Gravity pressure-stabilizing exhaust expansion tank for engine cooling system

Abstract

The invention discloses a gravity pressure-stabilizing exhaust expansion water tank for an engine cooling system, which comprises a water tank body, a cooling liquid inlet arranged on the side wall of the water tank body and a cooling liquid outlet arranged at the bottom of the water tank body; the exhaust pressure stabilizing unit is arranged on the upper portion of the water tank body and comprises an exhaust cavity communicated with the interior of the water tank body, a piston in sliding sealing fit with the inner wall of the exhaust cavity, a piston rod with the lower portion connected with the piston and the upper portion extending to the position above the exhaust cavity and a counterweight assembly arranged on the upper portion of the piston rod. And the exhaust cavity is provided with an exhaust port. According to the expansion water tank, the exhaust pressure is adjustable, the exhaust pressure provided by the counterweight assembly is constant, the exhaust sensitivity is improved, and then the cooling efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a gravity-pressure-stabilized exhaust expansion tank for an engine cooling system. Background Technology

[0002] During engine bench testing, phenomena such as localized boiling and insufficient vapor-liquid separation often occur within the cooling system, particularly in the high-temperature areas of the cylinder head and the hot end of the EGR cooler. Air bubbles carried in the high-temperature coolant accumulate in large quantities inside the water jacket, causing a sharp rise in localized temperature, leading to uneven cooling, increased localized thermal stress, and abnormal experimental data. To promptly expel these vaporized gases, engines typically have a degassing connector installed in the hot-end water passages, which is then connected to the expansion tank.

[0003] Most existing expansion tanks use spring-loaded pressure relief valves to achieve pressure stabilization and venting, with the venting pressure determined by the spring stiffness, such as the automatic pressure-stabilizing expansion tank cover disclosed in Chinese patent CN205117483U. However, this structure has the following shortcomings:

[0004] (1) The spring stiffness decays with temperature and usage time due to fatigue, resulting in exhaust pressure drift and poor long-term stability;

[0005] (2) The opening characteristics of the spring valve are relatively steep, and pressure fluctuations are likely to occur during the exhaust process, which is not conducive to the precise control of system pressure in bench tests.

[0006] (3) When local boiling is intense, the spring valve is limited by its structural characteristics and its exhaust response is not sensitive enough, which can easily lead to gas accumulating inside the engine for a long time, affecting the stability of the experiment or even damaging the engine. Summary of the Invention

[0007] To address the problems of existing technologies, the present invention aims to provide a gravity-controlled, pressure-stabilized exhaust expansion tank for engine cooling systems, which offers high stability and adjustable exhaust pressure.

[0008] Based on the above problems, the technical solution provided by the present invention is as follows:

[0009] Gravity-stabilized exhaust expansion tank for engine cooling systems includes:

[0010] The water tank body has a coolant inlet on its side wall and a coolant outlet at its bottom.

[0011] An exhaust pressure stabilizing unit is disposed on the upper part of the water tank body, including an exhaust chamber communicating with the interior of the water tank body, a piston that slides and seals with the inner wall of the exhaust chamber, a piston rod whose lower part is connected to the piston and whose upper part extends to the top of the exhaust chamber, and a counterweight assembly disposed on the upper part of the piston rod. The exhaust chamber has an exhaust port.

[0012] In one embodiment, a guide component is fixed to the upper end of the exhaust chamber, the guide component having a guide groove that runs vertically through the chamber, and the piston rod passes through the guide groove.

[0013] In one embodiment, the exhaust chamber is a cylindrical structure and is integrally formed on the upper end of the water tank body.

[0014] In one embodiment, a limit nut is fixed to the upper part of the piston rod, and the counterweight assembly is sleeved on the piston rod with its lower end abutting against the limit nut.

[0015] In one embodiment, the counterweight assembly includes several counterweight blocks stacked vertically.

[0016] In one embodiment, the exhaust port is provided with an upwardly bent exhaust pipe.

[0017] In one embodiment, a liquid level monitoring unit is also included, the liquid level monitoring unit comprising a liquid level gauge arranged along the height direction of the water tank body, a first connecting pipe connecting the lower part of the liquid level gauge to the lower part of the water tank body, and a second connecting pipe connecting the upper part of the liquid level gauge to the upper part of the water tank body.

[0018] In one embodiment, the level gauge is a transparent tube with graduations on its outer wall arranged along the height of the water tank body.

[0019] In one embodiment, a pressure monitoring unit is further included, which is a pressure gauge installed on the upper part of the water tank body, and the pressure measuring end of the pressure gauge is connected to the interior of the water tank body.

[0020] In one embodiment, a replenishment unit is also included, the replenishment unit comprising a water inlet disposed at the upper end of the water tank body and a sealing cap that cooperates with the water inlet.

[0021] Compared with the prior art, the advantages of the present invention are:

[0022] (1) The pressure is stabilized by the gravity of the counterweight assembly, which will not drift over time, overcomes the problem of exhaust pressure change caused by spring fatigue, has high long-term stability, effectively avoids abnormal engine temperature rise caused by local steam resistance and uneven cooling, and improves experimental stability and engine safety.

[0023] (2) High exhaust sensitivity; the pressure increase generated by local boiling can immediately drive the piston to open the exhaust passage, effectively reducing gas accumulation in the cylinder head and high-temperature area, and improving vapor-liquid separation efficiency and cooling efficiency.

[0024] (3) The exhaust pressure is adjustable. The exhaust opening pressure can be changed by adjusting the counterweight mass, which is suitable for bench testing of multiple engine models.

[0025] (4) Equipped with pressure monitoring unit and liquid level monitoring unit, it has pressure visualization and liquid level monitoring capabilities, enabling test personnel to grasp the operating status of the cooling system in real time, and improve test safety and data reliability. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. The accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of an embodiment of the gravity-stabilized exhaust expansion tank for an engine cooling system according to the present invention;

[0028] in:

[0029] 1. Water tank body; 1-1. Coolant inlet; 1-2. Coolant outlet;

[0030] 2. Exhaust chamber;

[0031] 3. Piston;

[0032] 4. Piston rod;

[0033] 5. Counterweight;

[0034] 6. Guide components;

[0035] 7. Limit nut;

[0036] 8. Exhaust pipe;

[0037] 9. Level gauge;

[0038] 10. First connecting tube;

[0039] 11. Second connecting pipe;

[0040] 12. Pressure gauge;

[0041] 13. Water injection port;

[0042] 14. Sealing cap. Detailed Implementation

[0043] The above-described solution will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. The implementation conditions used in the embodiments may be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are generally those in routine experiments.

[0044] See Figure 1 The diagram below is a schematic representation of an embodiment of the present invention. A gravity-regulated exhaust expansion tank for an engine cooling system is provided, comprising a tank body 1, and an exhaust pressure regulating unit, a liquid level monitoring unit, a pressure monitoring unit, and a liquid replenishment unit disposed on the tank body 1.

[0045] The water tank body 1 is a three-dimensional container structure for holding coolant, made of stainless steel. A coolant inlet 1-1 is provided on the side wall of the water tank body 1 to receive high-temperature liquid-gas mixture fluid from the hot end of the engine cylinder head or the degassing connector of the hot end of the EGR cooler. A coolant outlet 1-2 is provided at the bottom of the water tank body 1, communicating with the inlet of the test bench's circulating water system to achieve coolant return.

[0046] The exhaust pressure stabilizing unit is located on the upper part of the water tank body 1. It includes an exhaust chamber 2 communicating with the interior of the water tank body 1, a piston 3 that slides and seals against the inner wall of the exhaust chamber 2, a piston rod 4 connected to the piston 3 at the bottom and extending to the exhaust chamber 2 at the top, and a counterweight assembly located on the upper part of the piston rod 4. An exhaust port is provided on the exhaust chamber 2. When the air pressure inside the water tank body 1 changes, the piston 3 moves up and down in the exhaust chamber 2. When the piston 3 moves above the exhaust port, the gas inside the water tank body 2 can be discharged through the exhaust port. When the air pressure inside the water tank body 2 stabilizes, the piston 3 descends below the exhaust port under the action of gravity, thereby stabilizing the air pressure inside the water tank body 1.

[0047] In this example, the exhaust chamber 2 is a cylindrical structure and is integrally formed on the upper end of the water tank body 1. The piston 3 is made of stainless steel or aluminum alloy and is sealed with a sealing ring between it and the inner wall of the exhaust chamber 2.

[0048] To further optimize the implementation effect of the present invention and avoid the piston rod 4 from deviating and getting stuck during the up and down movement, a guide component 6 is fixed at the upper end of the exhaust chamber 2. The guide component 6 has a guide groove that runs through the upper and lower parts. The piston rod 4 passes through the guide groove. When the piston 3 moves up and down, the piston rod 4 can move up and down along the guide component 6 to avoid the problem of deviating.

[0049] To facilitate the installation of the counterweight assembly, a limit nut 7 is fixed on the piston rod 4. The counterweight assembly is sleeved on the piston rod 4 and its lower end abuts against the limit nut 7. Specifically, the upper part of the piston rod 4 can be a threaded rod body, and the limit nut 7 is threadedly connected to the threaded rod body.

[0050] The counterweight assembly provides a constant downward force to create the exhaust initiation pressure. It consists of several counterweight blocks 5 stacked vertically, each with a through-hole for mounting on the piston rod 4. When the pressure in the gas phase space inside the water tank 1 rises to a value greater than the ratio of the counterweight's weight to the effective pressure-bearing area of ​​the piston 3, the piston 3 moves upward to open the exhaust passage; when the pressure drops, the piston 3 moves downward to close the exhaust passage, thus achieving automatic pressure stabilization and exhaust.

[0051] The exhaust opening pressure P_start satisfies the balance relationship:

[0052]

[0053] in,

[0054] m - The total mass of the counterweight and piston rod, etc.

[0055] A - Effective pressure-bearing area of ​​the piston;

[0056] g - gravitational acceleration.

[0057] By adjusting the mass m of the counterweight 5 or the diameter of the piston 3 to change A, the exhaust pressure can be flexibly adjusted to adapt to different engine types and test conditions.

[0058] To improve exhaust safety, an upward-bent exhaust pipe 8 is provided at the exhaust port.

[0059] The liquid level monitoring unit is used to visually display the liquid level inside the water tank body 1. It includes a liquid level gauge 9 arranged along the height direction of the water tank body 1, a first connecting pipe 10 connecting the lower part of the liquid level gauge 9 to the lower part of the water tank body 1, and a second connecting pipe 11 connecting the upper part of the liquid level gauge 9 to the upper part of the water tank body 1. The liquid level gauge 9 is a transparent tube and has scale lines arranged along the height direction of the water tank body 1 on its outer wall.

[0060] The pressure monitoring unit is used to monitor the pressure changes of the engine cooling system. Specifically, the pressure monitoring unit is a pressure gauge 12 installed on the upper end of the water tank body 1, and the measuring end of the pressure gauge 12 is connected to the inside of the water tank body 1.

[0061] The coolant replenishment unit is used for replenishing and maintaining the coolant in the water tank body 1. It includes a water inlet 13 provided on the water tank body 1 and a sealing cap 14 that cooperates with the water inlet 13. The sealing cap 14 is detachably provided on the water inlet 13.

[0062] The working principle of this invention is as follows:

[0063] During engine operation, air bubbles enter the water tank body 1 along with the liquid and complete vapor-liquid separation inside; when the internal pressure of the water tank body 1 increases, the piston 3 moves upward to above the exhaust port under the action of air pressure to open the exhaust passage and release gas; after the pressure decreases, the piston 3 descends to below the exhaust port to automatically close the exhaust passage and achieve system pressure stabilization.

[0064] In summary, this expansion tank can adjust the exhaust pressure as needed, and the exhaust pressure is constant, solving the problems of insensitive exhaust response and difficulty in local gas accumulation, and improving the gas-liquid separation efficiency.

[0065] The above examples are merely illustrative of the technical concept and features of the present invention, intended to enable those skilled in the art to understand the content of the invention and implement it accordingly, and should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A gravity regulated vented expansion tank for an engine cooling system, characterized by, The application relates to a water tank, which comprises the following parts: a water tank body, the side wall of which is provided with a cooling liquid inlet and the bottom of which is provided with a cooling liquid outlet; an exhaust pressure stabilizing unit arranged on the upper part of the water tank body, which comprises an exhaust cavity in communication with the inside of the water tank body, a piston in sliding sealing cooperation with the inner wall of the exhaust cavity, a piston rod connected with the piston at the lower part and extending above the exhaust cavity at the upper part, and a counterweight assembly arranged on the upper part of the piston rod, wherein the exhaust cavity is provided with an exhaust port.

2. The gravity-stabilized, pressure-equalized, vented expansion tank for an engine cooling system of claim 1, wherein: The upper end of the exhaust cavity is fixed with a guide component, the guide component is provided with a guide groove penetrating from top to bottom, and the piston rod is arranged in the guide groove.

3. The gravity-primed, vented expansion tank for an engine cooling system of claim 1, wherein: The exhaust cavity is in a cylindrical structure and is integrally formed on the upper end of the water tank body.

4. The gravity-primed, vented expansion tank for an engine cooling system of claim 1, wherein: The upper part of the piston rod is fixed with a limiting nut, and the counterweight assembly is arranged on the piston rod and abuts against the limiting nut at the lower end.

5. The gravity-stabilized, pressure-equalized, drainable expansion tank for an engine cooling system of claim 4, wherein: The counterweight assembly comprises a plurality of counterweight blocks arranged in a stack from top to bottom.

6. The gravity-primed, vented expansion tank for an engine cooling system of claim 1, wherein: The exhaust port is provided with an exhaust pipe which is bent upwards.

7. The gravity-primed, vented expansion tank for an engine cooling system of claim 1, wherein: The water tank further comprises a liquid level monitoring unit, which comprises a liquid level meter arranged along the height direction of the water tank body, a first communication pipe in communication with the lower part of the liquid level meter and the lower part of the water tank body, and a second communication pipe in communication with the upper part of the liquid level meter and the upper part of the water tank body.

8. The gravity-stabilized, pressure-equalized, drainable expansion tank for an engine cooling system of claim 7, wherein: The liquid level meter is a transparent pipe body, and the outer wall of the liquid level meter is provided with scale lines arranged along the height direction of the water tank body.

9. The gravity-primed, vented expansion tank for an engine cooling system of claim 1, wherein: The water tank further comprises a pressure monitoring unit, which is a pressure gauge installed on the upper end of the water tank body, and the pressure measuring end of the pressure gauge is in communication with the inside of the water tank body.

10. The gravity-primed, vented expansion tank for an engine cooling system of claim 1, wherein: The water tank further comprises a liquid supplementing unit, which comprises a water inlet arranged on the upper end of the water tank body and a sealing cover matched with the water inlet.

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