. 2 and 3)

  However, in the proposal of the above-mentioned literature disclosure, there is basically no problem in that it is possible to detect the protruding and retracting position of the rod body with respect to the cylinder body in the shock absorber. It may be pointed out that there is a defect.

  That is, in the detection means disclosed in the above literature, the Hall sensor that detects the magnetic flux emitted from the rod body is disposed outside the so-called cylinder body that is the head end of the cylinder body. If there is a configuration that generates other magnetic flux, the Hall sensor reacts, and there is a risk that this detection means cannot operate correctly.

  And, when looking at the specific configuration, when the magnet is held on the outer periphery of the rod body, the stroke of the rod body in the cylinder body tends to be reduced, and the original vehicle height adjustment and damping force adjustment There is also an unfavorable problem from above.

  The present invention was devised in view of the above-described circumstances, and the object thereof is to have a detecting means for accurately detecting the protruding position of the rod body with respect to the cylinder body, and to adjust the vehicle height or to attenuate the vehicle. It is to provide a shock absorber that contributes to the realization of force adjustment and is optimal for expecting an improvement in its versatility.

  In order to achieve the above-described object, the shock absorber according to the present invention basically includes a cylinder body and a rod body connected to the cylinder body so as to be able to project and retract. And a detecting means for detecting the position of the rod body relative to the cylinder body at the time of expansion / contraction operation in which the rod body protrudes and retracts with respect to the cylinder body. Assume that the capacitance is changed.

  Therefore, in the shock absorber according to the present invention, the detecting means detects the protruding and retracting position of the rod body that protrudes and retracts with respect to the cylinder body when the rod body protrudes and retracts with respect to the cylinder body. You can grasp the expansion and contraction status.

  At this time, since the detecting means is not built in the shock absorber, the existing shock absorber can be used as it is without changing the configuration of the shock absorber to provide the detecting means, and the detecting means can tamper with the outer diameter of the shock absorber. Therefore, there is an advantage that the mountability to the vehicle is not lowered.

  And since a detection means does not utilize the existing what is called a sensor, the increase in the product cost in a buffer can be avoided, and there exists an advantage which does not reduce the versatility in a buffer.

  As a result, for example, when the shock absorber constitutes a suspension device in a four-wheel vehicle, vehicle height adjustment and damping force adjustment can be practiced according to the road surface condition on which the vehicle travels, and the ride comfort in the vehicle is optimized, The improvement of the versatility can be expected.

  The present invention will be described below on the basis of the illustrated embodiment. The shock absorber according to the present invention is a hydraulic shock absorber called an air suspension having an air chamber constituting an air spring as a suspension spring outside a so-called shock absorber body. The suspension device is arranged in each part of the four wheels in the four-wheeled vehicle to suspend each wheel.

  As shown in FIGS. 1 and 2, the shock absorber includes a cylinder body 1 serving as a lower end side member and a rod body 2 connected to the cylinder body 1 so as to be able to project and retract and serving as an upper end side member. Have.

  Although not shown, the piston body is slidably accommodated in the cylinder body 1, and this piston body is present in the cylinder body 1 while defining an extension side chamber and a pressure side chamber in the cylinder body 1. Connected to the tip of the rod body 2.

  The piston body allows the above-mentioned extension side chamber and the compression side chamber to communicate with each other under the presence of the damping means, and when the rod body 2 protrudes and retracts with respect to the cylinder body 1, the extension side chamber and the compression side chamber are connected to the hydraulic oil. It is possible to generate a damping force by the damping means by widening and narrowing by reciprocating.

  Although it is about the cylinder body 1, although not shown, there are cases where it is formed in a double cylinder type and cases where it is formed in a single cylinder type, and it has a reservoir whether it is a double cylinder type or a single cylinder type, In particular, in the case of a double cylinder type, there may be a compression side damping means between the cylinder body 1 and the reservoir.

  Further, the magnitude of the damping force generated by the damping means of the piston body housed in the cylinder body 1 may be adjusted by the control means disposed on the shaft core portion of the rod body 2, for example. is there.

  On the other hand, this shock absorber has an air chamber A that constitutes an air spring that is a suspension spring, and this air chamber A is defined by a rigid air piston 3 and an air chamber 4 and an elastic diaphragm 5. The

  And this air chamber A changes the air spring force by positively changing the air amount housed inside, while making the air spring force unchanged while keeping the air amount housed inside constant. The vehicle height may be adjusted by changing the air spring force.

  The air piston 3 is formed in a truncated conical cylinder shape converging below, and a lower end 3a is coupled to the outer periphery of the cylinder body 1 formed of a cylindrical body under a sealing structure, and the lower end 5a of the diaphragm 5 is connected to the upper end 3b. Bonded under the presence of the fixed band 6.

  The air chamber 4 is formed in a headed cylindrical shape that opens downward, and although not shown, the shaft core portion of the head is coupled to the rod body 2 under a sealing structure, and a lower end portion 4a is added as shown in the drawing. The upper end portion 5b of the diaphragm 5 is joined to the fastening end portion under backup by the fixing ring 7.

  The diaphragm 5 is made of a rubber film having an appropriate thickness, is formed in a generally cylindrical shape, and a lower end portion 5a bent inward is fastened to an upper end portion 3b of the air piston 3 by tightening a fixed band 6 adjacent to the outer periphery thereof. Combined.

  In this diaphragm, the upper end portion 5b with the fixing ring 7 adjacent to the inside is fitted into the lower end portion 4a of the air chamber 4, and the lower end portion 4a of the air chamber 4 is added under this state. The lower end 5b is coupled to the lower end 4a of the air chamber 4 by fastening.

  Therefore, in this diaphragm 5, when the rod piston 2 protrudes and retracts with respect to the cylinder body 1, when the telescopic operation is performed, that is, when the air piston 3 protrudes and retracts with respect to the air chamber 4, Moves up and down in the axial direction of the air piston 3 on the outer periphery of the air piston 3.

  That is, at the time of expansion / contraction operation of the shock absorber, in the diaphragm 5, the bent portion 5 c moves up and down in the axial direction of the air piston 3 on the outer periphery of the air piston 3 as indicated by symbols u and d in FIG. 1. This movement is the basis for the detection operation of the detection means S described later.

  By the way, according to the present invention, the detecting means S disposed between the cylinder body 1 side and the rod body 2 side during the expansion / contraction operation of the shock absorber in which the rod body 2 protrudes and retracts with respect to the cylinder body 1 is a cylinder. The appearance position of the rod body 2 with respect to the body 1 is detected.

  That is, as described above, in a vehicle in which four wheels are suspended by a suspension device having a shock absorber, vehicle height adjustment and damping force adjustment are practiced according to the road surface condition on which the vehicle travels. Preferably, for that purpose, it is best to detect the expansion / contraction state of the shock absorber, that is, the position of the rod body 2 in relation to the cylinder body 1.

  On the other hand, even when the expansion / contraction state of the shock absorber is accurately determined, when a so-called sensor is used, the vehicle mountability of the shock absorber may be reduced depending on the mode of the sensor as described above. In some cases, the cost of the shock absorber is likely to increase, and it is likely to be disadvantageous from the viewpoint of improving its versatility.

  Therefore, in the present invention, an inexpensively procured member called an artificial muscle (EPAM) is used as the detecting means S for detecting the protruding and retracting position of the rod body 2 with respect to the cylinder body 1 during the expansion and contraction operation of the shock absorber. .

  Further, this detecting means S is, in principle, for changing the electrostatic capacity according to the external force action, and detecting the amount of change in the electrostatic capacity, that is, the action state of the external force, that is, the rod relative to the cylinder body. It allows detection of the body's in / out position, that is, the in / out position of the air piston 3 with respect to the air chamber 4.

  Then, as shown in FIG. 3, the detection means S is made to be a flexible and extendable polymer film C as an intermediate member, and two flexible films that can sandwich the polymer film C. The structure principle includes conductive films E1 and E2.

  Therefore, this detecting means S has an external force action to sandwich its thickness as shown by a white arrow P in FIG. 3, or as shown by a white arrow T in FIG. When there is an external force action to pull in the axial direction, the capacitance is changed.

  In the embodiment shown in FIG. 1, the detection means S formed as described above is disposed on the outer peripheral portion of the air piston 3 in the axial direction of the air piston 3, and the air piston 3 protrudes and protrudes from the air chamber 4. Sometimes the capacitance is changed in accordance with the amount of movement of the diaphragm 5 that presses against the outer periphery.

  At this time, the detection means S is formed in a narrow tape shape and adhered to the outer periphery of the air piston 3 or formed in a narrow belt shape and formed in the outer periphery of the air piston 3. It is preferable to be inserted into the inside.

  As described above, in the embodiment shown in FIG. 1, the detection means S is provided on the outer periphery of the air piston 3, so that the outer diameter of the shock absorber is not increased unnecessarily. Do not decrease.

  Further, when the shock absorber is extended and contracted, especially when the air piston 3 is immersed in the air chamber 4, the detection means S may be partially provided in a linear manner, but it is covered from the outside by the moving diaphragm 5. Therefore, for example, it is possible to reduce the chance of a stepping stone colliding.

  The result detected by the detecting means S will be guided to the outside, for example, via a lead wire connected to the lower end of the detecting means S as shown by a broken line in FIG.

  From the above, it can be said that the detection means S described above may be arranged by a measure other than that shown in the illustrated embodiment as long as the position at which the rod body 2 appears and disappears from the cylinder body 1 is detected. However, in view of the case where almost all kinds of detection means are disposed in the shock absorber, it is preferable that the detection means is built in or close to that state.

  In the embodiment shown in FIG. 2, the detection means S is housed in the air chamber A and is spanned between the air chamber 4 and the air piston 4, and is generated when the air piston 3 moves in and out of the air chamber 4. The capacitance is changed according to the tension.

  At this time, the upper end S1 of the detection means S is fixedly connected to the inner peripheral wall of the air chamber 4 using an appropriate plug or the like, and the lower end S2 of the detection means S is the same as the lower end 5a of the diaphragm 5. It is fixedly connected using an appropriate plug or the like.

  Therefore, in this embodiment, the detection means S is disposed between the air chamber 4 and the air piston 3, that is, directly connected. As described above, the artificial means constituting the detection means S is provided. Since the muscles are excellent in expansion / contraction performance, the detection means S is formed in a narrow tape shape or a belt shape, so that even if the air piston 3 appears and disappears with a large stroke with respect to the air chamber 4, this detection means. There is no risk of breakage or the like, and even if the detection means S is directly connected to both, there is no risk of alienating the movement between the two.

  And in this embodiment, since the detection means S is arrange | positioned in the air chamber A, not only does not change the outer diameter of a shock absorber, but it does not reduce a vehicle-mounted property, and it is a collision of a stepping stone. Do not be afraid of anything.

  As in the case of the above-described embodiment, the detection result of the detection means S is, for example, via a lead wire connected to the upper end of the detection means S as indicated by a broken line in FIG. Will be guided to the outside.

  In the above description, it has been described that the shock absorber of the present invention is a hydraulic shock absorber called an air suspension having an air chamber A that constitutes an air spring that is a suspension spring. Is to detect the protruding position of the rod body 2 with respect to the cylinder body 1, so long as it is possible to be embodied in a normal hydraulic shock absorber having no air chamber A outside the shock absorber body. Of course.

  As long as the rod body 2 has a configuration in which the rod body 2 is projected and retracted with respect to the cylinder body 1, the present invention can be embodied. For example, the front fork as a shock absorber mounted on the front wheel side of the two-wheeled vehicle The invention may be embodied.

  In the above description, the processing of the result detected by the detection means S is not mentioned, but a conventional measure for processing the result detected by the detection means S of almost all kinds may be applied.

It is a partial front longitudinal cross-sectional view which shows the buffer by one Embodiment of this invention. It is a figure which shows the buffer of other embodiment similarly to FIG. It is a figure which shows a detection means in principle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder body 2 Rod body 3 Air chamber 4 Air piston 5 Diaphragm A Air chamber S Detection means

Claims (5)

In a shock absorber having a cylinder body and a rod body connected to the cylinder body so as to be able to appear and retract, an expansion / contraction operation is provided between the cylinder body side and the rod body side so that the rod body protrudes and retracts from the cylinder body. A shock absorber characterized by having a detecting means for detecting the protruding and protruding position of the rod body relative to the cylinder body, and the detecting means changing the capacitance in accordance with an external force action. An air piston that is coupled to the cylinder body, an air chamber that is coupled to the rod body, and a diaphragm that is coupled to the air piston and the air chamber form an air chamber as an air spring. The shock absorber according to claim 1, wherein the bumping position of the air piston with respect to the air chamber is detected at the time of expansion and contraction operation in which the rod body projects and retracts. The detecting means is provided on the outer peripheral portion of the air piston and is arranged in the axial direction of the air piston, and the capacitance is changed in accordance with the amount of movement of the diaphragm that presses against the outer periphery when the air piston moves into and out of the air chamber. Item 3. A shock absorber according to item 2. The shock absorber according to claim 2, wherein the detection means is spanned between the air chamber and the air piston, and the capacitance is changed in accordance with a tension generated when the air piston moves into and out of the air chamber. The detection means is composed of a polymer film that is flexible and can be expanded and contracted as an intermediate member, and two conductive films that can be expanded and contracted to sandwich the polymer film. 5. The shock absorber according to claim 1, wherein the capacitance is changed when the thickness of the conductive film is changed.

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