A carburetor heat insulation structure for a gasoline engine

Abstract

The present invention belongs to the field of gasoline engines, and in particular, relates to a carburetor heat insulation structure of a gasoline engine. It includes an intake bracket and an intake pipe, one end of the intake pipe is connected to the intake bracket, and the other end is fixedly connected to the cylinder. The intake bracket is arranged on one side of the carburetor, and an intake branch pipe is arranged on the other side opposite to the carburetor. The intake branch pipe and the intake bracket are fixedly connected and the carburetor is clamped. The intake bracket and the intake branch pipe are fixedly connected by screw connection; the intake bracket is fixedly connected by a snap-in insert embedded in the interior thereof and screws; the snap-in insert is a metal part. The present invention can prevent the carburetor part from being still above 58°C after the gasoline engine is shut down; the actual heating of the carburetor is reduced by step-by-step heat conduction; and the anti-seismic performance of the heat insulation structure is improved by segmented connection.

Description

Technical Field

[0001] The invention belongs to the field of gasoline engines, and in particular relates to a carburetor heat insulation structure of a gasoline engine. Background Art

[0002] When a gasoline engine is in normal operation, a large amount of heat is generated by the combustion of the mixed oil in the cylinder, and the temperature of the cylinder spark plug position and the outer periphery of the combustion chamber will reach over 240°C. Since traditional chainsaw gasoline engines are all cooled by the wind generated by the rotation of the flywheel, when the engine is stopped, the fan cooling of the flywheel is lost, and the cylinder temperature can only be reduced by natural cooling. The heat will be dissipated to the surrounding area through direct transfer or radiation. The screws that tighten the carburetor of traditional chainsaw gasoline engines are directly tightened on the cylinder, and the heat is quickly transferred to the carburetor. The temperature of the carburetor exceeds the temperature at which it can work normally, resulting in the gasoline engine being unable to start again in the hot engine state.

[0003] When the carburetor installation structure of the existing chain saw is used in weather with an ambient temperature above 30°C, the temperature of the carburetor will rise to above 58°C 15-25 minutes after the engine is stopped. When it is started again, the fuel will be gasified due to the excessively high temperature of the carburetor, and the engine cannot be started. This is mainly due to the imperfection of the existing carburetor insulation structure. The existing carburetor insulation structure adopts a one-stage connection structure, and the heat is quickly conducted linearly. The carburetor is directly located in the middle section of the linear heat transfer, and the heat dissipation is slow after the temperature rises, resulting in a temperature higher than the normal working temperature.

[0004] The existing technology cannot properly solve the problem of carburetor temperature being too high after the engine stops. For example, in CN2015208729024, a carburetor heat dissipation structure technical solution for a chainsaw adopts a method of setting ventilation holes and a fan to enhance heat dissipation, but the effect of enhancing heat dissipation stops after the engine stops, and good heat dissipation cannot be achieved. Summary of the invention

[0005] In order to solve the problem that the existing gasoline engine cannot effectively dissipate heat through the fan after shutdown, the temperature of the carburetor part quickly rises to higher than the normal working temperature and is difficult to cool down, resulting in the inability to restart in the hot state, and the prior art cannot avoid the overheating of the carburetor or cool it down in the shutdown state of the gasoline engine, the present invention provides a carburetor insulation structure for a gasoline engine.

[0006] The objects of the present invention are:

[0007] 1. Improve the existing carburetor insulation structure to prevent the carburetor from overheating after the gasoline engine is shut down;

[0008] Second, realize jump-type heat transfer through multi-stage structure;

[0009] 3. Improve the seismic performance of the overall insulation structure through multi-section connections.

[0010] To achieve the above objectives, the present invention adopts the following technical solutions.

[0011] A carburetor heat insulation structure for a gasoline engine comprises an intake bracket and an intake pipe, wherein one end of the intake pipe is connected to the intake bracket and the other end is fixedly connected to the cylinder, the intake bracket is arranged on one side of the carburetor, and an intake branch pipe is arranged on the other side opposite to the carburetor, the intake branch pipe is fixedly connected to the intake bracket and clamps the carburetor.

[0012] The air intake bracket and the air intake branch pipe are fixedly connected by screw connection;

[0013] The air intake bracket is fixedly connected by a clamping insert embedded in the air intake bracket and a screw;

[0014] The clamping insert is a metal part.

[0015] As a preference,

[0016] The air intake pipe is made of fluororubber, and the connecting end between the air intake pipe and the cylinder is embedded with metal.

[0017] As a preference,

[0018] A heat insulation pad is arranged between the air intake pipe and the cylinder.

[0019] As a preference,

[0020] Also includes: a housing;

[0021] The shell is composed of a box base and an upper cover, which are fixedly connected to cover the upper and lower sides of the thermal insulation structure.

[0022] As a preference,

[0023] An air guide cover is fixedly connected to the inner side of the upper cover;

[0024] A closed space is formed between the air guide cover and the upper cover, and the closed space is located between the cylinder and the carburetor.

[0025] Preferably, the upper cover is composed of a detachable large cover and a small cover, the air guide cover is fixedly connected to the inner side of the large cover to form a closed space; the large cover is fixedly connected to the box body seat, and the large cover is provided with an open slot;

[0026] The small cover is arranged at the slot to close the slot.

[0027] As a preference,

[0028] The upper cover is composed of a detachable large cover and a small cover;

[0029] The large cover is fixedly connected to the box body seat, and the large cover is provided with an open slot;

[0030] The small cover is arranged at the slot to close the slot.

[0031] The beneficial effects of the present invention are:

[0032] 1) Solved the problem of the chain saw gasoline engine being difficult to start when the ambient temperature is high;

[0033] 2) The actual heat of the carburetor is reduced by step-by-step heat conduction;

[0034] 3) The seismic performance of the insulation structure is improved through segmented connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of an explosion of the heat insulation structure of the present invention;

[0036] Figure 2 is a side cross-sectional schematic diagram of the heat insulation structure of the present invention;

[0037] Figure 3 for Figure 2 A magnified schematic diagram of part A;

[0038] Figure 4 is a top cross-sectional schematic diagram of the heat insulation structure of the present invention;

[0039] Figure 5 for Figure 4 A magnified schematic diagram of part B;

[0040] Figure 6 This is a graph showing the temperature measurement results of each component when the carburetor temperature reaches its peak after improving the thermal insulation structure;

[0041] Figure 7 This is a graph showing the temperature measurement results of each component when the carburetor temperature of the comparison sample structure reaches its peak value;

[0042] Figure 8 This is a curve of temperature change over time after shutdown.

[0043] In the figure: 100 carburetor, 200 intake branch pipe, 300 intake bracket, 301 snap-in insert, 302 snap-in groove, 400 screw, 401-403 screw holes, 403a internal thread, 500 screw, 600 intake pipe, 601 connecting end, 602 snap joint, 700 cylinder, 800 heat insulation pad, 900 box seat, 1000 upper cover, 1001 air guide cover, 1002 large cover, 1002a slot, 1003 small cover. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with specific embodiments and the accompanying drawings. A person of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention involved in the following description are generally only embodiments of a part of the present invention, rather than all embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative work should fall within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be understood that the terms "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, "multiple" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined, and "several" means one or more.

[0046] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all methods known to those skilled in the art.

[0048] Example

[0049] A kind of Figures 1 to 5 The carburetor heat insulation structure of the gasoline engine shown in the figure specifically comprises:

[0050] An intake bracket 300 is arranged on the side of the carburetor 100, and an intake branch pipe 200 is arranged on the other side opposite to the carburetor 100;

[0051] The intake branch pipe 200 and the intake bracket 300 are fixedly connected to achieve relative fixation and clamp the carburetor 100 to achieve clamping and fixing of the carburetor 100. In this embodiment, the intake branch pipe 200 and the intake bracket 300 are fixedly connected by screws 400, and the screws 400 pass through the screw holes 401 of the intake branch pipe 200, the screw holes 402 of the carburetor 100 and the screw holes 403 of the intake bracket 300 in sequence. The inner walls of the screw holes 401 and 402 are both smooth inner walls, and the inner wall of the screw holes 403 is provided with internal threads 403a that cooperate with the screws 400, so that during the installation process, the screws 400 can pass through the screw holes 401 and 402 more simply and efficiently, enter the screw holes 403, and then be tightened and fixed, thereby achieving a fixed connection between the three. The screws 400 are of a semi-threaded structure, and the smooth surfaces that contact the screw holes 401 of the intake branch pipe 200 and the screw holes 402 of the carburetor 100 are installed with heat-insulating sleeves.

[0052] The intake bracket 300 is provided with an intake pipe 600 on the opposite side of the intake bracket 300 connected to the carburetor 100. One end of the intake pipe 600 is fixedly connected to the intake bracket 300, and the other end is fixedly connected to the cylinder 700 by a screw 500.

[0053] The research results obtained by the researchers of the present invention show that in the traditional heat insulation structure, the intake pipe 600 is made of plastic, the intake bracket 300 is not set, and the plastic intake pipe, carburetor 100, and intake branch pipe 200 are directly fixed to the cylinder by long screws; the test found that because the screws used for threaded matching in the traditional heat insulation structure are the main heat conduction structure between the intake pipe 600 and the carburetor 100, a large amount of heat is quickly transferred to the screws 400, the intake pipe 600, and the carburetor 100 through the cylinder 700, causing the carburetor 100 to continuously increase in temperature under multiple temperature conduction conditions. Although threaded matching has the advantages of simple setting, efficient installation, and excellent stability, the existence of the above-mentioned heat conduction defects makes the carburetor 100 more prone to overheating problems;

[0054] Therefore, after improvement, in the present invention, the end of the intake pipe 600 facing the cylinder 700 is fixed with the intake pipe 600 and the cylinder 700 by using a screw 500, the end of the intake pipe 600 facing the intake bracket 300 is provided with a clamping joint 602, and the intake pipe 600 is correspondingly provided with an intake bracket 300, and the central through hole of the intake bracket 300 is provided with a clamping groove 302 adapted to the clamping joint 602;

[0055] A copper clamping insert 301 is provided in the screw hole 403 of the air intake bracket 300, and an internal thread 403a is provided on the inner surface of the clamping insert 301. The clamping insert 301 is provided with a side rib 301a and is clamped and fixed with the air intake bracket 300 through the side rib 301a. In the above structure, except that the connection end 601 between the air intake pipe 600 and the cylinder 700 is a metal plate coated with fluororubber, the rest of the air intake pipe 600 is made of perfluororubber, and the rest of the parts, except the screws which are necessary metal components, are all plastic materials commonly used in the heat insulation structure of the carburetor 100.

[0056] The arrangement of the above connection structure enables the cylinder 700, the intake pipe 600, the intake bracket 300, the carburetor 100 and the intake branch pipe 200 to form a stable connection structure but a discontinuous and jumpy heat conduction form;

[0057] The above structure was used for thermal analysis and detected by Japanese multi-channel data recorder GL840, and compared with a control sample. The difference between the control sample and the above embodiment structure is that the air intake bracket 300 is not provided, the air intake pipe 600 is made of an integrated PPS plastic material, the screw 400 passes through the air intake branch pipe 200, the carburetor 100 and the air intake pipe 600, and is fixed on the cylinder 700. The rest of the parts are exactly the same. The test process first keeps the cylinder 700 working for 30 minutes at an ambient temperature of 35°C, and then shuts down and cools naturally, and monitors the temperature in real time. After 1 minute of shutdown, the temperature of the cylinder 700 is close to 135°C, indicating that the actual test environment is very close, with validity and reliability; the temperature data of the components is recorded every 5 minutes, and the temperature conditions of each component when the carburetor temperature reaches the peak are recorded.

[0058] When the temperature of the carburetor of the above structure in this embodiment reaches the peak value, the temperature of each component is as follows: Figure 6 As shown in the figure, when the carburetor temperature of the comparison sample reaches the peak value, the temperature of each component is as follows: Figure 7 As shown, through Figure 6 and Figure 7 The comparison shows very clearly that Figure 6In the embodiment, due to the use of a fluororubber intake pipe with a smaller thermal conductivity, the temperature difference between the cylinder 700 and the intake bracket 300 is greater; due to the split arrangement, the snap-in insert 301 forms a very good rapid heat conduction component. When the intake pipe 600 conducts heat to the intake bracket 300, due to linear heat conduction, the heat of the intake pipe 600 is quickly conducted to the snap-in insert 301 through the intake bracket 300. Since the snap-in insert 301 is made of copper, it has very good thermal conductivity. , can be quickly transmitted to the intake branch pipe 200 through the screw 400, forming a three-step temperature difference distribution of the intake pipe 600-intake bracket 300 / card insert 301 / intake branch pipe 200-carburetor 100. The temperature of the intake bracket 300 is at a relatively high temperature of about 57.5°C. Similarly, the temperatures of the card insert 301, the screw 400 and the intake branch pipe 200 are also relatively close, forming a temperature ladder, while the temperature of the carburetor 100 is at a lower temperature of about 52.5°C. Figure 6 It can be seen that the high temperature of the intake bracket 300 and the card insert 301 is directly transferred to the intake branch pipe 200 through the screw 400, forming a jumping heat conduction, skipping the carburetor 100 and directly dissipating the heat to the outside, thus achieving good heat insulation protection for the carburetor 100;

[0059] and Figure 7 In the figure, the cylinder 700 directly transfers a large amount of heat to the intake pipe 600 and the carburetor 100 through the screw A, so that the intake pipe 600 is in a high temperature state of about 68°C, which in turn causes the temperature of the carburetor 100 to be also at a high temperature of nearly 65°C, and the temperature of the screw A is close to that of the carburetor 100, indicating that when the intake branch pipe 200, the carburetor 100, and the intake pipe 600 are directly fixed to the cylinder 700 through the screw A, the temperature peak of the carburetor 100 after shutdown is maintained at a relatively high level, and the temperature of the carburetor 100 is close to the temperature of the screw 400, and the overall linear heat conduction from the cylinder 700 to the intake branch pipe 200 is still presented.

[0060] Furthermore,

[0061] The end of the air intake pipe 600 connected to the cylinder 700 of the present invention is also provided with a heat insulation pad 800;

[0062] The thermal insulation pad 800 is arranged between the cylinder 700 and the intake pipe 600, and is provided with a screw hole which cooperates with the screw 500. Due to the setting of the thermal insulation pad 800, an intermediate barrier is formed when the cylinder 700 transfers heat to the intake pipe 600, and at the same time, the small local heat dissipation area formed by the cylinder 700-intake pipe 600 is further increased, so that the temperature of the intake pipe 600 can be further reduced. The test with the same setting as above is carried out. When the thermal insulation pad 800 is set, the temperature of the carburetor 100 is at about 50.5°C. At the same time, the test results show that the existence of the thermal insulation pad 800 reduces the temperature of the intake pipe 600, resulting in an integrated decrease in the temperature of the overall thermal insulation structure.

[0063] Furthermore,

[0064] The heat insulation structure is further provided with a shell, which includes a box seat 900 similar to the traditional heat insulation structure, and an upper cover 1000 improved by the technical solution of the present invention. The box seat 900 and the upper cover 1000 are fixedly connected and clamp the air intake bracket 300. In this embodiment, the box seat 900 and the upper cover 1000 are fixedly connected by self-tapping screws;

[0065] The upper cover 1000 is provided with an air guide 1001 on the inner side thereof, and the air guide 1001 is fixedly mounted on the inner side of the upper cover 1000, and a closed space λ is formed between the air guide 1001 and the upper cover 1000, and the closed space λ is located between the cylinder 700 and the carburetor 100; since the cylinder 700 and the carburetor 100 are both located in the shell in the conventional heat insulation structure, the high temperature of the cylinder 700 is easily directly conducted to the carburetor 100 by means of heat radiation, and the air guide 1001 and the upper cover are connected to each other. The formation of the enclosed space λ between 1000 can act as a "heat-insulating air chamber". In the process of heat radiation conduction from the cylinder 700 to the carburetor 100, it plays a "buffer" role similar to that of the card insert 301 in contact heat conduction, forming a stepped temperature difference and weakening the heat radiation conduction effect. Therefore, after the air guide cover 1001 is set to form the enclosed space λ, the same test as above is carried out, and the temperature of the carburetor 100 drops to only about 47.8°C, which produces a very obvious heat insulation effect.

[0066] At the same time, in order to clean and maintain the entire cylinder 700, the carburetor 100 and the various components of the insulation structure, the upper cover 1000 is composed of a large cover 1002 and a small cover 1003. The large cover 1002 is fixedly connected to the box seat 900 to form a shell, and the air guide cover 1001 is fixedly arranged on the inner side of the large cover 1002 to form a closed space λ. The large cover 1002 is provided with a slot 1002a, and the small cover 1003 is detachably arranged at the slot 1002a of the large cover 1002 to close the slot 1002a of the large cover 1002.

[0067] In addition, in the technical solution of the present invention, the cylinder 700-intake pipe 600-intake bracket 300 forms a one-section fixed connection, and the snap-in insert 301-carburetor 100-intake branch pipe 200 forms a two-section fixed connection, forming a segmented connection structure. Compared with the one-section connection using long screws in traditional thermal insulation structures, the thermal insulation structure of the present invention has better seismic resistance.

[0068] Furthermore, the technical solution of the present invention is subjected to dynamic temperature detection of the carburetor 100 after the gasoline engine is stopped, and the detection is specifically divided into the following groups:

[0069] Experimental group 1: no heat insulation pad 800 is provided, no enclosed space λ is formed between the air guide cover 1001 and the upper cover 1000, and the rest is the same as the above complete technical solution;

[0070] Control group: Different from the experimental group 1, the conventional connection structure is used, the air intake bracket 300 is not provided, the screw 400 passes through the air intake branch pipe 200, the carburetor 100 and the air intake pipe 600 in sequence to realize the fixed connection between the above parts and the cylinder 700, and the rest of the parts are exactly the same as the experimental group 1;

[0071] Test group 2: no enclosed space λ is formed between the air guide cover 1001 and the upper cover 1000, and the rest is the same as the above complete technical solution;

[0072] Experimental Group 3: It has all the structural features of the present invention recorded in this embodiment and is a complete technical solution of this embodiment.

[0073] The test results are as follows Figure 8 shown.

[0074] from Figure 8 It can be clearly seen that in the control group using the traditional thermal insulation structure, the temperature reaches a peak in a relatively short time after shutdown, and is much higher than the normal working temperature of the carburetor 100. It is mainly heated by contact heat transfer and thermal radiation, but also dissipates heat in this way. After 25 minutes of natural cooling, the temperature of the carburetor 100 is still higher than 58°C. After adding the intake bracket 300 and replacing it with the rubber intake pipe 600 to form the test group 1, a very significant difference can be seen. First, the temperature peak moves to the rear end of the time axis, that is, the high temperature peak is introduced later and the peak is significantly lower than the control group, indicating that the addition of the intake bracket 300 and the replacement of the rubber intake pipe completely change the heat transfer form of the thermal insulation structure, and the heat conduction rate is reduced, so that the carburetor 100 is less heated. After the test group 2 further set the thermal insulation pad 800, Figure 8It can be clearly seen that compared with test group 1, the temperature drops relatively steadily over the entire time period, and as time goes on, the cooling rate also shows a trend slightly greater than that of test group 1, indicating that the setting of the heat insulation pad 800 is conducive to reducing the peak temperature and overall heat received by the carburetor 100. After the air guide 1001 is set to form a closed space λ, test group 3 further shows a relatively stable temperature drop over the entire time period compared with test group 2, indicating that the closed space λ forms an obstacle to the form of radiation heat transfer, so that the carburetor 100 is better protected by heat insulation, and the carburetor is still within the normal operating temperature range when it rises to the peak temperature, which can effectively solve the problem of the carburetor 100 being unable to start when it is hot.

Claims

1. A carburetor heat insulation structure for a gasoline engine, comprising an intake bracket and an intake pipe, wherein one end of the intake pipe is connected to the intake bracket and the other end is fixedly connected to the cylinder, the intake bracket is arranged on one side of the carburetor, and an intake branch pipe is arranged on the other side opposite to the carburetor, the intake branch pipe is fixedly connected to the intake bracket and clamps the carburetor, and is characterized in that: The air intake bracket and the air intake branch pipe are fixedly connected by screw connection; The screw passes through the screw hole of the intake branch pipe, the screw hole of the carburetor and the screw hole of the intake bracket in sequence. The inner walls of the screw hole of the intake branch pipe and the screw hole of the carburetor are smooth inner walls. The inner wall of the screw hole of the intake bracket is provided with an internal thread matching with the screw. The screw is a semi-threaded structure, and a heat-insulating sleeve is installed on the smooth surface contacting with the screw hole of the intake branch pipe and the screw hole of the carburetor. A copper-made clamping insert is provided in the screw hole of the air intake bracket, an internal thread is provided on the inner surface of the clamping insert, and the screw is a metal component; The end of the intake pipe connected to the cylinder is also provided with a heat insulation pad; Also includes: a housing; The shell is composed of a box base and an upper cover, which are fixedly connected to cover the upper and lower sides of the thermal insulation structure; An air guide cover is arranged on the inner side of the upper cover, and the air guide cover is fixedly installed on the inner side of the upper cover, and a closed space λ is formed between the air guide cover and the upper cover, and the closed space λ is located between the cylinder and the carburetor.

2. A carburetor heat insulation structure for a gasoline engine according to claim 1, characterized in that: The air intake pipe is made of fluororubber, and the connecting end between the air intake pipe and the cylinder is embedded with metal.

3. A carburetor heat insulation structure for a gasoline engine according to claim 1, characterized in that: The upper cover is composed of a detachable large cover and a small cover, the air guide cover is fixedly connected to the inner side of the large cover to form a closed space; the large cover is fixedly connected to the box body seat, and the large cover is provided with an open slot; The small cover is arranged at the slot to close the slot.

4. A carburetor heat insulation structure for a gasoline engine according to claim 1, characterized in that: The upper cover is composed of a detachable large cover and a small cover; The large cover is fixedly connected to the box body seat, and the large cover is provided with an open slot; The small cover is arranged at the slot to close the slot.

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