Switching valve structure with electro-pneumatic emergency pressure maintaining function and control method

Abstract

The invention discloses a switching valve structure with an electro-pneumatic emergency pressure maintaining function and a control method, and belongs to the technical field of electro-pneumatic braking. The switching valve comprises a first switching valve and a brake pneumatic valve, and the first switching valve and the brake pneumatic valve are both communicated with the auxiliary air cylinder and the brake cylinder; an auxiliary air cylinder pressure passage 1F and a brake cylinder passage 1Z are formed in the first switching valve; the auxiliary air cylinder pressure passage 1F is communicated with the auxiliary air cylinder, and the air source charges air into the auxiliary air cylinder through the auxiliary air cylinder pressure passage 1F; a brake cylinder passage 2Z is formed in the brake pneumatic valve, and the brake cylinder passage 2Z and the brake cylinder passage 1Z are communicated with a brake cylinder through an external gas circuit; through the synergistic effect of multiple air paths and cooperation of the switching valve piston, the switching valve rubber plug and other assemblies, accurate switching of the air paths from air emergency braking to electric pneumatic emergency braking is achieved.

Description

Technical Field

[0001] This invention belongs to the field of electro-pneumatic braking technology, and specifically relates to a switching valve structure and control method with electro-pneumatic emergency pressure maintenance function. Background Technology

[0002] Currently, most electro-pneumatic braking systems for heavy-haul railway freight cars in China employ an electro-pneumatic control mechanism added to the existing air braking system to achieve electro-pneumatic braking. This is achieved by adding a switching mechanism between the air brake valve and the intermediate body, which connects the auxiliary air cylinder control air path and the brake cylinder control air path. The switching mechanism includes a switching valve. In electro-pneumatic braking mode, the switching valve cuts off the air braking path, using the auxiliary air cylinder as the air source. Air is supplied to and from the brake cylinder via a solenoid valve to control the brake cylinder pressure. The switching valve allows for free switching between electro-pneumatic and air braking modes. In case of a malfunction in the electro-pneumatic braking system, emergency braking can be automatically triggered. In electro-pneumatic braking mode, an emergency decompression of the train pipe will trigger an air emergency brake. However, because the brake cylinder pressures of electro-pneumatic and air emergency brakes differ, the deceleration will increase, leading to increased longitudinal force on the train and affecting operational safety. Summary of the Invention

[0003] The purpose of this invention is to provide a switching valve structure and control method with electro-pneumatic emergency pressure maintenance function to address the above-mentioned problems, and to improve the longitudinal impulse problem caused by the inconsistency between the air emergency braking and electro-pneumatic emergency braking cylinder pressures.

[0004] The technical solution adopted in this invention is as follows: a switching valve structure with electro-pneumatic emergency pressure maintenance function, the switching valve includes a first switching valve and a brake pneumatic valve, both of which are connected to the auxiliary air cylinder and the brake cylinder; The first switching valve has an auxiliary air cylinder pressure passage 1F and a brake cylinder passage 1Z; the auxiliary air cylinder pressure passage 1F is connected to the auxiliary air cylinder, and the air source charges the auxiliary air cylinder through the auxiliary air cylinder pressure passage 1F. The pneumatic brake valve has a brake cylinder passage 2Z, and the brake cylinder passage 2Z and the brake cylinder passage 1Z are connected to the brake cylinder through an external air passage. The first switching valve is equipped with a switching valve piston and a switching valve rubber plug, and the brake pneumatic valve is equipped with a brake pneumatic valve piston. The switching valve piston, the switching valve rubber plug, and the brake pneumatic valve piston are used to move according to the pressure change in the air circuit.

[0005] Furthermore, the switching valve piston and the switching valve rubber plug are connected by a spring. The switching valve piston is provided with a switching valve air groove. When the spring is compressed, the switching valve air groove moves in the direction in which the spring is compressed. The switching valve air groove is connected to the auxiliary air cylinder pressure passage 2F and the auxiliary air cylinder pressure passage 3F on the auxiliary air cylinder.

[0006] Furthermore, the first switching valve is also equipped with a base, and the switching valve rubber plug is connected to the base by a spring; the base is equipped with a brake cylinder pressure output passage 1K, which is used to connect with the brake cylinder passage 1Z. When the spring is compressed, the switching valve rubber plug contacts the base, cutting off the passage between the brake cylinder pressure output passage 1K and the brake cylinder passage 1Z; when the spring is reset, the passage between the brake cylinder pressure output passage 1K and the brake cylinder passage 1Z is connected.

[0007] Furthermore, the brake pneumatic valve piston moves the brake cylinder passage 2Z via a compression spring; When the brake pneumatic valve piston compresses the spring, the auxiliary air cylinder pressure passage 3F is connected to the brake cylinder passage 2Z. When the piston of the brake pneumatic valve moves away from the spring and the spring returns to its original position, the auxiliary air cylinder pressure passage 3F is cut off from the brake cylinder passage 2Z.

[0008] Furthermore, the brake cylinder passage 2Z is ​​externally connected to a pressure sensor and an exhaust solenoid valve.

[0009] Furthermore, a switching valve control method with electro-pneumatic emergency pressure holding function is provided. When the braking system is in electro-pneumatic braking mode, the pressurized air in the auxiliary air cylinder is injected into the upper end of the first switching valve through the auxiliary air cylinder pressure passage 1F. The switching valve piston overcomes the spring's action and compresses the spring downward, causing the switching valve rubber plug to contact the base, cutting off the connection between the brake cylinder pressure output passage 1K and the brake cylinder passage 1Z. Simultaneously, as the switching valve piston moves downward, it drives the switching valve air groove to move downward, connecting the auxiliary air cylinder pressure passage 2F and the auxiliary air cylinder pressure passage 3F. The pressurized air in the auxiliary air cylinder is introduced into the brake pneumatic valve, causing the brake pneumatic valve piston to move upward, connecting the auxiliary air cylinder pressure passage 3F and the brake cylinder passage 2Z. At this time, the pressurized air in the auxiliary air cylinder is injected into the brake cylinder through the auxiliary air cylinder pressure passage 2F, the auxiliary air cylinder pressure passage 3F, and the brake cylinder passage 2Z, completing the braking.

[0010] Furthermore, during emergency air braking, the air brake valve outputs a larger brake cylinder pressure to the brake cylinder pressure output passage 1K. The brake cylinder pressure, together with the spring, causes the switching valve piston to move upward against the auxiliary air cylinder pressure, connecting the brake cylinder pressure output passage 1K with the brake cylinder passage 1Z, and supplying air to the brake cylinder through the brake cylinder passage 2Z.

[0011] Furthermore, if the braking system is already in electro-pneumatic emergency braking state, the brake cylinder has the corresponding pressure. The pressure sensor connected to the brake cylinder passage 2Z detects that the pressure exceeds the upper limit set by the electro-pneumatic emergency braking system, and the exhaust solenoid valve is activated to exhaust the excess pressurized air.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: This invention achieves pressure transmission and switching between the brake cylinder passage and the auxiliary air cylinder by setting up various components related to air circuit pressure control, such as a brake pneumatic valve, a brake pneumatic valve piston, an auxiliary air cylinder air passage, a switching valve piston, a switching valve air groove, a spring, and a switching valve rubber plug. This enables brake cylinder pressure output control and ensures the normal operation of the braking system. Through the coordinated action of multiple air circuits and the cooperation of components such as the switching valve piston and the switching valve rubber plug, precise switching of the air circuit between air emergency braking and electro-pneumatic emergency braking is achieved. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the switching valve structure of the present invention.

[0014] Reference numerals: 1. First switching valve; 101. Switching valve piston; 102. Switching valve rubber plug; 111. Auxiliary air cylinder pressure passage 1F; 112. Auxiliary air cylinder pressure passage 2F; 113. Auxiliary air cylinder pressure passage 3F; 121. Brake cylinder pressure output passage 1K; 131. Switching valve air slot; 132. Base; 2. Brake pneumatic valve; 201. Brake pneumatic valve piston; 211. Brake cylinder passage 1Z; 212. Brake cylinder passage 2Z; 3. Spring. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings.

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0017] Currently, domestic heavy-haul railway freight car electro-pneumatic braking systems employ an electro-pneumatic control mechanism added to the air braking system to achieve electro-pneumatic braking. During electro-pneumatic braking, an emergency decompression of the train pipe triggers an air emergency brake. However, the pressure difference between the electro-pneumatic and air emergency brake cylinders causes increased deceleration and longitudinal force on the train, affecting operational safety. Therefore, this invention proposes a switching valve structure and control method with electro-pneumatic emergency pressure maintenance. By improving the switching valve structure, the brake cylinder pressure remains stable during electro-pneumatic emergency braking, preventing the superposition of braking forces caused by air emergency braking, which could lead to inconsistent braking forces among train vehicles and consequently, longitudinal impulse problems.

[0018] Example 1 like Figure 1 As shown, one embodiment of the present invention is a switching valve structure with electro-pneumatic emergency pressure holding function. The switching valve is used to control the transmission and switching of pressure in the brake air circuit, thereby realizing brake cylinder pressure output control and ensuring the normal operation of the braking system. The switching valve includes a first switching valve 1 and a brake pneumatic valve 2, both of which are connected to the auxiliary air cylinder and the brake cylinder. The first switching valve 1 has an auxiliary air cylinder pressure passage 1F111 and a brake cylinder passage 1Z211; the auxiliary air cylinder pressure passage 1F111 is connected to the auxiliary air cylinder, and the air source charges the auxiliary air cylinder through the auxiliary air cylinder pressure passage 1F111. The pneumatic brake valve 2 has a brake cylinder passage 2Z212, and the brake cylinder passage 2Z212 and the brake cylinder passage 1Z211 are connected to the brake cylinder through an external air passage. The auxiliary air cylinder and the brake cylinder are connected through the auxiliary air cylinder pressure passage and the brake cylinder passage. When the brake cylinder depressurizes for emergency braking, the passage between the auxiliary air cylinder and the brake cylinder opens, allowing compressed air in the auxiliary air cylinder to enter the brake cylinder and push the switching valve rubber plug 102 to generate braking force. When braking needs to be relieved, the switching valve rubber plug 102 contacts the base 132, cutting off the passage between the auxiliary air cylinder and the brake cylinder, and the brake cylinder is connected to the atmosphere to achieve rapid exhaust and depressurization.

[0019] The first switching valve 1 is provided with a switching valve piston 101 and a switching valve rubber plug 102, and the brake pneumatic valve 2 is provided with a brake pneumatic valve piston 201. The switching valve piston 101, the switching valve rubber plug 102 and the brake pneumatic valve piston 201 are used to move according to the pressure change in the air circuit.

[0020] Example 2 In another embodiment of the present invention, the switching valve piston 101 and the switching valve rubber plug 102 are connected by a spring 3. The switching valve piston 101 is provided with a switching valve air groove 131. When the spring 3 is compressed, the switching valve air groove 131 moves in the direction in which the spring 3 is compressed. The switching valve air groove 131 is connected to the auxiliary air cylinder pressure passage 2F112 and the auxiliary air cylinder pressure passage 3F113 on the auxiliary air cylinder.

[0021] When the spring 3 is relaxed, the switching valve air groove 131 is not connected to the auxiliary air cylinder pressure passage 2F112 and the auxiliary air cylinder pressure passage 3F113. When the spring 3 is compressed by air, the switching valve air groove 131 moves to the horizontal position of the auxiliary air cylinder pressure passage 2F112 and the auxiliary air cylinder pressure passage 3F113, so that the auxiliary air cylinder pressure passage 2F112 and the auxiliary air cylinder pressure passage 3F113 are connected, and the auxiliary air cylinder pressure is supplied to the brake pneumatic valve 2.

[0022] The switching valve piston 101 and the switching valve rubber plug 102 are equivalent to valve switches. When the spring 3 is relaxed, the valve is open, and when the spring 3 is compressed, the valve is closed. This controls the state of the air circuit according to different braking conditions, thereby reducing the longitudinal impulse caused by pressure changes.

[0023] Example 3 In another embodiment of the present invention, the first switching valve 1 is further provided with a base 132, and the switching valve rubber plug 102 is connected to the base 132 by a spring 3; the base 132 is provided with a brake cylinder pressure output passage 1K121 for communicating with the brake cylinder passage 1Z211, and the brake cylinder pressure output passage 1K121 is connected to the air brake valve brake cylinder pressure output passage.

[0024] When the spring 3 is compressed, the switching valve rubber plug 102 contacts the base 132, cutting off the passage between the brake cylinder pressure output passage 1K121 and the brake cylinder passage 1Z211; when the spring 3 is reset, the passage between the brake cylinder pressure output passage 1K121 and the brake cylinder passage 1Z211 is connected.

[0025] The base 132 and the switching valve rubber plug 102 constitute a valve. The switching valve rubber plug 102 is moved closer to and away from the base 132 by the compression spring 3, thereby opening and closing the valve. The valve controls the passage of the brake cylinder pressure output passage 1K121 and the brake cylinder passage 1Z211.

[0026] Example 4 In another embodiment of the present invention, the brake pneumatic valve piston 201 drives the brake cylinder passage 2Z212 to move via the compression spring 3; When the brake pneumatic valve piston 201 compresses the spring 3, the auxiliary air cylinder pressure passage 3F113 is connected to the brake cylinder passage 2Z212. When the brake pneumatic valve piston 201 moves away from the spring 3 and the spring 3 returns to its original position, the auxiliary air cylinder pressure passage 3F113 is disconnected from the brake cylinder passage 2Z212.

[0027] A passage is provided on the brake pneumatic valve piston 201, which is connected to the brake cylinder passage 2Z212. When the brake pneumatic valve piston 201 compresses the spring 3, the passage is connected to the auxiliary air cylinder pressure passage 3F113. When the brake pneumatic valve piston 201 moves away from the spring 3 and the spring 3 returns to its original position, the connection between the passage and the auxiliary air cylinder pressure passage 3F113 is cut off, so that the brake cylinder passage 2Z212 is not connected to the auxiliary air cylinder pressure passage 3F113.

[0028] Example 5 Another embodiment of the present invention is that the brake cylinder passage 2Z212 is externally connected to a pressure sensor and an exhaust solenoid valve.

[0029] When the pressure sensor detects excessive pressure in the brake cylinder, the exhaust solenoid valve activates to exhaust excess pressurized air from the brake cylinder, stabilizing the pressure within a safe range.

[0030] Example 6 Another embodiment of the present invention is a switching valve control method with electro-pneumatic emergency pressure holding function. The braking system has two modes: electro-pneumatic braking mode and air emergency braking mode. In order to keep the pressure of the brake cylinder stable during electro-pneumatic braking and avoid longitudinal impulse problems, the following settings are made. When the braking system is in electro-pneumatic braking mode, the pressurized air in the auxiliary air cylinder is injected into the upper end of the first switching valve 1 through the auxiliary air cylinder pressure passage 1F111. The switching valve piston 101 overcomes the action of the spring 3 and compresses the spring 3 downward, causing the switching valve rubber plug 102 to contact the base 132, cutting off the connection between the brake cylinder pressure output passage 1K121 and the brake cylinder passage 1Z211. At the same time, as the switching valve piston 101 moves downward, it drives the switching valve air groove 131 to move downward, connecting the auxiliary air cylinder pressure passage 2F112 and the auxiliary air cylinder pressure passage 3F113. The pressurized air in the auxiliary air cylinder is introduced into the brake pneumatic valve 2, causing the brake pneumatic valve piston 201 to move upward, connecting the auxiliary air cylinder pressure passage 3F113 and the brake cylinder passage 2Z212. At this time, the pressurized air in the auxiliary air cylinder is injected into the brake cylinder through the auxiliary air cylinder pressure passage 2F112, the auxiliary air cylinder pressure passage 3F113 and the brake cylinder passage 2Z212, completing the braking.

[0031] In electro-pneumatic braking mode, when the train brakes, when the pressure in the brake cylinder reaches the preset pressure, the brake pneumatic valve piston 201 moves down, cutting off the passage between the auxiliary air cylinder pressure passage 3F113 and the brake cylinder passage 2Z212, stopping the air supply to the brake cylinder, and the train is in a pressure-holding state, and the train stops moving.

[0032] Example 7 In another embodiment of the present invention, when the air brake is applied in an emergency, the air brake valve will output a large brake cylinder pressure to the brake cylinder pressure output passage 1K121. The brake cylinder pressure works together with the spring 3 to make the switching valve piston 101 move upward against the auxiliary air cylinder pressure, so that the brake cylinder pressure output passage 1K121 is connected to the brake cylinder passage 1Z211, and air is supplied to the brake cylinder through the brake cylinder passage 2Z212.

[0033] The brake cylinder pressure output passage 1K121 is connected to an external air brake valve. In emergency braking situations, the air brake valve outputs pressure to the brake cylinder pressure output passage 1K121 to perform emergency braking.

[0034] Example 8 In another embodiment of the present invention, if the braking system is already in an electro-pneumatic emergency braking state, the brake cylinder has corresponding pressure. The pressure sensor connected to the brake cylinder passage 2Z212 detects that the pressure exceeds the upper limit set by the electro-pneumatic emergency braking system, and the exhaust solenoid valve is activated to exhaust the excess pressurized air.

[0035] The pressure sensor detects the pressure in the brake cylinder and sets an upper pressure limit based on the specific application scenario. When the pressure sensor detects that the pressure in the brake cylinder exceeds the set upper pressure limit, it transmits a signal to the exhaust solenoid valve. The exhaust solenoid valve then activates to release the pressurized air from the brake cylinder, preventing excessive pressure and ensuring the safety of the switching valve. This stabilizes the brake cylinder pressure within the set range for electro-pneumatic emergency braking, preventing it from overlapping with air braking and ensuring a smooth stop for the train.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A switching valve structure with electro-pneumatic emergency pressure maintenance function, characterized in that, The switching valve includes a first switching valve and a brake pneumatic valve, both of which are connected to the auxiliary air cylinder and the brake cylinder. The first switching valve has an auxiliary air cylinder pressure passage 1F and a brake cylinder passage 1Z; the auxiliary air cylinder pressure passage 1F is connected to the auxiliary air cylinder, and the air source charges the auxiliary air cylinder through the auxiliary air cylinder pressure passage 1F. The pneumatic brake valve has a brake cylinder passage 2Z, and the brake cylinder passage 2Z and the brake cylinder passage 1Z are connected to the brake cylinder through an external air passage. The first switching valve is equipped with a switching valve piston and a switching valve rubber plug, and the brake pneumatic valve is equipped with a brake pneumatic valve piston. The switching valve piston, the switching valve rubber plug, and the brake pneumatic valve piston are used to move according to the pressure change in the air circuit.

2. The switching valve structure with electro-pneumatic emergency pressure maintenance function according to claim 1, characterized in that, The switching valve piston and the switching valve rubber plug are connected by a spring. The switching valve piston has a switching valve air groove. When the spring is compressed, the switching valve air groove moves in the direction that the spring is compressed. The switching valve air groove is connected to the auxiliary air cylinder pressure passage 2F and auxiliary air cylinder pressure passage 3F on the auxiliary air cylinder.

3. The switching valve structure with electro-pneumatic emergency pressure maintenance function according to claim 2, characterized in that, The first switching valve is also equipped with a base, and the switching valve rubber plug is connected to the base by a spring; the base is equipped with a brake cylinder pressure output passage 1K, which is used to connect with the brake cylinder passage 1Z. When the spring is compressed, the switching valve rubber plug contacts the base, cutting off the passage between the brake cylinder pressure output passage 1K and the brake cylinder passage 1Z; when the spring is reset, the passage between the brake cylinder pressure output passage 1K and the brake cylinder passage 1Z is connected.

4. The switching valve structure with electro-pneumatic emergency pressure maintenance function according to claim 3, characterized in that, The piston of the pneumatic brake valve moves the brake cylinder passage 2Z via a compression spring. When the brake pneumatic valve piston compresses the spring, the auxiliary air cylinder pressure passage 3F is connected to the brake cylinder passage 2Z. When the piston of the brake pneumatic valve moves away from the spring and the spring returns to its original position, the auxiliary air cylinder pressure passage 3F is cut off from the brake cylinder passage 2Z.

5. A switching valve structure with electro-pneumatic emergency pressure maintenance function according to claim 4, characterized in that, The brake cylinder passage 2Z is ​​connected to an external pressure sensor and an exhaust solenoid valve.

6. A control method for a switching valve with electro-pneumatic emergency pressure holding function, using the switching valve structure with electro-pneumatic emergency pressure holding function as described in any one of claims 1-5, characterized in that, When the braking system is in electro-pneumatic braking mode, the pressurized air in the auxiliary air cylinder is injected into the upper end of the first switching valve through the auxiliary air cylinder pressure passage 1F. The switching valve piston overcomes the spring and compresses the spring downward, causing the switching valve rubber plug to contact the base, cutting off the connection between the brake cylinder pressure output passage 1K and the brake cylinder passage 1Z. At the same time, as the switching valve piston moves downward, it drives the switching valve air groove to move downward, connecting the auxiliary air cylinder pressure passage 2F and the auxiliary air cylinder pressure passage 3F. The pressurized air in the auxiliary air cylinder is introduced into the brake pneumatic valve, causing the brake pneumatic valve piston to move upward, connecting the auxiliary air cylinder pressure passage 3F and the brake cylinder passage 2Z. At this time, the pressurized air in the auxiliary air cylinder is injected into the brake cylinder through the auxiliary air cylinder pressure passage 2F, the auxiliary air cylinder pressure passage 3F and the brake cylinder passage 2Z, completing the braking.

7. A switching valve control method with electro-pneumatic emergency pressure maintenance function according to claim 6, characterized in that, When the air brake is applied in an emergency, the air brake valve will output a large brake cylinder pressure to the brake cylinder pressure output passage 1K. The brake cylinder pressure, together with the spring, causes the switching valve piston to move upward against the auxiliary air cylinder pressure, so that the brake cylinder pressure output passage 1K is connected to the brake cylinder passage 1Z, and air is supplied to the brake cylinder through the brake cylinder passage 2Z.

8. A switching valve control method with electro-pneumatic emergency pressure maintenance function according to claim 7, characterized in that, If the braking system is already in electro-pneumatic emergency braking state, the brake cylinder has the corresponding pressure. The pressure sensor connected to the brake cylinder passage 2Z detects that the pressure exceeds the upper limit set by the electro-pneumatic emergency braking system, and the exhaust solenoid valve is activated to exhaust the excess pressurized air.

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