Upper cover plate for chain saw with pressure reducing valve

Abstract

The utility model belongs to the technical field of engines, and relates to an upper cover plate for a chain saw with a pressure reducing valve, a scavenging plug is embedded in an air outlet of a crankcase, the upper cover plate is covered on an air cylinder, a piston is arranged in the air cylinder, the pressure reducing valve is arranged at the top of the air cylinder, the upper cover plate is provided with a mounting hole corresponding to the pressure reducing valve, and the piston is arranged in the mounting hole. The mounting hole is provided with an annular flange extending outwards, the radial size of the mounting hole is larger than the maximum radial size of the pressure reducing valve, the annular flange is arranged outside the pressure reducing valve in a surrounding mode and is in clearance fit with the pressure reducing valve, and in the initial state, the top of the pressure reducing valve exceeds the upper end face of the annular flange. According to the upper cover plate for the chain saw with the pressure reducing valve, the pressure reducing valve can be detached more easily, and better heat dissipation performance can be provided.

Description

Technical Field

[0001] The utility model belongs to the technical field of engines and relates to an upper cover plate for a chain saw with a pressure reducing valve. Background Art

[0002] The power of a chain saw product is a small gasoline engine. For large-displacement power, a pressure reducing valve is often required to be added at the top of the cylinder to relieve the jerks during hand starting. The top of the pressure reducing valve is exposed, so that the operator can press the valve opening button before pulling the machine, so that the top of the cylinder is communicated with the atmosphere, and then it is very easy and fast for the operator to pull the starter. After pulling the machine, after the pressure reducing valve is induced by the piston moving upward to compress the gas, it immediately closes, isolating the cylinder combustion chamber from the outside world and starting ignition and combustion.

[0003] The upper cover plates of existing chain saws with pressure reducing valves are all provided with a small hole for the purpose of exposing the pressure reducing valve. However, the diameter of this small hole is generally only a little larger than the outer diameter of the pressure reducing valve, and there is almost no gap between the two, which causes inconvenience for the disassembly, maintenance and repair of the pressure reducing valve. Maintenance personnel must first remove the upper cover plate (the structures of different chain saws are different, and it may be necessary to remove other related accessories) to smoothly disassemble and assemble the pressure reducing valve. In addition, existing high-power professional chain saws have extremely high requirements for heat dissipation. After the hot engine stops, due to the too high body temperature, there will also be a phenomenon that it is difficult to start at high temperature. Summary of the Utility Model

[0004] Aiming at the deficiencies of the prior art, the utility model provides an upper cover plate for a chain saw with a pressure reducing valve, which can disassemble the pressure reducing valve more easily and can also provide better heat dissipation performance.

[0005] To solve the above technical problems, the purpose of the utility model is achieved through the following technical solutions:

[0006] An upper cover plate for a chain saw with a pressure reducing valve, the upper cover plate is covered on the cylinder, a piston is arranged in the cylinder, a pressure reducing valve is arranged at the top of the cylinder, the upper cover plate is provided with a mounting hole corresponding to the pressure reducing valve, the mounting hole is provided with an annular flange extending outwards, the radial dimension of the mounting hole is larger than the maximum radial dimension of the pressure reducing valve, the annular flange surrounds the pressure reducing valve and is in clearance fit with the pressure reducing valve, and in the initial state, the top of the pressure reducing valve exceeds the upper end surface of the annular flange.

[0007] In the above upper cover plate for a chain saw with a pressure reducing valve, the annular flange is a cylindrical ring.

[0008] In the above upper cover plate for a chain saw with a pressure reducing valve, the mounting hole, the annular flange and the pressure reducing valve are concentrically arranged.

[0009] In the above-mentioned upper cover plate for a chainsaw with a pressure reducing valve, the upper end surface of the annular flange is arranged parallel to the upper end surface of the pressure reducing valve.

[0010] In the above-mentioned upper cover plate for a chainsaw with a pressure reducing valve, the pressure reducing valve is disassembled by using a socket wrench, and the inner diameters of the mounting holes and the annular flange are adapted to the socket wrench used. In the present utility model, the inner diameters of the mounting holes and the annular flange being adapted to the socket wrench used means that the inner diameters of the mounting holes and the annular flange can just meet the size for the socket wrench to be naturally inserted to disassemble the pressure reducing valve.

[0011] In the above-mentioned upper cover plate for a chainsaw with a pressure reducing valve, the gap between the pressure reducing valve and the annular flange forms a first heat dissipation gap.

[0012] In the above-mentioned upper cover plate for a chainsaw with a pressure reducing valve, the upper cover plate is in clearance fit with the outer wall of the cylinder and forms a second heat dissipation gap, and the first heat dissipation gap and the second heat dissipation gap form a first heat dissipation channel.

[0013] In the above-mentioned upper cover plate for a chainsaw with a pressure reducing valve, a third heat dissipation gap is formed between the heat dissipation fins on the outer wall of the cylinder, and the first heat dissipation gap and the third heat dissipation gap form a second heat dissipation channel.

[0014] In the above-mentioned upper cover plate for a chainsaw with a pressure reducing valve, the first heat dissipation channel and the second heat dissipation channel can also cooperate to dissipate heat.

[0015] Compared with the prior art, the present utility model has the following beneficial effects:

[0016] 1. The present utility model provides an upper cover plate for a chainsaw with a pressure reducing valve. By providing mounting holes and an annular flange with large apertures, the disassembly requirement of the pressure reducing valve is met without disassembling the upper cover plate. At the same time, the annular flange can also protect the valve body of the pressure reducing valve, keeping the operator's hand as far away from the cylinder as possible when operating the pressure reducing valve to prevent being scalded by the high-temperature cylinder.

[0017] 2. The gap between the mounting holes and the annular flange of the present utility model and the pressure reducing valve can provide heat dissipation, improving the heat dissipation conditions at the top of the cylinder, enabling the hot engine to dissipate heat faster after shutdown and making it less likely to have the phenomenon of "difficult to start at high temperature". Description of the Drawings

[0018] Figure 1 is a perspective view of the chainsaw of the present utility model;

[0019] Figure 2 is a perspective view of the upper cover plate of the present utility model;

[0020] Figure 3 is a partial cross-sectional view of the chainsaw of the present utility model;

[0021] Figure 4 is Figure 3 a partial enlarged view of;

[0022] Reference numerals: 1, upper cover plate; 2, cylinder; 3, piston; 4, pressure reducing valve; 5, mounting hole; 6, annular flange; 7, first heat dissipation gap; 8, second heat dissipation gap; 9, heat dissipation fins; 10, third heat dissipation gap. Detailed implementation manners

[0023] The following further describes the present utility model with specific embodiments in conjunction with the attached drawings. Refer to Figures 1-4 :

[0024] An upper cover plate for a chainsaw with a pressure reducing valve, the upper cover plate 1 is covered on the cylinder 2, a piston 3 is arranged in the cylinder 2, a pressure reducing valve 4 is arranged at the top of the cylinder 2, the upper cover plate 1 is provided with a mounting hole 5 corresponding to the pressure reducing valve 4, the mounting hole 5 is provided with an annular flange 6 extending outwards, the radial dimension of the mounting hole 5 is larger than the maximum radial dimension of the pressure reducing valve 4, the annular flange 6 surrounds the pressure reducing valve 4 and is in clearance fit with the pressure reducing valve 4. In the initial state, the top of the pressure reducing valve 4 exceeds the upper end surface of the annular flange 6.

[0025] The usage method of the pressure reducing valve 4 in this embodiment is the same as that in the prior art: Before starting, the operator presses the pressure reducing valve 4, and the top of the cylinder 2 communicates with the atmosphere, so that the starter can be easily and quickly pulled by hand. After pulling the machine, the piston 3 moves upward to compress the gas, the pressure reducing valve 4 closes, isolating the combustion chamber of the cylinder 2 from the outside world, and starting ignition and combustion. Since this embodiment adopts a mounting hole 5 with a large aperture and an annular flange 6, the pressure reducing valve 4 is easier to disassemble, and the pressure reducing valve 4 can be disassembled and assembled without disassembling any other accessories. At the same time, this embodiment also uses the annular flange 6 to protect the pressure reducing valve 4, avoiding the disadvantage that the pressure reducing valve 4 is easily damaged due to the setting of the mounting hole 5 with a large aperture. In addition, by providing an annular flange 6 extending outwards, the operation can also be kept away from the cylinder 2 to avoid scalding.

[0026] In this embodiment, the annular flange 6 is a cylindrical ring.

[0027] Preferably, the mounting hole 5, the annular flange 6 and the pressure reducing valve 4 are concentrically arranged.

[0028] Preferably, the upper end surface of the annular flange 6 is parallel to the upper end surface of the pressure reducing valve 4.

[0029] This embodiment can also be adapted for disassembly with a tooling, that is: the pressure reducing valve 4 is disassembled by a socket wrench, and the inner diameters of the mounting hole 5 and the annular flange 6 are adapted to the socket wrench used. In this embodiment, the inner diameters of the mounting hole 5 and the annular flange 6 just meet the size for the socket wrench to be naturally inserted to disassemble the pressure reducing valve 4.

[0030] This embodiment can also improve the heat dissipation performance of the chainsaw:

[0031] The gap between the above-mentioned pressure reducing valve 4 and the annular flange 6 forms a first heat dissipation gap 7, and the heat inside the chainsaw, especially at the top of the cylinder 2, can be quickly dissipated to the outside through the first heat dissipation gap 7.

[0032] Furthermore, the upper cover plate 1 and the outer wall of the cylinder 2 are in clearance fit and form a second heat dissipation gap 8, and the first heat dissipation gap 7 and the second heat dissipation gap 8 form a first heat dissipation channel.

[0033] Furthermore, a third heat dissipation gap 10 is formed between the heat dissipation fins 9 on the outer wall of the cylinder 2, and the first heat dissipation gap 7 and the third heat dissipation gap 10 form a second heat dissipation channel.

[0034] Through the first heat dissipation channel and the second heat dissipation channel, the heat of other parts of the cylinder 2 can also be quickly dissipated.

[0035] The above-mentioned first heat dissipation channel and the second heat dissipation channel can also dissipate heat synergistically, that is, the heat of the cylinder 2 is dissipated to the outside through the first heat dissipation channel and the second heat dissipation channel at the same time, and the second heat dissipation channel can also transfer to the first heat dissipation channel for heat dissipation.

[0036] The above embodiments are only preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. An upper cover plate for a chain saw with a pressure reducing valve, wherein the upper cover plate (1) is covered on a cylinder (2), a piston (3) is arranged in the cylinder (2), and a pressure reducing valve (4) is arranged on the top of the cylinder (2), characterized in that: The upper cover plate (1) is provided with a mounting hole (5) corresponding to the pressure reducing valve (4); the mounting hole (5) is provided with an annular flange (6) extending outward; the radial dimension of the mounting hole (5) is greater than the maximum radial dimension of the pressure reducing valve (4); the annular flange (6) is arranged outside the pressure reducing valve (4) and is clearance-matched with the pressure reducing valve (4); in an initial state, the top of the pressure reducing valve (4) exceeds the upper end surface of the annular flange (6).

2. The upper cover plate for a chain saw with a pressure reducing valve according to claim 1, characterized in that: The annular flange (6) is a cylindrical ring.

3. The upper cover plate for a chain saw with a pressure reducing valve according to claim 2, characterized in that: The mounting hole (5), the annular flange (6) and the pressure reducing valve (4) are concentrically arranged.

4. The upper cover plate for a chain saw with a pressure reducing valve according to claim 3, characterized in that: The upper end surface of the annular flange (6) is arranged parallel to the upper end surface of the pressure reducing valve (4).

5. The upper cover plate for a chain saw with a pressure reducing valve according to claim 3, characterized in that: The pressure reducing valve (4) is disassembled using a socket wrench, and the inner diameters of the mounting hole (5) and the annular flange (6) are adapted to the socket wrench used.

6. The upper cover plate for a chain saw with a pressure reducing valve according to claim 1, characterized in that: The gap between the pressure reducing valve (4) and the annular flange (6) forms a first heat dissipation gap (7).

7. The upper cover plate for a chain saw with a pressure reducing valve according to claim 6, characterized in that: The gap between the upper cover plate (1) and the outer wall of the cylinder (2) is matched to form a second heat dissipation gap (8), and the first heat dissipation gap (7) and the second heat dissipation gap (8) form a first heat dissipation channel.

8. The upper cover plate for a chain saw with a pressure reducing valve according to claim 6, characterized in that: A third heat dissipation gap (10) is formed between the heat dissipation fins (9) on the outer wall of the cylinder (2), and the first heat dissipation gap (7) and the third heat dissipation gap (10) form a second heat dissipation channel.

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