CN108533420B

CN108533420B - Transshipment valve system for outdoor power equipment

Info

Publication number: CN108533420B
Application number: CN201810160903.4A
Authority: CN
Inventors: 大卫·罗斯
Original assignee: Briggs and Stratton Corp
Current assignee: Briggs Stratton Ltd
Priority date: 2017-03-02
Filing date: 2018-02-27
Publication date: 2021-03-09
Anticipated expiration: 2038-02-27
Also published as: CN108533421A; EP3369920B1; EP3369921B1; EP3369920A1; CN108533420A; CN108533421B; EP3369921A1

Abstract

An engine is provided that includes a fuel tank, a carburetor, a speed control lever, and a transfer valve. The carburetor includes a throttle valve movable between a first throttle position and a second throttle position. The speed control lever is connected to the throttle valve and is movable between a first position corresponding to a first throttle position and a second position corresponding to a second throttle position. The transfer valve is fluidly coupled between the fuel tank and the carburetor and includes a valve element movable between an open valve position that permits fuel flow between the fuel tank and the carburetor and a closed valve position that prevents fuel flow between the fuel tank and the carburetor. Movement of the speed control lever to the second position causes the valve member to move to the closed valve position to terminate fluid flow between the fuel tank and the carburetor.

Description

Transshipment valve system for outdoor power equipment

Technical Field

The present invention generally relates to the field of fuel delivery systems. More particularly, the present invention relates to a fuel delivery system for operating an engine of an outdoor power plant.

Background

Outdoor power equipment is typically powered by an internal combustion engine. The engine includes a carburetor that adds fuel to air flowing through the engine for a combustion process occurring within the engine. During transportation or long storage of outdoor power equipment, it is desirable to prevent fuel flow to the carburetor. Typically, a valve or stop cock is placed in the fuel line to selectively provide and prevent fuel flow to the carburetor.

Disclosure of Invention

One embodiment relates to an engine including a fuel tank, a carburetor, a speed control lever, and a transfer valve. The carburetor includes a throttle valve movable between a first throttle position and a second throttle position. The speed control lever is connected to the throttle valve and is movable between a first position corresponding to a first throttle position and a second position corresponding to a second throttle position. The transfer valve is fluidly coupled between the fuel tank and the carburetor and includes a valve element movable between an open valve position that allows fuel to flow between the fuel tank and the carburetor and a closed valve position that prevents fuel from flowing between the fuel tank and the carburetor. Movement of the speed control lever to the second position moves the valve member to the closed valve position to terminate fluid flow between the fuel tank and the carburetor.

Another embodiment relates to an engine shutdown system for an engine having a carburetor. The engine shutoff system includes a speed control lever and a valve that moves between an open position that allows fuel to flow to the carburetor and a closed position that prevents fuel from flowing to the carburetor in response to the speed control lever.

Another embodiment relates to a method of preventing fuel flow to a carburetor. The method includes moving a speed control lever from an open position to a closed position, and moving a valve closing element from an open position that allows fuel flow to a closed position where fuel flow is blocked in response to the speed control lever moving to the closed position.

Alternative exemplary embodiments relate to other features and combinations of features that may be broadly recited in the claims.

Drawings

The present invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1 is a front view of an engine including a delivery valve system according to one embodiment.

Fig. 2 is a top view of the engine of fig. 1.

Fig. 3 is a detailed view showing a speed control system of the engine of fig. 1.

FIG. 4 is a detailed perspective view of the speed control system of FIG. 3 showing an electrical disconnect switch.

Fig. 5 is a front right perspective view of the velocity control system of fig. 3.

Fig. 6 is a rear left perspective view of the velocity control system of fig. 3.

FIG. 7 is a right side view of the transit protection valve and carburetor of the speed control system of FIG. 3.

FIG. 8 is a cross-sectional view of the transportation protection valve and carburetor taken along line 8-8 of FIG. 3.

Fig. 9 is a cross-sectional view of the transport protection valve taken along line 9-9 of fig. 3.

Fig. 10 is a cross-sectional view of the shipping protection valve in the closed position taken along line 10-10 of fig. 3.

FIG. 11 is a cross-sectional view of the transport protection valve in an open position taken along line 10-10 of FIG. 3.

Fig. 12 is a detail view of a portion of the transport protection valve of fig. 11.

FIG. 13 is a cross-sectional view of another delivery valve system according to one embodiment.

FIG. 14 is a cross-sectional view of another delivery valve system according to one embodiment.

Detailed Description

Before turning to the figures, which illustrate exemplary embodiments in detail, it should be understood that the application is not limited to the details or methodology set forth in the description or illustrated in the figures. It is also to be understood that the terminology is for the purpose of description and should not be regarded as limiting.

Referring generally to the drawings, a delivery valve system for an engine is shown and described that includes a speed control system including a valve responsive to a speed control lever or another speed control component (e.g., a governor system component). The position of the speed control component may be remote from the engine or may be electronically controlled, for example, by a controller. The speed control member is arranged to affect the operating speed of the engine and is movable between an off position (off position) in which the engine is not operable and an on position range (a range of on positions) in which the engine is operable. The operating speed of the engine is controlled at least in part by the position of the speed control member within the range of open positions, and the speed control member can be manipulated to adjust the operating speed of the engine. When the speed control member is in the shutoff position, the valve moves to a closed position and shuts off fuel flow to the carburetor. In some embodiments, the delivery valve system further comprises an electrical disconnect switch that is also responsive to the speed control component. When the speed control member is in the off position, the electrical disconnect switch is actuated and the electrical system of the engine is shut down. In this manner, moving the speed control component to the shut-off position shuts off fuel flow and terminates the electrical system of the engine without the need for a separately actuated piston (or fuel shut-off valve) and electrical system switch.

As shown in fig. 1 and 2, engine 10 includes a fuel tank 14 and a speed control system 15, speed control system 15 including a carburetor 16, a speed control lever 17, a governor system 18, and a delivery valve system 19. The engine 10 may be used to power outdoor power equipment, portable field devices, or other equipment requiring a prime mover. Outdoor power equipment may include lawn mowers, riding tractors, snow throwers, high pressure cleaners, tillers, log splitters, zero turn radius mowers, walk-behind mowers, riding mowers, stand-up mowers, pavement preparation devices (forklift), industrial vehicles (e.g., forklifts), utility vehicles, commercial turf equipment (e.g., blowers), vacuums, chip loaders, seeders (oversleeders), power rakes, inflators, sod cutters, brush mowers (brush mowers), portable generators, and the like. For example, the outdoor power equipment may use the engine 10 to drive an implement, such as a rotating blade of a lawn mower, a pump of a high pressure washer, an auger of a snow blower, and/or a drive train of the outdoor power equipment. Portable field devices may include portable lighthouses, mobile industrial heaters, and portable light fixtures.

The carburetor 16 includes a throttle valve 16a (see FIG. 8) movable between a first position in the form of a low speed position and a second position in the form of a high speed position, and thereby controls the flow of the air/fuel mixture out of the carburetor 16 and into the combustion chamber of the engine 10, and the carburetor 16 also includes a choke lever 16b configured to adjust the position of the choke valve to control the flow of air into the carburetor 16. The carburetor 16 is arranged to mix fuel from the fuel tank 14 with air and provide the mixture to the combustion cylinder.

The engine 10 may be in the form of a small single cylinder four stroke internal combustion engine and includes an engine block, an intake port and an exhaust port. Inside the engine 10, the engine 10 includes a passage configured to guide air from an air inlet to a combustion chamber. Along this path, the fuel mixes with air in the carburetor 16 or other fuel injection device. As shown in FIG. 6, combustion in the combustion chamber converts chemical energy into mechanical energy (e.g., rotational motion; torque) via the piston 10a, connecting rod 10b, and crankshaft 10c, which crankshaft 10c may then be coupled to one or more rotating tools (e.g., blades, alternators, augers, impellers, teeth, drivelines, etc.) of the outdoor power equipment. In the embodiment shown, the crankshaft 10c is a horizontal crankshaft arranged to provide power to an output shaft 10d, which output shaft 10d is arranged to provide power to one or more tools. In other embodiments, the crankshaft 10c is a vertical crankshaft. In other embodiments, engine 10 includes two or more cylinders (e.g., two cylinders arranged in a V-twin engine configuration).

The speed control lever 17 is connected to the carburetor 16 through a governor system 18, and the speed control lever 17 and the governor system 18 cooperate to control the amount of fuel-air mixture provided to the combustion chambers of the cylinders and thereby vary the operating speed of the engine 10. A delivery valve system 19 is disposed in the fuel flow path between the fuel tank 14 and the carburetor 16 and is operated in response to the speed control lever 17 to selectively prevent fuel flow from the fuel tank 14 to the carburetor 16.

As shown in fig. 3, speed control lever 17 includes a speed control linkage (in the form of a speed control lever 20) connected to a governor system 18 and a fuel control linkage (in the form of a fuel control lever 21) connected to a delivery valve system 19. The speed control lever 17 is actuatable about a speed control axis a between a shut-off position (see fig. 2) and a range of open positions (one exemplary open position is shown in fig. 3). The range of open positions changes the flow of the fuel-air mixture from the carburetor and thus changes the speed of the engine 10. The speed control lever 17 also comprises a closing element in the form of a closing cam surface 22. The closing cam surface 22 defines an inclined profile.

A governor system 18 is connected between the speed control lever 17 and the carburetor 16 and controls the speed of the engine 10. The governor system 18 includes a speed control bell crank 18i that is movable in response to a speed control lever 20; a governor arm 23 connected to a governor plate 18i by a governor spring 18ii and controlled by a governor or a sensing device responsive to the speed of the engine 10; and a governor link 24 coupled to throttle valve 16a to control the fuel-air mixture provided to the combustion chambers of engine 10. In some embodiments, moving speed control lever 17 changes the tension of governor spring 18ii, thereby affecting the speed of engine 10 by changing the force balance in governor system 18 (moving throttle valve 16a through governor arm 23 and governor link 24). In some embodiments, this only affects the position of the throttle valve 16a if the engine 10 is running. When the engine 10 is closed, moving the speed control lever 17 does not affect the position of the throttle valve 16a, since the throttle valve 16a is held in a fully open state by the governor lost motion spring. Governor system 18 can also include counterweights, slider cups (slider cups), cranks, springs, linkages, and other components, as desired.

As shown in fig. 4, the speed control system 15 further includes an electrical disconnect switch 25 (e.g., a circuit breaker switch) arranged to interact with the closing cam surface 22 of the speed control lever 17. The electrical cut-off switch 25 is provided to selectively disconnect the power supply to the engine 10. In one embodiment, electrical disconnect switch 25 selectively disconnects power to engine 10 by grounding the ignition coil. In the illustrated embodiment, the electrical disconnect switch 25 is a blade stop switch, but in other embodiments a microswitch, such as a normally open or normally closed switch, or another type of switch may be used. The electrical disconnect switch 25 is movable between an ungrounded (i.e., on) state when the speed control lever is in the on position and a grounded (i.e., off) state when the speed control lever is in the off position.

As shown in fig. 5-6 and discussed above with respect to the governor system 18, the speed control lever 17 is movable to affect the position of the throttle valve 16a of the carburetor 16 and to control the transit guard system 19.

As shown in fig. 7, the delivery valve system 19 includes a fuel bowl 30, a valve housing 34, a fuel inlet barb 36(fuel inlet barb), a valve cap 38, a cam follower 42, and a cam 46. Typically, fuel enters the fuel inlet barb 36 from the fuel tank 14 and passes through the valve housing 34 and fuel bowl 30 before entering the carburetor 16. The cam 46 is coupled to the speed control rod 17 through the fuel rod 21, and the cam follower 42 moves in response to a change in position of the cam 46 caused by movement of the speed control rod 17. In one embodiment, a cam 46 is configured to rotate in response to movement of the speed control lever 17 and defines a cam profile 47 that interacts with the cam follower 42 to actuate the delivery valve system 19.

As shown in FIG. 8, the fuel cup 30 includes a coupling feature in the form of threads 50 and defines a fuel cavity 54 arranged to contain fuel.

The valve housing 34 includes a coupling feature in the form of threads 58, the threads 58 being sized to threadingly engage the threads 50 of the fuel cup 30. A fuel outlet 62 is formed in the valve housing 34 and is arranged to provide fuel to the carburetor 16. In other embodiments, the fuel outlet 62 may be formed in the fuel cup 30.

As shown in FIG. 9, the fuel passage 66 formed in the valve housing 34 provides a flow path from the valve seat 70 to the fuel cavity 54. The valve seat 70 shown is a separate element that is housed in the valve housing 34, but in other embodiments, the valve seat 70 may be formed as part of the valve housing 34 or may be coupled to the valve housing 34 in another manner. The valve chamber 74 is located upstream of the valve seat 70, and the housing fuel inlet 78 provides a flow path for fuel from the fuel inlet barb 36 into the valve chamber 74. The valve housing 34 also includes a housing flange 82 and a mounting flange 86 (see FIG. 7). The fuel inlet barb 36 is press fit into the housing fuel inlet 78 and is arranged to receive a fuel line connected to the fuel tank 14.

The valve cover 38 includes a cover flange 90 sized to mate with the housing flange 82, a cover cavity 94, a seal groove 98, and an actuator aperture 102. The valve cap 38 is configured to receive an actuation assembly 106, the actuation assembly 106 including a cam follower 42, an outer seal 110, an outer spring 114, an inner seal 118, a first button 122, a second button 130, and an inner spring 134. The cam follower 42 includes a follower cap 138, a follower shaft 142 (sized to fit within the actuator bore 102), and a protrusion 146 sized to engage the first button 122.

Valve closure assembly 150 is located in valve chamber 74 and includes a float 154 and a valve member 158 configured to engage valve seat 70. The float 154 is configured to provide a buoyancy bias when fuel is present in the valve chamber. In other words, when fuel is present in valve chamber 74, float 154 rises (as shown in FIG. 9) and valve member 158 disengages from valve seat 70 to allow fuel to flow through valve seat 70. The illustrated valve element 158 is substantially conical, formed of rubber, and is captured on the barb-like projection 162 of the float 154.

With continued reference to FIG. 9, the delivery valve system 19 is assembled by inserting the gasket 166 into the threads 58 of the valve housing 34 and screwing the fuel cup 30 into sealing engagement with the valve housing 34. Valve closure assembly 150 is then inserted into valve chamber 74. Diaphragm 170 and washer 172 are then placed over housing flange 82 such that valve closure assembly 150 is captured within valve chamber 74.

The outer seal 110 slides onto the follower shaft 142 until it abuts the follower cap 138. The inner seal 118 is then disposed in the seal groove 98 of the cap 38. The external spring 114 is then slid onto the driven shaft 142, and the driven shaft 142 is inserted through the actuator bore 102 such that the internal seal 118 engages the driven shaft 142. The first button 122 then engages the projection 146 of the cam follower 42.

Once assembled, the bonnet 38 and cam follower 42 are positioned on top of the diaphragm 170 and gasket 172 (as shown in fig. 9), with the bonnet flange 90 contacting the gasket 172 and the housing flange 82 contacting the diaphragm 170. The fasteners 174 then engage the bonnet flange 90 and the housing flange 82 to compress the diaphragm 170 and the gasket 172 between the bonnet flange 90 and the housing flange 82 (see fig. 10).

In operation, engine 10 is operated by a user by manipulating speed control lever 17. The movement of the speed control lever 17 provides three different operations. First, speed control lever 17 affects governor system 18, which governor system 18 in turn affects the amount of fuel-air mixture delivered from carburetor 16 to the combustion cylinders of engine 10 to control the operating speed of engine 10. Second, actuation of the speed control lever 17 moves the cam 46, thereby selectively preventing or allowing fuel flow through the delivery valve system 19 to the carburetor 16. Third, actuation of the speed control lever 17 moves the closing cam surface 22 such that the electrical disconnect switch 25 selectively prevents or allows operation of the electrical system of the engine 10.

When speed control lever 17 is disposed in the open position (as shown in FIG. 3), engine 10 may be operated and run. As shown in fig. 3, the closing cam surface 22 is disposed in an open state, so that the electrical cut-off switch 25 is disposed in an ungrounded position and allows operation of the electrical system. When the speed lever is disposed in the open position, the cam 46 is disposed in the open state (see fig. 11) and the external spring 114 biases the cam follower 42 to the extended position such that the first and

second buttons

122, 130 are separated and allow the valve closure assembly 150 to move to the open position by deflecting the diaphragm 170. The deflection of the diaphragm 170 is also shown in fig. 12. Internal spring 134 biases second button 130 away from first button 122 and tends to bias valve closure assembly 150 toward a closed position preventing fuel flow.

In order for fuel to flow through the valve seat 70, the buoyant bias of the float 154 must overcome the bias of the internal spring 134 and the diaphragm 170. The reverse flow of fuel through the valve seat 70 is inhibited by gravity, which causes the valve closure assembly 150 to drop downwardly toward the valve seat 70 when the engine 10 is in the normal operating position. Under normal conditions, engine 10 is allowed to operate and run with speed control lever 17 in the open position. The delivery valve system 19 allows fuel to flow. The speed control lever 17 can be manipulated in the open position to adjust the speed of the engine 10 without moving the cam 46 out of the open state.

When the speed control lever 17 is disposed in the closed position (see fig. 2), the engine 10 is prohibited from operating or running. The closing cam surface 22 is arranged in a closed state such that the electrical cut-off switch 25 is actuated to the grounding position and operation of the electrical system is inhibited. The cam follower 42 is urged into the retracted position by the cam profile 47 against the bias of the external spring 114 (see figure 10). The first button 122 is pushed toward the valve closure assembly 150 such that the second button 130 presses against the diaphragm 170 and the valve closure assembly 150 moves to a closed position in which fuel is prevented from flowing past the valve seat 70.

The above-described delivery valve system 19 allows a user to shut off fuel flow to the carburetor 16 at any time the speed control lever 17 is disposed in the closed position. This provides a number of advantages to the user. First, the user does not need to know that fuel flow during transportation of engine 10 is not ideal. Often the user may forget to turn off the typical stop cock and the carburetor 16 may fill with fuel while being transported (e.g., on a trailer). Second, speed control system 15 incorporates an electrical cut-off switch 25 so that whenever the user sets speed control lever 17 in the off position, fuel is cut off and the electrical system is deactivated. This simplifies and improves the user experience of using engine 10, while also improving the operation of engine 10.

The delivery valve system 19 and the speed control lever 17 are configured such that no more than six pounds of force is required to actuate the speed control lever 17 between the open and closed positions. In other embodiments, different force requirements may be met while remaining within the scope of the present invention. The illustrated delivery valve system 19 does not include an integrated choke feature, although one may be included.

In another embodiment shown in fig. 13, valve 196 replaces the first and second buttons with basket 122', basket coupler 126', button 130', and internal spring 134'. The basket coupler 126' connects the basket 122' and the button 130' while allowing relative movement of the button 130' with respect to the basket 122 '. An internal spring 134' is located between the basket 122' and the button 130' and biases the button 130' away from the basket 122 '.

Fig. 14 shows another embodiment similar to the embodiment described above with respect to fig. 13. In fig. 14, the valve 198 replaces the float 150 with a non-floating actuator 200, the non-floating actuator 200 being coupled to the button 130 "by a fastener 204 through the diaphragm 170. The basket 122 "couples the button 130" to the protrusion 146. The fastener 204 rigidly connects the non-floating actuator 200 to the button 130 ". The illustrated non-floating actuator 200 is a solid four-slotted inlet needle, and the valve element 158 is coupled to the non-floating actuator and is configured to selectively permit and prevent flow through the valve seat 70. The diaphragm 170 includes a hole through which a fastener passes and which is sealed between the button 130 "and the non-floating actuator 200 such that the upper chamber 94 is isolated from the valve chamber 74. The non-floating actuator 200 is actuated between the open and closed positions following the movement of the button 130 "in response to the cam 46.

The construction and arrangement of the delivery valve system as shown in the various exemplary embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or number of any process, logical algorithm, or method step may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present inventions.

Claims

1. An engine, comprising:

a fuel tank;

a carburetor including a throttle valve movable between a first throttle position and a second throttle position;

a governor system configured to move the throttle valve;

a speed control lever coupled to the governor system and movable between a first position corresponding to the first throttle position and a second position corresponding to the second throttle position; and

a transfer valve fluidly connected between a fuel tank and a carburetor, the transfer valve comprising:

a valve seat;

a valve element;

a float coupled to the valve element; and

a valve cavity;

wherein the float is configured to provide a buoyancy bias when fuel is present in the valve chamber;

wherein the valve element is movable relative to the valve seat between an open valve position that permits fuel flow between the fuel tank and the carburetor and a closed valve position that prevents fuel flow between the fuel tank and the carburetor;

wherein the buoyant bias may be overcome by the bias of the internal spring and diaphragm;

wherein the buoyancy bias is only capable of allowing fuel flow when the engine is in an on state; and

wherein movement of the speed control lever to the second position causes the valve element to move to the closed valve position to stop fluid flow between the fuel tank and the carburetor and move the throttle valve to the second throttle position.

2. The engine of claim 1, further comprising a cam coupled to the speed control lever and actuatable between an on state and an off state,

wherein the cam is in the closed state when the speed control lever is disposed in the second position.

3. The engine of claim 2, further comprising a cam follower arranged to urge the valve member towards a closed valve position when the cam is in a closed state, and a spring biasing the cam follower towards the cam.

4. The engine of claim 3, wherein the cam follower is located outside of fuel flow.

5. The engine of claim 3, further comprising a diaphragm positioned between the valve element and the cam follower.

6. The engine of claim 1, wherein the speed control lever controls engine speed by moving the throttle valve.

7. The engine of claim 1, further comprising an electrical disconnect switch arranged to prevent electrical operation of the engine when the speed control lever is in the second position.

8. The engine of claim 1, further comprising a spring biasing the valve element toward the closed valve position.

9. An engine shutdown system for an engine having a carburetor, the engine shutdown system comprising:

a speed control lever movable to change an operating speed of the engine; and

a valve that moves between an open position that allows fuel to flow to the carburetor and a closed position that prevents fuel from flowing to the carburetor in response to the speed control lever, the valve comprising:

a valve seat;

a valve element;

a float coupled to the valve element; and

a valve cavity; wherein the float is configured to provide a buoyancy bias when fuel is present in the valve chamber;

wherein the buoyancy bias is only capable of allowing fuel flow when the engine is in an on state.

10. The engine shutdown system of claim 9, further comprising:

a cam connected with the speed control lever and actuatable between an on state and an off state in response to movement of the speed control lever; and

a cam follower arranged to urge the valve towards the closed position when the cam is in the closed condition.

11. The engine shutoff system of claim 10, wherein the valve is isolated from the cam follower by a diaphragm.

12. The engine shutdown system of claim 9, further comprising an electrical disconnect switch arranged to prevent electrical operation of the engine in response to the speed control lever being arranged in a closed position.