Patent US5090728A successfully refreshed from Google Patents.
US5090728A
Expired / Lapsed
US
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Apparatus for controlling damping force of shock absorber
Assignee: Toyota Motor Corp
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Filing: 1991-02-12
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Granted: 1992-02-25
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Expires: 2011-02-12
Abstract
Abstract An apparatus for controlling a damping force of a shock absorber provided between a wheel of a vehicle and a body thereof includes a road surface condition detecting unit for detecting a roughness of a road surface on which the vehicle is traveling, and a damping force characteristic alteration unit for altering the setting of the damping force of the shock absorber on the basis of the roughness of the road surface detected by the road surface condition detecting unit. The apparatus also includes a damping force detecting unit, for detecting a magnitude of the damping force of the shock absorber, and an alteration speed control unit for controlling, on the basis of the magnitude of the damping force detected by the damping force detecting unit, an alteration speed at which the setting of the damping force is altered so that the alteration speed decreases as the magnitude of the damping force increases.
Inventors
- 👤 Yuji Yokoya
- 👤 Yasuhiro Tsutsumi
- 👤 Yutaka Suzuki
- 👤 Makoto Shiozaki
- 👤 Nobuyoshi Onogi
- 👤 Kazuo Takasou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:47
CPC Classifications
B; B60; B60G; B60G17/00; B60G17/015; B60G17/019; B60G17/01941; B60G2202/00; B60G2202/40; B60G2202/42; B60G2400/00; B60G2400/10; B60G2400/20; B60G2400/202; B60G2400/204; B60G2400/40; B60G2400/60; B60G2400/80; B60G2400/82; B60G2401/00; B60G2401/10; B60G2401/14; B60G2500/00; B60G2500/10; B60G2500/30; B60G2600/00; B60G2600/02; B60G2600/60; B60G2600/602; B60G2600/70; B60G2800/00; B60G2800/01; B60G2800/012; B60G2800/014; B60G2800/22; B60G2800/24
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
185 words
An apparatus for controlling a damping force of a shock absorber provided between a wheel of a vehicle and a body thereof, said shock absorber having at least two different characteristics of the damping force, said apparatus comprising: road surface condition detecting means for detecting roughness of a road surface on which the vehicle is traveling; damping force characteristic alteration means, coupled to said road surface condition detecting means, for altering the setting of the damping force of the shock absorber on the basis of the roughness of the road surface detected by said road surface condition detecting means; damping force detecting means, coupled to said shock absorber, for detecting a magnitude of the damping force of the shock absorber; and alteration speed control means, coupled to said damping force characteristic alteration means and said damping force detecting means, for controlling, on the basis of the magnitude of the damping force detected by said damping force detecting means, an alteration speed at which the setting of the damping force is altered so that the alteration speed decreases as the magnitude of the damping force increases.
Claim 2
Independent Claim
185 words
An apparatus for controlling a damping force of a shock absorber provided between a wheel of a vehicle and a body thereof, said shock absorber having at least two different characteristics of the damping force, said apparatus comprising: road surface condition detecting means for detecting roughness of a road surface on which the vehicle is traveling; damping force characteristic alteration means, coupled to said road surface condition detecting means, for altering the setting of the damping force of the shock absorber on the basis of the roughness of the road surface detected by said road surface condition detecting means; damping force detecting means, coupled to said shock absorber, for detecting a magnitude of the damping force of the shock absorber; and alteration speed control means, coupled to said damping force characteristic alteration means and said damping force detecting means, for controlling, on the basis of the magnitude of the damping force detected by said damping force detecting means, an alteration speed at which the setting of the damping force is altered so that the alteration speed decreases as the magnitude of the damping force increases.
Claim 3
Dependent Claim
74 words
An apparatus as claimed in claim 1, wherein: said apparatus further comprises memory means for storing a map which defines a relationship in which the alteration speed decreases as the magnitude of the damping force increases; and said alteration speed control means comprises means for determining the alteration speed corresponding to the magnitude of the damping force detected by said damping force detecting means by referring to said map stored in said memory means.
Claim 4
Dependent Claim
87 words
An apparatus as claimed in claim 1, wherein: said shock absorber comprises a piezoelectric actuator which causes said shock absorber to be switched between said two different characteristics of the damping force; said damping force characteristic alteration means comprises control means for controlling an amount of a charge stored in said piezoelectric actuator on the basis of the magnitude of the damping force detected by said damping force detecting means; and said alteration speed is based on the amount of the charge stored in said piezoelectric actuator.
Claim 5
Dependent Claim
101 words
An apparatus as claimed in claim 3, wherein: said apparatus further comprises memory means for storing a map which defines a relationship in which a charge variation amount decreases as the magnitude of the damping force increases; and said alteration speed control means comprises means for charging the amount of the charge stored in said piezoelectric actuator by said charge variation amount corresponding to the magnitude of the damping force detected by said damping force detecting means by referring to said map stored in said memory means, so that the alteration speed decreases as the magnitude of the damping force increases.
Claim 6
Dependent Claim
203 words
An apparatus as claimed in claim 3, wherein: said at least two different characteristics of the damping force comprise a first setting level of the damping force at which the shock absorber is maintained in a hard state and a second setting level of the damping force at which the shock absorber is maintained in a soft state; and said apparatus further comprises judging means for judging whether the damping force should be set to said first setting level or said second setting level, and wherein said control means comprises: first means for increasing the charge to be stored in said piezoelectric actuator by said charge variation amount which decreases as the magnitude of the damping force detected by said damping force detecting means increases when said judging means judges that the damping force of the shock absorber should be set to said second setting level; and second means for decreasing the charge to be stored in said piezoelectric actuator by said charge variation amount which decreases as the magnitude of the damping force detected by said damping force detecting means increases when said judging means judges that the damping force of the shock absorber should be set to said first setting level.
Claim 7
Dependent Claim
189 words
An apparatus as claimed in claim 3, wherein: said two different characteristics of the damping force comprise a first setting level of the damping force at which the shock absorber is maintained in a hard state and a second setting level of the damping force at which the shock absorber is maintained in a soft state, wherein said apparatus further comprises: charge amount detecting means for detecting the amount of the charge stored in said piezoelectric actuator; and first determining means for determining whether or not the amount of the charge detected by said charge amount detecting means is equal to or greater than a first predetermined charge amount which causes the shock absorber to be maintained in the soft state, and wherein said control means comprises first means for increasing the charge to be stored in said piezoelectric actuator by a charge variation amount which decreases as the magnitude of the damping force detected by said damping force detecting means increases when said first determining means determines that the amount of the charge detected by the charge amount detecting means is less than said first predetermined charge amount.
Claim 8
Dependent Claim
116 words
An apparatus as claimed in claim 6, wherein: said apparatus comprises second determining means for determining whether or not the amount of the charge detected by said charge amount detecting means is equal to a second predetermined charge amount which causes the shock absorber to be maintained in the hard state; and said control means comprises second means for decreasing the charge in said piezoelectric actuator by said charge variation amount which decreases as the magnitude of the damping force detected by said damping force detecting means increases when said second determining means determines that the amount of the charge detected by said charge amount detecting means is not equal to said second predetermined charge amount.
Claim 9
Dependent Claim
86 words
An apparatus as claimed in claim 7, wherein: said apparatus further comprises memory means for storing a map which defines a relationship in which said charge variation amount decreases as the magnitude of the damping force increases; said control means comprises reading means for reading the charge variation amount corresponding to the magnitude of the damping force detected by said damping force detecting means from said memory means; and said first means and said control means use said charge variation amount read by said reading means.
Claim 10
Dependent Claim
171 words
An apparatus as claimed in claim 7, wherein: said apparatus further comprises memory means for storing a first map which defines a first relationship in which the charge variation amount decreases as the magnitude of the damping force increases, and a second map which defines a second relationship in which the charge variation amount decreases as the magnitude of the damping force increases; said control means comprises reading means for reading the charge variation amount corresponding to the magnitude of the damping force detected by said damping force detecting means from said first map stored in said memory means when said first determining means determines that the amount of the charge is less than said first predetermined charge amount and for reading the charge variation amount corresponding to the magnitude of the damping force detected by said damping force detecting means from said second map stored in said memory means when said second determining means determines that the amount of the charge is not equal to said second predetermined charge amount.
Claim 11
Dependent Claim
73 words
An apparatus as claimed in claim 9, wherein: said first relationship defined in said first map shows that the alteration speed decreases at a first speed as the magnitude of the damping force increases; said second relationship defined in said second map shows that the alteration speed decreases at a second speed as the magnitude of the damping force increases; and said first speed and said second speed are different from each other.
Claim 12
Dependent Claim
17 words
An apparatus as claimed in claim 10, wherein said first speed is greater than said second speed.
Claim 13
Dependent Claim
137 words
An apparatus as claimed in claim 1, wherein: said road surface condition detecting means comprises damping force change rate detecting means for detecting a damping force change rate which indicates the rate of change of the damping force; said damping force characteristic alteration means comprises discerning means for discerning whether or not said damping force change rate detected by said damping force change rate detecting means is outside of a predetermined range; and when said discerning means discerns that said damping force change rate is outside of said predetermined range, said damping force characteristic alteration means alters the setting of the damping force so that the shock absorber is set to a soft state from a hard state, said soft state and said hard state corresponding to said at least two different characteristics of the damping force.
Claim 14
Dependent Claim
45 words
An apparatus as claimed in claim 12, wherein said apparatus further comprises soft state holding means for maintaining said shock absorber in said soft state during a predetermined soft state holding period immediately after said damping force change rate becomes outside of said predetermined range.
Claim 15
Dependent Claim
64 words
An apparatus as claimed in claim 13, wherein said apparatus further comprises: vehicle speed detecting means for detecting a speed of said vehicle; and adjusting means for adjusting said soft state holding period on the basis of the speed of said vehicle so that the soft state holding period decreases as the speed of said vehicle detected by said vehicle speed detecting means increases.
Claim 16
Dependent Claim
61 words
An apparatus as claimed in claim 13, wherein said apparatus further comprises: vehicle speed detecting means for detecting a speed of said vehicle; and adjusting means for adjusting said predetermined range on the basis of the speed of said vehicle so that said predetermined range becomes wider as the speed of said vehicle detected by said vehicle speed detecting means increases.
Claim 17
Dependent Claim
77 words
An apparatus as claimed in claim 13, wherein said discerning means of said damping force characteristic alteration means comprises means for determining whether or not said damping force change rate detected by said damping force change rate detecting means is continuously maintained in said predetermined range and for returning the shock absorber to said hard state from said soft state when it is determined that said damping force change rate is continuously maintained in said predetermined range.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-02-24 | 1995-08-26 | 1996-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-24 | 1999-08-26 | 2000-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-24 | 2003-08-26 | 2004-02-25 | $7700.00 | Window Closed / Lapsed |