JP5614247B2 - Cylinder device - Google Patents

Description

  The present invention relates to a cylinder device provided between two objects that are vertically arranged and move relative to each other, and particularly relates to a cylinder device that contains a porous body having pores and a working fluid and functions also as a colloidal damper. .

  The cylinder device described in the following patent document contains a colloidal solution in which a porous material such as hydrophobized porous silica gel and a working fluid are mixed, and operates on the pores of the porous material. It is configured to expand and contract as the liquid flows in and out. Since the hydraulic fluid flows into the pores against the surface tension, the pressure in the cylinder device is increased as the hydraulic fluid flows into the pores. In addition, the hydraulic fluid repeatedly flows in and out of the pores under the action of surface tension, thereby dissipating energy applied from the outside and functioning as a damper. A cylinder device that contains a colloidal solution therein is called a colloidal damper and has the characteristics described above.

  Further, as described above, the colloidal damper is configured such that the pressure in the cylinder device increases as the working fluid flows into the pores of the porous body. For this reason, the colloidal damper can support an object connected to the upper side of the cylinder device by the pressure in the cylinder device in a state where the working fluid flows into the pores of the porous body.

JP 2006-118571 A JP 2008-309250 A

  The cylinder device functioning as a colloidal damper described in the above-mentioned patent document is still under development, leaving much room for improvement. Therefore, it is considered that the practicality of the cylinder device functioning as the colloidal damper is improved by making various improvements. This invention is made | formed in view of such a situation, and makes it a subject to provide the cylinder apparatus which functions as a highly practical colloidal damper.

In order to solve the above-described problems, the cylinder device of the present invention includes (A) a housing, (B) a piston, and (C) these housings, which are respectively connected to a vehicle body and a wheel holding member that are arranged vertically and move relative to each other. A porous body and a working fluid having a large number of pores accommodated inside the chamber defined by the piston, and (D) a flexible, compartmented and sealed space inside the chamber. A sealing member that seals the porous body and a part of the working fluid in a mixed state in the sealed space and elastically deforms itself to allow a change in the volume of the sealed space; Depending on the pressure in the sealed space and the elastic reaction force of the sealing member caused by the state of the working fluid flowing into the pores of the material body, it is configured to handle all of the shared load of the wheel corresponding to itself (Ii) Car body and wheel holding Depending on the relative movement of the member, by the amount of hydraulic fluid that flows into the pores of the porous body is changed, and the relative movement with them vehicle body and the wheel holding member to damp.

The cylinder device of the present invention functions as both a spring and a damper between the vehicle body and the wheel holding member that are relatively operated, and the function as the spring is provided in the working fluid in the pores of the porous body. In addition to the pressure in the sealed space caused by the state in which the gas flows, it depends on the elastic reaction force of the sealing member. In other words, since the cylinder device of the present invention can generate a relatively large support force, it is possible to handle all of the shared load of the wheel only by itself without separately providing a spring parallel to the cylinder device. It becomes possible. By having such an advantage, the cylinder device of the present invention is highly practical.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

In each of the following items, the combination of items (1) , (11), and (12) corresponds to claim 1, and the technical features of item (2) are added to claim 1. The present invention is added to the second aspect, the technical feature of the third aspect is added to the first or second aspect, the third aspect is the third aspect, and the third aspect is the third aspect. The above-mentioned technical feature is added to claim 4 , and the technical feature of claim 4 to which the technical feature of (14) is added corresponds to claim 5 .

(1) A cylinder device provided between two objects that are arranged one above the other and move relative to each other,
A housing connected to one of the two objects;
A piston coupled to the other of the two objects and slidable within the housing;
A porous body and a working fluid having a large number of pores housed in a chamber defined by the housing and the piston;
It has flexibility, forms a sealed space inside the chamber, seals the porous body and a part of the hydraulic fluid in the sealed space in a mixed state, and elastically deforms itself. And a sealing member that allows a change in the volume of the sealed space.
An object located above the two objects depending on the pressure in the sealed space and the elastic reaction force of the sealing member caused by the state in which the hydraulic fluid flows into the pores of the porous body While generating the support force that is the force to support
As the amount of the working fluid flowing into the pores of the porous body changes according to the relative movement of the two objects, the relative movement of the two objects is attenuated, thereby providing a colloidal damper. A functioning cylinder device.

  The cylinder device described in this section, in which the colloidal solution in which the porous body and the hydraulic fluid are mixed, is called a colloidal damper and has a surface tension with respect to the pores of the porous body. It is configured to dissipate energy applied from the outside by repeatedly flowing in and out of the working fluid under the action. The colloidal damper is configured such that the pressure in the chamber increases as the working fluid flows into the pores of the porous body, and the pressure in the chamber when the working fluid flows into the porous body. Thus, it is possible to generate a supporting force for supporting an object located above itself.

  The cylinder device described in this section is also assumed to generate the supporting force, and further, the supporting force is generated only by the pressure in the sealed space generated by the state in which the working fluid flows into the pores of the porous body. Rather, it is configured to be generated depending on the elastic reaction force of the sealing member generated by the state. That is, the cylinder device of this section can generate a relatively large support force because the support force generated by the cylinder device depends on both the pressure in the sealed space and the elastic reaction force of the seal member. It is possible to support an object with a relatively large load.

  Also, the supporting force depending on the pressure in the sealed space depends on the characteristics of the colloidal solution. Specifically, it depends on the particle size of the porous material, the pore diameter of the porous material, and the degree of lyophobic treatment (such as the lyophobic rate) if the porous material has been lyophobized. To do. Because of their variations, there is a relationship between the amount of hydraulic fluid flowing into the pores of the porous body and the pressure in the sealed space, that is, the relationship between the stroke amount of the cylinder device and the pressure in the sealed space. May differ from the designed one. On the other hand, the supporting force depending on the elastic reaction force of the sealing member depends on the rigidity of the sealing member. Since the sealing member does not cause a large error in the manufacturing process, the relationship between the stroke amount of the cylinder device and the elastic reaction force of the sealing member can be relatively easily required in design. .

  Therefore, even if the relationship between the stroke amount of the cylinder device and the pressure in the sealed space varies, the stroke amount of the cylinder device can be determined by optimizing the relationship between the stroke amount of the cylinder device and the elastic reaction force of the sealing member. It is possible to make the relationship between the force and the supporting force as required in the design. Specifically, by making the rigidity of the sealing member appropriate, for example, when the cylinder device has a specified length, the magnitude of the supporting force generated is set to a designed size, The gradient of the change in the support force with respect to the change in the stroke amount of the device (which can be considered as the spring constant of the cylinder device) can be the designed change gradient.

  The cylinder device described in this section uses a colloidal solution in which a “porous body” and a “working fluid” are mixed. The types of these “porous bodies” and “hydraulic fluids” are not particularly limited, but they have low affinity to each other and are difficult to bind to each other. To put it plainly, the porous bodies are hardly soluble in the hydraulic fluid. It is desirable. As the “porous body”, it is possible to adopt μm (micrometer) order particulates (microparticles) having pores on the order of nm (nanometers). It is possible to adopt one that does not dissolve easily or one that is coated with a lyophobic substance. Specifically, for example, silica gel, aerogel, ceramics, zeolite, porous glass, porous polystyrene, or the like can be adopted as the porous body. In addition, for example, water, a mixed solution of water and an antifreezing agent (ethanol, ethylene glycol, propylene glycol, glycerin, etc.), mercury, molten metal, or the like can be used as the “working fluid”. Since water has a relatively large surface tension, when water is used as the working fluid, a large force is generated by the large surface tension when water flows into and out of the pores of the porous body. It becomes a colloidal damper. In addition, when water is used for the working fluid, as described above, it is desirable to use a porous body having a low hydrophilicity or a hydrophobized one.

  The cylinder device described in this section is configured so that the colloidal solution is sealed in the space formed by the sealing member, and the porous and working fluid do not flow out of the sealed space. That is, according to the aspect of this section, the porous body does not rub against the piston, and wear in the housing can be prevented. Therefore, according to the aspect of this section, a colloidal damper having excellent durability is realized.

  In the aspect described in this section, the remainder of the working fluid excluding a part of the working fluid isolated in the sealed space by the sealing member exists inside the chamber and outside the sealed space. In other words, the aspect of this section is an aspect configured to transmit the force applied to the housing and the piston to the sealing member via the hydraulic fluid outside the sealed space that is the remaining part of the hydraulic fluid. The “part of hydraulic fluid (hereinafter sometimes referred to as“ hydraulic fluid in sealed space ”)” described in this section and the above “remaining hydraulic fluid (fluid outside the sealed space)” are the same. It may be a liquid or may be liquids that are different in nature. From the viewpoint of easy transmission of the force applied to the housing and the piston to the sealing member, it is desirable to employ a highly viscous fluid outside the sealed space.

  The “sealing member” described in this section is for allowing a change in the volume of the colloidal solution accompanying the inflow / outflow of the working fluid into the porous body while maintaining the sealed state of the colloidal solution. The sealing member may form a space for sealing the colloidal solution only by the sealing member, or may form a space for sealing the colloidal solution in cooperation with the housing. Specifically, an embodiment in which the space for sealing the colloidal solution is formed only by the sealing member can be realized by, for example, a container-like sealing member that fills the colloidal solution therein. Moreover, the aspect in which the sealing member forms a space for sealing the colloidal solution in cooperation with the housing can be realized, for example, by fixing the outer peripheral portion of the flexible member to the inner surface of the housing. The sealing member is elastically deformed to change the volume in the sealed space. For example, a plate-shaped member, a bag-shaped member, or a member having elasticity can be used. Further, the material thereof is not particularly limited, and those made of rubber or metal can be adopted. Incidentally, when a relatively large load is applied, it is desirable to use a metal that generates a relatively large elastic reaction force.

  (2) The cylinder device according to (1), wherein the sealing member has a bellows portion formed in a bellows shape.

  The mode described in this section is a mode in which the shape of the sealing member is limited. The aspect of this term is an aspect in which the sealing member is configured to generate an elastic reaction force by expansion and contraction of the bellows part. In the aspect of this section, for example, the sealing member is accommodated in the housing so that the direction in which the bellows part expands and contracts is the same as the direction in which the piston slides. There is almost no contact with the inner wall, and the elastic reaction force of the sealing member can be reliably applied to the housing and the piston. In the aspect of this section, the rigidity of the sealing member, that is, the stroke amount of the cylinder device and the elasticity of the sealing member is changed by changing the thickness of the bellows part and the number of peaks and valleys constituting the bellows part. It is possible to change the relationship with the reaction force, and by adjusting the thickness of the bellows part and the number of peaks and valleys that make up the bellows part, the relationship between the stroke amount of the cylinder device and the support force It is possible to optimize

(3) The sealing member is
The cylinder device according to (1) or (2), which is a sealed container that forms the sealed space only by itself and seals the porous body and a part of the hydraulic fluid in a state where they are filled. .

  In the embodiment described in this section, the sealing member is a container, and the colloidal solution is accommodated only by itself. Therefore, the cylinder device according to this aspect can be configured by relatively simple assembly work by preparing a unit in which a sealed container is filled with a colloidal solution and then assembling the unit to the housing. It becomes.

  (4) The cylinder device according to any one of (1) to (3), wherein the hydraulic fluid is water.

  (5) The cylinder device according to item (4), wherein the porous body is a porous silica gel subjected to a hydrophobic treatment.

  The embodiments described in the above two sections are embodiments in which the configuration of the colloid solution is limited. As described above, since water has a large surface tension, it is suitable as a working fluid for a colloidal damper. When the working fluid is water, the porous body is desirably hydrophobic, and the latter mode is a desirable mode.

(6) When a part of the hydraulic fluid sealed in the sealed space is used as the hydraulic fluid in the sealed space,
The cylinder device according to any one of (1) to (5), wherein the remaining portion of the hydraulic fluid is accommodated outside the sealed space inside the chamber as hydraulic fluid outside the sealed space.

  The “hydraulic fluid in the sealed space” and the “fluid outside the sealed space” may be the same liquid as described above, for example, liquids that are different from each other in properties, characteristics, types, and the like. Also good.

  (7) The cylinder device according to (6), wherein the hydraulic fluid in the sealed space and the hydraulic fluid outside the sealed space are different from each other in nature.

  As described above, it is desirable that the hydraulic fluid in the sealed space mixed with the colloidal solution has a large surface tension, and the hydraulic fluid outside the sealed space transmits the force applied to the housing and the piston to the sealed space. It is desirable to be able to communicate efficiently. In the aspect of this section, it is possible to make the working fluid in the sealed space and the working fluid outside and outside the sealed space respectively adopt appropriate liquids according to such demands and the like. In the aspect of this section, the working fluid in the sealed space and the working fluid outside the sealed space may be different types of liquids, such as water and oil, for example, high-viscosity oil and low-viscosity oil. The same type of liquid may have different properties and characteristics.

  (8) The cylinder device according to (6) or (7), wherein the hydraulic fluid outside the sealed space is oil.

  The mode described in this section is a mode in which the hydraulic fluid outside the sealed space is limited, and for example, mineral oil, silicone oil that is synthetic oil, or the like can be employed. For example, consider a colloidal damper having a configuration in which the aspect of this section is combined with the aspect described above in which the working fluid in the sealed space is water. In general, since the viscosity of oil is higher than that of water, the force applied to the housing and the piston can be efficiently transmitted to the colloidal solution in the sealed space. For example, since this cylinder device is configured to support an object located on the upper side, the pressure in the chamber becomes relatively high. That is, in this cylinder device, it is necessary to ensure the sealing performance of the seal provided in the housing in order to keep the inside of the chamber at a high pressure. Oil with high viscosity is difficult to leak from the seal, and is particularly effective in a cylinder apparatus that needs to keep the inside of the chamber at a high pressure as described above. In general, oil has good lubricity, and the sliding of the piston in the housing can be made smooth.

  In general, the solidification temperature of oil is lower than the solidification temperature of water. For example, when the working fluid outside the sealed space starts to solidify, the force transmitted to the colloidal solution in the sealed space may vary with respect to the force applied to the housing and the piston. However, according to the aspect of this section, it is possible to reliably transmit the force applied to the housing and the piston to the colloidal solution by the oil that is difficult to solidify.

  Furthermore, in general, the thermal conductivity of oil is lower than the thermal conductivity of water. The water in the colloidal solution may solidify due to a decrease in the outside air temperature, but by configuring the sealed space with oil, the temperature of the water in the colloidal solution escapes to the outside by the oil with low thermal conductivity. It is possible to suppress this and prevent water from solidifying.

(11) The cylinder device is provided between the vehicle body as the two objects and a wheel holding member that rotatably holds the wheel,
The housing is connected to one of the vehicle body and the wheel holding member, and the piston is connected to the other of the vehicle body and the wheel holding member,
The cylinder device according to any one of (1) to (8), wherein the cylinder device constitutes a suspension device for a vehicle and is a suspension cylinder that suspends the vehicle body.

  The mode described in this section is a mode in which the cylinder device is a constituent element of the vehicle suspension device. Specifically, the mode described in this section is a mode in which the cylinder device functions as a shock absorber that attenuates the relative motion between the vehicle body and the wheel holding member, and also generates a force that supports the vehicle body as a suspension spring. is there.

(12) The cylinder device is
The cylinder device according to (11), wherein the cylinder device is configured to handle all of the shared load of the wheel corresponding to itself by the supporting force.

  The aspect described in this section is an aspect in which it is possible to handle all of the shared load of the wheels (so-called 1 W), and it is not necessary to separately provide a suspension spring, and a compact suspension device is realized. It will be.

(13) The cylinder device is
In a range where relative movement between the vehicle body and the wheel holding member is allowed, both the pressure in the sealed space and the elastic reaction force are both in proportion to the relative movement amount between the vehicle body and the wheel holding member. The cylinder device according to (11) or (12), configured to be

  In the aspect described in this section, both the supporting force depending on the pressure in the sealed space and the supporting force depending on the elastic reaction force of the sealing member are used in the entire stroke range of the cylinder device. It becomes the mode which functions as. In the aspect of this section, the gradient of the change in the supporting force depending on the pressure in the sealed space with respect to the change in the relative operation amount can be considered as a spring constant corresponding to the pressure in the sealed space. The gradient of the change in the supporting force depending on the elastic reaction force of the sealing member with respect to the change in the relative operation amount can be considered as a spring constant corresponding to the elastic reaction force of the sealing member. Furthermore, the sum of these spring constants can be considered as the spring constant of the cylinder device.

  By the way, as a general colloidal damper characteristic, the range in which the pressure in the space containing the colloidal solution and the flow rate of the working fluid into the porous body has a substantially linear relationship has been shown by conventional research and experiments. Is known to exist. Therefore, in order to configure the pressure in the sealed space to be in proportion to the relative operation amount between the vehicle body and the wheel holding member, the colloidal solution is accommodated within a range where the stroke of the cylinder device is allowed. This can be realized by configuring so that the pressure in the space and the inflow amount of the hydraulic fluid are within a linear relationship.

  Furthermore, in order for the stroke range of the cylinder device to be within the range where the pressure in the sealed space and the inflow amount of hydraulic fluid are in a linear relationship, for example, it is realized by configuring the cylinder device as follows: Is possible. First, the amount of hydraulic fluid flowing into the porous body is substantially equal to the amount of decrease in the volume of the chamber, for example, in a colloidal damper in which a single chamber is filled with a colloid solution. Further, for example, in an aspect in which the cylinder device has the same configuration as that of the hydraulic damper, the volume of the piston rod that has entered the housing is substantially equal to the amount of hydraulic fluid flowing into the porous body. Considering this, first, the volume of the porous body is determined by reducing the volume of the chamber when the cylinder device is stroked from the full rebound position to the full bound position (or volume fraction entering the piston rod housing). It is determined that the amount of hydraulic fluid can be made to flow in. Next, the amount of the working fluid is determined to be larger than the amount flowing into the porous body (= the volume reduction amount of the chamber). That is, the cylinder device of the above aspect can be configured by providing a colloidal solution in which they are mixed.

(14) The force depending on the pressure in the sealed space of the support force is defined as an internal pressure dependent support force, and the force dependent on the elastic reaction force of the support force is defined as an elastic reaction force dependent support force. In the case of
The sealing member is
In a range where relative movement between the vehicle body and the wheel holding member is allowed, the relative movement is performed so that the gradient of the change in the support force with respect to the change in the relative movement amount becomes a design change gradient required in design. The gradient of the change in the elastic reaction force-dependent support force with respect to the change in amount is equal to the change gradient difference that is the difference between the design change gradient and the gradient of the change in the internal pressure-dependent support force with respect to the change in the relative operation amount. The cylinder device according to item (13), wherein

  The aspect described in this section is an aspect in which the rigidity of the sealing member is made appropriate in order to set the spring constant of the cylinder device to the design value. As described above, since the characteristics of the colloidal solution vary, it is difficult to make it required in the design. However, according to the aspect of this section, it depends on the characteristics of the colloidal solution. By designing the sealing member, the spring constant of the cylinder device can be set as the design value.

(15) The sealing member is
It has a bellows part formed in a bellows shape,
The cylinder according to (14), wherein the thickness of the bellows portion is set such that a gradient of change with respect to a change in the relative operation amount of the elastic reaction force-dependent support force is equal to the change gradient difference. apparatus.

(16) The sealing member is
It has a bellows part formed in a bellows shape,
The number of crests and troughs forming the bellows is set so that the gradient of change with respect to the change in the relative motion of the elastic reaction force-dependent support force is equal to the change gradient difference. The cylinder device as set forth in (14).

  The modes described in the above two items are modes in which the method for optimizing the spring constant of the cylinder device is limited in the mode in which the sealing member is limited to the one having the bellows portion. As described above, the rigidity of the sealing member can be changed by changing the plate thickness of the bellows part or the number of peaks and valleys forming the bellows part. In this aspect, the thickness of the bellows portions and the number of peaks and valleys forming the bellows portions are optimized.

(21) a housing provided between the vehicle body and a wheel holding member that rotatably holds the wheel; (A) a housing connected to one of the vehicle body and the wheel holding member; and (B) the vehicle body and the wheel holding member. (C) a porous body having a large number of pores accommodated in a chamber defined by the housing and the piston, and an operation And (D) a flexible space, and a sealed space is defined in the chamber, and the porous body and a part of the working fluid are sealed in the sealed space in a state where they are mixed. A sealing member that allows a change in the volume of the sealed space by elastically deforming itself, and (i) the inside of the sealed space generated by the state in which the hydraulic fluid flows into the pores of the porous body Pressure and elastic reaction of the sealing member And (ii) depending on the relative movement between the vehicle body and the wheel holding member, and flows into the pores of the porous body. In the cylinder device that functions as a colloidal damper by attenuating the relative movement between the vehicle body and the wheel holding member by changing the amount of the hydraulic fluid that is changed, the change in the relative movement amount between the vehicle body and the wheel holding member A cylinder device design method for making the gradient of the change in the supporting force with respect to a design change gradient required in design,
In the case where the force depending on the pressure in the sealed space of the support force is an internal pressure dependent support force, and the force depending on the elastic reaction force of the support force is an elastic reaction force dependent support force. ,
A preparation step of preparing the same amount of the porous body to be sealed in the sealed space and the same part of the working fluid;
A measurement step of measuring a gradient of a change in pressure in the sealed space with respect to a change in volume of the sealed space, assuming that the prepared porous body and hydraulic fluid are sealed in the sealed space of the cylinder device When,
Based on the measured gradient of the pressure change in the sealed space with respect to the change in the volume of the sealed space, the gradient of the change in the internal pressure-dependent support force with respect to the change in the relative operation amount is estimated, and the estimated An estimation step of estimating a change gradient difference that is a difference between a change gradient of the internal pressure-dependent support force with respect to a change in the relative operation amount and the design change gradient;
A sealing member design step for designing the sealing member employed in the cylinder device so that the gradient of the change in the elastic reaction force dependent support force with respect to the change in the relative operation amount is equal to the change gradient difference. Device design method.

  The mode described in this section is a mode in which the category is a design method of the cylinder device. According to the cylinder device design method described in this section, as described above, the spring constant of the cylinder device can be set to a value required for design.

It is a front view of the suspension device for vehicles which used the cylinder device which is an example of claimable invention as one component. It is front sectional drawing of the cylinder apparatus which is an Example of claimable invention. It is sectional drawing which shows the porous body shown in FIG. 2 typically. It is front sectional drawing of the colloidal damper of the simple structure conventionally known. It is a figure which shows the relationship between the stroke in the colloidal damper shown in FIG. 4, and the pressure in a chamber. It is a figure which shows the relationship between the stroke in the cylinder apparatus which is an Example of claimable invention, and the pressure in sealed space. It is a figure which shows the relationship between the stroke in the cylinder apparatus which is an Example of claimable invention, and the supporting force to generate. It is front sectional drawing of the suspension apparatus for vehicles provided with the cylinder apparatus comprised by the other design method.

  Hereinafter, representative embodiments of the claimable invention will be described in detail with reference to the drawings. In addition to the following examples, the claimable invention is implemented in various modes including various modifications and improvements based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. can do.

<Configuration of suspension device>
As shown in FIG. 1, the cylinder device 10 of the present embodiment is a component of a vehicle suspension device. The vehicle suspension device is an independent suspension type provided corresponding to each of the wheels 12 of the vehicle, and is a multi-link suspension device. The suspension device includes a first upper arm 20, a second upper arm 22, a first lower arm 24, a second lower arm 26, and a toe control arm 28, each of which is a suspension arm. One end of each of the five arms 20, 22, 24, 26, 28 is rotatably connected to the vehicle body, and the other end is an axle carrier 30 as a wheel holding member that rotatably holds the wheel 12. It is connected to the pivotable. By these five arms 20, 22, 24, 26, and 28, the axle carrier 30 is allowed to move up and down along a certain locus with respect to the vehicle body. The cylinder device 10 is disposed between a mount portion 32 provided on a tire housing that is a part of the vehicle body and the second lower arm 26.

  FIG. 2 is a front sectional view of the cylinder device 10. The cylinder device 10 includes a generally cylindrical housing 42 and a piston 44 slidably disposed with respect to the housing 42. The piston 44 has a piston main body 50, and the piston main body 50 divides the inside of the housing 42 into an upper chamber 52 and a lower chamber 54 that are two chambers with the piston 42 interposed therebetween. The piston 44 further has a piston rod 58, which is connected to the piston main body 50 at the lower end portion and extends from a lid portion provided at the upper end portion of the housing 42. The piston rod 58 is connected to the lower surface side of the mount portion 32 via an upper support 62 configured to include an anti-vibration rubber 60 at the upper end portion. On the other hand, the housing 42 is connected to the second lower arm 26 via a bushing 64 at the lower end thereof.

  That is, the housing 42, the piston rod 58, and the piston 44 coupled thereto can be relatively moved in the axial direction in accordance with the approach and separation between the vehicle body (mount portion 32) and the wheel 12 (axle carrier 30). Yes. In other words, the cylinder device 10 can be expanded and contracted in accordance with the approach and separation between the vehicle body and the wheel 12.

  Incidentally, the cylinder device 10 includes a cover tube 70, which covers the piston rod 58 and the upper portion of the housing 42, and prevents entry of dust, mud, and the like from the outside. Yes.

  A metal bellows 80 is fixed to the lower end of the housing 42 and is accommodated in the lower chamber 54. The bellows 80 is hermetically sealed with a colloidal solution 90 in which a hydrophobic porous silica gel 82 and water 84 are mixed. The bellows 80 is configured to expand and contract in the vertical direction while being fixed in the housing 42. Therefore, the bellows 80 is formed in a container shape, and functions as a sealing member that forms a sealed space by itself and seals the colloidal solution 90 therein. The colloidal solution sealing body 92 including the bellows 80 and the colloidal solution 90 is provided. Further, the water 84 is a working fluid in the sealed space.

  FIG. 3 schematically shows a cross-sectional view of one particle of the hydrophobized porous silica gel 82. Hydrophobized porous silica gel particles 100 are spherical silica gel particles having an outer diameter D on the order of several μm to several tens of μm and an inner diameter d of the pores 102 on the order of several nm to several tens of nm. (Including the inside) is hydrophobized with a hydrophobic substance. That is, each of the hydrophobized porous silica gel particles 100 functions as a porous body.

  The lower chamber 54 is filled with a mineral oil 110 as a working fluid outside the sealed space in a state in which the colloidal solution sealing body 92 is accommodated. The upper chamber 52 is also filled with mineral oil 110. The piston body 50 described above is provided with a plurality of communication passages 112 that penetrate the piston main body 50 in the axial direction and communicate the upper chamber 52 and the lower chamber 54. That is, when the volumes of the upper chamber 52 and the lower chamber 54 change with the sliding of the piston 44 with respect to the housing 42, the mineral oil 110 is transferred between the upper chamber 52 and the lower chamber 54 by the communication passage 112. Distribution is allowed. Incidentally, as will be described in detail later, since the interior of the housing 42 is at a high pressure, a plurality of lids at the upper end portion and the lower end portion of the housing 42 have a plurality of portions in order to prevent the mineral oil 110 from leaking. High pressure seals 114 and 116 are provided. In particular, two seals 116 that are in contact with the sliding surface of the piston rod 58 are provided on the lid at the upper end where the piston rod 58 slides. Grease is sealed between the two seals 116 to improve the sealing performance.

  The cylinder device 10 includes a mechanism that restricts the approaching and separating operation between the vehicle body and the wheels, a so-called bound stopper, and a rebound stopper. Specifically, the bound stopper is configured to include an annular buffer rubber 140 attached to the upper inner end of the cover tube 70, and the upper end of the housing 42 contacts the cover tube 70 via the buffer rubber 140. It is configured to touch. The rebound stopper includes an annular cushioning rubber 142 attached to the lower surface of the upper lid portion of the housing 42, and the upper surface of the piston 44 and the upper lid portion of the housing 42 constitute the cushion rubber. It is comprised so that it may contact | abut via 142.

<Characteristics as colloidal damper>
i) Characteristics of General Colloidal Damper As described above, the present suspension device is mainly composed of the cylinder device 10, and the cylinder device 10 is a colloidal damper that accommodates the colloidal solution 90 therein. The function of the cylinder device 10 as a colloidal damper will be described in detail below. First, before describing the cylinder device 10, general characteristics of the colloidal damper will be described in detail with reference to FIG. 5 taking the colloidal damper 150 having a simple configuration shown in FIG. 4 as an example. The colloidal damper 150 includes a cylinder device 156 that includes a housing 152 and a piston 154 that slides in the housing 152. In the colloidal damper 150, a chamber 158 formed by the housing 152 and the piston 154 is filled with a colloidal solution 164 in which a porous body 160 and a working fluid 162 are mixed.

  FIG. 5 is a diagram showing the relationship between the relative movement amount S (stroke of the cylinder device 156) between the housing 152 and the piston 154 and the internal pressure p of the chamber 158. In the colloidal damper 150, when a force for contracting the cylinder device 156 is applied from the outside, first, the hydraulic pressure of the hydraulic fluid 162 in the chamber 158 increases greatly (with a steep gradient) (range (I) in FIG. 5). . When the hydraulic pressure of the hydraulic fluid 162 rises to a certain height, the hydraulic fluid 162 starts to flow into the pores of the porous body 160 against the surface tension of the hydraulic fluid 162, and the magnitude of the applied force is increased. The hydraulic fluid 162 flows in by a proportional amount (range (II) in FIG. 5). Due to the flow of the working fluid 162 into the porous body 160, the volume of the colloidal solution 164 decreases, and the cylinder device 156 is stroked to contract. That is, the inflow amount of the hydraulic fluid 162 and the volume change of the chamber 158 are equal, and it can be said that the inflow amount of the hydraulic fluid 162 and the stroke of the cylinder device 156 are in a linear relationship. Further, as the amount of the hydraulic fluid 162 flowing in increases, the internal pressure of the chamber 158 also increases. That is, as shown in the range of (II) in FIG. 5, the stroke S of the cylinder device 156 and the internal pressure p of the chamber 158 have a linear relationship. Then, when the hydraulic fluid 162 flows into the porous body 160 to the vicinity where it can flow, the hydraulic pressure of the hydraulic fluid 162 starts to increase greatly (range (III) in FIG. 5).

  Next, when the force applied to the cylinder device 156 is removed, the hydraulic pressure of the hydraulic fluid 162 is greatly reduced (with a steep slope) (range (IV) in FIG. 5). Thereafter, when the hydraulic pressure of the hydraulic fluid 162 decreases, the hydraulic fluid 162 flows out from the pores of the porous body 160 (range (V) in FIG. 5). Due to the outflow of the working fluid 162 from the porous body 160, the volume of the colloidal solution 164 increases, and the cylinder device 156 performs a stroke operation so as to extend. In the case where the hydraulic fluid 162 shown in the range of (V) in FIG. 5 flows out, the stroke S of the cylinder device 156 and the internal pressure p of the chamber 158 are linear as in the case where the hydraulic fluid 162 flows in. It has become a relationship.

  If the state between the porous body 160 and the working fluid 162 is described using the contact angle between the porous body 160 and the working fluid 162, the working fluid 162 flows into the porous body 160. The contact angle is large, and the contact angle decreases when the hydraulic fluid 162 flows out of the porous body 160. Therefore, as shown in FIG. 5, there is a difference between the internal pressure of the chamber 158 when the hydraulic fluid flows in (shrinks) and the internal pressure of the chamber 158 when the hydraulic fluid flows out (extension). That is, as shown in FIG. 5, hysteresis occurs in the change in the internal pressure p of the chamber 158 with respect to the change in the stroke S of the cylinder device 156. As a result, the colloidal damper 150 is configured to dissipate energy and attenuate the relative movement of two relatively moving objects. Incidentally, the area surrounded by the hysteresis in FIG. 5 corresponds to the dissipated energy.

ii) Characteristics of the Cylinder Device as a Colloidal Damper In this cylinder device 10, the colloidal solution 90 is sealed in the bellows 80, but the force applied from the outside is applied to the colloidal solution sealed body 92 via the mineral oil 110. Is transmitted to. And when the colloidal solution sealing body 92 applies force to itself, the hydraulic pressure of the water 84 accommodated in the bellows 80 will rise. When the hydraulic pressure of the water 84 rises to a certain height, the water 84 flows into the pores 102 of the hydrophobic porous silica gel particles 100 against the surface tension. Along with this, the bellows 80 contracts, and the volume of the colloidal solution sealing body 92 decreases. On the other hand, when the force applied to itself is lost, the hydraulic pressure of the water 84 decreases, and the water 84 flows out from the pores 102 of the hydrophobic porous silica gel particles 100. Accordingly, the bellows 80 expands, and the volume of the colloid solution sealing body 92 increases. That is, the cylinder device 10 also has the same characteristics as the colloidal damper 150 described above. FIG. 6 shows the relationship between the stroke S of the cylinder device 10 and the internal pressure p of the colloidal solution sealing body 92.

<Function of this cylinder device>
i) Function as Suspension Spring As described above, the cylinder device 10 is a main component of the suspension device. First, the cylinder device 10 has a function as a suspension spring. The cylinder device 10 is disposed between the mount portion 32 and the second lower arm 26, and receives a shared load (so-called 1W) of the wheel 12 corresponding to the cylinder device 10 and contracts. When the cylinder device 10 contracts, a certain amount of water 84 flows into the pores 102 of the hydrophobic porous silica gel 100, and the pressure in the colloidal solution sealing body 92 rises. Further, with the inflow of water 84 into the pores 102 of the hydrophobic porous silica gel 100, the bellows 80 sealing the colloidal solution 90 contracts, and the bellows 80 generates an elastic reaction force by the contraction. It will be. That is, the pressure outside the colloidal solution sealing body 92 in the lower chamber 54 depends on both the internal pressure of the colloidal solution sealing body 92 and the elastic reaction force of the bellows 80. Therefore, the cylinder device 10 is configured to generate a supporting force F that is a force for supporting the vehicle body, depending on both the internal pressure of the colloidal solution sealing body 92 and the elastic reaction force of the bellows 80. The supporting force F is responsible for the shared load of the wheels.

  First, the supporting force depending on the internal pressure of the colloidal solution sealing body 92 will be described in detail. As shown in FIG. 6, the cylinder device 10 is configured so that all water 84 does not flow out from the pores 102 of the hydrophobized porous silica gel particles 100 within a range where the stroke is allowed. The amount of water 84 flowing into the pores 102 of the hydrophobized porous silica gel particle 100 does not reach a limit value at which it can flow. As can be seen from FIG. 6, when the stroke is made so that the volume of the lower chamber 54 in which the colloid solution sealing body 92 is accommodated is reduced, in other words, when the cylinder device 10 is stroked so as to contract, the colloid is reduced. The internal pressure p of the solution sealing body 92 is proportional to the amount of water 84 flowing into the pores 102 of the hydrophobic porous silica gel particles 100. The amount of water 84 flowing into the pores 102 of the hydrophobized porous silica gel particles 100 is equal to the volume of the piston rod 58 that has entered the housing 42. That is, the internal pressure p of the colloid solution sealing body 92 has a magnitude proportional to the stroke amount of the cylinder device 10 (the relative movement amount between the vehicle body and the wheel holding member). Therefore, it can be considered that the cylinder device 10 generates a force responsible for 1 W in the entire stroke range of the cylinder device 10 determined by the rebound stopper and the bound stopper.

Further, as shown in FIG. 6, in the stroke range of the cylinder device 10, the gradient of the change in the internal pressure p of the colloid solution sealing body 92 with respect to the change in the stroke amount is substantially constant. Therefore, the change gradient with respect to the change in the stroke amount of the internal pressure-dependent support force F _C that is the support force depending on the internal pressure of the colloid solution sealing body 92 is also substantially constant. That is, the internal pressure-dependent support force can be considered as a part of the spring force generated by the cylinder device 10, and the change gradient of the internal pressure-dependent support force is a spring of spring force that depends on the internal pressure of the colloidal solution sealing body 92. It can be considered as a constant K _C.

  Next, the supporting force depending on the elastic reaction force of the bellows 80 will be described. The elastic reaction force of the bellows 80 is proportional to the contracted amount. Since the volume reduced by the colloidal solution sealing body 92 due to the contraction of the bellows 80 is equal to the amount of water 84 flowing into the pores 102 of the hydrophobic porous silica gel particle 100, the contraction amount of the bellows 80 is the hydrophobic porous silica gel particle. It is proportional to the amount of water 84 flowing into 100 pores 102. That is, it is considered that the elastic reaction force of the bellows 80 is also proportional to the inflow amount of the water 84. As described above, the amount of water 84 flowing into the pores 102 of the hydrophobic porous silica gel particles 100 is equal to the volume of the piston rod 58 that has entered the housing 42. Therefore, the elastic reaction force of the bellows 80 is also proportional to the stroke amount of the cylinder device 10 (the relative operation amount between the vehicle body and the wheel holding member). By the way, the bellows 80 does not reach the limit of contraction even when the cylinder device 10 is fully bound.

Further, in the stroke range of the cylinder device 10, the change gradient with respect to the change in the stroke amount of the elastic reaction force of the bellows 80 is substantially constant, and the elastic reaction force-dependent support force that is a support force that depends on the elastic reaction force of the bellows 80. gradient change with respect to the stroke amount of change in F _B also becomes substantially constant. That is, the elastic reaction force-dependent support force can be considered as a part of the spring force generated by the cylinder device 10, and the change gradient of the elastic reaction force-dependent support force depends on the elastic reaction force of the bellows 80. it can be considered as a spring constant K _B of the force.

FIG. 7 shows the relationship between the support force F generated by the cylinder device 10 and the stroke of the cylinder device 10. Supporting force F of the cylinder device 10 generates, as described above, because it depends on both the elastic reaction of the internal pressure and the bellows 80 of the colloidal solution seal 92, the above pressure-dependent supporting force F _C and the elastic reaction It is the sum of the force-dependent support force F _B and the following equation.
F = F _C + F _B
＝ K _C・ S + K _B・ S
Accordingly, the gradient of change of the support force F generated by the cylinder device 10 with respect to the change in stroke amount, that is, the spring constant K when the cylinder device 10 functions as a suspension spring is expressed by the following equation.
K = K _C + K _B
The spring constant K of the cylinder device 10 is a design spring constant K _P required in design.

Incidentally, as described above, the cylinder device 10 strokes in such a range that the internal pressure p of the cylinder device 10 is proportional to the amount of water 84 flowing into the pores 102 of the hydrophobic porous silica gel particles 100. It is configured. In order that the cylinder device 10 has such a configuration, the amount (volume) of the hydrophobized porous silica gel 86 accommodated in the colloidal solution sealing body 92 and the amount (volume) of the water 84 are determined. First, in the cylinder device 10, from the neutral position in the standard state (for example, the state where no one is on the vehicle, nothing is loaded, and the vehicle is stopped on the horizontal plane), the bound direction If the stroke amount S _b can be stroked in the rebound direction by the stroke amount S _r, the volume change ΔV that combines the upper chamber 52 and the lower chamber 54 of the cylinder device 10 will be different between full bound and full rebound. It is obtained as follows.
ΔV = A · (S _b + S _r )
Here, A is a pressure receiving area that is an area where the pressure in the housing 42 acts on the piston 44, and in the cylinder device 10, the cross-sectional area of the piston rod 58 corresponds to it.

In the cylinder device 10, it is necessary that the hydrophobic porous silica gel 86 can flow in an amount of water 84 equal to the volume change ΔV. In other words, if the ratio of the limit value at which the water 84 of the hydrophobic porous silica gel 86 can flow into the volume of the hydrophobic porous silica gel 86 is η, the necessary minimum amount (volume) of the hydrophobic porous silica gel 86 V _Smin Is determined by the following equation.
V _Smin = ΔV / η
In the hydrophobic porous silica gel 86, there is a case where all of the hydrophobic silica gel 86 is not hydrophobized and the water-absorbing silica gel remains. For example, if the ratio of the amount of hydrophobized silica gel excluding the amount of non-hydrophobized silica gel to the total amount subjected to hydrophobization treatment is defined as the hydrophobization rate β, the variation in the hydrophobization rate, etc. To accommodate this, the actual amount (in volume) V _S of the hydrophobized porous silica gel 86 is determined by the following equation and is greater than its required minimum amount V _{Smin of} the hydrophobized porous silica gel 86.
V _S = V _Smin / β
Further, since the amount V _{F of the} water 84 may be ΔV or more with respect to the amount V _{S of} the hydrophobic porous silica gel 86, in this cylinder device 10, V _F = V _S.

ii) Function as a shock absorber In this cylinder device 10, if the change in the internal pressure of the colloidal solution sealing body 92 in one cycle of operation from the neutral position is shown in relation to the stroke S of the cylinder device 10, FIG. It looks like a two-dot chain line. Similar to the general colloidal damper 150 described above, the cylinder device 10 includes an internal pressure of the colloidal solution sealing body 92 when the hydraulic fluid flows in (contraction) and a colloidal solution sealing body when the hydraulic fluid flows out (extension). As shown in FIG. 6, a hysteresis is generated in the change in the internal pressure p of the colloid solution sealing body 92 with respect to the change in the stroke S of the cylinder device 10. The area surrounded by the two-dot chain line in FIG. 6 corresponds to the energy dissipated in one cycle of operation. That is, the cylinder device 10 attenuates the relative movement between the vehicle body and the wheel 12, and functions as a shock absorber.

  <Characteristics of this colloidal damper>

  As described above, the cylinder device 10 having a function as a colloidal damper has not only a function as a shock absorber but also a function as a suspension spring. For this reason, the present suspension device does not require a separate suspension spring and has a simple configuration.

  The cylinder device 10 is configured such that a colloidal solution composed of a porous body and a working fluid is sealed in a sealed container, and the working fluid does not flow out of the sealed container. That is, the cylinder device 10 can prevent wear in the cylinder device 10 without the hydrophobic porous silica gel particles 100 having a relatively high hardness from rubbing against the housing 42 and the piston 44. In addition, for example, there is a colloidal damper having a configuration in which a porous body is isolated by a filter or a container from a portion where a piston of a housing slides. However, a colloidal damper with a structure in which the porous body is isolated by the filter or container is clogged or passed through the filter or container by the porous body that has been crushed by stress or the like. There is a problem of end. On the other hand, since the colloidal solution is sealed in the sealed container, the cylinder device 10 naturally does not flow out of the sealed container even if the porous body is crushed and reduced in size. Therefore, the cylinder device 10 is a colloidal damper having excellent durability.

  In addition, the cylinder device 10 includes chambers 52 and 54 for transmitting the working fluid in the sealed space that flows into and out of the pores 102 of the hydrophobic porous silica gel particles 100 and the force applied from the outside to the colloid solution sealing body 92. The hydraulic fluid outside the sealed space filled in is a different liquid and has different properties and characteristics. More specifically, the mineral oil 110 that is the hydraulic fluid outside the sealed space and the water 84 that is the hydraulic fluid inside the sealed space have different kinematic viscosities, and the dynamic viscosity of the hydraulic fluid outside the sealed space is different from that in the sealed space. It is higher than the kinematic viscosity of the liquid. Thereby, the mineral oil 110 that is the hydraulic fluid outside the sealed space can efficiently transmit the force applied to the cylinder device 10 to the colloidal solution sealing body 92. Moreover, since this cylinder apparatus 10 is responsible for 1 W, it is necessary to maintain the internal pressure of the cylinder apparatus 10 at a high pressure. In the present cylinder device 10, since the mineral oil 110 that is the working fluid outside the sealed space has a high viscosity, the sealing performance of the seals 114 and 116 provided in the housing 42 is ensured.

  Further, the mineral oil 110 that is the hydraulic fluid outside the sealed space and the water 84 that is the hydraulic fluid in the sealed space have different thermal conductivities, and the thermal conductivity of the hydraulic fluid outside the sealed space is different from that of the hydraulic fluid in the sealed space. It is lower than the thermal conductivity. The cylinder device 10 is configured such that the colloidal solution sealing body 92 is covered with the mineral oil 110. That is, in the cylinder device 10, the water 84, which is the working fluid in the sealed space, may solidify when the outside air temperature decreases, but the temperature of the water 84 escapes to the outside by the mineral oil 110 having low thermal conductivity. It is possible to suppress the temperature drop of the water 84.

  Furthermore, the mineral oil 110 that is the hydraulic fluid outside the sealed space and the water 84 that is the hydraulic fluid inside the sealed space have different solidification temperatures, and the solidification temperature of the hydraulic fluid outside the sealed space is the solidification temperature of the hydraulic fluid inside the sealed space. It is lower. For example, when the working fluid outside the sealed space starts to solidify, the force transmitted to the colloid solution sealing body 92 may vary with respect to the force applied to the cylinder device 10 from the outside. However, the cylinder device 10 can reliably transmit the force applied to the cylinder device 10 from the outside to the colloid solution sealing body 92 by the mineral oil 110 that is hard to solidify.

  Furthermore, the cylinder device 10 generates a relatively large support force because the support force it generates depends on both the internal pressure of the colloidal solution sealing body 92 and the elastic reaction force of the bellows 80. It is possible to handle a relatively large shared load.

Further, the supporting force depending on the internal pressure of the colloid solution sealing body 92 depends on the characteristics of the colloid solution 90. Specifically, it depends on the particle diameter of the hydrophobized porous silica gel 82, the diameter of the pores 102 it has, the degree of lyophobic treatment (such as the lyophobic rate). Because of these variations, the spring constant K _C of the spring force depending on the internal pressure of the colloid solution sealing body 92 may be different from the designed one. In other words, the cylinder device that generates the supporting force depending only on the internal pressure of the colloidal solution sealing body 92 has a problem that it is difficult to obtain a spring constant required by design. In contrast, the spring constant K _B of the spring force depends on the elastic reaction of the bellows 80, since there is no possibility that a large error occurs in the course of production of the bellows 80, and the relative ease that is required on the design basis can do. In this cylinder device 10, the bellows 80 is designed in consideration of an error in the design of the characteristics of the colloidal solution 90, and therefore, the spring constant K of the cylinder device 10 is the design spring constant K _P. is there. That is, even if this cylinder device 10 has a function as a colloidal damper, its spring constant has a high accuracy with a value required for design.

<Method for designing sealing member>
Below, the design method of this cylinder apparatus 10 and the design method of the bellows 80 mentioned above in detail are demonstrated. As described above, it depends on the internal pressure of the colloidal solution sealing body 92 depending on the particle diameter of the hydrophobized porous silica gel 82, the variation in the diameter of the pores 102 it has, and the degree of lyophobic treatment (such as the lyophobic rate). The spring constant K _C of the spring force may be different from the designed one. Therefore, first, the same amount of the same hydrophobized porous silica gel 82 and water 84 used in the cylinder device 10 is prepared. (Preparation process)

  Next, the hydrophobic porous silica gel 82 and the water 84 are filled into the chamber of the cylinder apparatus shown in FIG. A force for contracting the cylinder device is applied to the cylinder device, and a pressure in the chamber is measured with respect to a change in the volume of the chamber. Thereby, the change gradient of the internal pressure of the colloidal solution sealing body 92 with respect to the change of the stroke amount of the cylinder device 10 when the water 84 flows into the hydrophobic porous silica gel 82 is obtained. (Measurement process)

Subsequently, based on the change gradient of the internal pressure of the colloid solution sealing body 92 with respect to the change in the stroke amount of the cylinder device 10, the change gradient of the internal pressure-dependent supporting force F _C with respect to the change in the stroke amount of the cylinder device 10, that is, the colloid. A spring constant K _C depending on the internal pressure of the solution sealing body 92 is obtained. Then, as the spring constant K of the cylinder device 10 is designed spring constant K _P, based on its design spring constant K _P, and the spring constant K _C that depends on the internal pressure of the colloidal solution seal 92, the bellows 80 spring constant K _B is obtained according to the following equation. (Estimation process)
K _B = K _P -K _C

The bellows used in the cylinder device 10, such that it spring constant becomes the spring constant K _B obtained as described above, the number of ridges and valleys that form a thickness and the bellows are set The The bellows 80 is manufactured based on the plate thickness and the number of peaks and valleys. (Sealing member design process)

With such a design method, the spring constant of the spring force generated by the cylinder device 10, that is, the spring constant of the spring force generated by the suspension device is set to a substantially designed value. Incidentally, the bellows 80 is such a way as to select the one that spring constant advance Prepare the different plurality respectively, and has a nearest spring constant to the spring constant K _B obtained from them as described above Can also be adopted. Incidentally, in that case, for example, the plurality of bellows to be prepared may have different plate thicknesses, or may have different numbers of peaks and valleys.

<Other methods for designing a suspension device having a colloidal damper>
FIG. 8 shows the vehicle suspension apparatus 200 in which the spring constant of the spring force generated by the vehicle suspension apparatus is set to a substantially designed value, as in the above embodiment. The vehicle suspension device 200 includes a cylinder device 202 configured in the same manner as the cylinder device 10 of the above embodiment. That is, the cylinder device 202 has a bellows 204 that seals the colloidal solution 90 in which the hydrophobic porous silica gel 82 and the water 84 are mixed, as in the cylinder device 10 of the above embodiment. Depending on both the elastic reaction force and the elastic reaction force, a support force for supporting the vehicle body is generated.

  However, the suspension device 200 is responsible for a shared load that is greater than the shared load that the suspension device of the above-described embodiment has. That is, the suspension device 200 further includes a coil spring 210 provided in parallel with the cylinder device 202 in order to handle the large shared load. Therefore, the suspension device 200 generates a support force for supporting the vehicle body not only depending on both the internal pressure in the bellows 204 and the elastic reaction force of the bellows 204 but also on the spring force of the coil spring 210. It is configured as follows. The coil spring 210 secures the support force generated by the cylinder device 10, and the support force generated by the coil spring 210 is smaller than the support force generated by the cylinder device 10.

Therefore, the spring constant K of the spring force generated by the suspension device 200 is the spring constant K _C depending on the internal pressure of the bellows 204, the spring constant K _B depending on the elastic reaction force of the bellows 204, and the spring constant K _{S of the} coil spring 210. Will be added.
K = K _C + K _B + K _S
Therefore, in this suspension apparatus 200, in order to set the spring constant K of the suspension apparatus 200 to the set spring constant K _P , the spring constant K _C depending on the internal pressure of the bellows 204 and the spring constant of the coil spring 210 are set. based on the K _S, may be designed spring constant K _B of the bellows 204, on the basis of the spring constant K _B of the spring constant K _C and the bellows 204 which is dependent on the internal pressure of the bellows 204, the coil spring 210 The spring constant K _S may be designed. From the above, the suspension device 200 is a highly accurate suspension device in which the spring constant is set to a set value, similar to the suspension device including the cylinder device 10 of the embodiment.

  DESCRIPTION OF SYMBOLS 10: Cylinder apparatus (colloidal damper) 12: Wheel 26: 2nd lower arm 30: Axle carrier (wheel holding member) 32: Mount part (a part of vehicle body) 42: Housing 44: Piston 50: Piston main body 52: Upper chamber ( (Chamber) 54: lower chamber 58: piston rod 80: bellows (sealing member) 82: hydrophobized porous silica gel 84: water (hydraulic fluid in sealed space) 90: colloidal solution 92: colloidal solution sealed body 100: hydrophobized porous Silica gel particles (porous body) 102: pores 110: mineral oil (fluid outside the sealed space) 200: suspension device 202: cylinder device (colloidal damper) 204: bellows (sealing member) 210: coil spring

Claims (5)

A cylinder device provided between two objects that are arranged vertically and move relative to each other,
A housing connected to one of the two objects;
A piston coupled to the other of the two objects and slidable within the housing;
A porous body and a working fluid having a large number of pores housed in a chamber defined by the housing and the piston;
It has flexibility, forms a sealed space inside the chamber, seals the porous body and a part of the hydraulic fluid in the sealed space in a mixed state, and elastically deforms itself. And a sealing member that allows a change in the volume of the sealed space.
An object located above the two objects depending on the pressure in the sealed space and the elastic reaction force of the sealing member caused by the state in which the hydraulic fluid flows into the pores of the porous body While generating the support force that is the force to support
As the amount of the working fluid flowing into the pores of the porous body changes according to the relative movement of the two objects, the relative movement of the two objects is attenuated, thereby providing a colloidal damper. A functioning cylinder device ,
The cylinder device is provided between the vehicle body as the two objects and a wheel holding member that rotatably holds the wheel,
The housing is connected to one of the vehicle body and the wheel holding member, and the piston is connected to the other of the vehicle body and the wheel holding member,
The cylinder device constitutes a suspension device for a vehicle and is a suspension cylinder that suspends the vehicle body,
A cylinder device configured to handle all of the shared load of the wheel corresponding to itself by the supporting force.   The cylinder device according to claim 1, wherein the sealing member has a bellows portion formed in a bellows shape. The sealing member is
3. The cylinder device according to claim 1, wherein the cylinder device is a sealed container that forms the sealed space only by itself and seals the porous body and a part of the hydraulic fluid in a state where they are filled. The cylinder device is
In a range where relative movement between the vehicle body and the wheel holding member is allowed, both the pressure in the sealed space and the elastic reaction force are both in proportion to the relative movement amount between the vehicle body and the wheel holding member. The cylinder device according to any one of claims 1 to 3, wherein the cylinder device is configured as follows. In the case where the force depending on the pressure in the sealed space of the support force is an internal pressure dependent support force, and the force depending on the elastic reaction force of the support force is an elastic reaction force dependent support force. ,
The sealing member is
In a range where relative movement between the vehicle body and the wheel holding member is allowed, the relative movement is performed so that the gradient of the change in the support force with respect to the change in the relative movement amount becomes a design change gradient required in design. The gradient of the change in the elastic reaction force-dependent support force with respect to the change in amount is equal to the change gradient difference that is the difference between the design change gradient and the gradient of the change in the internal pressure-dependent support force with respect to the change in the relative operation amount. The cylinder device according to claim 4 , wherein the cylinder device is made.

Images