JPH048244B2 - - Google Patents

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 conjunction with a shock absorber.

(Prior art) A suspension that includes a shock absorber and 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. There is a system that allows the force and the spring constant of the air spring to 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 of 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. Stability can be appropriately matched according to 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, resulting in more optimal ride comfort and handling stability. 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 bush.

For example, in the cushion assembly disclosed in Japanese Utility Model Application Publication No. 57-199112, a pair of cushions having a sealed space on both sides is arranged with a fixing member in between, and both sealed spaces are communicated by 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 cushion assembly as a bush interposed between the shock absorber and the vehicle body, it is not possible to adjust the spring characteristics of the bush from the outside. Therefore, it cannot be matched with a shock absorber or 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 vehicle suspension in which the damping force of the shock absorber, the spring constant of the air spring, and the spring characteristics of the bushing, that is, the spring constant and the damping force, can be adjusted by a single actuator. be.

(Means for Solving the Problem) The suspension according to the present invention includes 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, and an air spring passing through the piston rod. the first hole for inserting the valve body and the second hole for inserting the valve body.
a valve base having a hole; and a bushing arranged radially outside the valve base and fixed to the vehicle body, the spring characteristic adjustment having at least two fluid chambers communicating with each other through the second hole. Contains possible publications. A first valve body for adjusting the damping force of the shock absorber and the spring constant of the air spring is rotatably arranged within the piston rod. A second valve body having a passage communicating with the fluid chamber for adjusting the spring characteristics of the bushing is attached to the second valve body of the valve base.
is rotatably disposed within the hole of. The first and second valve bodies are rotated by a single actuator.

(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 and an air spring 14.
and bush 16.

In the example shown in FIG. 2, the shock absorber 12 includes an inner cylinder 18 and an outer cylinder 20 spaced apart from the inner cylinder. This is the so-called twin inch tube type. As a shock absorber 12,
In addition to this, a so-called monotube type consisting of only a single tube is used.

A piston 22 is slidably disposed inside the inner cylinder 18, and 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 its end to connect the orifice member 26, and thus the piston rod 24, to the piston 22.

The piston 22 has a port 30 that allows liquid to flow when the piston rod 24 is extended and a port 32 that allows liquid to flow when the piston rod 24 is retracted.
A valve body 36 is biased by a spring 34 on the lower side of the port 30, and a spring 38 is biased on the upper side of the port 32.
The valve bodies 40 biased by the valve body 40 are arranged to constitute a valve that generates a damping force.

The piston rod 24 is provided with a hole 42 extending from the upper end face to the lower end face, and a first
A cometro rod portion 46 of the valve body 44 is rotatably arranged. Control rod part 46
The lower end of the hole 42 of the orifice member 26
It has entered into the hole 27 that was drilled in alignment with the
An orifice 47 extending diametrically is provided at this end. 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 illustrated position, the orifice 47 faces the hole 49, so the piston 2
The liquid chamber A on one side of the hole 4 and the liquid chamber B on the other side of the hole 4
8, communicates through orifice 47 and hole 49. As a result, the liquid in the inner cylinder 18 is transferred to the piston 22.
Flow is possible through the holes 48, 49 and orifice 47 outside the valve, which consists of a port and a valve body, which are originally provided in the valve. 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 degrees in the circumferential direction.

The piston rod 24 projects outwardly through a rod guide 50, a seal member 52, and a ring nut 54 located 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 axially spaced holes 56 and 58 are diametrically opened in the intermediate portion of the piston rod 24 protruding from the outer cylinder 20, and these holes form the axially extending hole 42. It is connected to the enlarged diameter part. A ring 60 having a hole 61 aligned with the lower hole 58 is attached to the piston rod 2.
4 and has a hole 63 on the upper side of this ring 60 that aligns with the 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, 58.
A cylindrical portion 69 of No. 6 is welded to the outer peripheral edge of the ceiling portion 67 and the partition portion 68. Cylindrical portion 69 of housing 66
A diaphragm 72 is stretched between the air piston 70 and the 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 portion 68 of the housing 66, and both air chambers are defined by the holes 42, 56, 58 of the piston rod 24.
It is connected through. Compressed air is sealed in both air chambers to form an air spring 14.

The first valve body 44 consists of 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.
and has. Hole 82 is the hole 56 of the piston rod.
Furthermore, the holes 83 can each communicate with the holes 58 of the piston rod. The stem portion 80 has a hole 81
The control rod portion 46 is connected by serration fitting therein. The upper end of the stem portion 80 is a flat portion 84 . The first valve body 44 is made airtight by an O-ring 86, and is prevented from coming off by a collar 88.
Rotatably disposed within bore 42 of piston rod 24.

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 includes a pair of hole portions 97a and a pair of holes with a diameter smaller than that of the hole portion 97a, which are provided at a portion sagging 60 degrees from the hole portion in the circumferential direction. It consists of a portion 97b. Also,
In the example shown in FIG. 4, the lower hole 98 includes a pair of hole portions 99a and a hole portion 99b having the same diameter as the hole portion 99a, which is provided at a portion slanting 60 degrees from the hole portion in the circumferential direction. and has. The holes 96 and 98 have the same phase relationship in plan view.

Insert the piston rod 2 into the hole 92 of the valve base 90.
4, abut the holder 62 fixed to the piston rod against the shoulder of the hole 92, and then remove the valve base 9.
The piston rod 24 is connected to the valve base 90 by applying a washer 100 and a bracket 102 to the part of the piston rod that protrudes from the piston rod 0 and screwing the nut 104 together.

The bush 16 has a first fluid chamber 110 and a second fluid chamber 112, and is disposed outside the valve base 90. In the illustrated example, the bush 16 is the inner cylinder 11.
It has 4. This inner cylinder 114 is used when forming the bush 16 and when the bush 16 is attached to the piston rod 2.
This inner cylinder 114 can also be made unnecessary, although this is for convenience when connecting to the inner cylinder 114.

The inner cylinder 114 has an annular groove 116 provided in 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.
and has. The inner cylinder 114 further includes an annular groove 118 provided in a portion facing the hole 98 of the valve base 90, and a plurality of holes 119 (four shown in FIG. 4) extending in the radial direction. Hole 117 is the first
The hole 119 is connected to the fluid chamber 110, and the hole 119 is connected to the second fluid chamber 1.
12, respectively. The inner cylinder 114 is coupled to the valve base 90 by fitting the valve base 90 equipped with a sealing O-ring into the inner cylinder 114 and caulking the valve base 90.

In the illustrated example, the bush 16 includes a first portion 120, a second portion 121, and a third portion 122, each of which is made of rubber and formed into an annular shape.

The first part 120 of the bushing is the inner surface, and the inner cylinder 1
They are vulcanized and bonded to the ends of the inner cylinder 114 that are above the holes 117 of No. 14, and to the ends above the circumferential part 125a of the outer cylinder 124 on the outer surface. The second part 121 of the bushing has a second bushing inner cylinder 1 on the inner surface.
26 and are each vulcanized and bonded to the second bushing outer cylinder 128 on the outer surface. This second part 121
In this case, the second bushing inner cylinder 126 is fitted into the part of the inner cylinder 114 that is below the hole 117, and the inner cylinder 114 is closed.
The second bushing outer cylinder 128 is fitted into the cylindrical portion 125a of the bushing outer cylinder 124.
As a result, a first fluid chamber 110 is defined between the first portion 120 and the second portion 121 of the bush.

In the illustrated example, the second bushing inner cylinder 126 has the hole 1.
19 and extends downwardly, and its lower end abuts member 130. The member 130 is fitted with an O-ring and fitted into the inner cylinder 114, and is fixed by caulking the inner cylinder 114. Hole 1 of the second bushing inner cylinder 126
The diameter is enlarged below the part facing the inner cylinder 1.
A gap is formed between 14 and 14. This gap is formed, on the one hand, through the hole 119 and the annular groove 118 into the hole 98 of the valve base 90, and on the other hand, through a plurality of notches 127 provided in the second bushing inner cylinder 126.
It communicates with the second fluid chamber 112 via. The reason why the second bush inner cylinder 126 is configured in this way is that
This is due to the convenience of positioning the bush inner cylinder 126.

The third portion 122 of the bushing is vulcanized and bonded to the retainer 132 at the upper end surface and to the member 130 at the inner periphery of the lower end surface. Retainer 132
A plurality of bolts 134 (only two are shown in the figure) having serrations are press-fitted into the bolts 134. These bolts 134 are passed through the flange portion 125b of the bushing outer cylinder 124 and the vehicle body 136, and nuts 138 are inserted into the bolts 134. The third portion 122 of the bushing is fixed to the vehicle body 136 by screwing them together. As a result, the second part 121 and the third part 122 of the bush
A second fluid chamber 112 is defined between the two.

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 is formed as a flat part 143. A cylindrical spacer 144 is press-fitted into the second hole 94 of the valve base 90, the second valve body 140 is rotatably arranged above the spacer, and the hole 1 of the second valve body is
42 with hole 96 in valve base 90.
A holder 146 equipped with an O-ring is inserted into the hole 94, and this holder 146 is held by a washer 100 to prevent the second valve body 140 from coming off.

The actuator 150, as shown in FIG.
Electric motor 154 attached to bracket 152
A first gear 156 is fixed to this output shaft. The second gear 158 and the third gear 160 are
Each tube is fixed to tubes 162 and 164 which are rotatably supported by a bracket 152, and 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. Bracket 152 is coupled to bracket 102 via plate 172, and bracket 152 is coupled to bracket 102 via plate 172.
02 is fixed to the piston rod 24. axis 16
The flat part 1 of the second valve body 140 is inserted into the slit 167 of 6.
43 and the flat part 84 of the piston rod 24 are inserted into the slit 169 of the shaft 168, respectively. 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, an acceleration sensor, a steering wheel rotation angular velocity sensor, or other sensors. to rotate the first valve body 44 and the second valve body 140.

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 the bore 49 of the piston rod 24 is further isolated from the bore 56 and the bore 58 by the first valve body 44.

When the second valve body 140 is in the position shown in FIG.
Damping force of the shock absorber 12, air spring 14
The spring constants of the bushing 16 and the spring constant of the bushing 16 are both kept stiff.

When the second valve body 140 rotates 60 degrees clockwise,
The hole 142 of the second valve body faces the hole portion 97a of the valve base 90. At this time, the first valve body 4 is arranged such that the hole 49 of the piston rod 24 further faces the passage portion with the smaller diameter.
It is preferable to form four orifices 47 and holes 82 and 83 in advance. As a result, the liquid chamber A and the liquid chamber B of the shock absorber 12 communicate with each other through a small diameter passage in addition to the valve originally provided in the piston 22, so that the damping force of the shock absorber 12 becomes intermediate. In addition, the main air chamber 7 of the air spring 14
4 and the auxiliary air chamber 76 communicate through a passage with a small diameter, so the spring constant is intermediate, and the
The first fluid chamber 110 and the second fluid chamber 112 of the bush 1 communicate with each other through a small diameter passage.
The spring constant of 6 is in the middle, and the damping force is large.

When the first and second valve bodies 44, 140 further rotate 60 degrees clockwise, the hole 49 of the piston rod 24 further communicates with the holes 56 and 58 through a large passage, and the hole 142 of the bush 16 communicates with the large passage. Connected through a 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 bush 16 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.

Operated by a single actuator,
The number of actuators can be reduced, reducing cost and weight.

The suspension according to the present invention is automatically controlled based on signals from various sensors to achieve anti-roll,
By performing anti-dive, anti-squat, and other attitude controls, it is possible to improve ride comfort and steering stability, and improve the overall performance of the vehicle.

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 bush 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. Moreover, by appropriately selecting the position of the hole in each valve body, for example, the damping force of the shock absorber and the spring constant of the air spring can be adjusted without changing the spring characteristics of the bush.
Characteristics can be changed according to the vehicle type and usage conditions.

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 cross-sectional view showing the main parts of the suspension according to the present invention, FIG. 2 is a cross-sectional view showing the main parts of the shock absorber, and FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 4 is a sectional view taken along the line 4--4 in FIG. 1, and FIG. 5 is a sectional view of the actuator. 10: Suspension, 12: Shock absorber, 14: Air spring, 16: Bush, 24:
Piston rod, 44: first valve body, 90: valve base, 140: second valve body, 150: actuator.

Claims (1)

[Claims] 1. A shock absorber with an adjustable damping force having a piston rod, an air spring with an adjustable spring constant formed surrounding the shock absorber, a first hole through which the piston rod passes, and a second hole for inserting a valve body. a valve base having a valve base disposed radially outside the valve base;
A bushing fixed to a vehicle body, the bushing having at least two fluid chambers communicating with each other through the second hole, the spring characteristics of which can be adjusted, and the damping force of the shock absorber and the spring constant of the air spring being adjusted. a first valve body rotatably disposed within the piston rod for adjusting the spring characteristics of the bush; and a second valve body for adjusting the spring characteristics of the bushing, the valve having a passage communicating with the fluid chamber. A vehicle suspension comprising: a second valve body rotatably disposed within the second hole of a base; and an actuator that rotates the first and second valve bodies.