JP2012097853A - Colloidal damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a colloidal damper which has two kinds of damping characteristics and has high practicality.SOLUTION: The colloidal damper is configured such that relative movement between a vehicle body 32 and a wheel retention member 26 is damped by causing operation liquid 84 to flow in and out to/from fine pores of a porous body 82 and is damped also by applying resistance for passage of the operation liquid 84 between two chambers 60, 62 on communication paths 120, 122 that a cylinder device 40 has. Thereby, according to two kinds of damping characteristics, the damping characteristic of the colloidal damper can be made appropriate, the damping characteristic suitable for relative movement of two objects is provided and, thereby, the relative movement of them can be effectively damped.

Description

  The present invention comprises a colloidal solution in which a porous body having pores and a liquid are mixed, and energy applied from the outside by utilizing the action of liquid flowing into and out of the pores of the porous body. It is related with the colloidal damper which can dissipate.

  The colloidal damper described in the following patent document uses a colloidal solution in which a porous material such as hydrophobized porous silica gel and a liquid are mixed, and the pores of the porous material in the colloidal solution On the other hand, it is configured to dissipate energy applied from the outside by repeatedly flowing in and out of the liquid under the action of surface tension. The colloidal damper has characteristics not found in conventional hydraulic dampers, for example, the amount of energy dissipation depends on the amplitude, and is expected to be applied in various fields.

International Publication No. 2008/029501 Pamphlet JP 2008-309250 A

  The 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 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 a highly practical colloidal damper.

  In order to solve the above-described problems, a colloidal damper according to the present invention includes (a) a housing connected to one of two relatively moving objects, (b) a piston that divides the housing into two chambers, and (c A cylinder device having one end connected to the piston and the other end extending from the housing and connected to the other of the two objects that move relative to each other and housed in the housing (A) In the relative movement of two relatively moving objects including a porous body having a large number of pores and (B) a working fluid, the working fluid flows in and out of the pores of the porous body. The cylinder device further includes a communication path that allows the two chambers to communicate with each other, and allows the hydraulic fluid to flow between the two chambers in the communication path. Resistance against Configured to include a Azukasuru mechanism.

  The colloidal damper according to the present invention attenuates the relative movement of two objects by flowing in and out of the porous fluid to the pores of the porous body, in addition to the flow of hydraulic fluid between the two chambers. On the other hand, it is configured to be attenuated by applying resistance, and has two types of attenuation characteristics. According to the colloidal damper of the present invention, it is possible to optimize the damping characteristic of the colloidal damper by using these two types of damping characteristics. By making the damping characteristics suitable for the relative motion of the two objects, It becomes possible to effectively attenuate the relative movement of the. By having such an advantage, the colloidal damper of the present invention becomes 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 item (1) corresponds to the item 1, and the technical feature of the item (2) is added to the item 1, the item 2, the item 2, the item 3, and the item 3. The technical feature of claim 3 is added to claim 3, the claim 2 to which the technical feature of (4) is added is claimed in claim 4, and any one of claims 1 to 4 is added. The technical feature of (11) is added to claim 5, and the technical feature of (15) and (17) is added to claim 5, to claim 6, to claim 5, or to claim 5. 6. The technical features of (15) and (18) are added to 6 and correspond to claim 7, respectively.

(1) (a) a housing connected to one of two relatively moving objects; (b) a piston that divides the interior of the housing into two chambers and is slidable within the housing; A piston rod disposed through one of the two chambers, having one end connected to the piston and the other end extending from the housing and connected to the other of the two objects; A cylinder device comprising:
(A) a porous body having a large number of pores and (B) a working fluid contained in the housing,
A colloidal damper configured to attenuate the relative movement of the two objects by flowing the hydraulic fluid into and out of the pores of the porous body during the relative movement of the two objects; There,
The cylinder device further comprises:
There is a communication path that allows the hydraulic fluid to flow between the two chambers as the piston slides by communicating the two chambers, and provides resistance to the flow of the hydraulic fluid in the communication path Colloidal damper equipped with a distribution resistance imparting mechanism.

  The colloidal damper described in this section not only attenuates the relative movement of the two objects by the inflow and outflow of the working fluid with respect to the pores of the porous body, but also resists the flow of the working fluid between the two chambers. It is comprised so that it may attenuate also by providing. The damping characteristics due to the inflow and outflow of hydraulic fluid to the pores of the porous body are attenuation characteristics in which the amount of energy dissipation depends on the relative motion amplitude of the two objects, giving resistance to the circulation of the hydraulic fluid. The attenuation characteristic due to the performance is an attenuation characteristic that depends on the speed of relative movement of the two objects, and the colloidal damper described in this section has both of these characteristics, in other words, these two kinds of attenuation. It has the characteristic which the characteristic combined. Therefore, it is possible to set various attenuation characteristics of the colloidal damper by these two types of attenuation characteristics. According to the aspect of this section, for example, the frequency band and amplitude of relative vibration of two objects, It is possible to optimize the damping characteristics of the colloidal damper so as to adapt to the relative motion of the two objects.

  In the following explanation, the damping characteristic due to the inflow / outflow of the working fluid to the pores of the porous body is called the colloid solution-dependent damping characteristic, and the damping characteristic by giving resistance to the circulation of the working fluid is the flow resistance. It may be called a dependent attenuation characteristic. Of the damping force generated by the colloidal damper, the damping force that is generated due to the inflow and outflow of the working fluid to the pores of the porous body is called colloidal solution-dependent damping force, and the colloidal damper is generated. Of the damping force to be generated, the damping force that is generated due to the resistance imparted by the flow resistance imparting mechanism may be referred to as a flow resistance dependent damping force.

  For the colloidal damper described in this section, a colloidal solution in which “porous body” and “working fluid” are mixed is used. 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. A colloidal damper is realized. 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 hydrophobic treatment.

  The damping characteristics due to the inflow / outflow of the hydraulic fluid to and from the pores of the porous body are explained by taking a simple configuration of a colloidal damper as an example. Specifically, a cylinder device is formed by a housing and a piston to form one chamber. This will be described in detail by taking as an example a colloidal damper in which the one chamber is filled with a colloidal solution in which the “porous body” and the “operating fluid” are mixed. In the colloidal damper having such a configuration, when a force that reduces the volume of the chamber is applied to the housing and the piston, first, the hydraulic pressure of the working fluid is increased in the colloidal solution. When the hydraulic pressure of the hydraulic fluid increases to a certain level, the hydraulic fluid flows into the pores of the porous body against the surface tension of the hydraulic fluid. The housing and the piston move relative to each other so that the volume of the chamber decreases due to the flow of the hydraulic fluid into the pores. On the other hand, when the force applied to the housing and the piston is lost, the hydraulic pressure of the hydraulic fluid is reduced and the hydraulic pressure of the hydraulic fluid is reduced. When the hydraulic pressure of the hydraulic fluid decreases, the hydraulic fluid flows out from the pores of the porous body. Then, the outflow of the working fluid from the pores causes the housing and the piston to move relative to each other so that the volume of the chamber increases.

  As described above, in the colloidal damper having the above-described configuration, the relative position between the housing and the piston and the inflow amount of the working fluid into the porous body are related to each other. Further, the pressure in the chamber changes according to the amount of hydraulic fluid flowing into the porous body. That is, the relative position between the housing and the piston and the pressure in the chamber are related to each other. Then, if the state between the porous body and the working fluid is explained using the contact angle between them, the contact angle becomes large when the working fluid flows into the porous body, When the hydraulic fluid flows out, the contact angle becomes small. Therefore, there is a difference between the pressure in the chamber when the hydraulic fluid flows in (shrinks) and the pressure in the chamber when the hydraulic fluid flows out (extension). In other words, hysteresis occurs in the change in the pressure in the chamber with respect to the change in the relative operation position of the housing and the piston, so that the colloidal damper dissipates, for example, the kinetic energy of the two objects that move relative to each other. The relative movement of two objects that move relative to each other is attenuated.

  The “communication path” included in the “flow resistance applying device” described in this section may be provided in a piston or a housing that divides two chambers, or may be formed by a piston and a housing. Moreover, the communicating path should just permit the distribution | circulation of a hydraulic fluid, and may also pass a porous body with a hydraulic fluid. However, as will be described in detail later, the colloidal damper configured to be filled with the colloidal solution in the chamber has a problem that the inside of the cylinder device is worn by the porous body. That is, from the viewpoint of preventing wear of the communication path formed, the colloidal damper described in this section is configured so that the porous body does not pass through the communication path, as will be described in detail later. Is desirable. The “distribution resistance applying device” described in this section is not particularly limited in configuration. For example, it can be configured by an orifice, a throttle valve or the like provided in the communication path.

(2) The colloidal damper
A flexible space is formed by itself or by itself and the housing to form a sealed space in one of the two chambers, and the porous body and a part of the hydraulic fluid are placed in the sealed space. And a sealing member that allows the volume of the sealed space to change due to inflow / outflow of a part of the hydraulic fluid with respect to the pores of the porous body by sealing in a mixed state and deforming itself. The colloidal damper according to item (1), which is configured.

  As described above, in the colloidal damper configured to be filled with the colloidal solution in the chamber, there is a problem that the inside of the cylinder device is worn by the porous body. In particular, abrasion of the piston seal member and the portion of the housing where the piston slides leads to leakage of the colloidal solution, which is a serious problem. Further, as described above, in the present colloidal damper in which the two chambers are communicated with each other through the communication path, there is a possibility that members constituting the communication path are worn. In order to cope with such a problem, there is a colloidal damper configured to isolate a porous body from a portion where a piston of a housing slides by a filter or a container. However, the porous body may be crushed and become smaller due to stress or the like. In other words, a colloidal damper having a structure in which a porous body is isolated by a filter or container allows the working liquid to pass through the filter or container. There is a problem of being clogged or passing through it.

  In contrast to the colloidal damper configured as described above, the colloidal damper described in this section is such that the colloidal solution is sealed in the space formed by the sealing member, and the porous and working fluid flows out of the sealed space. It is configured not to. That is, according to the aspect of this section, the porous body does not rub against the piston, and wear in the cylinder device can be prevented. Further, as described above, even if the porous body is pulverized and reduced in size, it naturally does not flow out of the sealed space. Therefore, according to the aspect of this section, a colloidal damper having excellent durability is realized. In this embodiment, the volume of the chamber of the cylinder device is changed by changing the volume of the sealed colloidal solution by flowing the hydraulic fluid into and out of the porous body during relative movement of the housing and the piston. That is, it is possible to configure so that the stroke movement of the cylinder device is allowed.

  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 is the sealed space in the one of the two chambers where the sealing member is provided. It will be present outside and inside the two chambers where the sealing member is not provided. In other words, the aspect of this section is an aspect configured to transmit the force applied to the cylinder device to the colloidal solution in the sealing member via the working fluid outside the sealed space which is the remaining part of the working 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 cylinder device, it is desirable to employ a high-viscosity hydraulic 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. Further, the sealing member may generate a force that restores its deformation, or may not generate the restoring force. Specifically, various things, such as a bag-like thing, the thing which has elasticity, and the thing which has elasticity, are employable, for example.

  (3) The colloidal damper according to item (2), wherein the sealing member is provided inside the two chambers through which the piston rod does not penetrate.

  (4) The colloidal damper according to (2), wherein the sealing member is provided inside the two chambers through which the piston rod passes.

  The modes described in the above two items are modes in which the sealed space is formed in any of the two chambers. In any of these aspects, when two objects move closer, in other words, when the cylinder device contracts, the pressure in the housing increases and the working fluid flows into the pores of the porous body. When the two objects move apart, in other words, when the cylinder device expands, the pressure in the housing decreases, and the hydraulic fluid flows out from the pores of the porous body.

  However, in this colloidal damper, since the housing is divided into two chambers and the cylinder device is provided with a flow resistance imparting mechanism, a differential pressure is generated between the two chambers in the process of expansion and contraction of the cylinder device. It will be. Specifically, in the process in which the cylinder device is contracting, the pressure in the chamber through which the piston rod does not penetrate becomes higher than the pressure in the chamber through which the piston rod penetrates, and the cylinder device In the extending process, the pressure in the chamber through which the piston rod penetrates becomes higher than the pressure in the chamber through which the piston rod does not penetrate. That is, according to the former aspect of the two terms, compared with the colloidal damper having the simple configuration described above, the pressure in the chamber where the sealing member is provided, that is, the force applied to the sealed space. Can be increased when the cylinder device is contracted and decreased when the cylinder device is extended. On the other hand, according to the latter mode of the two terms, the force applied to the sealed space can be reduced when the cylinder device is contracted and increased when the cylinder device is extended. Incidentally, in the former mode, the difference between the contracted size and the expanded size in the pressure in the chamber where the sealing member is provided is made larger than the colloidal damper having the simple configuration described above. As a result, it is possible to increase the energy dissipated in one cycle.

(5) The sealing member is
In any one of the items (2) to (4), the sealed chamber is formed at an end away from the piston inside the one of the two chambers. The described colloidal damper.

  The mode described in this section is a mode in which the position where the sealed space is formed is limited. According to the mode of this section, it is possible to prevent the sealing member from interfering with the operation of the piston. It is possible to reliably prevent obstruction of the sliding of the piston.

  (6) The colloidal damper according to any one of (2) to (5), wherein a part of the hydraulic fluid sealed in the sealed space is water.

  (7) The colloidal damper according to item (6), 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.

(8) When a part of the hydraulic fluid sealed in the sealed space is a first hydraulic fluid,
The remaining portion of the hydraulic fluid is not provided as the second hydraulic fluid outside the sealed space of the two chambers where the sealing member is provided and of the two chambers. The colloidal damper according to any one of items (2) to (7), which is housed inside.

  The “first hydraulic fluid” described in this section is a hydraulic fluid accommodated in the sealed space, and can also be referred to as a hydraulic fluid in the sealed space. On the other hand, the “second hydraulic fluid” It is a hydraulic fluid existing outside, and can also be referred to as a hydraulic fluid outside the sealed space. The “first hydraulic fluid” and the “second hydraulic fluid” may be the same liquid as described above, for example, may be liquids that are different from each other in properties, characteristics, types, and the like. .

  (9) The colloidal damper according to item (8), wherein the first hydraulic fluid and the second hydraulic fluid are different from each other in nature.

  As described above, it is desirable that the first hydraulic fluid mixed with the colloidal solution has a large surface tension, and the second hydraulic fluid efficiently applies the force applied to the cylinder device to the sealed space. It is desirable to be able to communicate. In the aspect of this section, it is possible to make the first hydraulic fluid and the second hydraulic fluid each adopt an appropriate liquid according to such a demand. In the aspect of this section, the first hydraulic fluid and the second hydraulic fluid may be different types of liquids, such as water and oil, and are the same as high viscosity oil and low viscosity oil. Different types of liquids may have different properties and characteristics.

  (10) The colloidal damper according to (8) or (9), wherein the second hydraulic fluid is oil.

  The aspect described in this section is an aspect in which the second hydraulic fluid is limited, and for example, mineral oil, silicon oil that is a synthetic oil, or the like can be employed. For example, consider a colloidal damper having a configuration in which the aspect of this section and the aspect described above in which the first hydraulic fluid is water are combined. In general, since the viscosity of oil is higher than that of water, the force applied to the cylinder device can be efficiently transmitted to the colloidal solution in the sealed space. Further, for example, when the colloidal damper is configured to support the vehicle body by configuring the suspension 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 of the cylinder device at a high pressure. There is. Oil with high viscosity is particularly effective in a colloidal damper that is difficult to leak from the seal and needs to maintain a high pressure in the chamber 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 second hydraulic fluid starts to solidify, the force transmitted to the colloidal solution in the sealed space may vary with respect to the force applied to the cylinder device. However, according to the aspect of this section, it is possible to reliably transmit the force applied to the cylinder device 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 two objects are a vehicle body 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 other end of the piston rod is connected to the other of the vehicle body and the wheel holding member,
The colloidal damper according to any one of items (1) to (10), wherein the colloidal damper constitutes a vehicle suspension device for suspending the vehicle body.

  The aspect described in this section is an aspect in which the colloidal damper is used as one component of the vehicle suspension apparatus. More specifically, it is an aspect in which at least a shock absorber that attenuates relative motion between the vehicle body and the wheel holding member is caused to function.

(12) The colloidal damper
The colloidal damper according to (11), wherein the colloidal damper is configured to support the vehicle body by a pressure in the housing in a state where the hydraulic fluid flows into the porous body.

(13) The colloidal damper
The colloidal damper according to (12), wherein the colloidal damper is configured to handle all of the load shared by the wheel corresponding to itself by the pressure in the housing in a state where the hydraulic fluid flows into the porous body.

  The modes described in the above two terms are modes in which the colloidal damper is responsible for at least a part of the wheel's shared load (so-called 1 W) corresponding to itself. That is, the modes of the above two terms are modes in which the colloidal damper is used not only as a shock absorber but also as a spring. The latter mode is a mode in which it is possible to handle all of the 1W. According to the latter mode, it is not necessary to separately provide a suspension spring, and a compact suspension device is realized. .

(14) The colloidal damper
In the range in which the vehicle body and the wheel holding member relatively move, the pressure in the housing is configured to be a magnitude proportional to the amount of the hydraulic fluid flowing into the porous body (12) or ( The colloidal damper according to item 13).

  Conventional research and experiments have shown that there is a range in which the pressure in the chamber and the flow rate of hydraulic fluid into the porous body have a substantially linear relationship, as a characteristic of general colloidal dampers. . The aspect of this section is, for example, the stroke range of a cylinder device or the range of relative movement of two relatively moving objects within the range in which the pressure in the chamber and the flow rate of hydraulic fluid are in a linear relationship. It can be constituted so that. In the aspect of this section, the vehicle body is always supported by the colloidal damper, in other words, the colloidal damper can always function as a suspension spring.

For example, the above-described aspect in which the stroke range of the cylinder device is in a range in which the pressure in the chamber and the inflow amount of the hydraulic fluid are in a linear relationship can be configured as follows, for example. is there. First, the amount of hydraulic fluid flowing into the porous body is approximately equal to the volume of the fluid entering the piston rod housing, assuming that the pressures in the two chambers are equal. In consideration of that, first, the amount of the porous body is caused to flow the same amount of hydraulic fluid into the housing of the piston rod when the cylinder device strokes from the full rebound position to the full bound position. Determine the possible amount. Next, the amount of the hydraulic fluid is determined to be larger than the amount flowing into the porous body (= the volume entering the piston rod housing). That is, the colloidal damper of said aspect can be comprised by providing the colloidal solution which mixed them.
Is desirable.

  (15) The reference of the magnitude of the damping force generated by the colloidal damper depending on the resistance applied to the flow of the hydraulic fluid by the flow resistance applying mechanism is defined as a flow resistance dependent attenuation coefficient ( The colloidal damper according to any one of items 11) to (14).

(16) The distribution resistance applying mechanism is
The flow resistance dependent attenuation coefficient in the separating operation of the vehicle body and the wheel holding member is configured to be larger than the flow resistance dependent attenuation coefficient in the approaching operation of the vehicle body and the wheel holding member (15). Colloidal damper described in 1.

  According to the aspect of this section, since the attenuation coefficient in the approaching operation is made smaller than the attenuation coefficient in the separating operation, it is possible to effectively mitigate the impact when traveling on the convex portion of the road surface.

(17) The distribution resistance applying mechanism is
The flow resistance dependent damping coefficient is configured to be a damping coefficient suitable for attenuating vibration of a component in an unsprung resonance frequency region in relative vibration between the vehicle body and the wheel holding member (15) or The colloidal damper according to any one of (16).

  The energy that can be dissipated by the inflow / outflow of the hydraulic fluid to / from the pores of the porous body decreases as the amplitude of relative vibration between the vehicle body and the wheel holding member decreases. That is, a general colloidal damper can effectively attenuate a vibration having a relatively large amplitude, such as a sprung vibration that is a vibration in a sprung resonance frequency range. However, a sufficient damping force cannot be obtained for vibration with a small amplitude even if the speed of the relative movement between the vehicle body and the wheel holding member is high, such as unsprung vibration that is vibration in the unsprung resonance frequency range. There is a fear. Since the colloidal damper described in this section can attenuate the unsprung vibration by the flow resistance imparting mechanism, it is possible to effectively attenuate the vibration between the vehicle body and the wheel holding member.

(18) The distribution resistance imparting mechanism is
The ratio of the flow resistance dependent damping coefficient to the critical damping coefficient in the approaching operation of the vehicle body and the wheel holding member is configured to be 0.1 or more and 0.3 or less (15) to (17) The colloidal damper according to any one of Items.

  The “ratio of the flow resistance-dependent damping coefficient to the critical damping coefficient” described in this section is a standard for the ability to attenuate the approaching action between the vehicle body and the wheel holding member by the flow resistance applying mechanism. It is. The mode in this section is a mode in which the ability to attenuate the flow resistance applying mechanism is limited, and the mode in which the damping ratio in the approaching operation is set relatively low, that is, the damping coefficient in the approaching operation is compared. This is a mode set to be low. In other words, the mode of this section is a mode in which vibration with a relatively high frequency can be effectively damped, and the flow resistance-dependent damping coefficient as described above is suitable for damping unsprung vibration. It can also be considered as one aspect of the aspect set to the attenuation coefficient.

It is a front view of the suspension apparatus for vehicles which used the colloidal damper which is an Example of claimable invention as one component. It is front sectional drawing of the colloidal damper which is an Example of claimable invention. It is sectional drawing which shows typically the porous body which comprises the colloidal solution shown in FIG. It is a front sectional view expanding and showing the colloidal damper shown in Drawing 2, and is a figure showing the flow of hydraulic fluid when a cylinder device expands and contracts. 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 of the cylinder apparatus in the colloidal damper shown in FIG. 5, and the internal pressure of a cylinder apparatus. It is a figure which shows the relationship between the stroke of the cylinder apparatus in the colloidal damper which is an Example of claimable invention, and the internal pressure of a cylinder apparatus when it is assumed that the internal pressure of each of two chambers is equal. It is a figure which shows the relationship between the stroke speed of a cylinder apparatus, and the damping force which a colloidal damper generates. It is a figure for showing the relationship between the amplitude of the stroke operation | movement of the cylinder apparatus in the colloidal damper which is an Example of claimable invention, and dissipated energy. It is a figure which shows the relationship between the stroke of the cylinder apparatus in the colloidal damper which is an Example of claimable invention, and the internal pressure of the chamber in which the colloidal solution sealing body was accommodated. It is front sectional drawing of the colloidal damper of a modification.

  Hereinafter, representative embodiments of the claimable invention will be described in detail with reference to the drawings as examples and modifications thereof. 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 colloidal damper 10 of this 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 colloidal damper 10 is disposed between a mount portion 32 provided in 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 colloidal damper 10. The colloidal damper 10 is mainly composed of a cylinder device 40, and the cylinder device 40 is disposed between the mount portion 32 and the second lower arm 26. The cylinder device 40 includes a generally cylindrical housing 42, a piston 44 slidably disposed with respect to the housing 42, a lower end portion connected to the piston 44, and an upper end portion extending from an upper portion of the housing 42. And a piston rod 46 to be taken out. The piston rod 46 is connected to the lower surface side of the mount portion 32 via an upper support 52 including an anti-vibration rubber 50 at the upper end portion, and the housing 42 is connected to the lower end portion thereof via a bush 54. Are connected to the second lower arm 26. That is, the housing 42, the piston rod 46, and the piston 44 coupled thereto can be relatively moved in the axial direction in accordance with the approach / separation between the vehicle body (mount portion 32) and the wheel 12 (axle carrier 30). Yes. In other words, the cylinder device 40 can be expanded and contracted according to the approach and separation between the vehicle body and the wheel 12.

  The piston 44 divides the interior of the housing 42 into an upper chamber 60 and a lower chamber 62 that are two chambers with the piston 44 interposed therebetween. The piston 44 has a Teflon-coated band 64 mounted on the outer periphery thereof, and slides smoothly with respect to the housing 42. The cylinder device 40 includes a cover tube 70. The cover tube 70 accommodates the piston rod 46 and the upper portion of the housing 42, and prevents entry of dust, mud, and the like from the outside. Yes.

  A rubber bellows 80 is fixed to the lower end of the housing 42 and is accommodated in the lower chamber 62. The bellows 80 is hermetically sealed with a colloidal solution 90 in which a hydrophobic porous silica gel 82 and water 84 as a first working liquid are mixed. That is, the bellows 80 functions as a sealing member that seals the colloidal solution 90 by itself, and the colloidal damper 10 includes a colloidal solution sealed body that includes the bellows 80 and the colloidal solution 90. 92 is provided.

  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 upper chamber 60 is filled with a mineral oil 110 as a second working fluid in a state in which the colloidal solution sealing body 92 is accommodated. The lower chamber 62 is also filled with mineral oil 110. As described above, the interior of the housing 42 is partitioned by the piston 44 into the upper chamber 60 and the lower chamber 62. As shown in FIG. 4, the piston 44 has three communication passages 120 for connection from the upper chamber 60 to the lower chamber 62, and three communication passages for connection from the lower chamber 62 to the upper chamber 60. 122 are alternately provided at positions equally spaced around the axis (one by one is shown in FIG. 4).

  Three valve plates 124 having a circular shape made of an elastic material are disposed on the lower surface of the piston 44. In normal times, the communication plate 120 of the piston 44 is substantially blocked by the valve plate 124. When the hydraulic pressure in the upper chamber 60 is higher than the hydraulic pressure in the lower chamber 62 and the hydraulic pressure difference between the two chambers 60 and 62 is small, the gap between the valve plate 124 and the communication passage 120 functions as an orifice. The flow of the mineral oil 110 from the upper chamber 60 to the lower chamber 62 is allowed. Further, when the hydraulic pressure in the upper chamber 60 is higher than the hydraulic pressure in the lower chamber 62 and the hydraulic pressure difference between the two chambers 60 and 62 is large, the valve plate 124 is bent to move from the upper chamber 60 to the lower chamber 62. A greater flow of mineral oil 110 is allowed.

  Further, a single valve plate 126 made of an elastic material and having a circular shape is disposed on the upper surface of the piston 44. In normal times, the communication plate 122 of the piston 44 is substantially blocked by the valve plate 126. When the hydraulic pressure in the lower chamber 62 is higher than the hydraulic pressure in the upper chamber 60 and the hydraulic pressure difference between the two chambers 60 and 62 is small, the gap between the valve plate 126 and the communication path 122 functions as an orifice. The flow of the mineral oil 110 from the lower chamber 62 to the upper chamber 60 is allowed. When the hydraulic pressure in the lower chamber 62 is higher than the hydraulic pressure in the upper chamber 60 and the hydraulic pressure difference between the two chambers 60 and 62 is large, the valve plate 126 is bent and the lower chamber 62 moves to the upper chamber 60. A greater flow of mineral oil 110 is allowed.

  Incidentally, as will be described in detail later, since the inside of the housing 42 has a high pressure, a plurality of lids on the upper side and a lower side of the housing 42 have a plurality of pieces in order to prevent leakage of the mineral oil 110. High pressure seals 130 and 132 are provided. In particular, two seals 132 that are in contact with the sliding surface of the piston rod 46 are provided on the upper lid portion on which the piston rod 46 slides. Grease is sealed between the two seals 132 to improve the sealing performance.

  The colloidal damper 10 has a mechanism for restricting the approaching and separating operation between the vehicle body and the wheel, 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 of colloidal damper>
i) Characteristics of General Colloidal Damper As described above, the present suspension device is composed mainly of the colloidal damper 10. The function of the colloidal damper 10 will be described in detail below. First, before describing the colloidal damper 10, general characteristics of the colloidal damper will be described in detail with reference to FIG. 6, taking the colloidal damper 150 having a simple configuration shown in FIG. 5 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. 6 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. 6). . 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. 6). 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. 6, 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 the hydraulic fluid can flow, the hydraulic pressure of the hydraulic fluid 162 starts to increase greatly (range (III) in FIG. 6).

  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. 6). 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. 6). 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. 6 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. 6, 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. 6, 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. 6 corresponds to the dissipated energy.

ii) Characteristics of the Colloidal Damper In the colloidal damper 10, the colloidal solution 90 is sealed in the bellows 80, but the force applied to the cylinder device 40 is transmitted to the colloidal solution sealing body 92 via the mineral oil 110. Is done. 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 first colloid 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, this colloidal damper 10 also has the same characteristics as the colloidal damper 150 described above. FIG. 7 shows the relationship between the stroke S of the cylinder device 40 in the colloidal damper 10 and the internal pressure p of the lower chamber 62.

  Incidentally, when the cylinder device 40 is in a stroke, there is a difference between the internal pressure of the upper chamber 60 and the internal pressure of the lower chamber 62, but the characteristic line shown in FIG. This is a case where it is assumed that the device 40 is stopped at the stroke position, in other words, a case where it is assumed that the internal pressure of the upper chamber 60 and the internal pressure of the lower chamber 62 are balanced at the stroke position. Note that the case where the differential pressure between the internal pressure of the upper chamber 60 and the internal pressure of the lower chamber 62 is taken into account will be described in detail later.

<Functions of this colloidal damper>
i) Function as Suspension Spring As described above, the colloidal damper 10 is a main component of the suspension device. First, the colloidal damper 10 has a function as a suspension spring. In the colloidal damper 10, when a certain amount of force is applied to the cylinder device 40 from the outside, the internal pressure of the cylinder device 40 rises to a magnitude corresponding to the magnitude of the force, and the force generated by the cylinder device 40 is externally applied. It will balance the applied force. Accordingly, the colloidal damper 10 is a cylinder that is generated in a state in which a certain load of water 84 flows into the pores 102 of the hydrophobized porous silica gel 100 with a shared load of the wheel 12 on which the colloidal damper 10 is provided (so-called 1 W). It takes charge by the internal pressure of the device 40.

  Then, as shown in FIG. 7, the colloidal damper 10 has a cylinder device 40 in a case where the cylinder device 40 performs a stroke operation so that the volume of the lower chamber 62 in which the colloidal solution sealing body 92 is accommodated is reduced. When the stroke operation is performed so as to contract, the internal pressure of the cylinder device 40 is configured to have a magnitude proportional to the amount of water 84 flowing into the pores 102 of the hydrophobic porous silica gel particles 100. In other words, the internal pressure of the cylinder device 40 is configured to have a magnitude proportional to the stroke amount of the cylinder device 40. More specifically, the colloidal damper 10 has a hydrophobic porous silica gel so that all the water 84 does not flow out from the pores 102 of the hydrophobic porous silica gel particles 100 within a range in which the cylinder device 40 performs a stroke operation. The amount of water 84 flowing into the pores 102 of the particles 100 is configured not to reach a limit value at which it can flow. That is, the colloidal damper 10 can be considered to generate a force that supports 1 W in the entire stroke range of the cylinder device 40 determined by the rebound stopper and the bound stopper.

Incidentally, in the present colloidal damper 10, the colloid so that the cylinder device 40 strokes within a range in which the internal pressure of the cylinder device 40 is proportional to the amount of water 84 flowing into the pores 102 of the hydrophobic porous silica gel particles 100. The amount (volume) of the hydrophobized porous silica gel 86 and the amount (volume) of water 84 to be accommodated in each of the solution sealing bodies 92 are determined. First, in the cylinder device 40, a standard position that is a neutral position in a standard state (for example, no one is on the vehicle, nothing is loaded, and the vehicle is stopped on a horizontal plane). Therefore, when the stroke amount S _b can be stroked in the bound direction and the stroke amount S _r can be stroked in the rebound direction, the volume change ΔV of the upper chamber 60 and the lower chamber 62 of the cylinder device 40 is the same as that at full bound and full rebound. With time, it is obtained as the following formula.
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 40, the cross-sectional area of the piston rod 46 corresponds.

In the colloidal damper 10, it is necessary that an amount of water 84 equal to the volume change ΔV can flow into the hydrophobic porous silica gel 86. 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 silica gel that has not been hydrophobized to the total amount of hydrophobized 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
In addition, since the amount V _{F of the} water 84 only needs to be ΔV / β or more, the colloidal damper 10 has V _F = V _S.

ii) Function of Colloidal Solution Sealed Body as Shock Absorber The colloidal damper 10 has an internal pressure of the cylinder device 40 in one cycle operation from the neutral position, which is a position where the driver gets on and stops on the horizontal plane. If the change is shown in relation to the stroke S of the cylinder device 40, it becomes like a two-dot chain line shown in FIG. Similar to the general colloidal damper 150 described above, the colloidal damper 10 includes an internal pressure of the cylinder device 40 when the hydraulic fluid flows in (shrinks) and an internal pressure of the cylinder device 40 when the hydraulic fluid flows out (extension). As shown in FIG. 7, hysteresis occurs in the change in the internal pressure of the cylinder device 40 with respect to the change in the stroke S of the cylinder device 40, as shown in FIG. The area surrounded by the two-dot chain line in FIG. 7 corresponds to the energy dissipated in one cycle of operation. That is, the colloidal damper 10 attenuates the relative movement between the vehicle body and the wheel 12, and functions as a shock absorber.

As described above, the colloidal damper 10 is configured to support the vehicle body by the pressure in the housing 152 in a state where water 84 flows into the pores 102 of the hydrophobic porous silica gel particles 100. Acts as a spring. When the stroke is performed so that the cylinder device 40 contracts, the internal pressure of the cylinder device 40 is configured to be proportional to the stroke amount of the cylinder device 40. That is, the spring force F _r that is generated by the colloidal damper 10 as a suspension spring is proportional to the internal pressure p _C when the cylinder device 40 is contracted.
F _r = A · p _C
On the other hand, when the cylinder device 40 extends, the force F _E (= A · p _E ) generated by the colloidal damper 10 is, as shown in FIG. 7, the rebound spring force F _r and the bounce force. It can be considered as a combined force of F _b .
F _E = F _r −F _b
The force F _{b in the} bound direction becomes a resistance force against the stroke operation of the cylinder device 40, that is, a damping force. That is, the damping force F _b by the colloid solution sealing body 92 is proportional to the difference between the internal pressure p _C when the cylinder device 40 is contracted and the internal pressure p _E when the cylinder device 40 is expanded, as shown by the following equation. It will be.
F _b = F _r −F _E
= A · (p _C -p _E )
Therefore, it is considered that the damping force by the colloid solution sealing body 92 is generated when the cylinder device 40 is extended.

iii) Damping function by flow resistance imparting mechanism The piston 44 is structured as described above. For example, when the piston 44 is moved upward in the housing 42, the hydraulic pressure in the upper chamber 60 Therefore, a part of the mineral oil 110 in the upper chamber 60 flows to the lower chamber 62 through the communication path 120. At that time, the mineral oil 110 passes through the orifice formed by the communication passage 120 and the valve plate 124, or the mineral oil 110 deflects the valve plate 124 and flows into the lower chamber 62, thereby causing the piston 44 to move. A resistance force is applied to the upward movement of the vehicle, and a damping force is generated by the resistance force against the separation operation of the vehicle body and the wheel 12.

  Conversely, when the piston 44 moves downward in the housing 42, the hydraulic pressure in the lower chamber 62 becomes higher than the hydraulic pressure in the upper chamber 60, so that part of the mineral oil 110 in the lower chamber 62 is Then, it flows from the lower chamber 62 to the upper chamber 60 through the communication passage 122. At that time, the mineral oil 110 passes through the orifice formed by the communication passage 122 and the valve plate 126, or the mineral oil 110 deflects the valve plate 126 and flows into the upper chamber 60, thereby causing the piston 44. A resistance force is applied to the downward movement of the vehicle, and a damping force for the approaching action between the vehicle body and the wheel 12 is generated by the resistance force.

  That is, a flow resistance imparting mechanism that provides resistance to the flow of the mineral oil 110 between the upper chamber 60 and the lower chamber 62 includes the communication passages 120 and 122, the valve plates 124 and 126, and the like. . The attenuation characteristic by the flow resistance applying mechanism is different between when the vehicle body and the wheel 12 are separated from each other and when the vehicle 12 is approaching. Specifically, the distribution resistance applying mechanism is configured such that the attenuation coefficient for the separating operation between the vehicle body and the wheel 12 and the attenuation coefficient for the approaching operation have different magnitudes. FIG. 8 shows the damping characteristics of the flow resistance applying mechanism in relation to the stroke speed V and the damping force F of the cylinder device 40. As shown in FIG. 8, the damping characteristic of the flow resistance applying mechanism is set to a relatively low damping coefficient of 1500 N · sec / m (approx. 0.15 in terms of damping ratio) for the approaching operation. On the other hand, the attenuation coefficient for the separating operation is set to a value larger than the attenuation coefficient for the approaching operation. Specifically, the damping coefficient for the separation operation is 4000 N · sec / m (about 0.4 in terms of damping ratio), which is set to a magnitude that is set for a conventional shock absorber.

  <Characteristics of this colloidal damper>

  As described above, the colloidal damper 10 has not only a function as a shock absorber but also a function as a suspension spring. Therefore, there is no need to provide a suspension spring, and the vehicle suspension apparatus using the colloidal damper 10 is used. Has a simple configuration.

  The colloidal damper 10 is configured so 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 colloidal damper 10 can prevent wear in the cylinder device 40 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 configured to isolate a porous body from a portion where a piston of a housing slides by a filter or a container. 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, in the present colloidal damper 10, since the colloidal solution is sealed in the sealed container, even if the porous body is crushed and reduced in size, it naturally does not flow out of the sealed container. Therefore, this colloidal damper 10 is a colloidal damper excellent in durability.

  Further, the colloidal damper 10 transmits the first hydraulic fluid (in-container hydraulic fluid) that flows into and out of the pores 102 of the hydrophobic porous silica gel particles 100 and the force applied to the cylinder device 40 to the colloidal solution sealing body 92. Therefore, the second working fluid (outside the container working fluid) filled in the chambers 60 and 62 is a different liquid, and has different properties and characteristics. Specifically, the mineral oil 110 that is the outside working fluid and the water 84 that is the inside working fluid have different kinematic viscosities, and the kinematic viscosity of the outside working fluid is the kinematic viscosity of the inside working fluid. It is higher. Thereby, the mineral oil 110 that is the outside-container working fluid can efficiently transmit the force applied to the cylinder device 40 to the colloidal solution sealing body 92. Further, since the colloidal damper 10 takes charge of 1 W, it is necessary to maintain the internal pressure of the cylinder device 40 at a high level. In the present colloidal damper 10, since the mineral oil 110 that is the outside-container working fluid has a high viscosity, the sealability of the seals 130 and 132 provided in the housing 40 is ensured.

  Further, the mineral oil 110 that is the outside working fluid and the water 84 that is the inside working fluid have different thermal conductivities, and the thermal conductivity of the outside working fluid is higher than the thermal conductivity of the inside working fluid. It is low. The colloidal damper 10 is configured such that the colloidal solution sealing body 92 is covered with the mineral oil 110. That is, the present colloidal damper 10 has the possibility that the water 84 that is the working fluid in the container is solidified when the outside air temperature is lowered, but the temperature of the water 84 is prevented from escaping to the outside by the mineral oil 110 having low thermal conductivity. It is possible to suppress the temperature drop of the water 84.

  Further, the mineral oil 110 that is the outside working fluid and the water 84 that is the inside working fluid have different coagulation temperatures, and the coagulation temperature of the outside working fluid is lower than the coagulation temperature of the inside working fluid. It has become. For example, when the working fluid outside the container starts to solidify, the force transmitted to the colloidal solution sealing body 92 may fluctuate with respect to the force applied to the cylinder device 40. However, the colloidal damper 10 can reliably transmit the force applied to the cylinder device 40 to the colloidal solution sealing body 92 by the mineral oil 110 that is difficult to solidify.

  The colloidal damper 10 not only attenuates the relative movement between the vehicle body and the wheel holding member by the inflow / outflow of water 84 with respect to the pores 102 of the hydrophobic porous silica gel particles 100, but also between the two chambers 60, 62. It is configured so as to be attenuated by giving resistance to the circulation of the mineral oil 110. That is, the attenuation characteristics of the colloidal damper 10 are the attenuation characteristics (colloidal solution dependent attenuation characteristics) due to the inflow / outflow of water 84 with respect to the pores 102 of the hydrophobic porous silica gel particles 100, and the two chambers 60, 62. This is combined with a damping characteristic (circulation resistance dependent damping characteristic) by imparting resistance to the circulation of the mineral oil 110. As described above, the colloid solution-dependent damping characteristic generates a damping force when the cylinder device 40 extends. On the other hand, the colloidal damper 10 is capable of attenuating the contracting operation of the cylinder device 40 that is hardly attenuated by the colloidal solution sealing body 92 by the flow resistance applying mechanism.

  Further, as can be seen from FIG. 9, the energy that can be dissipated by the colloidal solution sealing body 92 depends on the amplitude of relative vibration between the vehicle body and the wheel 12, and decreases as the amplitude decreases. That is, the colloidal solution-dependent damping characteristic has a relatively large amplitude such as sprung vibration that is vibration in the sprung resonance frequency range, body roll due to turning of the vehicle, body pitch due to vehicle acceleration / deceleration, etc. Vibration and motion can be effectively damped. However, there is a possibility that sufficient damping force cannot be obtained for vibration with small amplitude even at high speed, such as unsprung vibration that is vibration in the unsprung resonance frequency range. On the other hand, the colloidal damper 10 has a damping coefficient in the approaching action of the flow resistance applying mechanism set to a relatively low value capable of damping the unsprung vibration. It is possible to effectively dampen unsprung vibrations that cannot be damped by the flow resistance applying mechanism. From the above, the colloidal damper 10 can effectively attenuate the vibration between the vehicle body and the wheel holding member by the attenuation by the colloidal solution sealing body 92 and the attenuation by the flow resistance imparting mechanism. ing.

  Further, in the colloidal damper 10, when the cylinder device 40 is in a stroke, a differential pressure is generated between the upper chamber 60 and the lower chamber 62. Specifically, when the cylinder device 40 is contracted, the pressure in the lower chamber 62 is higher than the pressure in the upper chamber 60, and when the cylinder device 40 is expanded, the pressure in the lower chamber 62 is Lower than the pressure of. That is, the pressure in the lower chamber 62 is higher when the cylinder device 40 is contracted and lower when the cylinder device 40 is expanded than the internal pressure of the cylinder device 40 shown in FIG. In this case, it will change as shown in FIG. Therefore, as can be seen from FIG. 10, the energy that can be dissipated when operating for one cycle is increased, and the relative motion between the vehicle body and the wheel 12 can be effectively attenuated. Further, as can be seen from FIG. 10, more specifically, when the cylinder device 40 is switched from the stretching operation to the approaching operation, and when the cylinder device 40 is switched from the approaching operation to the stretching operation, the pores of the hydrophobic porous silica gel 100 are more specifically described. When the water 84 is switched between the state in which the water 84 flows in and the state in which the water 84 flows out, the change gradient of the internal pressure is steep. That is, in the present colloidal damper 10, the switching between the state in which the water 84 flows into and the state in which the water 84 flows into the pores 102 of the hydrophobic porous silica gel 100 can be made relatively quick. .

<Modification>
FIG. 11 is a front sectional view of a modified colloidal damper 200. In the colloidal damper 10 of the above embodiment, the colloidal solution is sealed in the lower chamber 62 which is the chamber of the two chambers 60 and 62 where the piston rod 46 does not penetrate. In the damper 200, a colloidal solution is sealed in an upper chamber 62 that is a chamber through which the piston rod 46 of the two chambers 60 and 62 passes. Below, the colloidal damper 200 of the modification is demonstrated in detail. The cylinder device 202 includes a spherical case 204 connected at the top of the housing 42. The case 204 has a rubber diaphragm 206 provided therein, and is divided into two volume change chambers by the diaphragm 206. The left volume change chamber 208 of the two volume change chambers communicates with the upper chamber 60 in the housing 42 and is filled with mineral oil 110 as the second working fluid. On the other hand, the volume change chamber 210 on the right side is a sealed space and is filled with a colloidal solution 90 in which a hydrophobic porous silica gel 82 and water 84 as a first working fluid are mixed. That is, the diaphragm 206 functions as a sealing member for sealing the colloid solution 90.

  Similar to the colloidal damper 10 of the above-described embodiment, the colloidal damper 200 of the present modified example is provided in the cylinder device 202 when the vehicle body and the wheel 12 move closer, in other words, when the cylinder device 202 contracts. When the pressure increases and water 84 flows into the pores 102 of the hydrophobized porous silica gel particle 100 and the vehicle body and the wheel 12 move apart, in other words, when the cylinder device 202 extends, The pressure in the apparatus 202 is reduced, and the water 84 flows out from the pores 102 of the hydrophobized porous silica gel particle 100. That is, in the colloidal damper 200 of the present modification, the attenuation characteristics due to the colloidal solution 90 are the characteristics shown in FIG. 7 as in the colloidal damper 10 of the above embodiment.

  Also in the colloidal damper 200 of this modification, when the cylinder device 202 is stroked by the flow resistance applying mechanism, the first chamber composed of the upper chamber 60 and the volume change chambers 208 and 210 and the lower chamber which is the second chamber. A differential pressure is generated between the first and second members. However, in the colloidal damper 200 of this modification, since the colloidal solution 90 is accommodated in the first chamber through which the piston rod 46 passes, the pressure in the first chamber is the virtual internal pressure described above. In contrast, the cylinder device 40 is configured to be lower when it is contracted and higher when it is expanded.

    10: Colloidal damper 12: Wheel 26: Second lower arm 30: Axle carrier (wheel holding member) 32: Mount part (part of the vehicle body) 40: Cylinder device 42: Housing 44: Piston 60: Piston body 62: Upper chamber ( (Chamber) 64: Lower chamber 68: Piston rod 80: Bellows (sealing member) 82: Hydrophobized porous silica gel 84: Water (first working fluid) 90: Colloid solution 92: Colloid solution sealed body 100: Hydrophobized porous silica gel Particle (porous body) 102: Fine pore 110: Mineral oil (second hydraulic fluid) 120, 122: Communication passage 124, 126: Valve plate 200: Colloidal damper 202: Cylinder device 204: Case 206: Diaphragm (sealing member)

Claims (7)

(a) a housing connected to one of two relatively moving objects; (b) a piston that divides the interior of the housing into two chambers and is slidable within the housing; and (c) the two chambers. And a piston rod that has one end connected to the piston and the other end extending from the housing and connected to the other of the two objects. A cylinder device;
(A) a porous body having a large number of pores and (B) a working fluid contained in the housing,
A colloidal damper configured to attenuate the relative movement of the two objects by flowing the hydraulic fluid into and out of the pores of the porous body during the relative movement of the two objects; There,
The cylinder device further comprises:
There is a communication path that allows the hydraulic fluid to flow between the two chambers as the piston slides by communicating the two chambers, and provides resistance to the flow of the hydraulic fluid in the communication path Colloidal damper equipped with a distribution resistance imparting mechanism. The colloidal damper
A flexible space is formed by itself or by itself and the housing to form a sealed space in one of the two chambers, and the porous body and a part of the hydraulic fluid are placed in the sealed space. And a sealing member that allows the volume of the sealed space to change due to inflow / outflow of a part of the hydraulic fluid with respect to the pores of the porous body by sealing in a mixed state and deforming itself. The colloidal damper of Claim 1 comprised.   The colloidal damper according to claim 2, wherein the sealing member is provided inside the two chambers through which the piston rod does not penetrate.   The colloidal damper according to claim 2, wherein the sealing member is provided inside the two chambers through which the piston rod passes. The two objects are a vehicle body 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 other end of the piston rod is connected to the other of the vehicle body and the wheel holding member,
The colloidal damper according to any one of claims 1 to 4, wherein the colloidal damper constitutes a vehicle suspension device for suspending the vehicle body. In the case where the reference of the magnitude of the damping force generated by the colloidal damper depending on the resistance given to the flow of the hydraulic fluid by the flow resistance applying mechanism is defined as a flow resistance dependent damping coefficient,
The distribution resistance applying mechanism is
6. The flow resistance-dependent damping coefficient is configured to be a damping coefficient suitable for attenuating vibration of a component in an unsprung resonance frequency region in relative vibration between the vehicle body and the wheel holding member. Colloidal damper. In the case where the reference of the magnitude of the damping force generated by the colloidal damper depending on the resistance given to the flow of the hydraulic fluid by the flow resistance applying mechanism is defined as a flow resistance dependent damping coefficient,
The distribution resistance applying mechanism is
The ratio of the flow resistance dependent damping coefficient to the critical damping coefficient in the approaching action of the vehicle body and the wheel holding member is configured to be 0.1 or more and 0.3 or less. The described colloidal damper.

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