Spray wall impingement testing device

Abstract

The invention provides a spray wall impingement testing device which is characterized in that a supporting base station is arranged in a constant volume bomb, and an accommodating cavity is reserved in the supporting base station; the characteristic piston is matched with the simulation cylinder sleeve, the oil sprayer is arranged in the simulation cylinder sleeve, a moving part is arranged at the bottom end of the characteristic piston, and position limiting is carried out through an annular boss arranged on the moving part; the buffer is arranged on the supporting base table, one end of the buffer can make contact with the annular boss, the other end of the buffer is connected with the limiting stopper arranged on the side wall of the constant volume bomb, and the limiting stopper is matched with the annular boss. The cam ejector rod mechanisms are arranged on the two sides of the supporting base table. A winding shaft and a transmission mechanism are arranged at the output end of the driving component, a traction rope is arranged on the winding shaft and connected with the moving part, an energy storage spring is further arranged at the bottom of the moving part, and the transmission mechanism is connected with the cam ejector rod mechanism. According to the invention, the flow field characteristics in the engine cylinder can be simulated in the constant volume bomb, and the squish flow in the cylinder can be well reduced.

Description

Technical Field

[0001] This application belongs to the technical field of piston engines for drones, and particularly relates to a spray wall-impingement test device. Background Technique

[0002] Due to reasons such as high technical maturity, low manufacturing cost, and low fuel consumption rate, piston engines have certain technical advantages in the power systems of medium and large-sized drones with long endurance. However, the altitude range of drone applications is very large, and the variation range of injection timing in engine calibration is much larger than that in vehicle working conditions. This will cause a large difference in the distribution of in-cylinder mixture, which will have an important impact on engine output power, fuel consumption rate, etc. Therefore, in the engine development stage, it is necessary to consider the spray process generated by a large variation range of injection timing, especially the accurate test of the spray wall-impingement process.

[0003] In the prior art, an optical engine can easily obtain the spray or even the ignition process from a single perspective, but it is difficult to obtain images from two perspectives that are 90° to each other; while a traditional constant-volume combustion bomb can obtain images from two perspectives that are 90° to each other, but it can only achieve the similarity of temperature, pressure, and the state of the wall of the limited space and the in-cylinder of the engine, and it is difficult to obtain the interaction between the in-cylinder flow field and the spray process. Summary of the Invention

[0004] In view of this, this application aims to propose a spray wall-impingement test device that can obtain a spray development and fuel spray wall-impingement process more similar to the in-cylinder flow field of the engine in a constant-volume bomb device, which can effectively support the development and application of the engine combustion system.

[0005] To achieve the above object, the technical solution of this application is realized as follows:

[0006] This application provides a spray wall-impingement test device, including:

[0007] A constant-volume bomb, in which a support base is provided, and a receiving cavity is reserved in the support base;

[0008] A cylinder simulation component, which includes a simulated cylinder liner, an injector, and a characteristic piston. The characteristic piston is matched with the simulated cylinder liner. The injector is arranged in the simulated cylinder liner and is located above the characteristic piston. A moving part is arranged at the bottom end of the characteristic piston. The moving part penetrates the support base and is position-limited by an annular boss arranged thereon to prevent it from separating out of the receiving cavity;

[0009] A buffer, which is arranged on the support base. One end of the buffer can contact the annular boss, and the other end of the buffer is connected to a limiter arranged on the side wall of the constant-volume bomb. The limiter is matched with the annular boss;

[0010] A cam tappet mechanism, and the cam tappet mechanism is arranged on both sides of the support base;

[0011] A driving member, a hoisting shaft and a transmission mechanism are arranged at the output end of the driving member, a towing rope is arranged on the hoisting shaft, the towing rope is connected with the moving member, an energy storage spring is further arranged at the bottom of the moving member, the transmission mechanism is connected with the cam tappet mechanism, the driving member is controlled to start, driving the cam tappet mechanism to act, and the cam tappet mechanism contacts the limiter to generate a reference signal for controlling the fuel injector to inject fuel.

[0012] Further, a port is opened in the middle of the support base, and the limiter is insulated and hinged to the side wall of the constant volume bullet and is located at the port;

[0013] The bottom edge position of the annular boss is arc-shaped, and an arc-shaped structure matching the annular boss is arranged on the limiter.

[0014] Further, the number of the buffers is two, the buffer includes a buffer member, a buffer spring is arranged between the buffer member and the inner top wall of the support base to offset the kinetic energy carried by the moving member, and the other end of the buffer member is connected with the limiter through a flexible connection rope;

[0015] The flexible connection rope moves up and down through a fixed pulley arranged on the support base.

[0016] Further, the cam tappet mechanism includes a transmission shaft, a cam and a tappet, the transmission shaft is rotatably arranged on the support base, the cam is fixedly arranged on the transmission shaft, a receiving groove is opened on the side wall of the constant volume bullet, and the tappet is slidably arranged in the receiving groove, and the tappet is driven to move up and down by the cam.

[0017] Further, a cavity is reserved between the support base and the bottom of the constant volume bullet;

[0018] The driving member includes a driving motor, the output shaft end of the driving motor is connected with a driving shaft through a speed reducer, the hoisting shaft is arranged on the driving shaft, and the hoisting shaft is located in the cavity, and the towing rope passes through the support base and is fixedly connected with the moving member.

[0019] Further, a first gear is arranged on the driving shaft, and the first gear meshes with a second gear arranged on the transmission shaft to drive the cam to rotate.

[0020] Further, the ejector rod is made of metal, and a +5V power signal line is provided inside the stopper. In response to the contact between the ejector rod and the stopper, the voltage between the stopper and the constant volume bomb is zero. In response to the disconnection between the ejector rod and the stopper, the voltage between the stopper and the constant volume bomb is 5V.

[0021] Further, a visual window is provided on the outer wall of the constant volume bomb, and the simulation cylinder liner and the characteristic piston are made of transparent tempered glass.

[0022] Compared with the prior art, the spray wall-impingement test device of the present application has the following beneficial effects:

[0023] (1) The present application can achieve the degree of simulating the in-cylinder flow field in the constant volume bomb with a relatively low processing cost, and can better restore the in-cylinder squish flow. For engines with weak in-cylinder vortex and tumble flows, the similarity of the restored in-cylinder flow field is extremely high.

[0024] (2) Compared with ordinary constant volume bombs, the test device of the present application can also conduct visual research on influencing factors such as engine speed, injection timing, and combustion chamber wall shape in addition to temperature and pressure. The manufacturing and use costs are much lower than those of optical engines.

[0025] (3) When the test device of the present application conducts visual research on different engine speeds, pistons with different cylinder diameters, and combustion chambers with different shapes, it is convenient to maintain and replace relevant parts, which is beneficial to shortening the test time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0027] Figure 1 is a plan sectional view of a spray wall-impingement test device according to an embodiment of the present application.

[0028] DESCRIPTION OF THE REFERENCE NUMERALS

[0029] 1 - Constant volume bomb; 2 - Support base; 3 - Simulation cylinder liner; 4 - Injector; 5 - Characteristic piston; 6 - Moving part; 7 - Buffer; 8 - Stopper; 9 - Transmission shaft; 10 - Cam; 11 - Ejector rod; 12 - Driving motor; 13 - Reduction gearbox; 14 - Driving shaft; 15 - Hoisting shaft; 16 - Traction rope; 17 - First gear; 18 - Second gear; 19 - Energy storage spring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] To make the objectives, technical solutions, and advantages of this application more clear and understandable, the following further elaborates on this application in detail with reference to specific embodiments and the accompanying drawings.

[0031] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the embodiments of this application should have the ordinary meanings understood by those with ordinary skills in the field to which this application belongs. The "first", "second", and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The terms such as "connected" or "linked" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right", etc. are only used to represent relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0032] Please refer to Figure 1 As shown, this embodiment provides a spray wall-impact test device, a constant-volume bomb 1, in which a support base 2 is provided, and a receiving cavity is reserved in the support base 2;

[0033] A cylinder simulation component, which includes a simulation cylinder liner 3, an injector 4, and a characteristic piston 5. The characteristic piston 5 cooperates with the simulation cylinder liner 3. The injector 4 is arranged in the simulation cylinder liner 3 and is located above the characteristic piston 5. A moving part 6 is arranged at the bottom end of the characteristic piston 5. The moving part 6 penetrates through the support base 2 and is position-limited by a ring-shaped boss provided thereon to prevent it from detaching outside the receiving cavity;

[0034] A buffer 7 is arranged on the support base 2. One end of the buffer 7 can contact the ring-shaped boss, and the other end of the buffer 7 is connected to a stopper 8 arranged on the side wall of the constant-volume bomb 1. The stopper 8 cooperates with the ring-shaped boss;

[0035] A cam push rod mechanism is arranged on both sides of the support base 2;

[0036] A driving component, the output end of the driving component is provided with a hoisting shaft 15 and a transmission mechanism. A traction rope 16 is arranged on the hoisting shaft 15. The traction rope 16 is connected to the moving part 6. A energy storage spring 19 is also arranged at the bottom of the moving part 6. The transmission mechanism is connected to the cam push rod mechanism. Controlling the driving component to start drives the cam push rod mechanism to act. The cam push rod mechanism contacts the stopper 8 to generate a reference signal for controlling the injector 4 to inject fuel.

[0037] Specifically, in this embodiment, a characteristic piston 5 is installed at the upper end of the moving part 6, and it obtains the required speed under the action of the energy storage spring 19 and enters the simulation cylinder liner 3. The fuel injector 4 adjusts the fuel injection timing according to the disconnection interval time between the limiter 8 and the cam push rod mechanism, and a spray development and fuel jet impingement process more similar to the in-cylinder flow field of the engine can be obtained in the constant volume bomb 1 device, which can effectively support the development and application of the engine combustion system.

[0038] In some embodiments, a port is provided in the middle of the support base 2. The limiter 8 is installed on the side wall of the constant volume bomb 1 in an insulated hinged manner and is located at the port. The setting height of the port can be determined according to the actual situation, and the lower edge position of the port can effectively limit the limiter 8.

[0039] The bottom edge position of the annular boss is arc-shaped, and the limiter 8 is provided with an arc-shaped structure that cooperates with the annular boss.

[0040] The number of the buffers 7 is two. The buffer 7 includes a buffer member. A buffer spring is provided between the buffer member and the inner top wall of the support base 2 to offset the kinetic energy carried by the moving part 6. The other end of the buffer member is connected to the limiter 8 through a flexible connection rope.

[0041] The flexible connection rope moves up and down through a fixed pulley provided on the support base 2.

[0042] Specifically, in this embodiment, the limiter 8 is a lever structure insulated and hinged on the constant volume bomb 1. The upper edge of the end close to the annular boss is a smooth arc-shaped surface, and the upper end surface of the end far from the annular boss is connected to the buffer 7 through a flexible connection rope. When the moving part 6 moves downward, it will present an avoidance state with the inside low and the outside high under the action of the self-weight of the buffer 7. When the moving part 6 moves below the limiter 8 and is not pulled, the limiter 8 will maintain a horizontal limiting state with the inside and outside at the same height under the action of the cam push rod mechanism. When the cam push rod mechanism disengages from the limiter 8, it presents a signal state with the inside high and the outside low. Since the cam push rod mechanism disengages from the limiter 8, the voltage acting between the limiter 8 and the cam push rod mechanism will change, and this signal is used as the reference signal for controlling the fuel injector 4.

[0043] It should be noted that the buffer member of the buffer 7 is located in the accommodation cavity. A buffer spring is provided between the base of the buffer member and the top wall of the accommodation cavity, and the base is connected to the limiter 8 through a flexible connection rope. Among them, the flexible connection rope realizes the stretching with the limiter 8 through a fixed pulley provided on the support base 2.

[0044] In some embodiments, the cam tappet mechanism includes a transmission shaft 9, a cam 10, and a tappet 11. The transmission shaft 9 is rotatably arranged on the support base 2, the cam 10 is fixedly arranged on the transmission shaft 9, a receiving groove (the receiving groove is not shown in the drawings) is formed on the side wall of the constant volume bullet 1, and the tappet 11 is slidably arranged in the receiving groove. The tappet 11 is driven to move up and down by the cam 10.

[0045] A cavity is also reserved between the support base 2 and the bottom of the constant volume bullet 1. The driving member includes a driving motor 12. The output shaft end of the driving motor 12 is connected to a driving shaft 14 through a reduction gearbox 13. A hoisting shaft 15 is arranged on the driving shaft 14, and the hoisting shaft 15 is located in the cavity. A traction rope 16 passes through the support base 2 and is fixedly connected to the moving part 6.

[0046] A first gear 17 is arranged on the driving shaft 14, and the first gear 17 meshes with a second gear 18 arranged on the transmission shaft 9 to drive the cam 10 to rotate.

[0047] Specifically, in this embodiment, the driving motor 12 drives the reduction gearbox 13 to compress the energy storage spring 19 of the traction feature piston 5 to the stopper 8, and then controls the driving motor 12 to reverse and release the steel wire rope for traction. The feature piston 5 will be in a compressed state under the action of the stopper 8. When the feature piston 5 is no longer controlled by the stopper 8, it will accelerate upward under the action of the energy storage spring 19 and enter the transparent simulation cylinder liner 3. When the feature piston 5 reaches the required speed (≤30 m / s) and position for testing, the fuel injector 4 is controlled to inject fuel. At this time, the visualization study of the spray process can be carried out through the visual window of the constant volume bullet 1.

[0048] Furthermore, the driving motor 12 drives the moving part 6 to move, compresses the energy storage spring 19 to store energy to the stopper 8, and then controls the driving motor 12 to reverse and release the steel wire rope connected to the moving part 6. When the driving motor 12 reverses to a sufficient length of the steel wire rope, the tappet 11 supported on the coaxial control first cam 10 starts to move downward. After the stopper 8 loses control of the tappet 11, the moving part 6 starts to accelerate under the action of the energy storage spring 19 and reaches a state that meets the test required speed.

[0049] After the moving part 6 obtains speed, the feature piston 5 installed on the top of the moving part 6 moves rapidly upward in the simulation cylinder liner 3. The potential difference change between the stopper 8 and the ground wire is used to provide the starting moment when the moving part 6 obtains speed. Based on this signal, by adjusting an appropriate time interval, the fuel injection moment of the fuel injector 4 is determined. In this way, the same piston speed as that of the engine and similar in-cylinder flow field characteristics can be obtained. In this state, the development of the restricted wall spray and the wall impingement process in the similar flow field characteristics at different fuel injection moments can be obtained.

[0050] When the moving part 6 reaches near the highest position, it will hit the buffer 7 to decelerate to a speed not higher than 30 m / s. Before the next test, the oil injected last time needs to be evaporated and discharged, and then the motor is controlled again to pull the moving part 6 downward to the stopper 8.

[0051] In some embodiments, the ejector rod 11 is made of metal. There is a +5V power signal line inside the stopper 8. In response to the contact between the ejector rod 11 and the stopper 8, the voltage between the stopper 8 and the constant-volume bullet 1 is zero. In response to the disconnection between the ejector rod 11 and the stopper 8, the voltage between the stopper 8 and the constant-volume bullet 1 is 5V.

[0052] The stopper 8 is internally equipped with a +5V weak-signal line, insulated and hinged to the constant-volume bullet 1. The stopper 8 is processed with a smooth convex arc surface on the upper surface at one end near the annular boss, which is convenient for the moving part 6 to pass through when being pulled downward; the lower surface is a plane to hold the moving part 6. The upper surface of the stopper 8 on the outer side of the accommodating cavity is flexibly connected to the buffer 7, and the lower surface of the stopper 8 contacts but is not connected to the ejector rod 11 at the upper end of the cam 10.

[0053] When the ejector rod 11 moves downward, the two stoppers 8 are pushed by the moving part 6 to present a state of being high in the middle and low on both sides. At this time, the moving part 6 accelerates upward; when the moving part 6 moves downward, the buffer 7 moves downward under its own weight and pulls the stopper 8 to the equilibrium position.

[0054] If pistons with different cylinder diameters need to be tested, or different piston speeds need to be tested, different energy storage springs 19 need to be replaced.

[0055] In terms of power transmission, when the driving motor 12 rotates forward, the hoisting shaft 15 and the first gear 17 on the driving shaft 14 are driven to rotate through the speed reducer 13. The hoisting shaft 15 can pull the moving part 6 and the characteristic piston 5 installed on its top through the steel wire rope. The second gear 18 meshed with the first gear 17 drives the cam 10 on the same axis to rotate. The ejector rod 11 can complete up and down movement in the vertical direction under the action of the cam 10 and its own gravity. The highest position of the ejector rod 11 is Figure 1 the position where the stopper 8 is kept horizontal. The stopper 8 is connected to the buffer 7 through a flexible connecting rope. When the base of the moving part 6 leaves Figure 1 the position and moves downward, the buffer 7 will move downward a certain distance under the action of gravity. At this time, the stopper 8 will reach the position of being high at both ends and low in the middle to make way, which is convenient for the widest part of the moving part 6 to pass through.

[0056] In terms of the motion relationship, when the driving motor 12 rotates forward, the moving part 6 and the characteristic piston 5 installed on its top start to move downward under the pulling force of the steel wire rope, compressing the energy storage spring 19. When the moving part 6 is lower than the stopper 8 in the equilibrium state, the ejector rod 11 is at the highest position at this time. Then, the control motor is reversed, the steel wire rope no longer has pulling force, the base of the moving part 6 moves upward under the push of the energy storage spring 19, and the annular protrusion on the moving part 6 will be caught by the stopper 8.

[0057] When the motor continues to rotate in reverse and the length of the loosened steel wire rope is sufficient to meet the maximum displacement of the moving part 6, the protruding height of the cam 10 in the vertical direction decreases, and the ejector rod 11 moves downward under the action of gravity. After the stopper 8 loses the support of the ejector rod 11, it becomes a state with lower ends and a higher middle, and can no longer restrict the movement of the moving part 6. Under the action of the energy storage spring 19, the moving part 6 begins to accelerate upward. When the ejector rod 11 is completely separated from the stopper 8, an electrical signal will be provided. Based on this signal, the injector 4 changes the injection timing by adjusting the interval time to simulate the spray state at different injection timings corresponding to different piston positions. When the moving part 6 is about to reach the limit position, the annular protrusion will contact the buffer 7, and the buffer spring in the buffer 7 will cancel out the kinetic energy carried by the moving part 6 to prevent the characteristic piston 5 at the top from hitting the injector 4.

[0058] In terms of control, the stopper 8 is installed on the constant volume bomb 1 by insulating hinges. There is a +5V power signal line inside the stopper 8. When the metal ejector rod 11 contacts the stopper 8, the voltage between the stopper 8 and the constant volume bomb 1 is zero. When the ejector rod 11 is disconnected from the stopper 8, the voltage between the stopper 8 and the constant volume bomb 1 is 5V. Taking the moment when the 5V signal appears as a reference, the injection timing of the injector 4 is adjusted by adjusting different time intervals.

[0059] During the test, it is necessary to fill the environment of the constant volume bomb 1 with inert gas at a certain temperature and pressure in advance to simulate the temperature and pressure at the end of compression in the engine cylinder. Then, the characteristic piston 5 is accelerated to the measured speed by the energy storage spring 19, the injection timing is adjusted to open the needle valve of the injector 4, and then the spray development and the process of the fuel jet hitting the wall are photographed by a high-speed camera outside the visual window (the visual window is not shown in the attached drawing). After the characteristic piston 5 stops, wait for the sprayed fuel to fully gasify, and then discharge the gas to perform the next test.

[0060] It should be noted that the simulated cylinder liner 3 and the characteristic piston 5 are made of transparent tempered glass material. The characteristic piston 5 is not a complete entity of the piston, and only the relevant structures inside the head and the pit need to be retained.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

[0062] Embodiments of the present application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the embodiments of the present application shall be included within the protection scope of the present application.

Claims

1. A spray wall impact test device, characterized in that, Comprising: A constant-volume bomb, in which a support base is arranged, and a containing cavity is reserved in the support base; A cylinder simulation component, which includes a simulation cylinder liner, an injector, and a characteristic piston. The characteristic piston is matched with the simulation cylinder liner. The injector is arranged in the simulation cylinder liner and is located above the characteristic piston. A moving part is arranged at the bottom end of the characteristic piston. The moving part penetrates through the support base and is position-limited by an annular boss arranged thereon to prevent it from detaching outside the containing cavity; A buffer, which is arranged on the support base. One end of the buffer can be in contact with the annular boss, and the other end of the buffer is connected to a stopper arranged on the side wall of the constant-volume bomb. The stopper is matched with the annular boss; A cam push rod mechanism, which is arranged on both sides of the support base; A driving component, the output end of which is provided with a winding shaft and a transmission mechanism. A traction rope is arranged on the winding shaft. The traction rope is connected to the moving part. A energy storage spring is also arranged at the bottom of the moving part. The transmission mechanism is connected to the cam push rod mechanism. When the driving component is controlled to start, the cam push rod mechanism is driven to act. The cam push rod mechanism contacts the stopper to generate a reference signal for controlling the injector to inject fuel.

2. A spray wall impact test device according to claim 1, characterized in that: A port is opened in the middle of the support base. The stopper is installed on the side wall of the constant-volume bomb in an insulating hinged manner and is located at the port; The bottom edge position of the annular boss is arc-shaped, and the stopper is provided with an arc-shaped structure matched with the annular boss.

3. A spray wall impact test device according to claim 1, characterized in that: The number of the buffers is two. Each buffer includes a buffer part. A buffer spring is arranged between the buffer part and the inner top wall of the support base to offset the kinetic energy carried by the moving part. The other end of the buffer part is connected to the stopper through a flexible connecting rope; The flexible connecting rope moves up and down through a fixed pulley arranged on the support base.

4. A spray wall impact test device according to claim 1, characterized in that: The cam push rod mechanism includes a transmission shaft, a cam, and a push rod. The transmission shaft is rotatably arranged on the support base. The cam is fixedly arranged on the transmission shaft. A containing groove is opened on the side wall of the constant-volume bomb. The push rod is slidably arranged in the containing groove, and the push rod is driven to move up and down by the cam.

5. A spray wall impact test device according to claim 4, characterized in that: A cavity is also reserved between the support base and the bottom of the constant-volume bomb; The driving component includes a driving motor. The output shaft end of the driving motor is connected to a driving shaft through a speed reducer. The winding shaft is arranged on the driving shaft, and the winding shaft is located in the cavity. The traction rope passes through the support base and is fixedly connected to the moving part.

6. A spray wall impact test device according to claim 5, characterized in that: A first gear is arranged on the driving shaft, and the first gear meshes with a second gear arranged on the transmission shaft to drive the cam to rotate.

7. The spray wall impact test device according to claim 1, wherein: The ejector rod is made of metal, and a +5V power signal line is arranged inside the stopper. In response to the contact between the ejector rod and the stopper, the voltage between the stopper and the constant volume bomb is zero. In response to the disconnection between the ejector rod and the stopper, the voltage between the stopper and the constant volume bomb is 5V.

8. The spray wall impact test device according to claim 1, wherein: A visual window is formed on the outer wall of the constant volume bomb, and the simulated cylinder liner and the characteristic piston are made of transparent tempered glass.

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