A valve for compressed natural gas cylinder for vehicle with new type flow limiting device

Abstract

The utility model discloses a kind of compressed natural gas bottle valves for vehicle with novel current-limiting device, including valve body, the upper end middle part position of valve body has gas outlet, the gas outlet is communicated with in valve body and has gas passage, valve body lower end is equipped with current-limiting device, current-limiting device includes the shell that is fixed in valve body lower end and is penetrated from top to bottom, a spring seat that is penetrated from top to bottom is placed in shell, a spring that extends from top to bottom is contained in spring seat, shell upper end has the flow guide passage and air inlet that are distributed from top to bottom, flow guide passage is communicated with gas passage, a piston is placed in shell, piston is composed of conical head and the rod portion located at the bottom of conical head, rod portion extends into spring seat, and spring is sleeved on the outer portion of rod portion, conical head is used to open or block flow guide passage lower end opening, shell lower end is fixed with a locking nut that is penetrated from top to bottom. The utility model reset mechanism is not only fast response, and sensitivity is high, greatly improve the working reliability and stability of CNG bottle valve.

Description

Technical Field

[0001] This utility model relates to the field of industrial gas cylinder valve technology, specifically a vehicle-mounted compressed natural gas cylinder valve with a novel flow limiting device. Background Technology

[0002] Compressed natural gas (CNG) is increasingly used in the automotive industry. CNG vehicles, as an environmentally friendly alternative to traditional gasoline and diesel vehicles, effectively reduce exhaust emissions and lower fuel costs by using CNG. These vehicles are equipped with specially designed fuel systems to achieve efficient CNG storage and injection.

[0003] As a key component used in CNG vehicles, CNG cylinder valves face increasingly stringent technical requirements with the booming development of the automotive industry. During vehicle operation, when the outlet pressure increases instantaneously, it is necessary to quickly and effectively limit the outlet flow to ensure the safe and stable operation of the system. However, existing technologies typically use a flow divider plate plane seal to achieve the flow limiting function. This method has significant shortcomings in practical applications, with poor reset effect after flow limiting and insufficient response, making it difficult to meet the ever-increasing technical demands. Utility Model Content

[0004] In view of the above-mentioned deficiencies of the prior art, the purpose of this utility model is to provide a vehicle compressed natural gas cylinder valve with a novel flow limiting device.

[0005] The technical solution of this utility model is: a vehicle-mounted compressed natural gas cylinder valve with a novel flow-limiting device, comprising a valve body, a valve assembly, a valve stem assembly fixedly connected to the valve assembly, and a handwheel fixedly connected to the valve stem assembly, all mounted on the left end of the valve body; an outlet is located at the middle of the upper end of the valve body; a sealing gasket for opening or blocking the outlet is mounted on the right end of the valve assembly; an outlet channel extending vertically within the valve body for communicating with the outlet is provided; and a flow-limiting device communicating with the outlet channel is mounted on the lower end of the valve body. The flow-limiting device includes components fixed to the lower part of the valve body. The housing is a vertically continuous shell. Inside the shell is a vertically continuous spring seat, and inside the spring seat is a vertically extending spring. The upper end of the shell has vertically distributed guide channels and an air inlet. The guide channels are connected to the air outlet. Inside the shell is a piston, which consists of a conical head and a rod located at the bottom of the conical head. The outer wall of the conical head slides vertically against the inner wall of the shell. The rod extends into the spring seat, and the spring is sleeved outside the rod. The conical head is used to open or block the lower opening of the guide channel. A vertically continuous locking nut is fixed at the lower end of the shell.

[0006] Furthermore, the spring seat has a first through hole extending vertically, and the top of the spring seat has a step, with the conical head of the piston resting against the top of the step.

[0007] Furthermore, the spring is housed in the first through hole, and a pressure ring is fitted onto the lower end of the rod. The spring is secured between the step and the pressure ring, and a retaining ring is fixed to the lower end of the rod, with the retaining ring blocking the bottom of the pressure ring.

[0008] Furthermore, the top of the locking nut rests against the bottom of the spring seat, and the locking nut has a second through hole that runs vertically through it. The lower end of the rod extends into the second through hole, and the second through hole communicates with the first through hole.

[0009] Furthermore, the air inlet is connected to the flow channel, and the outer wall of the cone head is a cone-shaped surface. When the piston moves upward, the cone-shaped surface of the cone head is used to block the lower opening of the flow channel.

[0010] The advantages of the CNG cylinder valve with a novel flow-limiting device provided by this invention are as follows: When the outlet pressure increases instantaneously, the gas pushes the piston upward, causing the conical head at the upper end of the piston to block the lower opening of the flow channel, thereby limiting the flow. After the flow limitation ends, the spring drives the piston to quickly return to its original position, ensuring that the flow channel is unobstructed and guaranteeing the normal gas supply. This reset mechanism is not only responsive but also highly sensitive, able to adapt to changes in outlet pressure in a timely manner, effectively avoiding system failures caused by untimely or incomplete reset, and greatly improving the reliability and stability of the CNG cylinder valve. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0012] Figure 2 This is a schematic diagram of the current limiting device of this utility model.

[0013] As shown in the figure: 1—valve body, 11—air outlet, 12—air outlet channel, 2—valve assembly, 21—sealing gasket, 3—valve stem assembly, 4—handwheel, 5—flow limiting device, 51—housing, 511—flow guide channel, 512—air inlet, 52—spring seat, 521—first through hole, 522—step, 53—spring, 54—piston, 541—conical head, 542—rod, 55—locking nut, 551—second through hole, 56—pressure ring, 57—retaining ring. Detailed Implementation

[0014] To provide a more intuitive and complete understanding of the technical solution of this utility model, the following non-limiting features are described in conjunction with the accompanying drawings:

[0015] like Figure 1 , Figure 2As shown, a vehicle-mounted compressed natural gas cylinder valve with a novel flow-limiting device includes a valve body 1. A valve assembly 2, a valve stem assembly 3 fixedly connected to the valve assembly 2, and a handwheel 4 fixedly connected to the valve stem assembly 3 are mounted on the left end of the valve body 1. An outlet 11 is located at the middle of the upper end of the valve body 1. A sealing gasket 21 for opening or blocking the outlet 11 is mounted on the right end of the valve assembly 2. An outlet channel 12 extending vertically and communicating with the outlet 11 is located inside the valve body 1. A flow-limiting device 5 communicating with the outlet channel 12 is mounted on the lower end of the valve body 1. The flow-limiting device 5 includes a housing 51 fixed to the lower end of the valve body 1 and extending vertically. A vertically extending... A spring seat 52 is provided, and a spring 53 extending vertically is placed inside the spring seat 52. The upper end of the housing 51 has a vertically distributed guide channel 511 and an air inlet 512. The guide channel 511 is connected to the air outlet channel 12. A piston 54 is placed inside the housing 51. The piston 54 consists of a conical head 541 and a rod 542 located at the bottom of the conical head 541. The outer wall of the conical head 541 slides vertically with the inner wall of the housing 51. The rod 542 extends into the spring seat 52, and the spring 53 is sleeved on the outside of the rod 542. The conical head 541 is used to open or block the lower opening of the guide channel 511. A locking nut 55 that extends vertically through the housing 51 is fixed at the lower end.

[0016] like Figure 2 As shown, in order to block the piston 54, the spring seat 52 has a first through hole 521 extending vertically, and the top of the spring seat 52 has a step 522, and the conical head 541 of the piston 54 rests against the top of the step 522.

[0017] like Figure 2 As shown, spring 53 is housed within the first through hole 521. A pressure ring 56 is fitted onto the lower end of rod 542. Spring 53 is engaged between step 522 and pressure ring 56. A retaining ring 57 is fixed to the lower end of rod 542, blocking the bottom of pressure ring 56. When the outlet pressure increases instantaneously, piston 54 moves upward, and pressure ring 56 also moves upward, compressing spring 53. After the air pressure recovers, piston 54 returns to its original position due to the elastic force of spring 53.

[0018] like Figure 2 As shown, in order to prevent the spring seat 52 from falling off, the top of the locking nut 55 rests against the bottom of the spring seat 52. The locking nut 55 has a second through hole 551 that runs vertically through the spring seat 52. The lower end of the rod 542 extends into the second through hole 551, and the second through hole 551 communicates with the first through hole 521.

[0019] like Figure 2As shown, the air inlet 512 is connected to the flow guide channel 511. The outer wall surface of the conical head 541 is conical. When the piston 54 moves upward, the conical surface of the conical head 541 is used to block the lower opening of the flow guide channel 511. When the conical surface contacts the lower opening of the flow guide channel 511, a line contact seal (a linear contact sealing method) can be achieved. Compared with a planar seal, line contact can generate a larger sealing pressure on a smaller contact area. When the piston 54 moves upward, and the conical surface gradually approaches and finally blocks the lower opening of the flow guide channel 511, due to the small contact area, the pressure per unit area is greater under the same force, which can more effectively prevent gas from passing through, thereby enhancing the sealing effect and better realizing the flow restriction function.

[0020] This utility model provides a vehicle-mounted compressed natural gas cylinder valve with a novel flow-limiting device. When the outlet gas pressure increases instantaneously, the gas pushes the piston 54 upward, causing the conical head 541 at the upper end of the piston 54 to block the lower opening of the guide channel 511, thereby limiting the flow. After the flow restriction ends, the spring 53 drives the piston 54 to quickly reset, ensuring that the guide channel 511 is unobstructed and guaranteeing the normal gas supply. This reset mechanism is not only responsive but also highly sensitive, able to adapt to changes in outlet gas pressure in a timely manner, effectively avoiding system failures caused by untimely or incomplete reset, and greatly improving the working reliability and stability of the CNG cylinder valve.

[0021] Of course, the above are only preferred embodiments of the present utility model, and do not limit the patent scope of the present utility model. Any simple modifications and equivalent structural changes made based on the contents of the present utility model specification and drawings should also be included within the patent protection scope of the present utility model.

Claims

1. A vehicle-mounted compressed natural gas cylinder valve with a novel flow-limiting device, comprising a valve body, a valve assembly, a valve stem assembly fixedly connected to the valve assembly, and a handwheel fixedly connected to the valve stem assembly, wherein an outlet is located at the middle of the upper end of the valve body, and a sealing gasket for opening or blocking the outlet is installed at the right end of the valve assembly, characterized in that: The valve body has an outlet channel extending vertically and used to connect to the outlet. A flow limiting device connected to the outlet channel is installed at the lower end of the valve body. The flow limiting device includes a housing fixed at the lower end of the valve body and extending vertically. A spring seat extending vertically is placed inside the housing. A spring extending vertically is placed inside the spring seat. The upper end of the housing has a guide channel and an inlet distributed vertically. The guide channel is connected to the outlet channel. A piston is placed inside the housing. The piston consists of a conical head and a rod located at the bottom of the conical head. The outer wall of the conical head slides vertically with the inner wall of the housing. The rod extends into the spring seat, and the spring is sleeved outside the rod. The conical head is used to open or block the lower opening of the guide channel. A locking nut extending vertically is fixed at the lower end of the housing.

2. The vehicle-mounted compressed natural gas cylinder valve with a novel flow-limiting device according to claim 1, characterized in that: The spring seat has a first through hole extending vertically, and the top of the spring seat has a step, with the conical head of the piston resting against the top of the step.

3. A vehicle-mounted compressed natural gas cylinder valve with a novel flow-limiting device according to claim 2, characterized in that: The spring is housed in the first through hole, and a pressure ring is fitted on the lower end of the rod. The spring is stuck between the step and the pressure ring, and a retaining ring is fixed to the lower end of the rod, which is blocked at the bottom of the pressure ring.

4. A vehicle-mounted compressed natural gas cylinder valve with a novel flow-limiting device according to claim 2, characterized in that: The top of the locking nut rests against the bottom of the spring seat. The locking nut has a second through hole that runs vertically through it. The lower end of the rod extends into the second through hole, and the second through hole communicates with the first through hole.

5. A vehicle-mounted compressed natural gas cylinder valve with a novel flow-limiting device according to claim 1, characterized in that: The air inlet is connected to the flow channel. The outer wall of the conical head is conical. When the piston moves upward, the conical surface of the conical head is used to block the lower opening of the flow channel.

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