JP6286496B2 - Leveling valve - Google Patents

Description

  The present invention relates to a leveling valve.

  Patent Document 1 describes a leveling valve that keeps the height of a vehicle body constant by supplying and discharging compressed air to and from an air spring provided between a vehicle body such as a railway vehicle and a carriage.

  In the leveling valve described in Patent Document 1, when the support height of the vehicle body by the air spring changes due to a change in the vehicle body load, the lever swings according to the change, and the piston connected to the tip of the lever moves in the axial direction. To do. With such movement of the piston, either the supply passage connected to the air pressure supply source or the exhaust passage opened to the atmosphere is selectively connected to the air spring passage connected to the air spring.

JP 2004-52889 A

  In the leveling valve described in Patent Document 1, the moving amount of the piston increases in proportion to the swing angle of the lever, and the moving amount of the piston increases and the flow rate of the compressed air flowing into and out of the air spring also increases. . Here, the flow rate of the compressed air flowing into and out of the air spring becomes maximum when the movement amount of the piston reaches a predetermined amount, and hardly changes even if the piston further moves. On the other hand, since the movement amount of the piston changes in proportion to the swing angle of the lever, it further increases after the flow rate of the compressed air flowing into and out of the air spring becomes maximum.

  Therefore, the length of the leveling valve in the moving direction of the piston is set according to the maximum moving amount of the piston, not the flow rate of the compressed air flowing into and out of the air spring. As a result, the overall length of the leveling valve becomes long, the mountability of the leveling valve to the vehicle body decreases, and the weight of the leveling valve may increase.

  The present invention has been made in view of the above problems, and an object of the present invention is to shorten the overall length of the leveling valve.

  According to a first aspect of the present invention, the guide groove formed in the piston has a first groove portion with which the protrusion of the rotor contacts when the rotation angle of the rotor that rotates according to the relative displacement of the vehicle body with respect to the carriage is equal to or less than a predetermined value. The second groove portion has a width that is larger in the sliding direction of the piston than the first groove portion, and a projection portion that contacts when the rotation angle of the rotor exceeds a predetermined value.

  In the first invention, when the relative displacement of the vehicle body with respect to the carriage increases and the rotation angle of the rotor exceeds a predetermined value, the protrusion of the rotor has a larger width in the sliding direction of the piston than the first groove. 2 Touches the groove. For this reason, the movement amount of the piston is limited to a certain size without increasing in proportion to the rotation amount of the rotor, that is, the relative displacement amount of the vehicle body with respect to the carriage.

  The second invention is characterized in that the second groove is formed in the piston so that the protrusion comes into contact when the amount of air flowing through the supply / discharge valve becomes constant regardless of the movement of the piston.

  In the second invention, the amount of movement of the piston is limited at a stage where the amount of air flowing through the supply / discharge valve does not change even if the piston moves. In a region where the amount of air flowing through the supply / discharge valve is constant, the flow rate of the compressed air supplied to and discharged from the air spring hardly changes even if the amount of movement of the piston is changed. Therefore, the total length of the leveling valve can be shortened without impairing the function as the leveling valve.

  According to a third aspect of the present invention, the degree of change in the amount of air flowing through the supply / exhaust valve with respect to the amount of movement of the piston of the second groove is greater than when the protrusion contacts the second groove than when the protrusion contacts the first groove. It is formed in a piston so that becomes small.

  In the third invention, the movement amount of the piston is limited in a region where the change amount of the air amount flowing through the supply / discharge valve with respect to the movement amount of the piston is relatively small. In a region where the amount of change in the amount of air flowing through the supply / discharge valve with respect to the amount of movement of the piston is small, the flow rate of the compressed air supplied to and discharged from the air spring hardly changes even if the amount of movement of the piston is changed. Therefore, the total length of the leveling valve can be shortened without impairing the function as the leveling valve.

  According to a fourth aspect of the present invention, the second groove portion has a first contact surface that restricts the projection from contacting the piston when the piston moves in one direction, and the piston moves in the other direction. And a second restricting surface for restricting the movement of the piston in one direction.

  In the fourth aspect of the invention, the displacement of the piston in the direction in which the amount of air flowing through the supply / discharge valve decreases is restricted by the first restriction surface and the second restriction surface. For this reason, it is possible to prevent the adjustment of the height of the vehicle body relative to the carriage from being slow.

  The fifth invention is characterized in that the first restriction surface and the second restriction surface are formed in parallel to each other.

  In the fifth invention, the shape of the guide groove is simplified by forming the first restricting surface and the second restricting surface in parallel with each other. An increase in the manufacturing cost of the leveling valve can be suppressed by easily processing the guide groove having the second groove portion.

  According to the present invention, the overall length of the leveling valve can be shortened.

FIG. 1 is a mounting diagram of a leveling valve according to an embodiment of the present invention. FIG. 2 is a sectional view in the axial direction of the leveling valve according to the embodiment of the present invention. 3 is a cross-sectional view of the leveling valve taken along line III-III in FIG. FIG. 4A is a diagram for explaining the movement of the piston of the leveling valve according to the embodiment of the present invention. FIG. 4B is a diagram for explaining the movement of the piston of the leveling valve according to the embodiment of the present invention. FIG. 4C is a diagram for explaining the movement of the piston of the leveling valve according to the embodiment of the present invention. FIG. 4D is a diagram for explaining the movement of the piston of the leveling valve according to the embodiment of the present invention. FIG. 4E is a view for explaining the movement of the piston of the leveling valve according to the embodiment of the present invention. FIG. 4F is a view for explaining movement of the piston of the leveling valve according to the embodiment of the present invention. FIG. 5 is a graph showing the amount of movement of the piston that changes according to the rotation angle of the rotor. FIG. 6 is a graph showing the amount of air flowing through the supply / discharge valve, which changes according to the amount of movement of the piston.

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

  First, an outline of a leveling valve 100 according to an embodiment of the present invention will be described with reference to FIG.

  The leveling valve 100 adjusts the expansion and contraction of an air spring provided between the vehicle body of the railway vehicle and the carriage, and maintains the height of the vehicle body relative to the carriage.

  As shown in FIG. 1, the leveling valve 100 is attached to the vehicle body 1 side and is connected to the carriage 2 via a lever 4 and a connecting rod 5. When the air spring 3 expands and contracts due to a load change of 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 vehicle body load increases and the air spring 3 contracts, that is, when the height of the vehicle body 1 with respect to the carriage 2 becomes lower than the specified height, the lever 4 is moved upward from the neutral position shown in FIG. It is pushed up in the direction of arrow A in FIG. When the lever 4 is displaced upward in this way, the air spring passage 6 communicating with the air spring 3 and the supply passage 9 communicating with the compressor 7 as a pneumatic source for supplying compressed air are communicated in the leveling valve 100. Thereby, compressed air is supplied from the compressor 7 to the air spring 3, and the air spring 3 expands. When the height of the vehicle body 1 with respect to the carriage 2 reaches a specified height due to the extension of the air spring 3, the lever 4 returns to the neutral position, and the supply of compressed air to the air spring 3 is stopped.

  On the other hand, when the vehicle body load decreases and the air spring 3 extends, that is, when the height of the vehicle body 1 with respect to the carriage 2 becomes higher than a specified height, the lever 4 moves downward from the neutral position (see FIG. 1). It is pulled down in the direction of arrow B). When the lever 4 is displaced downward in this way, the air spring passage 6 and the exhaust passage 8 are communicated with each other in the leveling valve 100. Since one end of the exhaust passage 8 is open to the atmosphere, the compressed air in the air spring 3 is discharged to the atmosphere, and the air spring 3 contracts. When the height of the vehicle body 1 with respect to the carriage 2 reaches a specified height due to the contraction of the air spring 3, the lever 4 returns to the neutral position and the discharge of the compressed air from the air spring 3 is stopped.

  In this way, the leveling valve 100 selectively communicates the air spring passage 6 with the supply passage 9 or the exhaust passage 8 in accordance with the turning direction of the lever 4 that turns with the relative displacement of the vehicle body 1 with respect to the carriage 2. ing. Thereby, the relative displacement generated between the vehicle body 1 and the carriage 2 is reduced, and the height of the vehicle body 1 with respect to the carriage 2 is maintained at a specified height.

  Next, the configuration of the leveling valve 100 will be described with reference to FIGS. 2 and 3. 2 is a cross-sectional view in the axial direction of the leveling valve 100, and FIG. 3 is a cross-sectional view in the radial direction of the leveling valve 100 along the line III-III in FIG.

  The leveling valve 100 includes a housing 10 in which an air spring passage 6, a supply passage 9 and an exhaust passage 8 are formed, a piston 20 slidably accommodated in the housing 10, and a relative displacement of the vehicle body 1 with respect to the carriage 2. A rotor 30 that transmits the amount to the piston 20 and a supply / discharge valve 40 that selectively connects the air spring passage 6 to the supply passage 9 or the exhaust passage 8 according to the moving direction of the piston 20 are provided.

  The housing 10 includes a main case 11 in which an accommodation hole 11a in which the piston 20 is accommodated is formed penetrating along the first central axis O1, and one opening of the accommodation hole 11a attached to one side surface of the main case 11. And a second cap member 13 that is attached to the other side surface of the main case 11 and that is formed through a through hole 13b that is concentric with the accommodation hole 11a. The first cap member 12 and the second cap member 13 are attached to the main case 11 via bolts (not shown). Further, the housing 10 is fixed to the vehicle body 1 by attaching the main case 11 to the vehicle body 1 via bolts (not shown).

  The main case 11 and the first cap member 12 are formed with passages 11c, 11d, and 12a constituting the air spring passage 6, respectively. The air spring 3 communicates with the supply / discharge valve 40 through these passages 11c, 11d, and 12a. The main case 11 and the second cap member 13 are formed with passages 11e and 13a constituting the supply passage 9, respectively. The compressor 7 communicates with the supply / discharge valve 40 through these passages 11e and 13a. The air spring passage 6 may be formed only in the main case 11 without passing through the first cap member 12. Similarly, the supply passage 9 may be provided only in the second cap member 13 without passing through the main case 11.

  Further, as shown in FIG. 3, the main case 11 is formed with a recess 11b that opens radially outward with respect to the accommodation hole 11a. The housing 10 further includes a cover member 14 that covers the recess 11b and is attached to the main case 11. By attaching the cover member 14 to the main case 11, an accommodation space 15 in which the rotor 30 is accommodated is defined.

  The cover member 14 is formed with a communication hole 14a that allows the accommodation space 15 to communicate with the outside. The communication hole 14a functions as an exhaust passage 8 that allows the supply / discharge valve 40 to communicate with the outside. A filter 16 is provided in the communication hole 14a in order to prevent foreign substances from entering from the outside.

  The supply / discharge valve 40 has a cylindrical valve case 41 having one end inserted into the housing hole 11a of the main case 11 and the other end inserted into the through hole 13b of the second cap member 13, and one end fixed to the piston 20 and the like. The end side is configured by a valve rod 42 inserted into the valve case 41, a valve body and the like disposed in the valve case 41. A specific configuration of the supply / discharge valve 40 will be described below.

  The valve case 41 includes a first cylindrical portion 41a inserted into the accommodation hole 11a, a second cylindrical portion 41c inserted into the second cap member 13, and a first cylindrical portion 41a and a second cylindrical portion 41c. And a flange portion 41b having an outer diameter larger than that of the first cylindrical portion 41a and the second cylindrical portion 41c and having an external thread formed on the outer peripheral surface. The valve case 41 is fixed to the main case 11 by screwing the flange portion 41b into the female screw portion 11f formed in the opening of the accommodation hole 11a. By restricting the second cap member 13 to the main case 11 so as to cover the second cylindrical portion 41c protruding from the main case 11, the second cap member 13 prevents the flange portion 41b from coming out of the main case 11. Is done. As a result, the valve case 41 is prevented from being detached from the main case 11.

  In addition, the valve case 41 is formed continuously with the first insertion hole 41d and the first insertion hole 41d, which is open to the first cylindrical portion 41a side and into which the valve rod 42 is inserted. A second insertion hole 41e having a larger inner diameter and a stepped portion 41f formed at a connection portion between the first insertion hole 41d and the second insertion hole 41e are provided. The second insertion hole 41e is opened on the second cylindrical portion 41c side, and a columnar plug 48 is inserted and fixed at the opening end of the second insertion hole 41e. Thus, the opening end of the second insertion hole 41e is closed by the plug 48.

  An annular first valve seat 41g centering on the first central axis O1 is formed at the portion near the inner periphery of the step 41f so as to protrude toward the plug 48 side. Further, an annular second valve seat portion 48a centering on the first central axis O1 is formed on the end surface of the plug 48 facing the step portion 41f so as to protrude toward the step portion 41f side. The plug 48 is provided with a passage 48 b having one end opened on the inner peripheral side of the second valve seat portion 48 a and the other end opened on the outer peripheral surface of the plug 48.

  In the second insertion hole 41e, a disc-shaped valve body 43 that is separated from and seated on the first valve seat portion 41g, a disc-shaped check valve body 44 that is seated and seated on the second valve seat portion 48a, and the valve body 43 are disposed. A spring 45 is provided that biases the first valve seat 41g toward the first valve seat 41g and biases the check valve body 44 toward the second valve seat 48a. That is, when the valve body 43 is seated on the first valve seat portion 41g and the check valve body 44 is seated on the second valve seat portion 48a by the biasing force of the spring 45, the space in the second insertion hole 41e is closed. It becomes a state. The valve body 43 is slidably supported by the second insertion hole 41e on the outer peripheral surface, and communicates the spaces partitioned by the valve body 43 through notch portions (not shown) provided on the outer peripheral surface. Similarly to the valve body 43, the check valve body 44 communicates with the spaces partitioned by the check valve body 44 through notch portions (not shown).

  The valve case 41 is formed with a passage 41 h that connects the passage 13 a formed in the second cap member 13 and the passage 48 b formed in the plug 48. The compressed air discharged from the compressor 7 is guided upstream of the check valve body 44 through these passages 11e, 13a, 41h, and 48b.

  When the pressure on the upstream side of the check valve body 44, that is, the pressure on the compressor 7 side is higher than the pressure on the downstream side of the check valve body 44, the check valve body 44 is second against the biasing force of the spring 45. It separates from the valve seat part 48a, and connects the supply passage 9 and the space in the second insertion hole 41e. On the other hand, when the pressure on the compressor 7 side is lower than the pressure on the downstream side of the check valve body 44, the check valve body 44 is seated on the second valve seat portion 48a, and inside the supply passage 9 and the second insertion hole 41e. Block communication with the space. Thus, the check valve body 44 functions as a check valve that allows only the flow toward the valve body 43.

  The valve rod 42 is a rod-like member, a sliding portion 42a that is slidably supported by the valve case 41, and a fixed portion 42b that is formed to have an outer diameter smaller than the sliding portion 42a and is inserted and fixed to the piston 20. And having.

  The sliding portion 42a has a non-through hole 42d opened on the end surface 42c on the side inserted into the valve case 41, and a plurality of through-holes communicating the space in the non-through hole 42d and the space in the accommodation hole 11a. 42e are formed. That is, the space in the non-through hole 42d communicates with the outside through the through hole 42e, the accommodation hole 11a, the accommodation space 15, and the communication hole 14a.

  The end surface 42 c of the valve rod 42 can be separated from and connected to the valve body 43. When the end surface 42 c is in contact with the valve body 43, the open end of the non-through hole 42 d is closed by the valve body 43.

  The valve rod 42 has a large-diameter portion 42f formed on the outer periphery of the tip inserted into the valve case 41, and a small-diameter portion 42g having a smaller diameter than the large-diameter portion 42f is formed continuously to the large-diameter portion 42f. The On the other hand, the first insertion hole 41d of the valve case 41 is provided with a reduced diameter portion 41i at a position facing the large diameter portion 42f and an enlarged diameter portion 41j at a position facing the small diameter portion 42g. An annular gap is formed between the large diameter portion 42f and the reduced diameter portion 41i.

  The airflow flowing through the annular gap corresponds to the flow path length of the annular gap in the first central axis O1 direction, that is, the length in which the large diameter portion 42f and the reduced diameter portion 41i overlap in the first central axis O1 direction. Channel resistance is applied. Here, the length over which the large diameter portion 42 f and the reduced diameter portion 41 i overlap varies depending on the amount of displacement of the valve rod 42 relative to the valve case 41. That is, when the displacement of the valve rod 42 with respect to the valve case 41 is relatively small and the flow path length of the annular gap is long, it becomes difficult for air to flow, and the displacement of the valve rod 42 with respect to the valve case 41 is relatively large and the flow path length of the annular gap. When is short, air becomes easy to flow.

  Further, the valve case 41 is opened to the first insertion hole 41d in the enlarged diameter portion 41j and to the outer peripheral surface of the valve case 41, and the space in the first insertion hole 41d is formed as a passage constituting the air spring passage 6. A plurality of through holes 41k communicating with 11c are formed. That is, the space surrounded by the first insertion hole 41d and the outer peripheral surface of the valve rod 42 is always in communication with the air spring 3 through the through hole 41k and the passages 11c, 12a, and 11d.

  According to the supply / discharge valve 40 configured as described above, when the end surface 42c of the valve rod 42 is in contact with the valve body 43 and the valve body 43 is seated on the first valve seat portion 41g, the air spring passage 6 and the supply passage 9 are provided. And the communication between the air spring passage 6 and the exhaust passage 8 are blocked.

  On the other hand, the valve rod 42 moves in the direction of entering the valve case 41 (the direction of arrow C in FIG. 2), and the valve body 43 is in the first valve seat portion 41g with the end surface 42c of the valve rod 42 in contact with the valve body 43. When separated from the position, the air spring passage 6 and the supply passage 9 communicate with each other, and the communication between the air spring passage 6 and the exhaust passage 8 is blocked.

  On the other hand, the valve rod 42 moves in the direction of retreating from the valve case 41 (the direction of arrow D in FIG. 2), the end surface 42c of the valve rod 42 is separated from the valve body 43, and the valve body 43 is moved to the first valve seat portion 41g. When seated, the communication between the air spring passage 6 and the supply passage 9 is cut off, and the air spring passage 6 and the exhaust passage 8 are in communication with each other.

  In this way, the supply / discharge valve 40 selectively communicates the supply passage 9 or the exhaust passage 8 with the air spring passage 6 in accordance with the movement of the valve rod 42 with respect to the valve case 41, and also with respect to the air spring passage 6. Communication between the supply passage 9 and the exhaust passage 8 can be blocked.

  Next, the piston 20 that moves the valve rod 42 and the rotor 30 that transmits the relative displacement amount of the vehicle body 1 with respect to the carriage 2 to the piston 20 will be described.

  The piston 20 is a cylindrical member in which a through hole 20a through which the fixed portion 42b of the valve rod 42 is inserted is formed in the center, and is supported by the accommodation hole 11a so as to be slidable in the first central axis O1 direction. As shown in FIG. 3, a guide groove 21 having a half-moon-shaped cross section is predetermined in a direction orthogonal to the sliding direction of the piston 20 (the first central axis O1 direction) on a part of the outer peripheral surface of the piston 20. It is formed with a width of The piston 20 is formed with a flow path (not shown) that communicates with both sides thereof. Thereby, when the piston 20 moves in the first central axis O1 direction, the air in the accommodation hole 11a can move through this flow path.

  The rotor 30 includes a cylindrical main body portion 31, a quadrangular columnar boss portion 32 that is formed to protrude from one end portion of the main body portion 31, and has a two-surface width smaller than the outer diameter of the main body portion 31. The flange portion 33 provided at the other end of the arm 31 and the arm portion 34 formed so as to protrude radially outward from the outer peripheral surface of the flange portion 33.

  As shown in FIG. 3, the main body 31 of the rotor 30 is supported by the support hole 14 b via bearings 17 and 18 provided in the cover member 14. Thus, the rotor 30 is supported by the housing 10 so as to be rotatable about the second central axis O2 extending in the direction orthogonal to the first central axis O1.

  In addition, a pin 35 as a protrusion is provided on the arm portion 34 of the rotor 30 that is offset from the second central axis O <b> 2 that is the rotation center of the rotor 30. The pin 35 is attached so that one end side is press-fitted into the arm portion 34 and the other end side protrudes from the arm portion 34. As shown in FIG. 3, the other end side of the pin 35 protruding from the arm portion 34 is inserted into the guide groove 21 of the piston 20 in a state where the rotor 30 is assembled to the housing 10.

  As shown in FIG. 1, the boss portion 32 is fitted into a fitting hole 4 a formed in the lever 4. Therefore, when the boss portion 32 is rotated in accordance with the rotation of the lever 4, the pin 35 press-fitted into the arm portion 34 is centered on the second central axis O2 in the direction of the arrow E or the arrow F shown in FIG. Moving. Since the pin 35 is in contact with the guide groove 21 of the piston 20, the rotation of the rotor 30 is transmitted to the piston 20 via the pin 35, and the piston 20 moves in the housing hole 11 a as the pin 35 moves. It moves in the direction of the central axis O1 (directions of arrows C and D in FIG. 2).

  Next, the guide groove 21 of the piston 20 with which the pin 35 contacts will be described.

  As shown in FIG. 4A, the guide groove 21 is formed to be continuous with the first groove portion 22 and the first groove portion 22 that are formed to have substantially the same width as the diameter of the pin 35, and the piston groove 20 is formed more than the first groove portion 22. And a second groove portion 23 having a large width in the sliding direction (first central axis O1 direction). The first groove portion 22 is formed at a position where the pin 35 contacts when the relative displacement of the vehicle body 1 with respect to the carriage 2 is relatively small, that is, when the amount of rotation of the rotor 30 is small. When the relative displacement of 1 is relatively large, that is, when the amount of rotation of the rotor 30 is large, the pin 35 is formed at a contact position.

  The first groove portion 22 faces the first supply side wall 22a in the sliding direction of the piston 20 and a first supply side wall 22a extending orthogonally to the sliding direction of the piston 20 (first central axis O1 direction). The first discharge side wall 22b is provided with two wall surfaces. When the pin 35 is pressed against the first supply side wall 22 a according to the rotation of the rotor 30, the piston 20 and the valve rod 42 move in a direction in which the air spring passage 6 and the supply passage 9 are communicated. On the other hand, when the pin 35 is pressed against the first discharge side wall 22 b according to the rotation of the rotor 30, the piston 20 and the valve rod 42 move in a direction in which the air spring passage 6 and the exhaust passage 8 are communicated. The distance between the first supply side wall 22 a and the first discharge side wall 22 b is set to be approximately the same as the diameter of the pin 35. For this reason, when the pin 35 exists in the 1st groove part 22, the pin 35 will be in the state which contacted both the 1st supply side wall 22a and the 1st discharge | emission side wall 22b.

  The second groove portion 23 includes a widened portion 24 formed with a predetermined width larger than the width of the first groove portion 22, and a width changing portion in which the width gradually increases from the first groove portion 22 toward the widened portion 24. 25.

  The widened portion 24 is provided to face the second supply side wall 24a in the sliding direction of the piston 20 and a second supply side wall 24a extending perpendicularly to the sliding direction of the piston 20 (first central axis O1 direction). And the second discharge side wall 24b. The distance between the second supply side wall 24a and the second discharge side wall 24b is set larger than the distance between the first supply side wall 22a and the first discharge side wall 22b.

  The width changing portion 25 includes a supply side connection wall 25a that connects the first supply side wall 22a and the second supply side wall 24a, a discharge side connection wall 25b that connects the first discharge side wall 22b and the second discharge side wall 24b, Have The interval between the supply side connection wall 25 a and the discharge side connection wall 25 b is set so as to gradually increase from the first groove portion 22 toward the widened portion 24.

  As described above, the distance between the second supply side wall 24a and the second discharge side wall 24b and the distance between the supply side connection wall 25a and the discharge side connection wall 25b are the same as the first supply side wall 22a and the first discharge side wall. It is set larger than the distance between the side wall 22b, that is, larger than the diameter of the pin 35. For this reason, when the pin 35 exists in the 2nd groove part 23, the pin 35 will be in the state which contacted only any one wall surface which opposes in the sliding direction of piston 20. As shown in FIG.

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

  When the vehicle body load increases and the air spring 3 contracts, that is, when the height of the vehicle body 1 with respect to the carriage 2 becomes lower than a specified height, the lever 4 moves upward from the neutral position (arrow A in FIG. 1). Direction). As the lever 4 is displaced upward, the rotor 30 connected to the lever 4 rotates about the second central axis O2 in the direction of arrow E in FIG. 2 and is provided on the arm portion 34 of the rotor 30. The pin 35 also moves in the direction of arrow E. Since the movement of the pin 35 is transmitted to the piston 20 through the guide groove 21, the piston 20 moves from the neutral position N in FIG.

  As the piston 20 moves in the direction of arrow C, the valve rod 42 connected to the piston 20 separates the valve body 43 from the first valve seat 41g against the urging force of the spring 45. As a result, the supply passage 9 and the air spring passage 6 communicate with each other. Specifically, the air is discharged from the compressor 7 that passes through the passages 11e, 13a, 41h, and 48b, passes between the check valve body 44 and the second valve seat portion 48a, and flows into the space in the second insertion hole 41e. The compressed air passes between the valve body 43 and the first valve seat portion 41g and between the large diameter portion 42f and the reduced diameter portion 41i, and passes through the through hole 41k and the passages 11c, 12a, and 11d to form an air spring. 3 is supplied.

  At this time, since the end surface 42 c of the valve rod 42 is pressed by the valve body 43, the open end of the non-through hole 42 d is closed by the valve body 43. That is, when the piston 20 moves from the neutral position N in the direction of arrow C, the supply valve constituted by the first valve seat portion 41g and the valve body 43 is opened, and the supply passage 9 and the air spring passage 6 communicate with each other. Then, the discharge valve formed by the valve body 43 and the end surface 42c of the valve rod 42 is closed, and the exhaust passage 8 and the air spring passage 6 are blocked.

  Thus, when the supply passage 9 and the air spring passage 6 communicate with each other, the 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 air spring 3 extends. When the air spring 3 extends, the height of the vehicle body 1 with respect to the carriage 2 increases, and the lever 4 also approaches the neutral position accordingly. As the lever 4 approaches the neutral position, the piston 20 also moves toward the neutral position N in FIG. 2 in the direction of the arrow D. When the height of the vehicle body 1 reaches a specified height, the piston 20 moves to the neutral position N. It reaches. At this time, since the valve body 43 is seated on the first valve seat portion 41g, the supply valve is closed. As a result, the communication between the supply passage 9 and the air spring passage 6 is blocked, and the supply of compressed air to the air spring 3 is stopped.

  On the other hand, when the vehicle body load is reduced and the air spring 3 is extended, that is, when the height of the vehicle body 1 with respect to the carriage 2 is higher than a specified height, the lever 4 is moved downward from the neutral position ( It is pulled down in the direction of arrow B in FIG. As the lever 4 is displaced downward, the rotor 30 connected to the lever 4 rotates about the second central axis O2 in the direction of arrow F in FIG. 2, and is provided on the arm portion 34 of the rotor 30. The pin 35 also moves in the direction of arrow F. Since the movement of the pin 35 is transmitted to the piston 20 through the guide groove 21, the piston 20 moves from the neutral position N in FIG.

  As the piston 20 moves in the direction of arrow D, the end surface 42 c of the valve rod 42 connected to the piston 20 is separated from the valve body 43. As a result, the air spring passage 6 and the exhaust passage 8 communicate with each other. Specifically, the compressed air in the air spring 3 passes through the passages 11d, 12a, 11c and the through hole 41k, and passes between the large diameter portion 42f and the reduced diameter portion 41i and between the valve body 43 and the end face 42c. It passes through and flows into the non-through hole 42d, and is further released to the atmosphere through the through hole 42e, the accommodation hole 11a, the accommodation space 15, and the communication hole 14a.

  At this time, since the valve body 43 is pressed against the first valve seat portion 41g by the biasing force of the spring 45, the annular space between the space in the second insertion hole 41e and the large diameter portion 42f and the reduced diameter portion 41i. The gap is cut off. That is, when the piston 20 moves from the neutral position N in the direction of the arrow D, the discharge valve constituted by the valve body 43 and the end surface 42c of the valve rod 42 is opened, and the air spring passage 6 and the exhaust passage 8 communicate with each other. Then, the supply valve composed of the first valve seat portion 41g and the valve body 43 is closed, and the communication between the supply passage 9 and the air spring passage 6 is blocked.

  As described above, when the air spring passage 6 and the exhaust passage 8 communicate with each other, the compressed air in the air spring 3 is released to the atmosphere through the air spring passage 6 and the exhaust passage 8, and the air spring 3 contracts. When the air spring 3 contracts, the height of the vehicle body 1 with respect to the carriage 2 decreases, and the lever 4 also approaches the neutral position accordingly. As the lever 4 approaches the neutral position, the piston 20 also moves toward the neutral position N in FIG. 2 in the direction of arrow C. When the height of the vehicle body 1 reaches a specified height, the piston 20 moves to the neutral position N. It reaches. At this time, since the end surface 42c of the valve rod 42 contacts the valve body 43, the discharge valve is closed. As a result, the communication between the air spring passage 6 and the exhaust passage 8 is blocked, and the discharge of compressed air from the air spring 3 is stopped.

  In this way, the leveling valve 100 selectively communicates the air spring 3 with the compressor 7 or the atmosphere according to the turning direction of the lever 4 that turns with the relative displacement of the vehicle body 1 with respect to the carriage 2. Adjustment is made so that the height of the vehicle body 1 with respect to the carriage 2 becomes a specified height.

  Next, a change in the movement amount S of the piston 20 with respect to the rotation angle α of the rotor 30 will be described with reference to FIGS. 4A to 4F are views mainly showing the guide groove 21 portion of the piston 20 and show how the movement amount S of the piston 20 changes as the rotor 30 rotates. 5 is a graph showing a change in the movement amount S of the piston 20 with respect to the rotation angle α of the rotor 30. FIG. 6 shows the amount of air flowing through the supply / discharge valve 40 with respect to the movement amount S of the piston 20. It is the graph which showed the change of Q.

  First, how the movement amount S of the piston 20 changes as the height of the vehicle body 1 with respect to the carriage 2 gradually decreases from a predetermined height will be described.

  When the height of the vehicle body 1 with respect to the carriage 2 is at a specified height, as shown in FIG. 4A, the rotation angle α of the rotor 30 that rotates according to the displacement of the lever 4 becomes zero, and the piston 20 It will be in the state located in the neutral position N. At this time, the pin 35 inserted into the guide groove 21 comes into contact with the first supply side wall 22a and the first discharge side wall 22b of the first groove portion 22 so that the position of the piston 20 is held at the neutral position N. To work. Thus, the movement of the piston 20 when the height of the vehicle body 1 with respect to the carriage 2 is at a prescribed height and the relative displacement of the vehicle body 1 with respect to the carriage 2 is zero, that is, the rotation angle α of the rotor 30 is zero. The quantity S is zero, as also shown in FIG.

  In this state, the end face 42c of the valve rod 42 is in contact with the valve body 43, and the valve body 43 is pressed against the first valve seat 41g by the urging force of the spring 45. That is, the air spring passage 6 is disconnected from the exhaust passage 8 and the supply passage 9. For this reason, the amount of air Q flowing through the supply / discharge valve 40 becomes zero as shown in FIG.

  When the height of the vehicle body 1 with respect to the carriage 2 slightly decreases from the specified height, as shown in FIG. 4B, the rotor 30 rotates in the direction of the arrow E about the second central axis O2, and the rotation of the rotor 30 The moving angle α is the first rotation angle α1. At this time, the pin 35 that moves with the rotation of the rotor 30 is pressed against the first supply side wall 22 a of the first groove 22. As the pin 35 is pressed against the first supply side wall 22a in this way, the rotation of the rotor 30 is transmitted to the piston 20 via the pin 35. As a result, the piston 20 is moved from the neutral position N to the first distance S1 by the arrow C. Move in the direction of.

  In this state, the pin 35 is in contact with both wall surfaces of the first supply side wall 22a and the first discharge side wall 22b of the first groove portion 22. For this reason, even if the relative displacement amount of the vehicle body 1 with respect to the carriage 2 slightly changes, the change in the relative displacement amount is transmitted to the piston 20 via the pin 35. That is, as long as the pin 35 is in the first groove 22, the movement amount S of the piston 20 changes with good responsiveness in proportion to the rotation angle α of the rotor 30 in a sine wave shape as shown in FIG. 5. Will be.

  Further, when the piston 20 moves in the direction of the arrow C, the valve body 43 is pressed in a direction away from the first valve seat portion 41g by the valve rod 42 that moves together with the piston 20. As a result, the supply passage 9 and the air spring passage 6 communicate with each other, and the compressed air is supplied to the air spring 3.

  Here, when the movement amount of the valve rod 42 with respect to the valve case 41 is small, as described above, the length in which the large diameter portion 42f and the reduced diameter portion 41i overlap in the first central axis O1 direction is long. For this reason, while the movement amount S of the piston 20 is relatively small, for example, until reaching the first distance S1, the compressed air hardly flows and the air amount Q flowing through the supply / discharge valve 40 as shown in FIG. The degree of change is also suppressed. Thus, when the relative displacement amount of the vehicle body 1 with respect to the carriage 2 is relatively small, the flow rate of the compressed air supplied to and discharged from the air spring 3 becomes a very small amount, so that fine adjustment to a specified height is possible. It becomes.

  When the height of the vehicle body 1 with respect to the carriage 2 is further lowered and the rotation angle α of the rotor 30 becomes a second rotation angle α2 larger than the first rotation angle α1 as shown in FIG. The first supply side wall 22a of the first groove portion 22 and the vicinity of the boundary between the supply side connection wall 25a of the width changing portion 25 of the second groove portion 23 are reached. Since the pin 35 is pressed against the first supply side wall 22a while the rotation angle α of the rotor 30 changes from the first rotation angle α1 to the second rotation angle α2, the piston 20 is moved along with the movement of the pin 35. Moves from the neutral position N in the direction of arrow C by a second distance S2 that is further than the first distance S1.

  As described above, when the piston 20 moves to the second distance S2, the amount of movement of the valve rod 42 with respect to the valve case 41 increases. Therefore, compared to when the piston 20 is at the first distance S1, the large diameter portion 42f and The length over which the reduced diameter portion 41i overlaps is shortened. For this reason, until the movement amount S of the piston 20 reaches the second distance S2, the resistance applied to the compressed air flowing through the supply / discharge valve 40 gradually decreases, and as shown in FIG. The amount of air Q flowing through 40 increases as the amount of movement S of the piston 20 increases. That is, when the relative displacement amount of the vehicle body 1 with respect to the carriage 2 is relatively large, the flow rate of the compressed air supplied to and discharged from the air spring 3 changes greatly according to the relative displacement amount of the vehicle body 1 with respect to the carriage 2. Convergence to a specified height can be improved.

  When the height of the vehicle body 1 with respect to the carriage 2 is further lowered and the rotation angle α of the rotor 30 becomes a third rotation angle α3 larger than the second rotation angle α2 as shown in FIG. In this state, the second groove 23 is pressed against the supply-side connecting wall 25a of the width changing portion 25. As shown in FIGS. 4E and 4F, the height of the vehicle body 1 with respect to the carriage 2 is further reduced, and the rotation angle α of the rotor 30 is larger than the third rotation angle α3. When the fifth rotation angle α5 is larger than the fourth rotation angle α4, the pin 35 is pressed against the second supply side wall 24a of the widened portion 24 of the second groove portion 23.

  Here, when the width of the second groove portion 23 is the same as that of the first groove portion 22, that is, when the guide groove 21 is formed of a pair of wall surfaces parallel to each other, the movement amount S of the piston 20 is As shown by a broken line in FIG. 5, it increases monotonously in a sinusoidal shape in proportion to the rotation angle α of the rotor 30.

  On the other hand, in this embodiment, since the width of the second groove portion 23 is formed larger than that of the first groove portion 22, the pin 35 is placed in the second groove portion 23 as shown in FIGS. 4D to 4F. Even if the piston 20 is pressed against the supply side connection wall 25a or the second supply side wall 24a, the movement amount S of the piston 20 does not continuously increase and is limited to a certain size as shown by a solid line in FIG. .

  As described above, in the leveling valve 100 according to the present embodiment, the second groove portion 23 having a width larger than that of the first groove portion 22 when the rotation angle α of the rotor 30 exceeds a predetermined value (transition rotation angle αL). Since the pin 35 is in contact with the piston 35, the range in which the piston 20 moves is greatly limited. When the moving range of the piston 20 is reduced, the valve case 41 and the first cap member 12 that may come into contact with the piston 20 can be disposed closer to the piston 20, and leveling in the moving direction of the piston 20 is possible. The overall length of the valve 100 can be shortened. That is, compared with the case where the movement amount of the piston 20 increases monotonously in proportion to the rotation angle α of the rotor 30, in the present embodiment, the movement range of the piston 20 is small. The overall length can be greatly shortened. Furthermore, since the overall length of the leveling valve 100 is shortened, the weight of the leveling valve 100 can be reduced, and the mountability of the leveling valve 100 to the vehicle body 1 can be improved.

  Further, as shown in FIG. 6, the air amount Q flowing through the supply / discharge valve 40 becomes substantially constant when the movement amount S of the piston 20 exceeds a predetermined amount. This is because, when the large diameter portion 42f and the reduced diameter portion 41i do not overlap in the first central axis O1 direction, the flow path between the valve body 43 and the second insertion hole 41e and the other formed in the housing 10 This is because the amount of air Q flowing through the supply / discharge valve 40 is limited by the cross-sectional area of the passage.

  As described above, in the region where the air amount Q flowing through the supply / discharge valve 40 is substantially constant, the flow rate of the compressed air supplied to and discharged from the air spring 3 hardly changes even if the movement amount S of the piston 20 is changed. . Accordingly, in a region where the air amount Q flowing through the supply / discharge valve 40 is substantially constant regardless of the movement amount S of the piston 20, that is, a region where the air amount Q flowing through the supply / discharge valve 40 does not change even when the piston 20 moves. If the movement amount S of the piston 20 is limited at a reached stage, the overall length of the leveling valve 100 can be shortened without impairing the function of the leveling valve 100.

  For this reason, in the leveling valve 100 according to the present embodiment, the pin 35 comes into contact with the second groove portion 23 when the air amount Q flowing through the supply / discharge valve 40 is substantially constant regardless of the movement amount S of the piston 20. The position of the second groove portion 23 with respect to the first groove portion 22 is set. More specifically, as shown in FIG. 6, the movement amount S of the piston 20 when the air amount Q flowing through the supply / discharge valve 40 becomes a predetermined reference air amount QL is defined as a restriction movement amount SL, and is shown in FIG. As described above, when the rotation angle α of the rotor 30 when the movement amount S of the piston 20 reaches the limit movement amount SL is the transition rotation angle αL, the rotation angle α of the rotor 30 exceeds the transition rotation angle αL. The position of the second groove portion 23 with respect to the first groove portion 22 is set so that the pin 35 sometimes contacts the second groove portion 23.

  Further, from the viewpoint of the degree of change in the amount of air Q flowing through the supply / discharge valve 40, the movement amount S of the piston 20 is the same as when the movement amount S of the piston 20 is between zero and the second movement amount S2. The region in which the degree of change in the air amount Q with respect to is relatively large is an important region for exerting the function of the leveling valve 100. On the other hand, the region in which the movement amount S of the piston 20 exceeds the second movement amount S2 and the change amount of the air amount Q with respect to the movement amount S of the piston 20 is very small is a region in which the function of the leveling valve 100 is not significantly affected. Absent.

  Therefore, the degree of change in the air amount Q flowing through the supply / discharge valve 40 with respect to the movement amount S of the piston 20 is smaller when the pin 35 is in contact with the second groove portion 23 than when the pin 35 is in contact with the first groove portion 22. Thus, by setting the position of the second groove portion 23 with respect to the first groove portion 22, it is possible to shorten the overall length of the leveling valve 100 while sufficiently exerting the function as the leveling valve 100.

  Since the width of the second groove portion 23 is formed larger than the width of the first groove portion 22, for example, as shown in FIGS. 4D to 4F, when the pin 35 is in the second groove portion 23, the piston 20 is further movable in the direction of arrow C in the figure. However, as described above, when the pin 35 is in the second groove portion 23, the amount of air Q flowing through the supply / discharge valve 40 is substantially maximum, and therefore the piston 20 is further moved in the direction of the arrow C. However, the function of the leveling valve 100 is not affected.

  However, if the piston 20 moves in the direction opposite to the arrow C, the amount of air Q flowing through the supply / discharge valve 40 decreases, and the adjustment of the height of the vehicle body 1 relative to the carriage 2 may be slow. On the other hand, in this embodiment, the piston 20 is opposite to the arrow C because the second supply side wall 24a of the widened portion 24 of the second groove portion 23 and the supply side connection wall 25a of the width changing portion 25 abut on the pin 35. The movement in the direction is restricted. Thus, since the 2nd supply side wall 24a and the supply side connection wall 25a function as a 1st control surface, it is prevented that the air quantity Q which flows through the supply / discharge valve 40 falls as mentioned above.

  In addition, about the change of the moving amount S of the piston 20 when the height of the vehicle body 1 with respect to the carriage 2 gradually increases from the specified height, the height of the vehicle body 1 with respect to the carriage 2 decreases from the specified height. On the other hand, the movement direction of the piston 20 is the opposite direction (the direction of the arrow D in FIG. 2), and the only difference is that the air spring passage 6 and the exhaust passage 8 are communicated by the supply / discharge valve 40. Yes, the movement amount S of the piston 20 changes as shown in FIG. 5, and the air amount Q flowing through the supply / discharge valve 40 changes as shown in FIG. Therefore, the description thereof is omitted. Further, in this case, the second discharge side wall 24b of the widened portion 24 of the second groove portion 23 and the discharge side connection wall 25b of the width changing portion 25 come into contact with the pin 35 so that the piston 20 is in the direction opposite to the arrow D. It functions as a second restriction surface that restricts movement.

  According to the above embodiment, there exist the following effects.

  In the leveling valve 100, when the rotation angle α of the rotor 30 that rotates according to the relative displacement amount of the vehicle body 1 with respect to the carriage 2 exceeds a predetermined value, the pin 35 coupled to the rotor 30 is more than the first groove portion 22. The piston 20 contacts the second groove 23 having a large width in the sliding direction. For this reason, the movement amount S of the piston 20 is limited to a certain amount without monotonously increasing in proportion to the rotation angle α of the rotor 30, that is, the relative displacement amount of the vehicle body 1 with respect to the carriage 2. As a result, the overall length of the leveling valve 100 in the moving direction of the piston 20 is shortened, the weight of the leveling valve 100 can be reduced, and the mountability of the leveling valve 100 to the vehicle body 1 can be improved.

  In the leveling valve 100, the second supply side wall 24a of the widened portion 24 of the second groove portion 23 is formed in parallel with the first supply side wall 22a of the first groove portion 22, and the second discharge of the widened portion 24 of the second groove portion 23. Since the side wall 24b is formed in parallel with the first discharge side wall 22b of the first groove portion 22, the movement amount S of the piston 20 once reaches the limit movement amount SL as shown by the solid line in FIG. After slowly decreasing, it increases proportionally again.

  Instead, the second supply side wall 24a and the second discharge side wall 24b are formed to be curved so that the movement amount S of the piston 20 reaches the limit movement amount SL and then becomes a constant movement amount S. Also good. In this case, the amount of air Q flowing through the supply / discharge valve 40 can be made constant within a range in which the movement amount S of the piston 20 is suppressed. However, if the second groove portion 23 is formed to be curved, the processing time is increased and the manufacturing cost is increased. Therefore, in order to suppress the manufacturing cost, as shown in FIG. 4A, the second supply side wall 24a and the second discharge are provided. The side wall 24b is preferably formed in parallel.

  Further, in the leveling valve 100, the second supply side wall 24a of the widened portion 24 of the second groove portion 23 is provided at a position separated from the first supply side wall 22a of the first groove portion 22 by a predetermined distance in the first central axis O1 direction. In addition, the second discharge side wall 24b of the widened portion 24 of the second groove portion 23 is provided at a position away from the first discharge side wall 22b of the first groove portion 22 by a predetermined distance in the first central axis O1 direction. The width of the second groove portion 23 is larger than the width of the first groove portion 22. Instead, the first central axis is formed by forming the second supply sidewall 24a flush with the first supply sidewall 22a or by forming the second discharge sidewall 24b flush with the first discharge sidewall 22b. You may make the width | variety of the 2nd groove part 23 larger than the width | variety of the 1st groove part 22 to either one side of O1 direction. Also in this case, the movement amount S of the piston 20 toward one side in the first central axis O1 direction is suppressed, and as a result, the overall length of the leveling valve 100 can be shortened.

  In the leveling valve 100, the transition rotation angle αL, which is the rotation angle α of the rotor 30 when the pin 35 contacts the second groove 23, is set based on the reference air amount QL. However, the transition rotation angle αL may be any angle as long as the movement amount S of the piston 20 is limited. For example, the transition rotation angle αL is smaller than the second rotation angle α2. Also good.

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

  The leveling valve 100 is rotated by the housing 10 in which an air spring passage 6 communicating with the air spring 3 is formed, a piston 20 slidably accommodated in an accommodation hole 11 a formed in the housing 10, and the housing 10. A rotor 30 that is freely supported and rotates according to the relative displacement amount of the vehicle body 1 with respect to the carriage 2 and moves the piston 20, and the piston 20 moves in one direction from the neutral position N (in the direction of arrow C as the rotor 30 rotates). ) Causes the air spring 3 and the compressor 7 to communicate with each other, and as the rotor 30 rotates, the piston 20 moves from the neutral position N in the other direction (in the direction of arrow D) to allow the air spring 3 to communicate with the atmosphere. The piston 20 has a guide groove 21 formed on the outer periphery and extending in a direction perpendicular to the sliding direction, and the rotor 30 has a second central axis O2. The guide groove 21 has a pin 35 that protrudes toward the piston 20 at the offset position and is inserted into the guide groove 21. The guide groove 21 has a rotation angle α of the rotor 30 that is equal to or smaller than a predetermined value (transition rotation angle αL). The first groove portion 22 that is sometimes in contact with the pin 35 and the first groove portion 22 are formed continuously, the width in the sliding direction of the piston 20 is larger than the first groove portion 22, and the rotation angle α of the rotor 30 is a predetermined value. And a second groove portion 23 with which the pin 35 comes into contact when exceeding (transition rotation angle αL).

  According to this configuration, when the rotation angle α of the rotor 30 that rotates according to the relative displacement amount of the vehicle body 1 with respect to the carriage 2 exceeds a predetermined value (transition rotation angle αL), the pin 35 coupled to the rotor 30. However, it is in contact with the second groove portion 23 having a larger width in the sliding direction of the piston 20 than the first groove portion 22. For this reason, the movement amount S of the piston 20 is limited to a certain amount without monotonously increasing in proportion to the rotation angle α of the rotor 30, that is, the relative displacement amount of the vehicle body 1 with respect to the carriage 2. As a result, the overall length of the leveling valve 100 in the moving direction of the piston 20 is shortened, the weight of the leveling valve 100 can be reduced, and the mountability of the leveling valve 100 to the vehicle body 1 can be improved.

  The second groove 23 is formed in the piston 20 so that the pin 35 contacts when the air amount Q flowing through the supply / discharge valve 40 becomes constant regardless of the movement of the piston 20.

  According to this configuration, the pin 35 contacts the second groove 23 when the amount of air Q flowing through the supply / discharge valve 40 is constant regardless of the movement of the piston 20. That is, the movement amount S of the piston 20 is limited at a stage where the air amount Q flowing through the supply / discharge valve 40 does not change even when the piston 20 moves. In the region where the air amount Q flowing through the supply / discharge valve 40 is substantially constant, the flow rate of the compressed air supplied to and discharged from the air spring 3 hardly changes even if the movement amount S of the piston 20 is changed. Therefore, the overall length of the leveling valve 100 can be shortened without impairing the function as the leveling valve 100.

  Further, in the second groove portion 23, the degree of change of the air amount Q flowing through the supply / discharge valve 40 with respect to the movement amount S of the piston 20 is more in contact with the second groove portion 23 than when the pin 35 is in contact with the first groove portion 22. The piston 20 is formed so that the time is smaller.

  According to this configuration, the change in the amount of air Q flowing through the supply / discharge valve 40 relative to the movement amount S of the piston 20 is greater when the pin 35 is in contact with the second groove 23 than when the pin 35 is in contact with the first groove 22. The degree is reduced. That is, in this configuration, the movement amount S of the piston 20 is limited in a region where the change amount of the air amount Q flowing through the supply / discharge valve 40 with respect to the movement amount S of the piston 20 is relatively small. In a region where the change amount of the air amount Q flowing through the supply / discharge valve 40 with respect to the movement amount S of the piston 20 is small, the flow rate of the compressed air supplied to and discharged from the air spring 3 even if the movement amount S of the piston 20 is changed. Almost no change. Therefore, the overall length of the leveling valve 100 can be shortened without impairing the function as the leveling valve 100.

  Further, the second groove portion 23 is a second supply side wall that restricts movement of the piston 20 in the other direction (arrow D direction) when the piston 20 moves in one direction (arrow C direction). 24a and the supply side connection wall 25a and the second discharge that regulates the movement of the piston 20 in one direction (arrow C direction) when the piston 20 moves in the other direction (arrow D direction). It has the side wall 24b and the discharge | emission side connection wall 25b, It is characterized by the above-mentioned.

  According to this configuration, when the second supply side wall 24a and the supply side connection wall 25a abut on the pin 35, the piston 20 is restricted from moving in the direction opposite to the arrow C direction, and the second discharge side wall 24b and the discharge side are restricted. When the side connection wall 25b abuts on the pin 35, the piston 20 is restricted from moving in the direction opposite to the arrow D direction. As described above, since the piston 20 is restricted from being displaced in the direction in which the air amount Q flowing through the supply / discharge valve 40 decreases, it is possible to prevent the adjustment of the height of the vehicle body 1 relative to the carriage 2 from being slow. it can.

  Further, the second supply side wall 24a and the second discharge side wall 24b are formed in parallel to each other.

  According to this configuration, the second supply side wall 24a and the second discharge side wall 24b are formed in parallel to each other. As described above, since the guide groove 21 is simplified by simplifying the shape of the guide groove 21, an increase in the manufacturing cost of the leveling valve 100 is suppressed even when the second groove portion 23 is provided. can do.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  DESCRIPTION OF SYMBOLS 100 ... Leveling valve, 1 ... Vehicle body, 2 ... Cart, 3 ... Air spring, 4 ... Lever, 6 ... Air spring passage, 7 ... Compressor (pneumatic source), 8 ... exhaust passage, 9 ... supply passage, 10 ... housing, 11a ... accommodating hole, 20 ... piston, 21 ... guide groove, 22 ... first groove, 22a ..First supply side wall, 22b ... first discharge side wall, 23 ... second groove, 24 ... widened portion (second groove), 24a ... second supply side wall (first regulating surface) 24b ... second discharge side wall (second regulating surface), 25 ... width changing portion (second groove), 25a ... supply side connecting wall (first regulating surface), 25b ... discharge side Connection wall (second regulating surface), 30 ... rotor, 35 ... pin (projection), 40 ... supply / discharge valve, O1 ... first central axis, O ... second central axis rotation angle (rotation center), alpha ... rotor 30, the moving amount of S ... piston 20

Claims (5)

A leveling valve for adjusting the height of an air spring provided between a vehicle body and a carriage,
A housing formed with an air spring passage communicating with the air spring;
A piston slidably accommodated in an accommodation hole formed in the housing;
A rotor that is rotatably supported by the housing, rotates according to a relative displacement amount of the vehicle body with respect to the carriage, and moves the piston;
When the piston moves in one direction from the neutral position with the rotation of the rotor, the air spring communicates with the air pressure source, and when the piston moves in the other direction from the neutral position with the rotation of the rotor, A supply / exhaust valve for communicating the air spring and the atmosphere,
The piston has a guide groove formed on the outer periphery and extending in a direction perpendicular to the sliding direction,
The rotor has a protrusion that protrudes toward the piston at a position that is offset from the rotation center, and a tip is inserted into the guide groove;
The guide groove has a first groove portion that contacts the protrusion when the rotation angle of the rotor is equal to or less than a predetermined value, and a width in the sliding direction of the piston larger than that of the first groove portion. A leveling valve comprising: a second groove portion that contacts the protrusion when a corner exceeds the predetermined value.   The said 2nd groove part is formed in the said piston so that the said projection part may contact | connect when the air quantity which flows through the said supply / discharge valve becomes constant irrespective of the movement of the said piston. Leveling valve.   The second groove portion has a degree of change in the amount of air flowing through the supply / discharge valve with respect to the movement amount of the piston when the protrusion portion contacts the second groove portion than when the protrusion portion contacts the first groove portion. The leveling valve according to claim 1, wherein the leveling valve is formed on the piston so as to be smaller.   The second groove includes a first restricting surface that restricts movement of the piston in the other direction when the piston moves in the one direction, and the piston moves in the other direction. 4. The device according to claim 1, further comprising: a second restriction surface that contacts the protrusion when moved and restricts movement of the piston in the one direction. 5. Leveling valve.   The leveling valve according to claim 4, wherein the first restriction surface and the second restriction surface are formed in parallel to each other.

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