EP0390546B1

EP0390546B1 - Railway rolling stock

Info

Publication number: EP0390546B1
Application number: EP19900303341
Authority: EP
Inventors: Yoshio Hara; Hitoshi Nagaoka; Motomi Hiraishi; Toshi Yasui; Masao Harada; Katsuuki Tereda
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1989-03-31
Filing date: 1990-03-29
Publication date: 1996-12-27
Anticipated expiration: 2010-03-29
Also published as: DE69029482T2; EP0390546A2; DE69029482D1; EP0390546A3

Description

The present invention relates to railway rolling stock and, more particularly, to railway rolling stock running on a curved area of a track at a higher speed than a running speed corresponding to a cant of the track.
A car body bearing apparatus adopted in conventional rolling stock incorporates various devices in order to improve riding comfort during a high-speed operation. For example, a vibration control device is known which restrains vertical vibration passing from the track up to a car body through a truck frame. For example, a vibration control device as disclosed for example in Laid-Open Japanese Patent No. 56-17754 is designed to control an actuator mounted alongside of an air spring.
As an example of a conventional car body bearing apparatus for railway rolling stock, a car body tilting apparatus is known, which is designed to tilt the car body to the right or left of the car body when the rolling stock runs at a high speed on a curved track. This car body tilting apparatus supports the car body through rollers, swing bolsters, and air springs. When the rolling stock is running on a curved track, there takes place a lateral displacement of the car body between the rollers and the swing bolsters, tilting the car body in a lateral direction of the car body. The aforesaid lateral displacement of the car body between the rollers and the swing bolsters is caused to occur by the operation of the actuator disposed between the rollers and the swing bolsters and an excessive centrifugal force acting on the car body. The car body tilting apparatus functions to tilt the car body in the lateral direction of the car body, thereby reducing the excessive centrifugal force acting on passengers. Accordingly it is possible to improve the riding comfort to the passengers by diminishing the passengers' unpleasantness resulting from the excessive centrifugal force acting on the passengers. The car body tilting apparatus described above has been disclosed for example in Laid-Open Japanese Patent No. 61-108053.
In place of the rollers and the swing bolsters of the car body tilting apparatus, the use of a car body tilting apparatus is also known for tilting the car body by means of hydraulic cylinders disposed between air springs and the car body or the truck.
The aforementioned vibration control device is of the constitution that an actuator for restraining car body vibration is disposed off the car springs. Therefore, when this vibration control device is adopted, there shall be provided a space wide enough to mount the air springs and the actuator for vibration control between the car body and the truck. Also, in a rolling stock using the vibration control device, an increased number of equipment are to be mounted between the car body and the truck, consequently requiring much labour and time for manufacture and maintenance work.
The car body tilting apparatus, having the actuator between the rollers and the swing bolsters, requires a space wide enough to mount the actuator. Furthermore, this car body tilting apparatus, like the vibration control device, requires much labour and time for manufacture and maintenance work because of an increased number of equipment disposed between the truck and the car body. Furthermore, the car body tilting apparatus, provided with the rollers, swing bolsters and air springs disposed vertically in line, will become long in the vertical direction. Rolling stock equipped with the car body tilting apparatus, therefore, is required to be extended in the longitudinal direction of the truck itself in order to provide a space for mounting the car body bearing apparatus, resulting in increased size and weight.
In the rolling stock, functions of both the aforementioned vibration control device and the car body tilting apparatus as a car body bearing apparatus are needed to restrain the vertical vibration of the car body and to reduce the excessive centrifugal force acting on passengers. However, the following problem is encountered when the actuator for vibration control and the actuator for tilting the car body are mounted between the truck and the car body. That is, a larger-size truck has to be employed, resulting in increased weight of the truck for the purpose of providing a space wide enough to install the actuator for vibration control and the actuator for tilting the car body. There was the possibility, therefore, that the use of a larger, heavier truck would increase the weight of the whole body of the rolling stock.
Furthermore, no adequate consideration was given to the simplification of constitution of the vibration control device and the car body tilting apparatus.
Accordingly it is an object of the present invention to provide rolling stock the whole body of which has been decreased in weight by building a small-type car body bearing apparatus having a function to restrain car body vibration and a function to reduce an excessive centrifugal force acting on passengers.
It is another object of the present invention, in addition to the above-mentioned object, to provide rolling stock added with the car body bearing apparatus having a function to restrain the longitudinal tilt of the car body itself.
The foregoing objects and other objects of the present invention will become more apparent from the following detailed description thereof, when read in connection with the accompanying drawings.
A feature of the present invention resides in that, in rolling stock comprising a truck, a car body, a spring means mounted between the truck and the car body to support the car body on the truck, a vibration control means for restraining vertical vibration of the car body, and a posture control means for controlling the posture of the car body, there have been mounted an actuator for vibration control constituting the aforesaid vibration control means, and an actuator for posture control constituting the aforesaid posture control means within a range corresponding to the space delimited by the mounting range of one single of said spring means.
Another feature of the present invention is that, in the rolling stock comprising a truck, a car body, spring means mounted between the truck and the car body to support the car body on the truck, a vibration control means for restraining vertical vibration of the car body, and a posture control means for controlling the posture of the car body, there have been mounted a vibration control actuator constituting the aforesaid vibration control means, and a posture control actuator constituting the aforesaid posture control means between the spring means and the truck of the car body.
According to the present invention, the mounting area of the car body bearing apparatus can be reduced by installing the vibration control actuator and the posture control actuator within a range corresponding to the space delimited by the mounting range of one single of said spring means.
Furthermore, according to the present invention, the posture control means is capable of restraining the longitudinal tilt of the car body. The rolling stock disclosed in the present invention has a function to restrain the longitudinal tilt of the car body in addition to the function for restraining the car body vibration and the function for decreasing the excessive centrifugal force acting upon passengers. Therefore, according to the present invention, riding comfort can be improved.
In the drawings:

Fig. 1 is a vertical sectional view showing a car body bearing apparatus used in rolling stock according to a first embodiment of the present invention;
Fig. 2 is a side view of the rolling stock according to the first embodiment of the present invention;
Fig. 3 is a plan view showing the condition of a truck of the rolling stock shown in Fig. 2 which is running on a curved track;
Fig. 4 is a front view of the rolling stock shown in Fig. 2 running on a curved track;
Fig. 5 is a side view of the rolling stock shown in Fig. 2 which is running;
Fig. 6 is a block diagram showing the control system of a car body bearing apparatus shown in Fig. 1;
Fig. 7 is a block diagram showing the control system of the car body bearing apparatus of rolling stock according to a second embodiment of the present invention;
Fig. 8 is a vertical sectional view showing the car body bearing apparatus used in rolling stock according to a third embodiment of the present invention;
Fig. 9 is a vertical sectional view showing the car body bearing apparatus in rolling stock according to a fourth embodiment of the present invention; and
Fig. 10 is a vertical sectional view showing the car body bearing apparatus in rolling stock according to a fifth embodiment of the present invention.

Hereinafter the first embodiment of the rolling stock according to the present invention will be described with reference to Figs. 1 to 6. On a track 1 are laid a pair of rails 1a, 1b. A truck 2 runs on the track 1. The truck 2 consists of a truck frame 2a, axle springs 2b and wheelsets 2c. The truck 2 is provided with a car body bearing apparatus 3 laterally mounted on both sides. A car body 4 is supported on the truck 2 through the car body bearing apparatus 3. Major members constituting the car body bearing apparatus 3 include an actuator 5 for posture control, an actuator 6 for vibration control, and air springs 7. The actuator 5 for posture control is constituted of a cylinder 5a and a piston 5b. The cylinder 5a is vertically mounted on the truck frame 2a in the axial direction of the cylinder 5a. The piston 5b slides inside of the cylinder 5a. Between the side walls of the cylinder 5a and the piston 5b is formed a fluid chamber of airtight construction. The fluid chamber between the cylinder 5a and the piston 5b is divided into two chambers by a flange 5c which extends from the side wall of the piston 5b to the side wall of the cylinder 5a. That is, the fluid chamber is separated into a fluid chamber 16a and a fluid chamber 16b. The piston 5b is moved with a control fluid supplied to the fluid chamber 16a or 16b.
The piston 5b is generally formed in a cylindrical form, serving also as a cylinder 6a of the actuator 6 for vibration control. Therefore, the actuator 6 for vibration control is constituted of a cylinder 6a formed inside of the piston 5b and a piston 6b. The cylinder 6a is formed near one end of the piston 5b. Between the side walls of the cylinder 6a and the piston 6b is formed a fluid chamber of airtight construction. The fluid chamber between the cylinder 6a and the piston 6b is separated into two parts by the flange 6c extending from the side wall of the piston 6b to the side wall of the cylinder 6a. That is, the fluid chamber is separated into a fluid chamber 17a and a fluid chamber 17b. The fluid chamber 17a or the fluid chamber 17b is supplied with a control fluid, the piston 6b being operated. This piston 6b is formed in a cylindrical shape with its one end opening while the other end closed.
In the sliding part between the cylinder 5a and the piston 5b and between the cylinder 6a and the piston 6b is adopted a fluid seal 10. When there is a great force acting in a direction perpendicular to the axial direction of the actuator 5 for posture control and the actuator 6 for vibration control, it is necessary to use a bearing in line with the fluid seal 10. In this embodiment, this bearing is not described.
The axial center position of the actuator 5 for posture control and that of the actuator 6 for vibration control coincide within the horizontal plane, and they operate in a vertical direction. The actuator 5 for posture control has a larger diameter than the actuator 6 for vibration control. The operation stroke of the actuator for posture control will become about a maximum ±110 mm when for example the car body width is 2600 mm and the maximum inclination angle is 5 degrees. The operation stroke of the actuator for vibration control is generally about a maximum ±25 mm.
The air spring 7 is disposed between the top end of the piston 5b and the lower surface of the car body 4. The air spring 7 is a spring means which elastically supports the car body 4 on the truck 2. The air spring 7 is constituted of a lower plate 7a, an upper plate 7b and a diaphragm 7c connecting these plates. The upper plate 7b is connected to a seat 12 provided on the lower surface of the car body 4. The upper plate 7b is mounted on the seat 12 for positioning. The lower plate 7a is connected to the top end of the piston 5b. The air chamber 18 is formed by the lower plate 7a, the upper plate 7b and the diaphragm 7c. The lower plate 7a is mounted in the top end section of the piston 5b. Also, the upper plate 7b is mounted on the lower surface of the car body 4. The height of the air spring 7 is always kept fixed by a height control valve 19 for air spring. The height control valve 19 for air spring is operated by the time constant of the order of 3 seconds. Between the lower plate 7a and the upper plate 7b is provided a flexible and elastic diaphragm 14. This diaphragm 14 is smaller in diameter than the aforementioned diaphragm 7c and disposed at the axial center position of the air spring 7. In the air spring 7 is formed a through part 15 by the diaphragm 14. The piston 6b is connected to the lower surface of the car body 4 by a rod 8. In the connecting section between the rod 8 and the piston 6b and between the rod 8 and the car body 4, there is provided a connecting piece 13 which permits the relative horizontal displacement of the car body and the piston 6b. The connecting piece 13 employed is for example a swivel bearing or an universal joint. Allowing the relative horizontal displacement of the car body 4 and the truck 2, the rod 8 and the connecting piece 13 transmit the control power of the piston 6b to the car body 4. By the way, the actuator 5 for posture control and the actuator 6 for vibration control are disposed within the mounting range of the air spring 7 in the horizontal plane. Namely, the actuator 5 for posture control and the actuator 6 for vibration control are disposed within a range in which the lower plate 7a of the air spring 7 and the truck frame 2a face each other. Furthermore, the axial center position of the air spring 7 and that of the actuator 5 for posture control and the actuator 6 for vibration control coincide within the horizontal plane.
To the actuator 5 for posture control, a control fluid of oil is supplied from a fluid supply source 31 through a control valve 21 for posture control. Between the actuator 5 for posture control and the control valve 21 for posture control and between the control valve 21 for posture control and the fluid supply source 31 are connected pipes 21a, 21b. The actuator 6 for vibration control is supplied with the control fluid of oil from the fluid supply source 31 through a control valve 20 for vibration control. Also between the actuator 6 for vibration control and the control valve 20 for vibration control and between the control valve 20 for vibration control and the fluid supply source 31, pipes 20a, 20b are connected. The control valve 21 for posture control is mounted on the piston 5b. The control valve 20 for vibration control is mounted on the piston 6b. A vertical vibrational accelerometer 22 which detects the vertical vibrational acceleration of the car body 4 is mounted on the car body 4. This vertical vibrational accelerometer 22 is disposed correspondingly to the car body bearing apparatus 3 installed in four places of the car body 4, to detect the vertical vibrational acceleration of the order of 0.7 to 10 Hz in the car body 4 and outputs to the control circuit 28 for vibration control. The longitudinal tilt sensor 23 functions to detect a part of gravity on the floor of the car body 4 in the longitudinal direction of the car body when the car body 4 has tilted longitudinally, outputting to the control circuit 27 for posture control. The longitudinal tilt sensor 23 consists of an accelerometer which detects only a low-frequency component below about 0.7 Hz and is mounted on the car body 4. A displacement sensor 24 detects a relative displacement of slowly changing about 0.7 Hz or less of the piston 5b and the piston 6b and outputs to the control circuit 28 for vibration control. The displacement sensor 24 is connected to the piston 5b and the piston 6b. In the meantime, a displacement sensor 25 functions to detect a slowly varying relative displacement of about 0.7 Hz or less of the cylinder 5a and the piston 5b, outputting to the control circuit 27 for posture control. This displacement sensor 25 is connected to the cylinder 5a and the piston 5b.
A displacement target generator 26 for posture control functions to output a control command value, or a target displacement h for posture control, necessary for posture control when the car body makes a lateral tilt. This displacement target generator 26 for posture control retains information such as a distance from a reference point to a curved track, curvature, cant, and length of each curved track of a railway line. Furthermore, the displacement target generator 26 for posture control functions to select a necessary information as to the curved track from a distance run by the rolling stock, computing and outputting the posture control target displacement h on the basis of the information inputted and a running speed of the rolling stock at that time. The control circuit 27 for posture control computes a control signal value on the basis of a difference of the target displacement h for posture control and the output of a displacement sensor 25, and the output of the longitudinal tilt sensor 23, then outputs the control signal value to the control valve 21 for posture control. The control circuit 28 for vibration control receives signals outputted from the vertical vibration accelerometer 22 and the displacement sensor 24. This control circuit 28 adjusts the input phase of the vertical vibrational accelerometer 22 such that, of the pressure working on the piston 6b, an about 0.7 to 10 Hz pressure will advance about 100 degress over the input from the vertical vibrational accelerometer 22. Also, the control circuit 28 for vibration control adds the time constant of about 3 seconds throughout the frequency range of about 0.7 Hz and less to the input signal from the displacement sensor 24. Furthermore, the control circuit 28 outputs a control signal value added with a result of the aforementioned two computation, to the control value 20 for vibration control.
The control device 29 for posture control is composed of the displacement target generator 26 for posture control, the displacement sensor 25, the longitudinal tilt sensor 23, the control circuit 27 for posture control, and the control valve 21 for posture control. The control device 30 for vibration control is composed of the vertical vibrational accelerometer 22, the displacement sensor 24, the control circuit 28 for vibration control, and the control valve 20 for vibration control. An air source 33 supplies compressed air to the air spring 7 through the air spring height control valve 19.
The car body bearing apparatus 3 is disposed one on either side of the upper part of the truck 2 as shown in Figs. 2 and 3. Accordingly, the car body 4 is supported on two trucks 2 through four sets of car body bearing apparatus 3. To the four sets of car body bearing apparatus 3 are connected the control device 29 for posture control and the control device 30 for vibration control. Usually, the control device 29 for posture control and the control device 30 for vibration control are mounted on the car body 4. A fluid supply source 31 also is mounted on the car body 4, supplying the control fluid to each actuator of the four sets of car body bearing apparatus 3. In the first embodiment of the present invention, the vibration control means is composed of the actuator 6 for vibration control, the control device 30 for vibration control, and the fluid supply source 31. Also, the posture control means is composed of the actuator 5 for posture control, the control device 29 for posture control and the fluid supply source 31.
Symbols necessary for the description of details of control operation of the control system are defined as follows. Fy: a centrifugal force acting on passengers, W: gravitational force, φ: angle of the gravitational force W to the normal line of the floor of the car body 4, Q: resultant force of the gravitational force W and the centrifugal force Fy, Mθ: pitching moment acting on the car body 4, Z₀: track displacement representing the roughness of the track 1, Zt: truck displacement relative to ground, Z₁: displacement of the piston 5b of the actuator 5b for posture control relative to ground, Zb: displacement of the car body relative to ground, θb: longitudinal tilt angle of the car body 4 by pitching moment Mθ, ΔZ₁: relative displacement of the piston 5b and the truck 4 which is detected by the displacement sensor 25 and expressed by a difference between the displacement Z₁ of the piston 5b and truck displacement Zt, ΔZb: relative displacement of the piston 6b and the piston 5b which is detected by the displacement sensor 24 and expressed by a difference between the car body displacement Zb and the displacement Z₁ of the piston 5b, h: target displacement for posture control, S: Laplace operator, Z̈b: vertical vibrational acceleration of the car body detected by the vertical vibrational accelerometer 22.
Next, the operation of the rolling stock will be explained. Generally, when the rolling stock runs on a curved track faster than a safety speed set for the cant of the curved track, the centrifugal force Fy acts on passengers. In the rolling stock, therefore, controls described below are performed in order to reduce excessive centrifugal force ( $Fy-W·φ$
) due to the centrifugal force Fy. Namely, in the control device 29 for posture control, the target displacement h for posture control is outputted from the displacement target generator 26 for posture control, and a difference between the target displacement h for posture control and the output of the displacement sensor 25 is inputted to the control circuit 27 for posture control. This control circuit 27 functions to compute the control input, outputting the control signal value to the control valve 21 for posture control. Thus the control valve 21 for posture control is operated by the control signal value outputted from the control circuit 27 for posture control. The control valve 21 for posture control controls the control fluid supplied from the control fluid supply source 31 to the actuator 5 for posture control by means of the control signal value. The control valve 21 for posture control changes the amount of control fluid between the fluid chamber 16a and the fluid chamber 16b of the actuator 5 for posture control. The piston 5b of the actuator 5 for posture control operates slowly, while supporting the load of the car body 4, with a response of 0.7 Hz or less, by changing the amount of control fluid between the fluid chamber 16a and the fluid chamber 16b. Of the four actuators 5 for posture control which support the car body 4, the actuators 5 for posture control located on the outer side of the curved track expand, while the actuators 5 for posture control located on the inner side of the curved track contract. Therefore, the car body 4 tilts inwardly of the curved track, thereby reducing the excessive centrifugal force ( $Fy - W . φ$
) acting on the passengers. The tilting condition of the car body 4 will be explained in detail. As shown in Fig. 4, in the car body bearing apparatus 3 on the outer side of the curved track, the relative displacement ΔZ₁ of the piston 5a of the actuator 5 for posture control is increased on the + side by the control valve 21 for posture control, therefore raising the car body 4. On the other hand, in the car body bearing apparatus 3 on the inner side of the curved track, the relative displacement ΔZ₁ of the piston 5 of the actuator 5 for posture control is decreased in the reverse direction of ΔZ₁ by the control valve 21 for posture control, thus lowering the car body 4. Therefore, the car body 4 tilts inwardly of a curve. With the operation of a plurality of actuators 5 for posture control, the angle φ of the car body 4 increases and a difference between the centrifugal force Fy and the gravitational force W x the angle φ approaches zero, thereby enabling a decrease in the excessive centrifugal force the passengers feel.
The car body 4 can be tilted by increasing the relative displacement ΔZ₁ of the piston 5a of the car body bearing apparatus 3 on the outer side of the curved track twice as large as the above-described value towards the + side and leaving at zero the relative displacement ΔZ₁ of the piston 5a of the car body bearing apparatus 3 on the inner side of the curved track.
Next, the control of the longitudinal tilt of the car body 4 of the rolling stock when the car body receives the pitching moment Mθ due to air force will be explained. In the conrtol device 29 for posture control, when the output from the longitudinal tilt sensor 23 is fed back to the control circuit 27 for posture control, a control signal value is calculated by the control circuit 27 for posture control. The control valve 21 for posture control is operated by the control signal value outputted from the control circuit 27 for posture control, thereby controlling, similarly as described above, the displacement of the piston 5a of the actuator 5 for posture control. In Fig. 5, the arrow G indicates the direction of travel of the rolling stock. As shown in Fig. 5, when no posture control is effected, the axle spring 2b of each truck 2 are deflected by the pitching moment Mθ. Therefore, the truck 2 at the front in the direction of travel lowers, while the truck 2 at the rear in the direction of travel rises, resulting in the occurrence of a displacement difference ht. Accordingly the car body 4 tilts forwardly as indicated by a broken line. However, when the above-mentioned posture control is done, the relative displacement ΔZ₁ of the piston 5, in the car body bearing apparatus of the truck 2 at the front in the direction of travel, gradually increases by about several ten millimeters, whereas, in the truck 2 at the rear in the direction of travel, the relative displacement ΔZ₁ of the piston 5a decreases by about several ten millimeters. Thus the car body 4 is kept level as indicated by a full line, bringing the quasi-static longitudinal acceleration the passengers feel, close to zero and accordingly reducing the longitudinal acceleration.
The air spring 7 is controlled at a slow rate at a time constant of about 3 seconds at a fixed level of a range by the air spring height control valve 19. Therefore, the car body 4 supported by the air springs 7 on the actuator 5 for posture control is displaced nearly as much as the actuator 5 for posture control. That is, the actuator 5 for posture control will not be affected by the air spring 7 and also the posture control capacity of the actuator 5 for posture control will not be varied by the air spring 7.
Next, the vibration control of the rolling stock will be explained. In the control device 30 for vibration control, the output of the vertical vibrational accelerometer 22 that has detected 0.7 to 10 Hz components of vibration is fed back to the control circuit 28 for vibration control. The control circuit 28 for vibration control calculates a control signal value by an input supplied from the vertical vibrational accelerometer 22, which outputs the control signal value to the control valve 20 for vibration control. The control valve 20 for vibration control is operated by the control signal value fed from the control circuit 28 for vibration control. This control valve 20 for vibration control controls the control fluid supplied from the fluid supply source 31 to the actuator 6 for vibration control. Furthermore, the control valve 20 for vibration control functions to control the operation of the piston 6b by changing the pressure between the fluid chamber 17a and the fluid chamber 17b of the actuator 6 for vibration control. And furthermore the control valve 20 for vibration control operates the piston 6b for about ±25 max. The piston 6b is disposed in parallel with the air spring 7. The control power of the piston 6b is led about 100 degrees in phase to cacel an inertial force caused by the vibrational acceleration of the car body 4, being transmitted to the car body 4. The vibrational acceleration of the car body 4, therefore, can be decreased. Generally, since vibration occurs in both the positive and negative directions, it is possible that the mean displacement of the piston 6b is small, but there occur a long-period drift of the piston 6b. To remove the long-period drift of displacement of the piston 6b, the output of the displacement sensor 24 must be fed back to the control circuit 28 for vibration control. Then, the control circuit 28 for vibration control slowly controls the mean displacement of the piston 6b at the time constant of about 3 seconds, thereby eliminating the displacement drift of the piston 6b.
The control power of the piston 6b is less than that of the piston 5b because the actuator 6 for vibration control is disposed parallelly with the air spring 7. Namely, the control power of the piston 6b, controlling only the vibration component of the car body 4 which is smaller than the weight of the car body 4, is less than the control power of the piston 5b.
In the above-described rolling stock, even when the vibration control and lateral and longitudinal posture controls of the car body 4 are performed at the same time, each control can be done smoothly because the frequency range of the control system is divided to prevent interference with each other.
According to the first embodiment of the present invention, the actuators 5 and 6 for posture and vibration controls are disposed within the mounting range of the air spring 7 in a horizontal plane. Therefore it is possible to make narrow the space for mounting the actuators 5 and 6 as compared with conventional rolling stock in which the actuators are mounted apart from the air spring. Because the air spring 7, the actuator 5 for posture control and the actuator 6 for vibration control are vertically arranged in a line, a horizontal space for mounting these actuators may be narrow. And accordingly, it is possible to make smaller the whole body of the car body bearing apparatus 3 which supports the car body 4 on the truck 2, thereby preventing the use of a large-sized truck 2 and accomplishing the reduction of weight of the rolling stock. Since the axial center axis of the actuator for posture control coincides with that of the actuator 6 for vibration control, the piston 5b and the cylinder 6a can be constituted of one member. This is particularly effective in forming both the actuator 5 for posture control and the actuator 6 for vibration control into one body. Also, because the axial center axes of the actuator 5 for posture control and the actuator 6 for vibration control coincide with the center axis of the air spring 7, the posture control force and the vibration control force will never cause an unnecessary moment to occur.
In the first embodiment of the present invention, the air spring 7 and the rod 8 of the car body bearing apparatus 3 are connected to the car body 4, and the actuator 5 for posture control is mounted on the truck frame 2a. The car body bearing apparatus 3, if reversed in arrangement, can achieve the same effect as described above. That is, the air spring 7 and the rod 8 of the car body bearing apparatus 3 are connected to the truck frame 2a and can properly function if the actuator 5 for posture control is mounted on the car body 4. In the rolling stock of such a constitution, however, the mounting position of the air spring 7 in the vertical direction is removed downwardly from the centroid position of the car body 4. Therefore, although a consideration is required to be taken for the stabilization of the car body 4, no problem in particular will occur because the car body 4 is posture-controlled by means of the actuator 5 for posture control.
The piston 6b of the car body bearing apparatus 3 is connected to the car body 4 through the rod 8 and a couple of connecting pieces 13. The car body bearing apparatus 3, therefore, is able to transmit the posture control force and the vibration control force to the car body 4 therefrom while allowing a horizontal displacement between the car body 4 and the truck 2. The rod 8 is disposed through a through part 15 of the air spring 7, and therefore it is not necessary to provide a space for mounting the rod 8 around the air spring 7. Further, as oil is used for the vibration control fluid, the car body bearing apparatus can be made smaller in size by increasing the fluid pressure, thereby enabling the reduction of weight of the car body bearing apparatus 3 and an improvement in controllability. Accordingly the car body bearing apparatus 3 is best suited as a car body bearing apparatus of a high-speed vehicle such as a levitated-type vehicle which is required to be extremely light in weight. Furthermore, since the control valve 20 for vibration control, the displacement sensor 24, the control valve 21 for posture control, and the displacement sensor 25 are mounted inside of the car body bearing apparatus 3, the car body bearing apparatus 3 has such an advantage as good environmental resistance to rain, oil and snow. In addition, the pipes 20a and 21a to be connected between the control valve 20 for vibration control and the actuator 6 for vibration control and between the control valve 21 for posture control and the actuator 5 for posture control can be made shorter. The use of the short pipes 20a and 21a in which the control fluid pressure frequently changes while passing therethrough can prevent the delay of operation of the actuators 5 and 6.
The fluid chambers 17c and 17b of the actuator 6 for vibration control are connected by a pipe in which a throttle and a solenoid valve are inserted, such that, in the event of some abnormality in the vibration control system, these fluid chambers 17a and 17b communicate with each other through the throttle, thereby enabling the use of the actuator 6 for vibration control as a damper. when there has occurred some abnormality in the posture control system, the control fluid in the actuators 5 for posture control mounted on both the right and left sides of the car body 4 may be returned simultaneously into the fluid reservoir constituting the control fluid supply source 31.
In the first embodiment, the longitudinal tilt of the car body 4 can be controlled by inputting a signal from the longitudinal tilt sensor 23 mounted on the car body, into the control circuit 27 for posture control. The posture control apparatus of a conventional rolling stock primarily functions to control the lateral tilt of the car body, not to control the lateral and longitudinal tilt of the car body as in the case of the first embodiment. The function of the first embodiment as described above is specially effective in a magnetic levitated train running at a high speed.
Next, the second embodiment of the present invention will be described with reference to Fig. 7.
The second embodiment is a modification of the control circuit 29 for posture control according to the first embodiment changed only in construction. The control device 29A for posture control of the first embodiment is provided with a car body lateral accelerometer 34 which detects the excessive centrifugal acceleration $(Fy - W . φ)/W$
of the car body in place of the displacement target value generator 26 and the displacement sensor 25 of the first embodiment. In this embodiment, the excessive centrifugal acceleration of the car body 4 is fed back to the posture control system. Also in this embodiment, the tilt of the car body 4 delays from the point of time when the excessive centrifugal force acts on the car body 4. Therefore, this embodiment is suitable to the rolling stock in which the excessive centrifugal force works at a slow rate as in the case of a long relaxation curve or when the rolling stock travels at a low speed. In this embodiment, posture control is done such that the excessive centrifugal acceleration acting on the car body 4 will become zero. Further, this embodiment does not require the displacement target generator 26 for posture control and the displacement sensor 25 both employed in the aforementioned first embodiment, and uses the lateral accelerometer 34. Because of such a constitution, the construction of the rolling stock can be simplified.
Subsequently, the third embodiment of the present invention will be explained with reference to Fig. 8.
In Fig. 8, the numerals used in the first embodiment and those used in this third embodiment denote the same members. Differences in the construction of this embodimet from the first embodiment are the construction of connection between the air spring 7 and the car body 4 and the construction of connection between the piston 6b of the actuator 6 for vibration control and the upper plate 7b of the air spring 7. That is, the upper plate 7b of the air spring 7 supports the car body 4 through a horizontally elastic piece 9. The horizontally elastic piece 9 is constituted of a laminated rubber part produced for example by alternately laminating rubber plates and metal plates and bonding them by vulcanization. This horizontally elastic piece 9 is designed to have a little spring costant in a direction parallel with the metal plate, that is, in the horizontal direction, and a great spring constant in a direction rectangular to the metal plate, that is, in the perpendicular direction. The horizontally elastic piece 9 has a function to allow the horizontal displacement of the truck 2 and the car body 4 and a function to recover the truck 2 and the car body 4 from a horizontal displacement. The piston 6b of the actuator 6 for vibration control is fixed directly on the upper plate 7b of the air spring 7. Namely, as the horizontally elastic piece 9 permits the horizontal displacement of the truck 2 and the car body 4, the piston 6b can be fixed directly to the upper plate 7b. This embodiment has the same functions and effect as the first embodiment. Furthermore, this embodiment does not require the rod 8 and the diaphragm 14, and therefore can be made simple in constitution as compared with the first embodiment. Further, this embodiment, having the horizontally elastic piece 9, has the advantage that structural rigidity in the horizontal direction can be selected.
Next, the fourth embodiment of the present invention will be explained by referring to Fig. 9.
In Fig. 9, the same numerals as those used in the first embodiment indicate the same members. A difference in the constitution of the present embodiment from that of the first embodiment is that a coil spring 11 is employed in place of the air spring 7. In this embodiment, therefore, the air spring height control valve 19 is also not needed. Excepting the coil spring 11, the constitution of this embodiment is the same as that of the first embodiment. Also, this embodiment has the same functions and effect and furthermore since the air spring height control valve 19 and the diaphragm 14 are not required, its construction is simple. Besides, since no air spring is employed, no air leakage will occur in this embodiment. Consequently, it is possible to make the whole body of the car body bearing apparatus inexpensive and maintenance-free. In addition, according to the present invention, it is possible to prevent a change in the height of the car body 4 caused by variation in the number of passengers, because of the use of the coil springs 11. That is, the amount of deflection of the coil spring 11 is detected by the displacement sensor 24, and the actuator 5 for posture control is operated on the basis of a result of this detection. As the amount of deflection of the coil spring 11 can be corrected by the actuator 5 for posture control, the car body 4 can be kept at a fixed level.
Finally, the fifth embodiment of the present invention will be explained with reference to Fig. 10.
In Fig. 10, the same numerals as those used in the first embodiment indicate the same members. A difference in the construction of this embodiment from the first embodiment resides in that the vertical vibrational accelerometer 22 and the longitudinal tilt sensor 23 are built in the air spring 7. The vertical vibrational accelerometer 22 and the longitudinal tilt sensor 23 are mounted on the upper plate 7b of the air spring 7. The upper plate 7b is mounted on the lower surface of the car body 4 and functions similarly as the car body 4. Therefore, vertical vibration and longitudinal tilt of the car body can easily be detected by the vertical vibrational accelerometer 22 and the longitudinal tilt sensor 23 mounted on the upper plate 7b. According to the present embodiment, since the vertical vibrational accelerometer 22 and the longitudinal tilt sensor 23 are built in the car body bearing apparatus 3, the car body bearing apparatus 3 can easily be mounted on the car body 4 and the truck 2.
By the way, in each of the above-described embodiments, oil is used as the control fluid supplied to the actuator 6 for vibration control and the actuator 5 for posture control. In the present invention, the use of air as the control fluid is permitted. When the air is used in place of the oil for the control fluid, there is no problem of stain by oil leaks, thereby enabling to improve the maintainability and reliability of the car body bearing apparatus including the control system.
In the present invention, it is possible to use oil as the control fluid to be supplied to the actuator 6 for vibration control and air as the control fluid to be supplied to the actuator 5 for posture control. In this case, not only the response characteristics of the vibration control system can be improved but also the maintainability and reliability of the posture control system which requires much control fluid can be enhanced.
Also, in the present invention, it is possible to use air as the control fluid to be supplied to the actuator 6 for vibration control and oil as the control fluid to be supplied to the actuator 5 for posture control. In this case, the maintainability and reliability of the vibration control system can be improved when not so quick response is required. Only the posture control system can meet a demand for quick response.
According to the present invention, it is possible to make small the car body bearing apparatus having a function to restrain car body vibration and a function to reduce the excessive centrifugal force acting on the passengers, thereby reducing the weight of the whole body of the rolling stock.
Further according to the present invention, the longitudinal tilt of the car body can be restrained in addition to the reduction of the weight of the whole body of the rolling stock.

Claims

Rolling stock comprising a car body (4); a truck (2); spring means (7,11) which are disposed between said truck (2) and said car body (4) and support said car body (4) on said truck (2); vibration control means (6,30,31) which restrain vertical vibration of said car body (4), and posture control means (5,29,29A,31) which control the posture of the car body (4) characterised in that an actuator (6) for vibration control which constitutes said vibration control means (6,30,31) and an actuator (5) for posture control which constitutes said posture control means (5,29,29A,31) are disposed within a range corresponding to the space delimited by the mounting range of one single of said spring means (7,11).
Rolling stock as claimed in claim 1, wherein a center axis extending in the direction of operation of said actuator (6) for vibration control and a center axis extending in the direction of operation of said actuator (5) for posture control are aligned.
Rolling stock as claimed in claim 2, wherein a cylinder (6a) constituting said actuator (6) for vibration control is formed in a piston (5b) of said actuator (5) for posture control.
Rolling stock as claimed in claims 1 and 2, wherein said center axis extending in the direction of operation of said actuator (6) for vibration control and said center axis extending in the direction of operation of said actuator (5) for posture control are disposed in a central position in the horizontal direction of said spring means (7,11).
Rolling stock as claimed in one of claims 1 to 4, wherein one end of said actuator (6) for vibration control is connected to said truck (2) or said car body (4) through said spring means (7,11), and the other end of said actuator (6) for vibration control is connected to said actuator (5) for posture control, and also one end of said actuator (5) for posture control is mounted to said spring means (7,11) and other end of said actuator (5) for posture control is mounted to a car body (4) or a truck (2) not connected to said spring means (7,11).
Rollling stock as claimed in claim 5, wherein said spring means is an air spring (7) which permits the horizontal relative displacement of said truck (2) and said car body (4), said air spring (7) being provided with a through part (15) at a central position within a horizontal plane; said actuator (6) for vibration control is connected to said truck (2) or said car body (4) through said through part (15); and said actuator (6) for vibration control is connected to said truck (2) or said car body (4) by a connecting piece (13) which permits horizontal relative displacement of said truck (2) and said car bdy (4).
Rolling stock as claimed in claim 5, wherein said spring means is a coil spring (11); said actuator (6) for vibration control is conneced to said truck (2) or said car body (4) through the axial center of said coil spring (11); and said actuator (6) for vibration control is connected to said truck (2) or said car body (4) by a connecting piece (13) which permits the horizontal relative displacement of said truck (2) and said car body (4).
Rolling stock as claimed in one of claims 1 to 4, wherein said spring means (7) has a horizontally elastic piece (9) between said truck (2) and said car body (4) which permits relative displacement in the horizontal direction of said truck (2) and said car body (4); one end of said actuator (6) for vibration control is connected to said horizontally elastic piece (9) through said spring means (7), and furthermore the other end of said actuator (6) for vibration control is connected to said actuator (5) for posture control; and one end of said actuator (5) for posture control is mounted to said spring means (7), and the other end of said actuator (5) for posture control is mounted to said car body (4) or said truck (2) to which said spring means (7) is not connected.
Rolling stock as claimed in one of claims 1 to 4, wherein the upper end of said spring means (7,11) is mounted to said car body (4); one end of said actuator (6) for vibration control is connected to said car body (4) through said spring means (7,11); the other end of said actuator (6) for vibration control is connected to said actuator (5) for posture control; one end of said actuator (5) for posture control is mounted to the lower end of said spring means (7,11); and the other end of said actuator (5) for posture control is mounted to said truck (2).
Rolling stock as claimed in claim 1, wherein said vibration control means has a control circuit (30) for vibration control, and a control valve (20) for vibration control constituting said control circuit (30) for vibration control is mounted to a piston (6b) constituting said actuator (6) for vibration control.
Rolling stock as claimed in claim 1, wherein said posture control means has a control circuit (29) for posture control, and a control valve (21) for posture control which constitutes said control circuit (29) for posture control is installed in a piston (5b) constituting said actuator (5) for posture control.
Rolling stock as claimed in claim 1, wherein a control circuit (29) for posture control which constitutes said posture control means has a longitudinal tilt sensor (23) which detects the amount of longitudinal tilt of said car body (4), and a feedback circuit which feeds back a result of detection by said longitudinal tilt sensor (23).
Rolling stock as claimed in claim 1, wherein said vibration control means has a control circuit (30) for vibration control; said posture control means has a control circuit (29) for posture control; and a vertical vibrational accelerometer (22) constituting said control circuit (29) for vibration control and said longitudinal tilt sensor (23) constituting said control circuit (29) for posture control are mounted on the upper plate (7b) of said spring means (7).