JPH04334656A - Double acting type differential pressure regulating valve for rolling stock - Google Patents

Abstract

PURPOSE:To automatically adjust differential pressure generated between air springs due to the change of load in an air spring type truck for rolling stock. CONSTITUTION:A spring 7 is contractedly provided between pistons 4, 5 slidably fitted into a valve body 3, and springs 11, 12 are also contractedly provided in chambers 9, 10 formed between the springs 4, 5 and the respective end walls of the valve body 3. A duct 13 led out from an air spring 1 on the piston 4 side is communicated with the chamber 9, and the piston 5 on the opposite side is further communicated with the other chamber 10. The same applies to an air spring 2 on the piston 5 side.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential pressure valve for automatically adjusting the differential pressure generated between air springs due to changes in load in air spring bogies for railway vehicles.

0002

2. Description of the Related Art Conventional differential pressure valves have a structure in which single-acting safety valves (or check valves) are combined in parallel and opposite directions, and the operating set pressure is fixed at a constant value. In other words, this type of differential pressure valve is usually installed between two air springs in a bogie, but regardless of the size of the load that the air springs bear, a pressure difference that is greater than the set pressure will occur between the two air springs. Then, the differential pressure valve operates to prevent the pressure difference from increasing any further and to prevent the unbalance of the load borne by the air spring from becoming excessive.

On the other hand, the function of the differential pressure valve is to prevent an excessive imbalance between the loads borne by the two air springs as described above, but in order to ensure ride comfort and prevent unnecessary load movement, The set pressure must be determined so that the differential pressure valve will not operate as long as the air spring is functioning normally. In other words, the differential pressure valve must not operate up to the level of differential pressure that can normally be observed under full vehicle conditions.

However, in the case of a commuter train with a large difference in load and load, when the car is empty, the set pressure of the differential pressure valve determined from the condition of full car is too large, and the load when an (abnormal) pressure difference occurs is It is conceivable that the imbalance cannot be suppressed to a sufficiently small range.

For example, when the internal pressure of a full car is 0.5 MPa and the differential pressure valve setting pressure is 0.2 MPa, the internal pressures of the two air springs operate at 0.6 and 0.4 MPa when the car is full, so the imbalance from the average value is The ratio is (0.6-0.5)/0.5
, (0.4-0.5)/0.5, which is ±20%,
If the empty car internal pressure is 0.2 MPa, the air spring internal pressure is 0.2 MPa.
3 and 0.1 MPa, the above unbalance ratio is (0.3-0.2)/0.2, (0.1-0.2)
/0.2, it reaches ±50%.

[0006]

[Problems to be Solved by the Invention] Here, the present invention is capable of determining the operating set pressure separately for the empty condition and the full condition of the railway vehicle, and the set pressure can be changed from the empty condition to the full condition. Therefore, by continuously changing the pressure, it is attempted to overcome the drawbacks of the conventional differential pressure valves of this type.

[0007]

[Means for Solving the Problems] That is, in the present invention, a piston (4) and a piston (5) are slidably fitted inside a cylindrical valve body (3).
) and the piston (5), and a spring (7) is compressed between the piston (4) and the piston (5) in a chamber (6) that is communicated with the atmosphere.
) and the respective pistons (4) and (5), and the springs ( 1
1), the spring (12) is compressed, the pipe line (13) led out from the air spring (1) is branched into two, one branch line (14) is opened into the chamber (9), and the other branch line (14) is opened into the chamber (9); Branch road (1
5) is opened in the peripheral wall of the piston (5).
6) to the communication passage (1) formed in this piston (5).
7), the pipe line (18) that can be opened into the chamber (10) and led out from the air spring (2) is branched into two, and one branch line (19) is connected to the chamber (10). Open it,
The other branch passage (20) is opened from a port (21) opening in the peripheral wall of the piston (4) to the chamber (9) via a communication passage (22) formed in the piston (4). This paper proposes a double-acting differential pressure valve for railway vehicles, which is characterized by the following features:

[0008]

[Operation] The differential pressure valve with the above configuration automatically changes the setting of the differential pressure that causes the differential pressure valve to operate, depending on the difference in the load borne by the air spring, such as when the vehicle is empty or when the vehicle is full. It is something that can be done.

[0009]

[Example] Figure 1 shows two air springs 1 and 2.
This shows a differential pressure valve in a state where no load is applied to it, that is, there is no pressure, and the structure is basically symmetrical. Inside the cylindrical valve body 3, a piston 4 and a piston 5 are provided.
The piston 4 is slidably fitted in the chamber 6 formed between the piston 4 and the piston 5.
A spring 7 is compressed between the piston 5 and the piston 5, and the chamber 6 is opened to the atmosphere through a port 8.

Both end walls of the valve body 3 and each piston 4, 5
Also in the chambers 9 and 10 formed between them, springs 11 and 12 are compressed between each end wall and each piston 4 and 5.

A pipe line 13 led out from the air spring 1 is branched into two, one branch line 14 opening into the chamber 9, and the other branch line 15 opening into the peripheral wall of the piston 5.
6 opens into the chamber 10 via a communication passage 17 formed within the piston 5.

Further, the pipe line 18 led out from the air spring 2 is branched into two branches, and one branch line 19 is opened to the chamber 10,
The other branch passage 20 connects from a port 21 opening in the peripheral wall of the piston 4 to a communication passage 22 formed within the piston 4.
It opens into the chamber 9 through.

[0013] In the absence of pressure, the branch passage 15 and the port 16 and the branch passage 20 and the port 21 may or may not communicate with each other as described above. .

FIGS. 2 and 3 show a case where the load borne by the air spring is small and the pressure is low, such as when the car is empty. In this case, the internal pressure moves the pistons 4 and 5 toward the center to a position where they balance the combined spring force of the air springs 1, 2, and 7 (FIG. 2). When the internal pressure of the air spring 1 becomes higher than the internal pressure of the air spring 2 and a pressure difference occurs, the pistons 4 and 5 begin to move to the right in the figure. When the differential pressure rises to the set pressure, the communication passage 17 of the piston 5 finally communicates the air spring 1 with the chamber 10, and the differential pressure valve operates (see FIG. 3).

In this case, the amount of compression of the spring 7 is determined only by the average value of the internal pressures of the air springs 1 and 2, and the amount of deviation of the pistons 4 and 5 in the left-right direction is
It is determined only by the difference in internal pressure between air spring 1 and air spring 2, that is, the magnitude of the differential pressure between them.

FIGS. 4 and 5 show a case where the load borne by the air spring is large and the pressure is high, such as when the vehicle is full. Due to the higher pressure than in the empty vehicle condition described above, the spring 7 is further compressed and the pistons 4 and 5 are moved further towards the center (FIG. 4). When a differential pressure is generated here, the pistons 4 and 5 begin to move to the right in the figure as in FIG. 2, but since the amount of compression of the spring 7 has increased, the air spring 1 and the chamber 10 communicate with each other. In this case, the pistons 4 and 5 require more movement to the right than in FIG. 3, ie a larger pressure difference is reached before the differential pressure valve is activated (see FIG. 5).

[0017]

Effects of the Invention As described above, the double-acting differential pressure valve of the present invention can independently determine the operating set pressure for the empty condition and the full condition of the vehicle, and the set pressure is different from the empty condition. Since the pressure can be changed continuously as the condition changes from full to full, the drawbacks of conventional differential pressure valves can be overcome.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the differential pressure valve of the present invention in a non-pressurized state.

FIG. 2 is a sectional view showing a state in which the air spring is loaded with low pressure, such as when the vehicle is empty, in the differential pressure valve of the present invention.

FIG. 3 is a cross-sectional view showing a state in which the differential pressure valve operates under the conditions shown in FIG. 2;

FIG. 4 is a sectional view showing a state in which the air spring is loaded with high pressure, such as under a full vehicle condition, in the differential pressure valve of the present invention.

5 is a sectional view showing a state in which the differential pressure valve operates under the conditions shown in FIG. 4. FIG.

[Explanation of symbols]

1, 2 Air spring 3 Valve body 4,5 Piston 6 Room 7 Spring 8 Port Room 9,10 11, 12 Spring 13 Pipeline 14,15 Branch road 16 Port 17　　　　　　Communication path 18 Pipeline 19,20 Branch road 21 Port 22 Communication path

Claims (1)

[Claims] Claim 1: A piston (4) and a piston (5) are slidably fitted inside a cylindrical valve body (3),
A spring (7) is compressed between the piston (4) and the piston (5) in a chamber (6) formed between the piston (4) and the piston (5) and communicated with the atmosphere. Also in the chamber (9) and chamber (10) formed between both end walls of the main body (3) and each piston (4), piston (5), each end wall and each piston (4), piston (5)
A spring (11) and a spring (12) are compressed between them, and a pipe line (13) led out from the air spring (1) is branched into two, with one branch line (14) opening into the chamber (9). and the other branch passage (15) is connected to the chamber (10) from a port (16) opening in the peripheral wall of the piston (5) through a communication passage (17) formed in the piston (5). ), and is led out from the air spring (2).
18) into two branches, and one branch path (19) is connected to the chamber (
10) and the other branch passage (20) is opened in the circumferential wall of the piston (4) through a communication passage (22) formed in the piston (4). A double-acting differential pressure valve for a railway vehicle, characterized in that a chamber (9) can be opened.