JPS629451B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a suspension system used in vehicles such as automobiles. Conventionally, various vehicle suspension systems incorporating shock absorbers have been developed. However, conventional suspension systems have the problem that either ride comfort or handling stability must be sacrificed in any case. Therefore, as shown in Utility Model Application Publication No. 55-114708, for example, a driving device is provided that can make the orifice of the shock absorber variable and change the flow area of the orifice, thereby damping the shock absorber according to the running conditions of the vehicle. Suspension systems configured to switch power are known. In addition, as shown in Japanese Patent Laid-open No. 53-26021, for example, in addition to the main fluid spring chamber, an auxiliary fluid spring chamber is provided which is communicated with the main fluid spring chamber via an on-off valve, so that A suspension system is also known in which the spring constant is changed by opening or closing the on-off valve. By the way, increasing the damping force of the suspension will reduce the displacement speed of the vehicle body, and increasing the spring constant will reduce the amount of displacement of the vehicle body.
Ideally, a more effective effect can be achieved by making both the damping force and the spring constant variable. However, none of the above-mentioned prior art discloses a suspension system in which both damping force and spring constant can be switched.
Furthermore, at present, a suspension system that has a compact mechanism that enables switching of both the damping force and the spring constant has not yet been developed. The present invention has been devised in view of the above, and changes the damping force of the shock absorber and the spring constant of the air spring according to the usage conditions of the vehicle while the vehicle height is maintained constant to improve riding comfort and steering stability. The purpose of the present invention is to provide a suspension system for a vehicle that can improve performance. Therefore, the present invention provides a piston fitted into a cylinder, an orifice passage formed in the piston to communicate the first and second chambers in the cylinder partitioned by the piston, and an orifice passage in the piston. A piston rod that is connected to each other and extends upward, a control rod that extends in the longitudinal direction of the piston rod within the piston rod and is movable relative to the piston rod, and a control rod that is attached to the lower end of the control rod. In a vehicle suspension incorporating a damping force switching type shock absorber comprising a control valve body that can change the effective flow area of the orifice passage,
A main air spring chamber is disposed coaxially with the piston rod in the upper part of the shock absorber, and a sub air spring chamber is provided coaxially with the piston rod directly above the main air spring chamber. An on-off valve having a passage bored through the piston rod and the control rod is provided to communicate with and shut off the air spring chamber and the auxiliary air spring chamber, and the control valve body and the on-off valve are interlocked with each other. The present invention is characterized in that a drive mechanism is provided for selectively sliding the control rod to a plurality of control positions in order to switch the control rod to a plurality of opening/closing modes. Hereinafter, a vehicle suspension system as an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a sectional view showing the overall configuration, and the states shown in FIGS. Arrow sectional view, −arrow sectional view, −
FIGS. 3 to 5 are cross-sectional views in the direction of arrows, and each of a to c in FIGS. 3 to 5 shows a vehicle suspension system as a modification of the present invention, and the states in FIGS. FIG. 1 is a cross-sectional view taken in the direction of - arrows, a cross-sectional view in the direction of - arrows, and a cross-sectional view taken in the direction of - arrows in FIG. As shown in Fig. 1, this suspension system incorporates a strut type damping force switching type shock absorber 4, and this shock absorber 4 has a cylinder 1a attached to the front wheel or rear wheel side. , and a piston 19 that is slidably inserted into the cylinder 1a. The piston 19 also includes orifice passage portions 19a, 19b, 19 that are communicatively connected to each other.
an orifice passage 19d consisting of a
b, 1c can be communicated with each other. Furthermore, the piston 19 includes a piston rod 5.
The piston rod 5 extends upward and passes through the first chamber 1b in a fluid-tight manner, and the upper end of the piston rod is supported by the body frame 9 via a bearing 6 and a mount rubber 7. There is. This support is performed using bolts or the like, and is fixed at several locations. Incidentally, the vertical movement of the piston rod 5 is restricted by a nut or the like, but rotation is allowed by a bearing 6. By the way, a control rod 15 is provided inside the piston rod 5, and this control rod 15 extends in the longitudinal direction of the piston rod 5 and is provided so as to be rotatable relative to the piston rod 5. It is being The lower end of the control rod 15 extends into a space forming a part of the orifice passage 19d in the piston 19, and a shutter 15a as a control valve body is attached to the lower end of the control rod. This shutter 15
As shown in FIG. The orifice passage portion 19a can be opened and closed by opening and closing the orifice passage portion 19a. Further, the upper end of the control rod 15 extends further upward than the upper end of the piston rod 5, and a two-position solenoid as a drive mechanism is attached to the upper end of the control rod via a drive gear 14 and a rack 13a. A mechanism 13 is connected. This solenoid mechanism 13 is switched in three stages including the off position, so that the control rod 15 can be discretely rotated to positions of, for example, 0°, 60°, and 120°. It can be selectively rotated into three control positions. The communication passage 15a' of the shutter 15a is aligned with the orifice passage portion 19a when the control rod 15 is at the 0° control position, and when the control rod 15 is at the 60° and 120° control positions. It is positioned so as to be out of alignment with the orifice passage portion 19a. (Refer to the states in Fig. 2 a to c) Therefore, when the solenoid mechanism 13 is driven, the rack 13a rotates the control rod 15 through the drive gear 14 from 0° to 60° and further rotates by 60°. As the shutter 15a at the lower end of the control rod also rotates, the orifice passage portion 19a can be closed or opened. As a result, the effective flow area of the orifice passage 19d can be changed, and the damping force can be switched (hard or soft). In this way, the damping force switching mechanism D is constituted by the solenoid mechanism 13, the control rod 15, the shutter 15a, etc. Therefore, in this damping force switching type shock absorber 4, the cylinder 1a on the outside of the body moves up and down with respect to the piston rod 5 in accordance with the up and down movement of the wheel, thereby exerting a damping effect according to the position of the shutter 15a. It is now able to absorb shots effectively. The solenoid mechanism 13 is automatically controlled by a control means that receives a signal from an acceleration sensor (not shown) and outputs a control signal. Incidentally, a main air spring chamber 2 is provided in the upper part of the shock absorber 4 coaxially with the piston rod 5.
is installed. Further, a sub air spring chamber 10 is disposed coaxially with the piston rod 5 directly above the main air spring chamber 2 . Furthermore, these air spring chambers 2 and 10 are connected to each other via a communication passage 11 bored across the control rod 15 and the piston rod 5, and an on-off valve 12 is connected to this communication passage 11. It has been intervened. This on-off valve 12 has a first valve portion 12a and a second valve portion 12a.
The valve portion 12b is configured to include a valve portion 12b. As shown in FIGS. 2a to 2c, the first valve portion 12a has a passage 18a formed in the piston rod 5 and communicating with the auxiliary air spring chamber 10, and a communication passage formed in the control rod 15. A wide passage 18b communicating with the sub air spring chamber 11 is configured to control the opening and closing of the valve by aligning or not aligning with the rotation of the control rod 15. The communication path 11 can be cut off from the communication path 11. The second valve portion 12b has a passage 17a formed in the piston rod 5 and communicating with the main air spring chamber 2, and a passage 17a formed in the control rod 15, as shown in FIGS. 2a to 2c. A wide passage 17b communicating with the communication passage 11 is configured to control opening and closing of the valve by aligning or not aligning the same with the rotation of the control rod 15. Communication between the chamber 2 and the communication path 11 can be cut off. In addition, the opening/closing mode of the valve portions 12a and 12b is as follows.
It's exactly the same. That is, when the first valve section 12a is open, the second valve section 12b is also open, and conversely, when the first valve section 12a is closed, the second valve section 12b is also closed. Furthermore, since the passages 17b and 18b are formed wide, even if the control rod 15 rotates 0° and 60°, each valve portion 12a and 12b remains open, and the control rod 15 remains open. It closes when it is rotated further 60° and takes the control position of 120°. Therefore, when the valve portions 12a, 12b are in the open mode, the main air spring chamber 2 and the auxiliary air spring chamber 10 are brought into communication, and the spring constant is reduced (soft).
When the valve portions 12a, 12b are in the closed mode, the main air spring chamber 2 and the secondary air spring chamber 10
The spring constant can be made larger (harder) by putting this in a cut-off state. Therefore, by rotating the control rod 15, the on-off valve 12 can be opened and closed, and by this opening and closing, the spring chamber capacity can be changed. By changing this spring chamber capacity, the spring constant of the suspension can be changed. The opening/closing control of the opening/closing valve 12 is automatically performed by a control means that outputs an opening/closing control signal in response to a signal from the above-mentioned acceleration sensor or the like. By the way, a coil spring 3 is disposed coaxially with the piston rod 5 so as to surround the main air spring chamber 2 and the on-off valve 12.
has a lower end supported by a spring receiver 16a with a shock absorber 4, and an upper end supported by a spring receiver 16b formed on the lower surface inside the sub air spring chamber 10.
is supported by. Compressed air for adjusting the vehicle height is supplied through a pipe 1 connected to a compressor (not shown) and a communication passage 11 of a partially pipe-shaped control rod 15. Therefore, in order to set the suspension at a predetermined vehicle height position, the vehicle height may be adjusted by first supplying compressed air from the compressor to each spring chamber 2, 10 through the pipe 1. At this time, the on-off valve 12 is left open. As a result, the pressure inside the auxiliary air spring chamber 10 is adjusted to the same pressure as inside the main air spring chamber 2. When the vehicle height adjustment is completed in this manner, the valve attached to the pipe 1 may be closed to stop the supply of compressed air. In addition, the reference numeral 8 in the figure indicates a bump stopper for preventing damage to the wall surface of the main air spring chamber 2 due to the relative rise of the cylinder portion of the shock absorber 4 on rough roads etc.
20 indicates a bellows forming part of the main air spring chamber 2. With the above-described configuration, by rotating the control rod 15, the shutter 15a as a control valve body and the on-off valve 12 can be switched to three stages of on-off mode. That is, in the first stage mode, the control rod 15 does not rotate and the on-off valve 12 is open (both valve parts 12a and 12b are open) as shown in Figure 2a, so the spring constant is soft. At the same time, the shutter 15a serving as a control valve element opens the orifice passage portion 19a, so that the effective flow area of the orifice passage 19d increases, resulting in a low damping state (soft). In the second stage mode, the control rod 15 is rotated 60 degrees clockwise by the two-position solenoid mechanism 13. At this time, as shown in FIG. 2b, the on-off valve 12 is still open and the spring constant remains soft. On the other hand, the shutter 15a as a control valve body
closes the orifice passage portion 19a, so the effective flow area of the orifice passage 19d becomes smaller, resulting in a high damping state (hard). That is, the orifice passage portions 19b, 19c
As a result, the effective circulation area becomes smaller. Furthermore, in the third stage mode, the control rod 15 is further rotated 60 degrees clockwise by the two-position solenoid mechanism 13, for a total of 120 degrees, so that the on-off valve 1
2 is closed (both valve portions 12a and 12b are closed), and the spring constant becomes hard. At this time, the shutter 15a as a control valve still closes the orifice passage portion 19a, so the effective flow area of the orifice passage 19d remains small.
A high damping state (hard) is maintained. In this way, with this system, the spring constant and damping force can be switched between multiple modes depending on the usage conditions of the vehicle, making it possible to further improve ride comfort and handling stability. In addition, as shown in each of a to c in FIGS. 3 to 5, in the modified example of the present invention, the valve structure of the on-off valve 12 and the shutter 15a as a control valve element is changed to further improve the fineness. This allows for detailed control of In the modification shown in FIGS. 3a to 3c, the shutter 15a as a control valve body is connected to a control rod 15 by a two-position solenoid mechanism 13.
The on-off valve 12 is configured to be open when the control rod 15 is rotated at 0 degrees and 60 degrees, and closed at other times, and the effective flow area is large when the control rod 15 is rotated through 0 degrees, and small at other times. has been done. In the modification shown in FIGS. 4a to 4c, the shutter 15a as a control valve body has a large (soft) effective flow area when the control rod 15 is rotated at 0°, and a large effective flow area when the control rod 15 is rotated at 60°. is medium (medium), and the effective circulation area is small (hard) when rotated 120 degrees. The modifications shown in FIGS. 5a to 5c are a combination of the above two modifications. As described above, in the embodiment of the present invention and its modifications, the spring constant and damping force in each mode are as shown in the following table.

【table】

[Table] Furthermore, the on-off valve 12 and the control valve body are configured so that the opening and closing of the valve can be switched in three or more stages by sliding the control rod 15 against the piston rod 5 in the longitudinal direction. Good too. In this case, the control rod 15 is slid up and down by a solenoid mechanism driven in the longitudinal direction, and the on-off valve 12 and the orifice passage 19d are caused to change their states in accordance with this up and down movement. It is. Furthermore, the sliding direction of the control rod 15 may be a combination of the rotational direction and the longitudinal direction to open and close each valve. In this way, this suspension system adjusts the damping force and spring constant according to the usage conditions of the vehicle (normal driving conditions, sudden braking, driving conditions on sharp curves, driving conditions on rough roads, etc.). It is possible to accurately and automatically control switching, so depending on the usage situation, you can improve riding comfort,
It can improve steering stability. Note that it is of course possible to perform switching control between the damping force and the spring constant using a signal from a manual switch. Furthermore, by displacing the control rod 15 relative to the piston rod 5, both the damping force and the spring constant can be changed, so the position of the control rod 15 can be changed with one actuator (solenoid mechanism 13). Both the damping force and the spring constant can be switched to multiple modes by controlling the damping force, and even if the control rod 15 is configured as a manual type, the damping force can be changed by simply manipulating the position of the control rod 15. The effect is that both force and spring constant can be switched between multiple modes. It is also possible to adjust the vehicle height by changing the amount of compressed air supplied. Furthermore, the main air spring chamber 2 and the auxiliary air spring chamber 10 are provided so as to overlap on the upper part of the shock absorber 4, and an on-off valve 12 is provided to control communication between the main air spring chamber 2 and the auxiliary air spring chamber 10. Since the suspension unit is built into the piston rod 5, the suspension unit as a whole can be constructed extremely compactly, and the upper end of the coil spring 3 is supported by the spring support 16b formed on the lower surface of the auxiliary air spring chamber 10. Because things are done,
By standardizing parts, even more compact integration can be realized. Moreover, when the device of the present invention is used for the front wheels of a vehicle, the piping 1 can rotate with the rotation of the coil spring 3 and the auxiliary air spring chamber 10 due to steering of the front wheels, which can also contribute to simplifying the structure. It is. Furthermore, since the spring constant and damping force can be controlled, when passing through a long wave-shaped road, the spring constant and damping force can be initially set to a low spring constant and low damping force to improve riding comfort, and then the spring constant and high damping force can be set to a low spring constant and high damping force during the course of the trip. It is possible to suppress changes in the switching and vehicle body posture. Furthermore, when driving at high speeds, it is possible to perform control such as improving steering stability by using a high spring constant and high damping force. As detailed above, according to the vehicle suspension system of the present invention, the damping force of the shock absorber and the spring constant of the air spring can be changed as appropriate by the drive mechanism, so the riding comfort can be adjusted depending on the situation. This has the advantage of providing both comfort and safety. Furthermore, by displacing the control rod relative to the piston rod, both the damping force and the spring constant can be switched to multiple modes, so one drive mechanism can control both the damping force and the spring constant. This has the effect of being able to switch to a plurality of modes. Furthermore, the valve mechanism that controls the communication between the main air spring chamber and the auxiliary air spring chamber is composed of a piston rod and a control rod built into the piston rod, making the entire device extremely compact with the shock absorber at its center. This has the advantage that it can be incorporated into

[Brief explanation of the drawing]

The figures show a vehicle suspension system as an embodiment of the present invention. Fig. 1 is a cross-sectional view showing its overall configuration, and the states shown in Figs. They are a sectional view, a sectional view taken in the direction of arrows, and a sectional view taken in the direction taken in the direction indicated by the arrows. The states in Figures a to c are respectively a cross-sectional view taken along the arrows -, a cross-sectional view taken along the arrows -, and a cross-sectional view taken along the arrows -, respectively. 1... Piping, 1a... Cylinder, 1b... First
Chamber, 1c...Second chamber, 2...Main air spring chamber, 3...Coil spring, 4...Shock absorber, 5...Piston rod, 6...Bearing, 7...Mount rubber, 8...Bump stopper, 9...Body frame, 10...Sub-air spring chamber, 11...Communication passage, 12...Opening/closing valve, 12a,
12b...Valve part, 13...2 as a drive mechanism
Position type solenoid mechanism, 13a...Rack, 14...Drive gear, 15...Control rod, 15a...Shutter as control valve body, 1
6a, 16b... Spring holder, 17a, 17b, 18
a, 18b... passage, 19... piston, 19
a, 19b, 19c...orifice passage part, 1
9d... Orifice passage, 20... Bellows, D
...damping force switching mechanism.

Claims (1)

[Claims] 1 A piston fitted into a cylinder, an orifice passage formed in the piston to communicate the first and second chambers in the cylinder partitioned by the piston, and an orifice passage connected to the piston and extending upward. a control rod that extends in the longitudinal direction of the piston rod and is movable relative to the piston rod; and a control rod that is attached to the lower end of the control rod and that controls the effective flow of the orifice passage. In a vehicle suspension incorporating a damping force switching type shock absorber comprising a control valve body whose area can be changed, a main air spring chamber is provided above the shock absorber and coaxially arranged with the piston rod, A sub air spring chamber is provided coaxially with the piston rod directly above the main air spring chamber, and the piston rod and control rod are connected to communicate and disconnect the main air spring chamber and the sub air spring chamber. An on-off valve having a passage bored in the is provided,
A driving mechanism is provided for selectively sliding the control rod to a plurality of control positions in order to interlock the control valve body and the opening/closing valve to switch to a plurality of opening/closing modes. Vehicle suspension system.