Single diaphragm automatic switching dual fuel carburetor

Abstract

The utility model discloses a single diaphragm formula automatic switching's double fuel carburetor, including carburetor body and be used to automatic switching fuel switching device, and switching device includes needle valve core and air chamber cavity, and air chamber cavity is separated into power chamber and drive chamber by a diaphragm, diaphragm and needle valve core are free contact in drive chamber and can drive needle valve core to close carburetor's first fuel passage, and needle valve core is applied to the return pre -tension of diaphragm, power chamber links second fuel passage, the utility model discloses can avoid diaphragm wear, and service life is long, and there is no diaphragm connection to drive deviation, and needle valve core can guarantee the accuracy of sealing to avoid fuel leakage, guarantee the stable operation of engine.

Description

Technical Field

[0001] This utility model relates to the field of engine components, specifically to a single-diaphragm type automatic switching dual-fuel carburetor. Background Technology

[0002] A dual-fuel carburetor is a carburetor that can switch between two fuels to supply fuel to the engine. Such carburetors are typically equipped with a switching device for changing fuels. With technological advancements and further market demands, the switching device increasingly adopts an automatic switching structure. For example, Chinese patent (patent number: 202220524673.7) discloses an automatic switching device that uses a structure where two diaphragms form a three-chamber drive needle valve core. The tail of the needle valve core is connected to one of the diaphragms through a recess formed on the diaphragm. Thus, when the diaphragm is deformed by air pressure, it drives the needle valve core to close the fuel passage, thereby switching to natural gas for combustion in the engine. Structurally, the valve core is driven by two diaphragms, forming a stable drive structure and extending the service life of the diaphragms. However, the tail of the needle valve core is connected to one of the diaphragms. The reciprocating motion of the needle valve core will increase the stress at the diaphragm connection, leading to wear and damage. At the same time, assembly problems may cause misalignment between the connection and the guide hole of the needle valve core, which will also lead to uneven wear at the connection. Furthermore, misalignment will affect the sealing effect of the needle valve core, causing fuel to seep into the passage and affecting the normal operation of the engine.

[0003] Therefore, it is necessary to improve the existing dual-fuel switching device of the carburetor to avoid the stress on the diaphragm caused by the movement of the needle valve core, thereby avoiding wear or damage at the connection. At the same time, it is necessary to ensure the coaxiality of the reciprocating motion of the valve core, thereby ensuring good sealing, preventing fuel leakage and entry into the engine, and ensuring the normal operation of the engine. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a single-diaphragm automatic switching dual-fuel carburetor, which avoids the stress formed on the diaphragm by the movement of the needle valve core, thereby avoiding wear or damage at the connection. At the same time, it ensures the coaxiality of the reciprocating motion of the valve core, thereby ensuring good sealing, preventing fuel leakage and entry into the engine, and ensuring the normal operation of the engine.

[0005] This utility model relates to a single-diaphragm type automatic switching dual-fuel carburetor, comprising a carburetor body and a switching device for automatic fuel switching. The switching device includes a needle valve core and a gas chamber. The gas chamber is divided into a power chamber and a drive chamber by a diaphragm. The diaphragm and the needle valve core are in free contact in the drive chamber and can drive the needle valve core to close the first fuel passage of the carburetor. The needle valve core is also subjected to a return preload force toward the diaphragm. The power chamber is connected to the second fuel passage.

[0006] Furthermore, the needle valve core can be guided to reciprocate, thereby being driven to close or open the first fuel passage.

[0007] Furthermore, a drive seat is fixedly provided in the middle of the diaphragm, and the diaphragm drives the needle valve core to close the first fuel channel through the drive seat.

[0008] Furthermore, the drive seat is integrally formed on the diaphragm.

[0009] Furthermore, the drive seat extends beyond the diaphragm body at both the front and rear, forming a front section and a rear section of the drive seat, respectively. A front annular groove is formed between the front section of the drive seat and the diaphragm body, and a front reinforcing ring is engaged in the front annular groove.

[0010] Furthermore, a rear annular groove is formed between the rear section of the drive seat and the diaphragm body, and a rear reinforcing ring is engaged in the rear annular groove.

[0011] Furthermore, the carburetor body is provided with a guide hole, and a guide valve seat is provided in the guide hole. The guide valve seat is provided with a valve hole that communicates with the first fuel passage at the position opposite to the front end of the needle valve core. The needle valve core is installed on the guide valve seat and is driven to form a reciprocating motion to close or open the valve hole, thereby closing or opening the first fuel passage.

[0012] Furthermore, the radial dimension of the front section of the drive seat is greater than the radial dimension of the rear section of the drive seat.

[0013] Furthermore, the end face of the rear section of the drive seat is concave to form a pressure groove.

[0014] Furthermore, the air chamber is formed by a chamber cover integrated into the carburetor body, and the diaphragm is sealed and fixed to the chamber cover.

[0015] The beneficial effects of this utility model are as follows: The single-diaphragm automatic switching dual-fuel carburetor of this utility model adopts a structure in which the needle valve core and the driven diaphragm freely abut against each other, and the two do not interfere with each other. This avoids stress caused by the connection between the needle valve core and the diaphragm, which leads to easy wear and extends the service life of the diaphragm. At the same time, without the deviation driven by the diaphragm connection, the needle valve core can ensure the accuracy of the seal, thereby avoiding fuel leakage and ensuring the stable operation of the engine. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0017] Figure 1 This is a cross-sectional view of the present invention;

[0018] Figure 2 This is a cross-sectional view of the diaphragm. Detailed Implementation

[0019] like Figure 1 As shown, the present invention relates to a single-diaphragm automatic switching dual-fuel carburetor, comprising a carburetor body 1 and a switching device for automatic fuel switching. The switching device includes a needle valve core 2 and a gas chamber. The gas chamber is divided into a power chamber 4 and a drive chamber 3 by a diaphragm 6. This structure is a general design of a diaphragm switching device. Meanwhile, the gas chamber is generally formed by a housing, which can be integrated into the carburetor body 1 or set separately. Of course, it needs to be able to drive the needle valve core, which will not be elaborated here.

[0020] The diaphragm 6 and the needle valve core 2 are in free contact within the drive chamber 3, and the needle valve core 2 can be driven to close the first fuel passage 5 of the carburetor (generally a liquid fuel passage, usually fuel oil), and the needle valve core is subjected to a return preload force toward the diaphragm; Figure 1 As shown, in a typical structure, the needle valve core 2 is used to close and open the first fuel passage. Free contact means that the two are in contact without constraint except in the driving direction. The tail of the needle valve core 2 forms free contact with the diaphragm 6. When the diaphragm deforms, it drives the needle valve core 2 to close the first fuel passage 5. The preload of the needle valve core 2 is generally provided by a spring, such as... Figure 1 As shown, spring 7 is sleeved on needle valve core 2, with one end abutting against a baffle near the tail of needle valve core 2, and the other end abutting against a corresponding position on carburetor body 1 (the figure shows another baffle abutting against the carburetor body, which is a general structure for spring to form preload), forming a preload towards diaphragm 6; the power chamber 4 is connected to the second fuel passage, which is not specifically shown in the figure, but as shown, the power chamber 4 is connected to channel 9, which is connected to the second fuel passage (generally a gas passage) through a connector; of course, the second fuel passage can also directly enter the power chamber 4 through channel 9, and the power chamber 4 is provided with an outlet for discharging the second fuel, delivering fuel gas to the engine. In this structure, the outlet flow area is smaller than the inlet flow area to ensure the stability of the air pressure in the power chamber, thereby ensuring the sealing stability of the needle valve core and achieving better performance. When the engine uses natural gas as fuel, the gas pressure in the second fuel passage is transmitted to passage 9 and enters the power chamber 4. The pressure causes the diaphragm 6 to deform forward, driving the needle valve core 2 to compress the spring 7 forward and move, blocking the first fuel passage 5 at the front end and preventing fuel from passing through. In order to ensure that the diaphragm 7 will not deform backward after long-term use (because the pressure of the fuel acts on the diaphragm, this deformation will become permanent after long-term use), a limiting component can be set in the power chamber to limit the backward deformation of the diaphragm, so as to ensure the sensitivity and accuracy of the drive.

[0021] In the above structure, the movement of the needle valve core 2 is accomplished by the diaphragm 6 and the spring 7. It is not connected to the diaphragm, so there is no interference except for the drive. This ensures that the reciprocating motion of the needle valve core 2 will not generate a flipping torque, avoids uneven wear of the slide and the needle valve core, thus ensuring the smoothness of the movement, thereby avoiding abnormal wear of the diaphragm 6, and also ensuring the centering of the needle valve core 2, ultimately achieving good sealing performance.

[0022] In this embodiment, the needle valve core 2 can be guided to form a reciprocating motion, thereby being driven to close or open the first fuel passage 5. Being guided means that it is constrained during the reciprocating motion, and can only move forward or backward. Of course, it can also rotate, but it cannot generate a reversing torque. This can be achieved using a conventional channel, which will not be elaborated here.

[0023] In this embodiment, a drive seat 601 is fixedly provided in the middle of the diaphragm 6. This can be achieved through existing mechanical connection methods such as integral molding, gluing, or detachment, which will not be elaborated here. The diaphragm 6 drives the needle valve core 2 to close the first fuel passage 5 through the drive seat 601. Figure 1 As shown, the front end of the drive seat 601 is in free contact with the tail end of the needle valve core 2. The drive seat 601 drives the needle valve core 2, which avoids the diaphragm 6 being directly subjected to force, increases the overall strength of the drive part, thereby avoiding wear of the diaphragm 6. At the same time, it reduces the deformation of the drive part and enhances the driving force.

[0024] In this embodiment, the drive seat 601 is integrally formed on the diaphragm 6; the integrally formed structure can ensure the sensitivity and strength of the drive, avoid stress concentration at the connection, and for a thinner diaphragm, it helps to ensure the overall service life of the diaphragm; at the same time, it simplifies the processing technology, reduces assembly requirements, avoids complex assembly processes, and improves production efficiency.

[0025] In this embodiment, the drive seat 601 extends beyond the diaphragm body of the diaphragm 6 at both the front and rear, forming a front section and a rear section of the drive seat to ensure sufficient connection strength. A front annular groove 6011 is formed between the front section of the drive seat and the diaphragm body, and a front reinforcing ring 602 is fitted inside the front annular groove 6011. The front section of the drive seat refers to the part located on the front side of the diaphragm body, and the rear section of the drive seat refers to the part located on the rear side of the diaphragm body, which will not be described in detail here. The diaphragm is generally made of non-metallic materials (such as rubber). However, during the driving of other components, a large stress concentration will occur between the driving part and the diaphragm body, which will cause fatigue damage to the diaphragm body. Through the design of the flange disk 6011 and the reinforcing ring 602 (generally made of metal, such as aluminum alloy, which is lightweight but has sufficient strength), stress concentration and fatigue damage can be better avoided, and sufficient driving strength and driving sensitivity can be ensured during the driving process.

[0026] In this embodiment, a rear annular groove 6013 is formed between the rear section of the drive seat and the diaphragm body of the diaphragm 6, and a rear reinforcing ring 603 is engaged in the rear annular groove. In this structure, the rear reinforcing ring and the front reinforcing ring together form a clamping structure for the diaphragm body, which enhances the overall load-bearing capacity of the diaphragm body, increases the driving capacity of the drive seat 601, further reduces the strength difference between the drive seat and the diaphragm body, and avoids stress concentration and fatigue damage.

[0027] In this embodiment, the carburetor body 1 is provided with a guide hole, and a guide valve seat 8 is provided in the guide hole. The guide valve seat 8 has a valve hole 801 communicating with the first fuel passage 5 at a position opposite to the front end of the needle valve core 2. The needle valve core 2 is installed on the guide valve seat 8 and is driven to reciprocate, closing or opening the valve hole 801, thereby closing or opening the first fuel passage. Figure 1 As shown, the guide valve seat 8 is fixed (generally an interference fit) and embedded in the guide hole, and has a bushing structure. The needle valve core 2 is sleeved inside the guide valve seat 8. The diameter of the valve hole 801 is smaller than the inner diameter of the guide part of the guide valve seat 8. It is opened at the front end of the guide valve seat 8 and is coaxial with the guide valve seat and also with the needle valve core 2. The front end of the needle valve core 2 has a conical structure. After being driven forward, the conical structure covers the valve hole 801, which has a guiding function to ensure the centering of the needle valve core 2 while forming a relatively tight seal. At the same time, the side wall of the guide valve seat 8 also has a through hole 802 for connecting the first fuel passage. When the needle valve core 2 retracts, the through hole 802 and the valve hole 801 are connected inside the guide valve seat. This will not be described in detail here.

[0028] In this embodiment, the radial dimension of the front section of the drive seat is larger than the radial dimension of the rear section of the drive seat, so as to ensure that the tail of the needle valve core is fully covered in the driving direction and that there is sufficient driving strength; and while ensuring sufficient connection strength between the drive seat and the diaphragm body, the deformability of the diaphragm is also ensured.

[0029] The drive unit 601 is usually a cylindrical structure, and its radial dimension is consistent with the radial dimension of the diaphragm. The radial dimension usually accounts for 15%-30% of the radial dimension of the diaphragm, generally around 22-25%, which will not be elaborated here.

[0030] In this embodiment, the end face of the rear section of the drive seat is conically recessed to form a pressure groove 6013, as shown in the figure. The pressure groove 6013 is a conical groove. Under the guidance of the conical shape, the air pressure fully acts on the drive seat, thereby driving the diaphragm to deform together with the air pressure acting on the diaphragm. This avoids stress concentration caused by excessive air pressure distribution on the diaphragm, thus ensuring the service life of the diaphragm.

[0031] In this embodiment, the air chamber is formed by a chamber cover integrated into the carburetor body 1, resulting in a compact structure; the diaphragm 6 is sealed and fixed to the chamber cover 10; the structure of the chamber cover 10 is not limited, as long as it can be sealed and fixed with the diaphragm 6 to form a corresponding chamber; for example... Figure 1 As shown, the front end of the chamber cover 10 is open and fixed to the carburetor body 1, and a diaphragm 6 is sealed between the cover and the carburetor body 1. The carburetor body 1 is recessed in this position and forms a drive chamber 3 between the cover and the diaphragm 6, providing space for the deformation of the diaphragm 6. This will not be described in detail here.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A single-diaphragm type automatic switching dual-fuel carburetor, characterized in that: The invention includes a carburetor body and a switching device for automatically switching fuels. The switching device includes a needle valve core and a gas chamber. The gas chamber is divided into a power chamber and a drive chamber by a diaphragm. The diaphragm is in free contact with the needle valve core in the drive chamber and can drive the needle valve core to close the first fuel passage of the carburetor. The needle valve core is subjected to a return preload force toward the diaphragm. The power chamber is connected to a second fuel passage.

2. The single-diaphragm automatic switching dual-fuel carburetor according to claim 1, characterized in that: The needle valve core can be guided to reciprocate, thereby being driven to close or open the first fuel passage.

3. The single-diaphragm automatic switching dual-fuel carburetor according to claim 1, characterized in that: A drive seat is fixedly provided in the middle of the diaphragm, and the diaphragm drives the needle valve core to close the first fuel channel through the drive seat.

4. The single-diaphragm automatic switching dual-fuel carburetor according to claim 3, characterized in that: The drive seat is integrally formed on the diaphragm.

5. The single-diaphragm automatic switching dual-fuel carburetor according to claim 4, characterized in that: The drive seat extends beyond the diaphragm body at both the front and rear, forming a front section and a rear section of the drive seat, respectively. A front annular groove is formed between the front section of the drive seat and the diaphragm body, and a front reinforcing ring is engaged in the front annular groove.

6. The single-diaphragm automatic switching dual-fuel carburetor according to claim 5, characterized in that: A rear annular groove is formed between the rear section of the drive seat and the diaphragm body, and a rear reinforcing ring is engaged in the rear annular groove.

7. The single-diaphragm automatic switching dual-fuel carburetor according to claim 2, characterized in that: The carburetor body is provided with a guide hole, and a guide valve seat is provided in the guide hole. The guide valve seat is provided with a valve hole that communicates with the first fuel passage at the front end of the needle valve core. The needle valve core is installed on the guide valve seat and is driven to form a reciprocating motion to close or open the valve hole, thereby closing or opening the first fuel passage.

8. The single-diaphragm automatic switching dual-fuel carburetor according to claim 5, characterized in that: The radial dimension of the front section of the drive seat is greater than the radial dimension of the rear section of the drive seat.

9. The single-diaphragm automatic switching dual-fuel carburetor according to claim 5, characterized in that: The end face of the rear section of the drive seat is conical and recessed to form a pressure groove.

10. The single-diaphragm automatic switching dual-fuel carburetor according to claim 1, characterized in that: The air chamber is formed by a chamber cover integrated into the carburetor body, and the diaphragm is sealed and fixed to the chamber cover.

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