JPS61122016A - Suspension for car - Google Patents

Abstract

PURPOSE:To artificially adjust the characteristics of a suspension with an air spring by allowing the adjustment of the respective characteristics of a buffer, air spring, and bush using the turning of the piston rod of the buffer. CONSTITUTION:When an actuator 150 is operated by the artificial operation of a driver or the sensor signal, valve bodies 44 and 140 are rotated. By the rotation of the valve body 140, the hole 142 of the valve body 140 is opposed to the hole 97a of a valve base 90 and the hole of a piston rod 24 is opposed to holes 56 and 58 through the orifice 47 of the valve body 44 and holes 82 and 83. In addition, the valve bodies are rotated further and the diameter is increased. Consequently, the two chambers of a buffer 12 are connected. Besides, the main and sub air flow 74 and 76 of an air spring 14 and the first and second fluid chambers 110 and 112 of a bush 16 are connected, respectively, and the damping force or spring contact are decreased along with the angle of rotation. As a result of this structure, the characteristics can be made suitable to the driver.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a vehicle suspension, and more particularly to a suspension including an air spring formed by a housing and a diaphragm in relation to a shock absorber.

(Prior art) A suspension that includes a shock absorber, an air spring formed by surrounding the shock absorber with a housing and a diaphragm to form an air chamber, and filling this air chamber with compressed air, can reduce the damping force of the shock absorber. There is a system in which the spring constant and the spring constant of the air spring can be adjusted simultaneously from the outside (used in some passenger cars as an electronically controlled suspension).

(Problems to be Solved by the Invention) According to the above-mentioned suspension, the damping force to the shock absorber and the spring constant of the air spring can be adjusted from the outside at the same time according to the driving conditions of the automobile. Steering stability can be matched to suit the vehicle type, vehicle speed, and driver preference.

On the other hand, even in the above-mentioned suspension, the spring constant of the rubber bushing interposed between the shock absorber and the vehicle body is fixed and cannot be changed. There are limits to what you can get. This is because the spring constant and damping force of the entire suspension are determined as a whole including the shock absorber, air spring, and bushing.

For example, in the cushion assembly disclosed in Japanese Utility Model Application Publication No. 57-199112, a pair of cushions having a closed space on both sides are arranged with a fixing member in between, and the closed spaces are communicated with each other through an orifice. A fluid is sealed inside. When a small vibration is applied, the fluid flows through the orifice and generates a damping force, but when a large vibration is applied, the fluid acts like a rigid body and does not generate a damping force. Although it is possible to improve the spring constant and damping force of the entire suspension by incorporating such a tension assembly as a bushing interposed between the shock absorber and the vehicle body, it is not possible to adjust the spring characteristics of the bushing from the outside. Therefore, it cannot be matched with a shock absorber/air spring.

An object of the present invention is to provide a vehicle suspension in which the spring constant and damping force of the entire suspension can be adjusted manually or automatically from the outside.

Another object of the present invention is to provide a suspension system for a vehicle in which the damping force of a shock absorber, the spring constant of an air spring, and the spring characteristics of a bushing, that is, the spring constant and damping force, can be adjusted by a single actuator. It is in.

(Means for Solving the Problems) A suspension according to the present invention includes: a shock absorber having an adjustable damping force having a piston rod; an air spring with an adjustable spring constant formed surrounding the shock absorber; a /~lube base having a first hole through which a piston rod is passed and a second hole for inserting a valve body; a bushing with adjustable spring characteristics arranged on the outside of the /<lube base; and a damping of the shock absorber. a first valve body rotatably disposed within the piston rod for adjusting the force and spring constant of the air spring; and a second hole in the valve base for adjusting the spring constant of the bushing. The valve includes a second valve body rotatably disposed within the valve body, and an actuator that rotates the first and second valve bodies.

(Example) Examples of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the vehicle suspension 10 includes a shock absorber 12, an air spring 14, and a bushing.
6.

In the example shown in FIG. 2, the shock absorber 12 is connected to the inner cylinder 1
8 and an outer tube 20 arranged at a distance from the inner tube, which is a so-called twin tube type. As the shock absorber 12, a so-called monotube type, which consists of only a single cylinder, is also used.

A piston 22 is slidably disposed inside the inner cylinder 18,
A piston rod 24 is coupled to the piston 22 . In the illustrated example, the piston rod 24 has a hollow hole 25 at its lower end, into which an orifice member 26 is press-fitted. The orifice member 26 is passed through the piston 22 and a nut 28 is threaded onto the end of the orifice member 26 . A piston rod 24 is thus connected to the piston 22.

Piston 22 has a boat 30 that allows liquid to flow when piston rod 24 is extended, and a boat 32 that allows liquid to flow when piston rod 24 retracts. A valve body 36 biased by a spring 34 is located on the lower side of the boat 30.
A valve body 40 biased by a spring 38 is disposed above the valve body 2, and each valve body generates a damping force.

A hole 42 extending from an upper end face to a lower end face is provided in the piston rod 24, and a control rod portion 46 of a first valve body 44 is rotatably disposed within this hole 42.

The lower end of the control rod section 46 extends into a bore 27 of the orifice member 26, which is aligned with the bore 42, and has a diametrically extending orifice 4 at this end.
7 is provided. On the other hand, the orifice member 26 is provided with a hole 48 extending beyond the piston 22 from the end surface and a hole 49 extending radially from the hole 48 .

When the orifice 47 is in the position shown, the orifice 4
7 faces the hole 49, the liquid chamber A on one side of the piston 24 and the liquid chamber B on the other side communicate with each other through the hole 48, the orifice 47, and the hole 49. As a result, the liquid in the inner cylinder 18 can flow out of the valve consisting of the port and valve body originally provided in the piston 22, through the bore 48, 49 and the orifice 47. When the orifice 47 is rotated, for example, by 60 degrees, the control rod portion 46 closes the hole 49 and both liquid chambers A and B are shut off.

In this way, the damping force of the shock absorber 12 is adjusted. In this case, it is preferable to provide another orifice having a diameter different from that of the orifice 47 so as to intersect the orifice 47 at an angle of, for example, 60° in the circumferential direction.

The piston rod 24 protrudes to the outside through a rod guide 50, a seal member 52, and a rigid nut 54 disposed at the upper ends of the inner cylinder 18 and the outer cylinder 20, and is coupled to the valve base as described below. On the other hand, the outer cylinder 20 is connected to a suspension arm (not shown), which is known per se, and supports the wheel.

As shown in FIG. 1, two holes 5B and 58 are diametrically opened at an interval in the axial direction in the middle portion of the piston rod 24 protruding from the outer cylinder 20, and these holes extend in the axial direction. It is connected to the enlarged diameter part of 42. A ring 60 having a hole 61 aligned with the lower hole 58 is welded to the piston rod 24, and on the upper side of this ring 60,
O-ring 64 with hole 63 aligned with upper hole 56
A holder 62 that is airtight is arranged.

The inner circumferential edge of the ceiling portion 67 of the housing 66 is welded to the holder 62 above the upper hole 56, and the inner circumferential edge of the partition portion 68 of the housing 66 is welded to the holder 62 between the upper and lower holes 56 and 58. A cylindrical portion 69 is welded to the outer peripheral edges of the ceiling portion 67 and the partition portion 68. Housing 6
A diaphragm 72 is stretched between the cylindrical portion 69 of No. 6 and an air piston 70 fixed to the outer cylinder 20. As a result, a main air chamber 74 is defined by the housing 66 and the diaphragm 72, and a sub-air chamber 76 is defined above the partition 68 of the housing 66, and both air chambers are connected to each other through the holes 42, 56, 58 of the piston rod 24. It's communicating. Compressed air is sealed in both air chambers to form an air spring 14.

The first valve body 44 includes a control rod portion 46 and a stem portion 80. The stem portion 80 has a hole 81 opened in the axial direction from the lower end surface, and holes 82 and 83 opened in the diametrical direction at intervals in the axial direction. The hole 82 can communicate with the hole 56 of the piston rod, and the hole 83 can communicate with the hole 58 of the piston rod. The stem portion 80 connects the control rod portion 46 by fitting the control rod portion 46 into the hole 81 through serrations. The upper end of the stem portion 80 is a flat portion 84 . 1st
The valve body 44 is made airtight by an O-ring 86, and the collar 8
8 prevents it from coming off, and the hole 42 of the piston port and door 24
is rotatably arranged within.

The valve base 90 has a first hole 92 through which the piston rod 24 passes, and a second hole 94 extending from the upper end surface parallel to the first hole 92 to the middle. Extending diametrically from the second hole 94 are two axially spaced holes 96,98. In the example shown in FIG. 3, the upper hole 96 has a pair of hole portions 97a and a hole 96 extending circumferentially from this hole portion.
The lower hole 98 consists of a pair of hole portions 97b having a diameter smaller than that of the hole portion 97a, which are provided at a portion that protrudes from the hole portion 97a.In the example shown in FIG.
and a hole portion 99b having the same diameter as the hole portion 99a, which is provided at a portion extending 60° from the hole portion in the circumferential direction. The holes 96 and 98 have the same phase relationship in plan view.

Insert the piston rod 24 into the hole 92 of the valve base 90, and insert the holder 62 fixed to the piston rod into the hole 92.
The piston rod 24 is coupled to the valve base 90 by applying a washer lOO and a bracket 102 to the shoulder of the piston rod and protruding from the valve base 90, and screwing a nut 104.

The bushing 16 has a first fluid chamber 110 and a second fluid chamber 112, and is located outside the valve base 90. In the illustrated example, the bushing 16 has an inner cylinder 114 . This inner cylinder 114 is used when forming the bushing 16 and when forming the bushing 16.
Although this is for convenience when connecting the inner cylinder 114 to the piston rod 24, the inner cylinder 114 can also be omitted.

The inner cylinder 114 has an annular groove 116 provided at a portion facing the hole 96 of the valve base 90, and a plurality of holes 117 (four shown in FIG. 3) extending in the radial direction. Inner cylinder 11
4 further includes an annular groove 118 provided in a portion of the valve base 90 facing the hole 98, and a plurality of grooves (1) extending in the radial direction.
There are four holes 119 (four shown in FIG. 4). Hole 11
7 communicates with the first fluid chamber 110, and the hole 119 communicates with the second fluid chamber 112, respectively. 0 for sealing in the inner cylinder 114
The inner cylinder 114 is coupled to the valve base 90 by fitting the valve base 90 equipped with the ring and caulking the valve base 90.

In the illustrated example, the bushings 16 each have an annular first portion 120. It consists of a second portion 121 and a third portion 122.

The first part 120 of the bushing is vulcanized and bonded to the end of the inner cylinder 114 above the hole 117 of the inner cylinder 114 on the inside surface, and to the end above the cylindrical part 125a of the outer cylinder 124 on the outside surface. ing. The second portion 121 of the bushing is vulcanized and bonded to the second inner bushing cylinder 126 on the inner side and to the second outer bushing cylinder 128 on the outer side. This second part 1
21 is fixed to the inner cylinder 114 by fitting the second bushing inner cylinder 126 into a portion below the hole 117 of the inner cylinder 114, and attaching the second bushing outer cylinder 128 to the cylindrical portion 125a of the bushing outer cylinder 124. It is fitted. As a result, a first fluid chamber 1 is formed between the first part 120 and the second part 121 of the bushing.
10 are divided.

In the illustrated example, the second bushing inner cylinder 126 extends downward beyond the hole 119, and the O member 130 whose lower end abuts the member 130 is fitted with an O ring and fitted into the inner cylinder 114, The inner cylinder 114 is fixed by caulking. The diameter of the second bush inner cylinder 126 is enlarged below the portion facing the hole 119.

A gap is formed between the inner cylinder 114 and the inner cylinder 114 . This gap is connected to the hole 98 of the valve base 90 via the hole 119 and the annular groove 118 on the one hand, and to the second bushing inner cylinder 126 on the other hand.
the second fluid chamber 1 through a plurality of notches 127 provided in the
Connects to 12.

The reason why the second bush inner cylinder 126 is configured in this way is for convenience in positioning the second bush inner cylinder 126.

The third portion 122 of the bushing is connected to the retainer 132 at the upper end surface.
In addition, they are each vulcanized and bonded to the member 130 at the inner periphery of the lower end surface. A plurality of ports 134 (only two are shown in the figure) having serrations are press-fitted into the retainer 132, and these ports 134 are inserted into the bush outer cylinder 12.
4 through the flange portion 125b of the bushing and the vehicle body 136, and screw the nut 138 into the port 134.
Portion 122 is secured to vehicle body 136. As a result, a second fluid chamber 112 is defined between the second portion 121 and the third portion 122 of the bushing.

The second valve body 140 has a hole 141 extending in the axial direction and a hole 142 opened in the diametrical direction, and the upper end portion is formed as a flat portion 143. /Press-fit a cylindrical spacer 144 into the second hole 94 of the help base 90, rotatably arrange the second valve body 140 above the spacer, and insert the hole 142 of the second valve body into the valve base 90. Align the hole 96 with the hole 96. Holder 146 with an O-ring installed in hole 94
is inserted and this holder 146 is held with a washer lOO to prevent the second valve body 140 from coming off.

As shown in FIG. 5, the actuator 150 includes an electric motor 11154 attached to a bracket 152, and a first gear 156 is fixed to the output shaft. 2nd gear 1
58 and the third gear 160 are respectively connected to the bracket 152.
A shaft 166 is connected to one tube 162 and a shaft 168 is connected to the other tube 164 by a pin 170. The second gear 158 is a stepped gear and meshes with the first gear 156 on one side and the third gear 160 on the other side. The bracket 152 connects to the bracket 1 via the plate 172.
02, and the bracket 102 is connected to the piston rod 2.
It is fixed at 4. The flat part 143 of the second valve body 140 is inserted into the slit 167 of the shaft 166, and the flat part 143 of the second valve body 140 is inserted into the slit 167 of the shaft 166.
The flat portions 84 of the piston rod 24 are inserted into the respective holes 69 . A fluid motor can also be used instead of the electric motor 154.

(Operation of the embodiment) A fluid, that is, oil or other liquid, air or other gas, or a mixture of liquid and gas is sealed in the first and second fluid chambers 110 and 112 for use.

When the vehicle is running, the actuator 150 is activated by manual operation by the driver or by operation of a controller that receives signals from a speed sensor, acceleration sensor, steering wheel rotation angular velocity sensor, or other sensor. , the first valve body 44 and the second valve body 1
Rotate 40.

When the second valve body 140 is in the position shown in FIG.
The phases of the first and second valve bodies are determined in advance so that they are shut off by the valve body 44 of FIG.

When the second valve body 140 is in the position shown in FIG.

The damping force of the system absorber 12, the spring constant of the air spring 14, and the spring constant of the bush 16 are all kept stiff.

When the second valve body 140 rotates 60″ clockwise, the second
The hole 142 of the valve body faces the hole portion 97a of the valve base 90. At this time, the hole 49 of the piston rod 24 is
Further, the orifice 47 and the hole 8 of the first valve body 44 are arranged so that the hole 56 and the hole 58 face the passage portion having a small diameter.
2.83. As a result, the liquid chamber A and the liquid chamber B of the shock absorber 12 are connected to the piston 2.
In addition to the valve originally provided in the shock absorber 2, the damping force of the shock absorber 12 is intermediate because the shock absorber 12 communicates through a passage with a small diameter. Also, since the main air chamber 74 and the sub air chamber 76 of the air spring 14 communicate through a passage with a small diameter, the spring constant is intermediate, and the first fluid chamber 110 and the second fluid chamber 112 of the bushing 16 are small. Since the bushings 16 communicate through the diameter passages, the spring constant of the bushing 16 is intermediate and the damping force is large.

When the first and second valve bodies 44.140 are further rotated 60'' clockwise, the bore 49 of the piston rod 24 further communicates with the bores 56 and 58 through a large passage, and the bore 142 of the bushing 16 They communicate through a large passage.As a result, the damping force of the shock absorber 12 becomes smaller.
The spring constant of the air spring becomes softer, and the spring constant and damping force of the bushing 1B become smaller.

(Effects of the Invention) According to the present invention, since the damping force of the shock absorber, the spring constant of the air spring, and the spring characteristics of the bushing can be adjusted, the overall damping force and spring constant of the suspension can be optimized, and ride comfort and handling can be improved. Stability can be improved.

Since it can be operated by a single 7 actuators, the number of actuators can be reduced, reducing cost and weight.

The suspension according to the present invention can be automatically controlled based on signals from various sensors to achieve anti-roll, anti-dive,
By performing anti-suffocation and other posture controls,
It provides a comfortable ride and improves steering stability.
The overall performance of the vehicle can be improved.

Since the damping force of the shock absorber and the spring constant of the air spring are rotated by one valve element, and the spring characteristics of the bushing are rotated by another valve element, both valve elements can be rotated at different angles. , there is a large degree of freedom when designing the valve body and other parts, and by appropriately selecting the position of the hole in each valve body, for example, the damping force of the shock absorber can be adjusted without changing the spring characteristics of the bushing. The characteristics can be changed according to the vehicle type and usage conditions by adjusting the spring constant of the air spring and the spring constant of the air spring.

Since the two valve bodies rotate to change the positions of the holes, an electric motor can be used as the actuator, and the responsiveness of the actuation can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main parts of the suspension according to the present invention, FIG. 2 is a sectional view showing the main parts of the shock absorber,
Figure 3 is a sectional view taken along line 3-3 in Figure 1, Figure 4 is a sectional view taken along line 4-4 in Figure 1, and Figure 5 is a sectional view taken along line 4-4 in Figure 1.
The figure is a sectional view of the actuator. 10: Suspension. 12 Niji 2-piece absorber, 14: Air spring, 16: Push, 24: Piston rond, 44: First valve body. 90: Valve base, 14o: Second valve body, 150:
actuator. Agent Patent Attorney Nobuyuki Matsunaga Figure 2

Claims (1)

[Scope of Claims] A shock absorber having an adjustable damping force and having a piston rod, an air spring with an adjustable spring constant formed surrounding the shock absorber, a first hole passing through the piston rod, and a valve body. 2nd for insertion
a valve base having a hole in the valve base, a bushing with adjustable spring characteristics arranged on the outside of the valve base, and rotatable within the piston rod for adjusting the damping force of the shock absorber and the spring constant of the air spring. a second valve body rotatably disposed within the second hole of the valve base for adjusting the spring constant of the bush; and an actuator that rotates a second valve body.