JP2023170205A - leveling valve - Google Patents

Abstract

To provide a leveling valve capable of suppressing abrasion of a contact surface between a piston and a housing.SOLUTION: A leveling valve 100 includes a piston 20 stored in a storage hole 11 formed in a case 10 to move in an axial direction with the rotation of a lever 4, a stem 50 with one end inserted into a through-hole 22 formed in the piston 20 to move in an axial direction together with the piston 20, and a supply and exhaust valve 80 for communicating an air spring 3 with a compressor 7 by making the stem 50 move from a neutral position to one direction and communicating the air spring 3 with an exhaust passage 8 by making the stem 50 from the neutral position to the other direction. The piston 20 is fitted in the stem 50 to be movable in an axial direction and a radial direction.SELECTED DRAWING: Figure 4

Description

The present invention relates to a leveling valve.

Patent Document 1 describes a leveling valve that maintains a constant support position of a railway vehicle by the air springs by supplying compressed air to or releasing air from the air springs of the railway vehicle.

In the leveling valve described in Patent Document 1, when the support height of the car body by the air spring changes due to a change in the load on the car body, this change causes the lever to swing through the link, and the leveling valve is moved through the piston connected to the tip of the lever. The stem moves in the axial direction. Then, by opening and closing the supply and exhaust valves in response to the movement of this stem, the air spring passage connected to the air spring is selected to be either the supply passage connected to the compressor or the exhaust passage opened to the atmosphere. connected.

JP2018-119641A

In the leveling valve described in Patent Document 1, the piston is fixed to the stem with a nut. Furthermore, in the leveling valve described in Patent Document 1, a portion of the stem is inserted into an insertion hole formed in the valve case, and the stem moves in the axial direction while being guided by the insertion hole.

When a piston is fixed to a stem by tightening a nut as in the leveling valve described in Patent Document 1, the central axis of the stem and the central axis of the piston may be fixed in a misaligned state. When the stem and piston move in the axial direction with the center axis of the stem and the piston misaligned, the piston will come into contact with the housing because the stem is guided by the insertion hole in the valve case. There is a risk of it moving back and forth. If the piston repeatedly moves back and forth while in contact with the housing, the contact surface between the piston and the housing will wear out, which may reduce the reliability of the leveling valve.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a leveling valve that can suppress wear on the contact surface between the piston and the housing.

The present invention selectively communicates an air spring provided between a bogie and a car body with a compressed air source or an exhaust passage depending on the direction of rotation of a lever that rotates in response to relative displacement of a car body with respect to a bogie of a railway vehicle. A leveling valve that adjusts the height of an air spring by using a piston, which is housed in a housing hole formed in a housing and moves in the axial direction of the housing hole as a lever rotates, and one end of which is formed in the piston. The stem is inserted into a through hole that moves in the axial direction together with the piston, and the stem moves in one direction from a neutral position, thereby communicating the air spring with the compressed air source, and the stem moves in the other direction from the neutral position. The piston is characterized in that the piston is fitted to the stem so as to be movable in the axial direction and the radial direction.

In this invention, the piston is fitted to the stem so as to be movable in the axial direction and the radial direction. In other words, since the piston is not fixed to the stem, the outer circumferential surface of the piston and the inner circumferential surface of the accommodation hole are Even if the piston makes contact, the piston can move in a direction away from the contact portion, so that it is possible to prevent the outer peripheral surface of the piston from reciprocating while being pressed against the inner peripheral surface of the accommodation hole. Thereby, wear of the contact surface between the piston and the housing can be suppressed.

In addition, the present invention provides a system in which the stem includes a main body portion provided at its tip with a valve portion constituting a part of the supply/discharge valve, and a stem formed to have a smaller diameter than the main body portion and a smaller diameter than the through hole of the piston. The piston has an insertion part that is inserted through the through hole of the piston, and a first stage part that is formed by the boundary between the main body part and the insertion part and has a larger diameter than the through hole of the piston. It is characterized in that it is movable between the locking member fixed to the insertion part.

According to the present invention, the piston can be fitted to the stem so as to be movable in the axial direction and the radial direction without adding any new parts, so an increase in cost can be suppressed.

In addition, the present invention provides a stem that is formed at the end of the insertion portion opposite to the main body portion, has a small diameter portion that is smaller in diameter than the insertion portion, and has a male screw thread formed on the outer peripheral surface of the small diameter portion to which the nut is fastened. and a second stage portion formed by a boundary portion between the insertion portion and the small diameter portion, and the locking member is a washer through which the small diameter portion is inserted and has a larger diameter than the through hole of the piston; The washer is fixed between the nut and the second step by fastening the nut to the male thread, and the length between the first and second steps is in the axial direction of the through hole of the piston. It is characterized by being longer than the length of .

In this invention, the locking member is positioned in the axial direction by the nut and the second step. Thereby, the allowable amount of movement of the piston in the axial direction can be set with high accuracy.

According to the present invention, it is possible to provide a leveling valve that can suppress wear on the contact surface between the piston and the housing.

FIG. 1 is an installation diagram of a leveling valve according to an embodiment of the present invention. FIG. 2 is an axial cross-sectional view of a leveling valve according to an embodiment of the present invention. FIG. 3 is a radial cross-sectional view of a leveling valve according to an embodiment of the invention. FIG. 4 is an enlarged view of the vicinity of the piston in the leveling valve according to the embodiment of the present invention. FIG. 5 is an enlarged view of the vicinity of the supply/discharge valve in the leveling valve according to the embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.

A leveling valve 100 according to an embodiment of the present invention will be described. First, an overview of the leveling valve 100 will be explained with reference to FIGS. 1 and 2.

The leveling valve 100 has the function of maintaining the car body 1 at a constant height by adjusting the height of the air spring 3 provided between the car body 1 and the bogie 2 of the railway vehicle.

As shown in FIG. 1, the leveling valve 100 is installed between a vehicle body 1 and a bogie 2. Specifically, the leveling valve 100 is attached to the vehicle body 1 and connected to the truck 2 via the lever 4 and the connecting rod 5. When the air spring 3 expands and contracts due to changes in the load on the vehicle body 1 and the height of the vehicle body 1 changes, this change is transmitted to the leveling valve 100 via the connecting rod 5 and the lever 4.

When the air spring 3 is bent due to an increase in the vehicle body load, the lever 4 is pushed upward from the neutral position (rotation in the direction of arrow A in FIG. 1), and accordingly, the piston 20 of the leveling valve 100 (rotation in the direction of arrow A in FIG. 2) moves, an air supply valve 80A, which will be described later, opens, and an air spring passage 6 communicating with the air spring 3 and a supply passage 9 communicating with a compressor 7 serving as a compressed air source communicate with each other. As a result, compressed air from the compressor 7 is supplied to the air spring 3. When the air spring 3 is restored to a constant height, the lever 4 returns to the neutral position, the air supply valve 80A of the leveling valve 100 closes, and the supply of compressed air is cut off.

On the other hand, when the air spring 3 is expanded due to a decrease in the vehicle body load, the lever 4 is pulled down from the neutral position (rotation in the direction of arrow B in FIG. 1), and accordingly the leveling valve 100 is Valve 80B opens, and air spring passage 6 and exhaust passage 8 communicate with each other. Since the exhaust passage 8 communicates with the atmosphere, the compressed air of the air spring 3 is exhausted to the atmosphere. When the air spring 3 is restored to a constant height, the lever 4 returns to the neutral position, the exhaust valve 80B of the leveling valve 100 closes, and the discharge of compressed air is cut off.

In this manner, the leveling valve 100 selectively communicates the air spring 3 with the compressor 7 or the exhaust passage 8 according to the rotational direction of the lever 4, which rotates in accordance with the relative displacement of the vehicle body 1 with respect to the bogie 2. The vehicle body 1 is maintained at a constant height by automatically adjusting the relative displacement generated between the vehicle body 1 and the bogie 2.

Next, a specific configuration of the leveling valve 100 will be described with reference to FIGS. 2 and 3. FIG. 2 is an axial cross-sectional view of the leveling valve 100, and FIG. 3 is a radial cross-sectional view of the leveling valve 100. Note that the "axial direction" in this embodiment means the direction of the central axes of the piston 20 and the stem 50, and the "radial direction" means the radial direction of the piston 20 and the stem 50.

The leveling valve 100 includes a case 10 that is fixed to a vehicle body 1 and has a housing hole 11 formed to penetrate inside, and a first cap that is attached to one side of the case 10 and closes one opening of the housing hole 11. The valve case 12 includes a member 12, a second cap member 13 attached to the other side of the case 10, and a cylindrical valve case 40 that closes the other opening of the accommodation hole 11.

The first cap member 12 includes a columnar insertion portion 12a that is inserted into the accommodation hole 11, and a flange portion 12b that is formed continuously with the insertion portion 12a and has a larger diameter than the insertion portion 12a. The first cap member 12 is attached to the case 10 by inserting bolts (not shown) through through holes (not shown) provided in the flange portion 12b and fastening them to bolt holes formed in the case 10.

A male threaded portion 40b is formed on a part of the outer peripheral surface of the valve case 40. The valve case 40 includes a first cylindrical portion 40a and a second cylindrical portion 40c, with a male threaded portion 40b as a boundary. The first cylindrical portion 40a and the male threaded portion 40b are inserted into the accommodation hole 11. The male threaded portion 40b is formed near the opening of the accommodation hole 11 and is screwed into the female threaded portion 11a. Thereby, the valve case 40 is fixed to the case 10.

The second cap member 13 is fixed to the case 10 so as to cover the outer peripheral surface of the second cylindrical portion 40c of the valve case 40 and the side surface of the male threaded portion 40b on the second cylindrical portion 40c side. This prevents the valve case 40 from coming off from the case 10. The second cap member 13 is formed with a flow path 13a that connects the flow path 10b formed in the case 10 and the through hole 46 that connects the inside and outside of the valve case 40.

As shown in FIG. 3, the case 10 is formed with a recess 16 that opens in the radial direction with respect to the accommodation hole 11. As shown in FIG. The recess 16 is formed so as to be connected to the accommodation hole 11 .

The leveling valve 100 further includes a cover member 70 that covers the recess 16 and is attached to the case 10. By attaching the cover member 70 to the case 10, an accommodation space 17 that accommodates a rotor 30, which will be described later, is formed.

A communication hole 72 is formed in the cover member 70 to communicate the housing space 17 with the outside. A filter 73 is provided in the communication hole 72 to prevent foreign matter from entering from the outside.

In the leveling valve 100, a housing is configured by the case 10, the first cap member 12, the second cap member 13, the cover member 70, and the valve case 40.

As shown in FIGS. 2 and 3, the leveling valve 100 includes a piston 20 that is housed in a housing hole 11 of a case 10 and moves in the axial direction as the lever 4 rotates, and a piston 20 that transmits the rotation of the lever 4 to the piston 20. a rotor 30 for moving the air spring 3; a stem 50 whose one end is inserted into a through hole 22 formed in the piston 20 and moves in the axial direction together with the piston 20; and the compressor 7, and a supply/discharge valve 80 that communicates the air spring 3 and the exhaust passage 8 by moving the stem 50 from the neutral position in the other direction.

The piston 20 is movably supported within the housing hole 11 of the case 10 by a stem 50. A slight gap is provided between the outer peripheral surface of the piston 20 and the inner peripheral surface of the accommodation hole 11. As a result, the outer circumferential surface of the piston 20 does not slide on the inner circumferential surface of the accommodation hole 11, so that no frictional resistance is generated. As shown in FIG. 3, a groove 21 having a semicircular cross-section is formed in a part of the outer peripheral surface of the piston 20. As shown in FIG.

As shown in FIG. 3, the rotor 30 is rotatably supported in a support hole 71 formed in the cover member 70 via bearings 14 and 15. The rotor 30 includes a cylindrical main body 31 supported by bearings 14 and 15, and is formed to protrude from one end of the main body 31, and has a width across flats smaller than the outer diameter of the main body 31. A square columnar boss portion 32, a flange portion 33 provided at the other end of the main body portion 31, and an arm portion 34 formed to protrude radially outward from the outer peripheral surface of the flange portion 33; has. The boss portion 32 is fitted into a fitting hole 4a formed in the lever 4 (see FIG. 1). As shown in FIGS. 2 and 3, a pin 35 is press-fitted into the arm portion 34. As shown in FIGS. The pin 35 is inserted into the sleeve 36 and movably inserted together with the sleeve 36 into the groove 21 of the piston 20 . As a result, when the boss portion 32 rotates with the rotation of the lever 4, the pin 35 press-fitted into the arm portion 34 rotates in the direction of the arrow shown in FIG. Since the pin 35 is inserted into the groove 21 of the piston 20, the piston 20 moves in the axial direction within the accommodation hole 11 as the pin 35 rotates.

As shown in FIG. 2, the stem 50 is formed into a rod shape that extends in the moving direction of the piston 20 (the axial direction of the accommodation hole 11). As shown in FIGS. 2 and 4, the stem 50 includes a main body 50A, which is provided with a valve part 53 that constitutes a part of the supply/discharge valve 80 at its tip, and a main body 50A that is smaller in diameter than the main body 50A and has a smaller diameter than the piston 20. It is formed by an insertion part 50B that is formed to have a smaller diameter than the through hole 22 and is inserted through the through hole 22 formed in the piston 20, and a boundary part between the main body part 50A and the insertion part 50B, and is smaller than the through hole 22 of the piston 20. A stepped portion 50C as a large-diameter first step portion, a small-diameter portion 50D formed at the end of the insertion portion 50B opposite to the main body portion 50A, and a small-diameter portion 50D having a smaller diameter than the insertion portion 50B, and an outer peripheral surface of the small-diameter portion 50D. It has a male threaded portion 50E formed therein and to which the nut 60 is fastened, and a stepped portion 50F as a second stepped portion formed by the boundary portion between the insertion portion 50B and the small diameter portion 50D.

As shown in FIGS. 2 and 4, the main body portion 50A of the stem 50 is provided with an axial hole 51 that extends in the axial direction. A plurality of through holes 52 are provided in the radial direction on the insertion portion 50B side of the main body portion 50A, which communicate the axial hole 51 and the accommodation hole 11. The axial hole 51 communicates with the outside through the through hole 52, the accommodation hole 11, the accommodation space 17, and the communication hole 72. The axial hole 51, the through hole 52, the accommodation hole 11, the accommodation space 17, and the communication hole 72 constitute the exhaust passage 8.

As shown in FIG. 2, an annular groove 54 is formed on the outer peripheral surface of the main body portion 50A of the stem 50. A valve portion 53 having a smaller diameter than the piston 20 side of the stem 50 and a larger diameter than the annular groove 54 is formed on the distal end side of the stem 50 so as to be adjacent to the annular groove 54 . The valve portion 53 will be explained in detail later.

The stem 50 is connected to the piston 20 by fastening the nut 60 to the male threaded portion 50E with the insertion portion 50B inserted into the through hole 22 formed in the piston 20. Further, as shown in FIGS. 2 and 4, a washer 61 having an outer diameter larger than the inner diameter of the through hole 22 of the piston 20 and inserted into the small diameter portion 50D is disposed between the insertion portion 50B and the nut 60. provided. The washer 61 is fixed between the nut 60 and the stepped portion 50F (see FIG. 4) by fastening the nut 60 to the male thread portion 50E. The washer 61 functions as a locking member that prevents the piston 20 from falling off the stem 50.

The leveling valve 100 further includes an annular ring member 81 that is disposed opposite to the outer periphery of the distal end of the stem 50 and is movable in the radial direction. The ring member 81 has a valve seat portion 81a formed on one end surface, and is disposed within the valve case 40.

Here, the valve case 40 and the internal structure of the valve case 40 will be described with reference to FIGS. 2 and 5.

The valve case 40 includes a first through hole 41 into which the distal end side of the stem 50 is inserted, a second through hole 42 formed with a larger diameter than the first through hole 41, and the first through hole 41 and the second through hole 42. and a stepped portion 43 forming a boundary between the two.

An O-ring 44 that seals between the inner peripheral surface of the first through hole 41 and the outer peripheral surface of the stem 50 is provided near the tip of the first through hole 41 on the piston 20 side.

Inside the second through hole 42, a ring member 81, a cylindrical collar member 86 having an internal space 86a, and a plug 84 that closes the opening of the second through hole 42 are provided. The plug 84 is locked by a retaining ring 87 that is engaged in the second through hole 42 by pressing the ring member 81 against the step portion 43 via the collar member 86.

In the internal space 86a of the collar member 86, there are formed a valve body 82 that seats and separates from the valve seat portion 81a of the ring member 81, a spring 83 that urges the valve body 82 toward the valve seat portion 81a, and a plug 84. A check valve element 85 is provided which is seated on and off the valve seat part 84a and is biased toward the valve seat part 84a by a spring 83.

A gap is provided between the outer circumferential surface of the ring member 81 and the inner circumferential surface of the second through hole 42, and an O-ring 90 is provided to prevent leakage of compressed air from the gap. Since this O-ring 90 has elasticity, the ring member 81 can move in the radial direction within the second through hole 42.

As shown in FIG. 5, the ring member 81 includes a valve seat portion 81a formed on one end surface, and an annular protrusion portion 81b formed to protrude radially inward from the inner peripheral surface on the one end side. Equipped with At the tip of the stem 50, a minute annular gap S is formed by a gap between the inner circumferential surface of the protrusion 81b and the outer circumferential surface of the valve portion 53 of the stem 50, which restricts the flow of compressed air as the supply/discharge valve 80 opens and closes. (See Figure 5). The annular gap S is formed between the annular groove 54, the through hole 45 formed in the valve case 40, the passage 10a formed in the case 10, and the inner peripheral surface of the case 10 and the insertion portion 12a of the first cap member 12. It communicates with the air spring 3 through the formed annular flow path 10c and a through flow path 10d formed in the case 10 and connected to the annular flow path 10c. The air spring passage 6 is constituted by the annular gap S, the annular groove 54, the through hole 45, the passage 10a, the annular passage 10c, and the through passage 10d.

As shown in FIG. 2, a flow path 84b is formed inside the plug 84. The flow path 84b communicates with the compressor 7 through the through hole 46 of the valve case 40, the flow path 13a of the second cap member 13, and the flow path 10b of the case 10.

The check valve body 85 is seated on and off the valve seat portion 84a of the plug 84. When the pressure on the compressor 7 side (flow path 84b) is higher than the pressure on the downstream side (internal space 86a) of the check valve body 85, the check valve body 85 is moved away from the valve seat portion 84a against the biasing force of the spring 83. Separate. Conversely, when the pressure on the compressor 7 side (flow path 84b) is lower than the pressure on the downstream side (internal space 86a) of the check valve body 85, the check valve body 85 is seated on the valve seat portion 84a. In the leveling valve 100, the supply passage 9 is configured by the internal space 86a, the flow path 84b, the through hole 46, the flow path 13a, and the flow path 10b.

The valve case 40 includes a supply/discharge valve 80 therein. The supply/discharge valve 80 includes an air supply valve 80A that controls communication or isolation between the supply passage 9 and the air spring passage 6, and an exhaust valve 80B that controls communication or isolation between the air spring passage 6 and the exhaust passage 8. Be prepared. This will be explained in detail below.

The valve body 82 has an elastic seat portion 82a. The seat portion 82a is seated on and off the valve seat portion 81a of the ring member 81. When the seat portion 82a of the valve body 82 is seated on the valve seat portion 81a of the ring member 81, communication between the supply passage 9 and the air spring passage 6 is cut off. On the other hand, by separating the seat portion 82a of the valve body 82 from the valve seat portion 81a of the ring member 81, the supply passage 9 and the air spring passage 6 are brought into communication. In this way, the seat portion 82a of the valve body 82 and the valve seat portion 81a of the ring member 81 constitute the air supply valve 80A that controls the air supply to the air spring 3.

The valve portion 53 of the stem 50 is seated on and off the seat portion 82a of the valve body 82. When the valve portion 53 of the stem 50 is seated on the seat portion 82a of the valve body 82, communication between the air spring passage 6 and the exhaust passage 8 is cut off. On the other hand, by separating the valve portion 53 of the stem 50 from the seat portion 82a of the valve body 82, the air spring passage 6 and the exhaust passage 8 are brought into communication. In this way, the valve portion 53 of the stem 50 and the seat portion 82a of the valve body 82 constitute an exhaust valve 80B that controls exhaust from the air spring 3.

The operation of the leveling valve 100 configured as above will be explained.

As described above, when the air spring 3 is bent due to an increase in the vehicle body load, the lever 4 is pushed upward from the neutral position (rotation in the direction of arrow A in FIG. 1). Accordingly, the rotor 30 connected to the lever 4 rotates to the right in FIG. 2, so that the pin 35 provided on the arm portion 34 of the rotor 30 rotates to the right about the main body portion 31. The pin 35 rotates to the right while moving downward in FIG. 2 within the groove 21 of the piston 20. As a result, the piston 20 moves to the right in FIG. Accordingly, the stem 50 connected to the piston 20 pushes the valve body 82 against the biasing force of the spring 83 to separate it from the valve seat portion 81a of the ring member 81. This allows the supply passage 9 and the air spring passage 6 to communicate with each other. Specifically, the compressed air discharged from the compressor 7 passes through the flow path 10b, the flow path 13a, the through hole 46, the flow path 84b, the internal space 86a, the annular gap S, the annular groove 54, the through hole 45, the path 10a, The air is supplied to the air spring 3 through the annular flow path 10c and the through flow path 10d.

At this time, since the valve portion 53 of the stem 50 is pressed against the seat portion 82a of the valve body 82, the axial hole 51 and the annular gap S are maintained in a state where they are blocked. That is, when the piston 20 moves to the right from the neutral position, the air supply valve 80A becomes open and the supply passage 9 and the air spring passage 6 communicate with each other, and the exhaust valve 80B becomes closed and the exhaust passage 8 and The air spring passage 6 is then cut off.

When the supply passage 9 and the air spring passage 6 communicate with each other, compressed air from the compressor 7 is supplied to the air spring 3 through the supply passage 9 and the air spring passage 6, and the height of the air spring 3 increases. Therefore, the height of the vehicle body 1 increases, and the lever 4 also approaches the neutral position accordingly. As the lever 4 approaches the neutral position, the piston 20 and stem 50 also move to the left in FIG. Eventually, when the height of the vehicle body 1 returns to the specified position, the lever 4 returns to the neutral position, and the seat portion 82a of the valve body 82 seats on the valve seat portion 81a of the ring member 81. That is, the air supply valve 80A of the leveling valve 100 is closed. As a result, communication between the supply passage 9 and the air spring passage 6 is cut off, and the supply of compressed air to the air spring 3 is cut off.

On the other hand, when the air spring 3 is expanded due to a decrease in the vehicle body load, the lever 4 is pushed down from the neutral position (rotation in the direction of arrow B in FIG. 1). Accordingly, the rotor 30 connected to the lever 4 rotates to the left in FIG. 2, so that the pin 35 provided on the arm portion 34 of the rotor 30 rotates to the left about the main body 31. The pin 35 rotates to the left while moving downward in FIG. 2 within the groove 21 of the piston 20. As a result, the piston 20 moves to the left in FIG. The stem 50 moves to the left together with the piston 20. Accordingly, the valve portion 53 of the stem 50 is separated from the seat portion 82a of the valve body 82. This allows the air spring passage 6 and the exhaust passage 8 to communicate with each other. Specifically, the compressed air in the air spring 3 flows through the through passage 10d, the annular passage 10c, the passage 10a, the through hole 45, the annular groove 54, the annular gap S, the axial hole 51, the through hole 52, and the accommodation hole. 11, the accommodation space 17, and the communication hole 72, and are released into the atmosphere.

At this time, the seat portion 82a of the valve body 82 is pressed against the valve seat portion 81a of the ring member 81 by the urging force of the spring 83, so that the internal space 86a of the collar member 86 and the annular gap S are cut off. Become. That is, when the piston 20 moves leftward from the neutral position, the exhaust valve 80B becomes open and the air spring passage 6 and the exhaust passage 8 communicate with each other, and the air supply valve 80A becomes closed and the supply passage 9 and The air spring passage 6 is then cut off.

When the air spring passage 6 and the exhaust passage 8 communicate with each other, compressed air from the air spring 3 is released to the atmosphere through the air spring passage 6 and the exhaust passage 8, and the height of the air spring 3 is reduced. Therefore, the height of the vehicle body 1 becomes lower, and the lever 4 also approaches the neutral position accordingly. As the lever 4 approaches the neutral position, the piston 20 and stem 50 also move to the right in FIG. Eventually, when the height of the vehicle body 1 returns to the specified position, the lever 4 returns to the neutral position, and the valve portion 53 of the stem 50 seats on the seat portion 82a of the valve body 82. In other words, the exhaust valve 80B of the leveling valve 100 is closed. As a result, communication between the air spring passage 6 and the exhaust passage 8 is cut off, and exhaust of compressed air from the air spring 3 is cut off.

In this way, the leveling valve 100 selectively connects the air spring 3 to the compressor 7 or the atmosphere, depending on the direction of rotation of the lever 4, which rotates in accordance with the relative displacement of the vehicle body 1 with respect to the truck 2. Adjust the height.

Next, the function of the annular gap S will be explained.

For example, when a railway vehicle is running, the height of the vehicle body 1 changes little by little due to vibrations and the like. If the height of the air spring 3 changes little by little accordingly, the ride comfort will deteriorate. For this reason, the leveling valve 100 is provided with an annular gap S. As a result, when the amount of change in the height of the vehicle body 1 is small, that is, when the amount of change in the stem 50 is small, even if the intake valve 80A or the exhaust valve 80B is opened, the annular gap S exists, so that the air spring passage The flow rate supplied to or discharged from the air spring passage 6 is limited. This prevents the height of the air spring 3 from following small changes in the height of the vehicle body 1. This can prevent the ride comfort from deteriorating. Even if the annular gap S is provided, when the stem 50 moves to a position where the valve portion 53 and the protruding portion 81b are shifted in the axial direction, the annular gap S disappears and a large flow rate of compressed air can flow.

By the way, in the leveling valve 100, for example, when the piston 20 is fixed to the stem 50 by tightening the nut 60, the piston 20 and the stem 50 may be fixed with their central axes shifted from each other. In this way, when the piston 20 and the stem 50 move in the axial direction in a state where the center axes of the piston 20 and the stem 50 are shifted and fixed, the stem 50 is inserted into the first through hole 41 formed in the valve case 40. Since the piston 20 is guided, there is a risk that the piston 20 will reciprocate while in contact with the accommodation hole 11 of the case 10. In this way, when the piston 20 reciprocates while contacting the housing hole 11 of the case 10, the contact surface between the piston 20 and the housing hole 11 of the case 10 will wear out.

Therefore, in the leveling valve 100 of this embodiment, the piston 20 is connected to the stem 50 with play. In other words, the piston 20 is fitted onto the stem 50 so as to be movable in the axial and radial directions. Here, the connection structure between the piston 20 and the stem 50 will be specifically explained with reference to FIG. 4.

As shown in FIG. 4, the axial length L1 of the wall portion 23 in which the through hole 22 of the piston 20 is formed is the axial length L1 between the stepped portion 50C and the stepped portion 50F (washer 61) of the stem 50. It is shorter than the length L2. As a result, a gap S1 corresponding to L2-L1 exists in the axial direction between the wall portion 23 of the piston 20 and the stepped portions 50C and 50F (washer 61) of the stem 50, so that the piston 20 is allowed to move by this gap S1 in the axial direction.

Further, as shown in FIG. 4, the inner diameter D1 of the through hole 22 of the piston 20 is larger than the outer diameter D2 of the insertion portion 50B of the stem 50. Since there is a gap S2 of D1-D2 in the axial direction between the through hole 22 of the piston 20 and the insertion part 50B of the stem 50, the piston 20 has a gap S2 of D1-D2 in the radial direction. Movement is allowed.

In this way, in the leveling valve 100 of this embodiment, the piston 20 is allowed to move in the axial direction and radial direction relative to the stem 50 by the gaps S1 and S2. That is, in the leveling valve 100, the center axes of the piston 20 and the stem 50 are not fixed in a shifted state. Therefore, even if the outer circumferential surface of the piston 20 and the inner circumferential surface of the housing hole 11 of the case 10 come into contact, the piston 20 can move away from the contact portion, that is, in the direction in which the piston 20 escapes from the contact portion. . Thereby, it is possible to suppress the outer circumferential surface of the piston 20 from reciprocating while being pressed against the inner circumferential surface of the housing hole 11, so that wear of the contact surface of the piston 20 with the case 10 can be suppressed.

In addition, in the above embodiment, the case where the piston 20 is connected to the stem 50 using the nut 60 and the washer 61 was explained as an example, but the invention is not limited to this. The piston 20 may be connected to the stem 50 using a so-called flanged nut. Further, the piston 20 may be connected to the stem 50 only by the nut 60 without providing the washer 61.

Furthermore, instead of using the nut 60 and the washer 61, the piston 20 may be connected to the stem 50 by attaching a split pin, a press-fit pin, or the like to the stem 50.

According to the above embodiment, the following effects are achieved.

In the leveling valve 100, the piston 20 is fitted into the stem 50 so as to be movable in the axial direction and the radial direction. Therefore, even if the outer circumferential surface of the piston 20 and the inner circumferential surface of the housing hole 11 of the case 10 come into contact, the piston 20 can move away from the contact portion, that is, in the direction in which the piston 20 escapes from the contact portion. . Thereby, it is possible to suppress the outer circumferential surface of the piston 20 from reciprocating while being pressed against the inner circumferential surface of the accommodation hole 11 . Therefore, wear of the contact surface of the piston 20 with the case 10 can be suppressed, so that the durability and reliability of the piston 20 and the case 10 can be improved.

Furthermore, in the leveling valve 100, the amount of play between the piston 20 and the stem 50 in the axial direction can be easily adjusted by adjusting the position of the stepped portion 50F. Similarly, by adjusting the inner diameter of the through hole 22 of the piston 20 or the outer diameter of the insertion part 50B of the stem 50, the amount of play (gap S1, S2) in the radial direction between the piston 20 and the stem 50 can be easily adjusted. can do.

The configuration, operation, and effects of the embodiment of the present invention configured as described above will be collectively described.

The leveling valve 100 connects an air spring 3 provided between the bogie 2 and the car body 1 to a compressed air source (compressor 7 ) or the exhaust passage 8 to adjust the height of the air spring 3. The leveling valve 100 also includes a piston 20 that is accommodated in a housing hole 11 formed in a housing (case 10) and moves in the axial direction as the lever 4 rotates, and a through hole that has one end formed in the piston 20. 22 and moves in the axial direction together with the piston 20, and the stem 50 moves in one direction from the neutral position to communicate between the air spring 3 and the compressed air source (compressor 7), and the stem 50 moves in the neutral position. The piston 20 is fitted to the stem 50 so as to be movable in the axial direction and the radial direction. .

In this configuration, the piston 20 is fitted to the stem 50 so as to be movable in the axial direction and the radial direction. In other words, since the piston 20 is not fixed to the stem 50, the outer peripheral surface of the piston 20 and the accommodation hole Even if the inner circumferential surface of the housing hole 11 makes contact, the piston 20 can move away from the contact portion, so that the outer circumferential surface of the piston 20 can reciprocate while being pressed against the inner circumferential surface of the housing hole 11. can be suppressed. Thereby, wear of the contact surface between the piston 20 and the housing (case 10) can be suppressed. Therefore, the durability and reliability of the piston 20 and the case 10 can be improved.

In the leveling valve 100, the stem 50 has a main body part 50A provided with a valve part 53 forming a part of the supply/discharge valve 80 at its tip, and a body part 50A having a diameter smaller than that of the main body part 50A and smaller than the through hole 22 of the piston 20. The insertion portion 50B is formed to have a small diameter and is inserted through the through hole 22 of the piston 20, and the step portion 50C (the second step portion) is formed by the boundary between the main body portion 50A and the insertion portion 50B and has a larger diameter than the through hole 22 of the piston 20. The piston 20 is movable between the step portion 50C (first step portion) and a washer 61 (locking member) fixed to the insertion portion 50B.

With this configuration, the piston 20 can be fitted to the stem 50 so as to be movable in the axial and radial directions without adding any new parts to the conventional configuration, so an increase in cost can be suppressed.

In the leveling valve 100, the stem 50 includes a small diameter portion 50D formed at the end of the insertion portion 50B opposite to the main body portion 50A, and a small diameter portion 50D formed to have a smaller diameter than the insertion portion 50B, and a stem 50 formed on the outer peripheral surface of the tip side of the small diameter portion 50D. The locking member further includes a male threaded portion 50E to which the nut 60 is fastened, and a step portion 50F (second step portion) formed by a boundary portion between the insertion portion 50B and the small diameter portion 50D. The small diameter portion 50D is inserted through the washer 61, which has a larger diameter than the inner diameter of the through hole 22 of the piston 20. By fastening the nut 60 to the male threaded portion 50E, the washer 61 connects the nut 60 with the stepped portion 50F (second The length between the step portion 50C (first step portion) and the step portion 50F (second step portion) is longer than the axial length of the through hole 22 of the piston 20.

In this configuration, the washer 61 (locking member) is positioned in the axial direction by the nut 60 and the step portion 50F (second step portion). Thereby, the amount of play (allowable movement amount) of the piston 20 in the axial direction can be set with high accuracy.

Although the embodiments of the present invention have been described above, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. do not have.

100...Leveling valve, 1...Car body, 2...Dolly, 3...Air spring, 4...Lever, 6...Air spring passage, 7...Compressor (compressed air source) , 8... Exhaust passage, 9... Supply passage, 10... Case (housing), 11... Accommodation hole, 12... First cap member (housing), 12c... Guide hole, 13... Second cap member (housing), 20... Piston, 21... Groove, 30... Rotor, 35... Pin, 40... Valve case (housing), 50... Stem, 50A...Body part, 50B...Insertion part, 50C...Step part (first step part), 50D...Small diameter part, 50E...Male thread part, 50F...Step part (2nd stage part), 53... Valve part, 60... Nut, 61... Washer, 80... Supply/discharge valve, 80A... Air supply valve, 80B... Exhaust valve

Claims (3)

An air spring provided between the bogie and the car body is selectively communicated with a compressed air source or an exhaust passage according to the rotation direction of a lever that rotates in response to a relative displacement of the car body with respect to the bogie of the railway vehicle. A leveling valve that adjusts the height of an air spring,
a piston that is housed in a housing hole formed in a housing and moves in the axial direction of the housing hole as the lever rotates;
a stem whose one end is inserted into a through hole formed in the piston and moves in the axial direction together with the piston;
The stem moves in one direction from the neutral position to communicate the air spring with the compressed air source, and the stem moves in the other direction from the neutral position to communicate the air spring with the exhaust passage. and a supply/discharge valve for
A leveling valve characterized in that the piston is fitted to the stem so as to be movable in the axial and radial directions. The leveling valve according to claim 1,
The stem is
a main body portion provided with a valve portion constituting a part of the supply/discharge valve at its tip;
an insertion portion that is formed to have a smaller diameter than the main body portion and a smaller diameter than the through hole of the piston, and that is inserted through the through hole of the piston;
a first stage portion formed by a boundary portion between the main body portion and the insertion portion and having a larger diameter than the through hole of the piston;
The leveling valve is characterized in that the piston is movable between the first stage portion and a locking member fixed to the insertion portion. The leveling valve according to claim 2,
The stem is
a small diameter portion formed at an end of the insertion portion opposite to the main body portion and having a smaller diameter than the insertion portion;
a male threaded portion formed on the outer peripheral surface of the small diameter portion and to which a nut is fastened;
further comprising a second step portion formed by a boundary portion between the insertion portion and the small diameter portion,
The locking member is a washer through which the small diameter portion is inserted and which has a larger diameter than the inner diameter of the through hole of the piston,
The washer is fixed between the nut and the second step by fastening the nut to the male thread,
A leveling valve characterized in that a length between the first step portion and the second step portion is longer than a length of the through hole of the piston in the axial direction.

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