JP2012117442A - Engine and engine working machine equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine suitably mounted on an engine working machine which enables easy start operation by enhancing the certainty of start-fuel supply.SOLUTION: A chain saw 1001 has a primary pump 31, a fuel reservoir chamber 36 that can store fuel of 4 cc or more therein, and a control circuit 37 built therein, while an operator can operate a start-fuel supply device by way of an operation panel 38. Furthermore, a temperature display panel 45 is mounted to allow the operator to easily grasp whether a fuel supply button 39 is available or not, and half-throttle release timing in using an engine tool including a manual half throttle trigger, thereby providing an engine 1 with significantly improved startability.

Description

  The present invention relates to an engine, particularly an engine suitable for a portable engine working machine such as a brush cutter or a chain saw.

  Conventionally, in order to facilitate starting of an engine at a low temperature or the like, for example, as shown in Patent Document 1, a starting fuel supplier that supplies an appropriate amount of starting auxiliary fuel to the intake passage to increase the fuel concentration of the mixture is provided. Engines equipped are known.

Japanese Utility Model Publication No. 64-29248

  In the above-described engine, there is a scene in which an operator cannot grasp the state of the engine and supply fuel, and an appropriate amount of fuel cannot be supplied by the starting fuel supplier.

  The present invention has been made in view of the above-described problems, and provides an engine capable of performing start operation more easily by increasing the reliability of fuel supply for start, and an engine work machine including the engine. Objective.

  In order to achieve the above object, an engine according to the present invention is characterized in that a starting fuel is first filled in a fuel storage by a primary pump, and then an electronic circuit for supplying a starting fuel is operated. . The electronic circuit is configured to operate by a battery pack, a dry battery, or a power supply by cranking, and is provided with a lamp such as a light bulb or LED that informs the operator that the circuit operates without any problem.

  Further, this circuit is provided with a thermocouple for detecting the surface temperature of the cylinder, and the supply amount of the starting fuel is varied depending on the temperature of the cylinder. In addition, when the cylinder temperature becomes equal to or higher than a certain temperature, it is possible to suppress engine fog and the like by adopting a configuration in which fuel is not supplied.

  As a result, cranking in the half throttle state after fuel supply makes it possible to start the engine with a small number of cranking operations. However, if the half throttle is released immediately, the engine will burn. Stops for a short time because less gas is needed. In order to improve this, the half-throttle may be maintained until the cylinder temperature rises to a certain temperature. In this control circuit, the current cylinder temperature detected by the thermocouple is indicated by a lamp such as a light bulb or LED. Is displayed.

  For this reason, since it becomes possible to determine the release timing of the half throttle by checking the lighting state of a lamp such as a light bulb or LED, it is easy even with an engine tool incorporating a manual half throttle trigger. It is now possible to start the engine.

  According to the engine of the present invention, after 2 cc or more of fuel is stored in the fuel storage chamber of the starting fuel supply device, the temperature of the cylinder is detected by a thermocouple, and starting at 40 ° C. or more without starting fuel. On the other hand, when the temperature of the cylinder is below normal temperature, the starter fuel suitable for the temperature of the cylinder is placed inside the insulator, and therefore, a supply system with excellent startability that is not affected by the temperature environment is provided. Can do.

1 is an external view of a chain saw equipped with a two-cycle engine according to an embodiment of the present invention. It is a side view of the chain saw carrying the 2 cycle engine concerning the embodiment of the present invention. It is the schematic diagram which showed the structure of the fuel supply apparatus for starting of the brush cutter which mounts the 2-cycle engine concerning embodiment of this invention. It is the schematic which showed the fuel storage chamber of the starting fuel supply apparatus of the chain saw carrying the 2 cycle engine concerning embodiment of this invention. It is the schematic which showed the lighting state of the LED lamp of the starter fuel supply apparatus of the chain saw carrying the 2 cycle engine concerning embodiment of this invention. It is the schematic which showed the lighting state of the temperature display panel of the starting fuel supply apparatus of the chain saw carrying the 2 cycle engine concerning embodiment of this invention. It is an external view of the chain saw carrying the 2-cycle engine concerning 2nd embodiment of this invention. It is the schematic which shows the fuel storage chamber of the starting fuel supply apparatus of the chain saw carrying the 2 cycle engine concerning 2nd embodiment of this invention.

  Embodiments of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 and 2, a chain saw 1001 equipped with a two-cycle engine 1 (hereinafter referred to as an engine) includes an engine case 1002 that houses the engine 1, and a guide bar 1004 that projects from the engine case 1002 and guides the saw chain 1003. A front handle 1005 and a rear handle 1006 held by the operator, and a starter handle 1007 for starting the engine 1. The output of the engine 1 is controlled by a throttle lever (not shown) provided on the rear handle 1006 and transmitted to the saw chain 1003 via a known drive mechanism.

  As shown in FIG. 3, a crankcase 4 is attached to the cylinder block 3 of the engine 1. In the cylinder bore 5 of the cylinder block 3, the piston 6 slides up and down (up and down in FIG. 3) in the direction of the axis 7 of the cylinder bore 5. In FIG. 3, the piston 6 is located at the bottom dead center. A spark plug 8 is attached to the cylinder head inner wall surface of the cylinder head portion facing the top surface of the piston 6 above the cylinder bore 5. The cylinder bore 5 is connected to the crank chamber 9 in the crankcase 4 at the lower side. The piston 6 is connected to a crankshaft 12 rotatably supported by the crankcase 4 via a piston pin 10 and a connecting rod 11. A crank weight 13 is attached to the crankshaft 12.

  An exhaust opening 15 connected to the exhaust port 14, an intake opening 17 connected to the intake port 16, and a scavenging opening (not shown) connected to a scavenging passage (not shown) are opened on the inner peripheral wall of the cylinder bore 5. A muffler 18 is connected to the cylinder block 3 so as to communicate with the exhaust port 14.

  An insulator 19 having an intake passage 22 communicating with the intake port 16 is connected to the cylinder block 3, and a carburetor 21 connected to an air cleaner 20 is connected to the insulator 19. Note that the primary pump 31 repeats compression deformation and elastic recovery to suck the fuel into the inside from the fuel suction port 32, while discharging the fuel sucked into the inside from the fuel discharge port 33. The operation unit 35 is provided.

  By repeatedly pressing the operation part 35 of the primary pump 31, the fuel storage device 36 is filled with the fuel storage part 25 of the carburetor 21, but this elastically deformable translucent operation part. Since 35 is disposed immediately in front of the fuel tank 29, the operator can visually confirm the filling state of the fuel storage device 36. When the fuel filling to the fuel storage device 36 is completed, the fuel storage part 25 of the carburetor 21 is filled with sufficient fuel, so that the fuel in the fuel storage part 25 of the carburetor 21 is insufficient and the engine It is possible to suppress the occurrence of a fundamental problem that 1 does not start.

  As shown in FIG. 4, the chain saw 1001 incorporates a primary pump 31 and a fuel storage device 36 capable of storing about 4 cc of fuel, and a control circuit 37. The operator drives the starting supply device by an operation panel 38. can do.

  When the primary pump 31 is pushed, the fuel 41 is filled in the fuel storage device 36 that can store about 4 cc of fuel. It is configured to return to the fuel tank provided on the handle 1006.

  The control circuit 37 can be operated by an operation panel 38 provided in the engine case 1002, and a fuel supply button 39 and an LED lamp 40 are disposed on the operation panel 38. By driving the fuel supply unit 62 formed of a solenoid valve by the fuel supply button 39, it becomes possible to supply the starting fuel stored in the fuel storage chamber 36. In the present embodiment, the control circuit 37, the fuel storage device 36, the fuel supply unit 62, and the like constitute a fuel supply device.

  As shown in FIG. 5, when the LED lamp 40 is lit when the fuel / fuel supply button 39 is pressed, this indicates that the control circuit is operating normally, and the fuel has been reliably supplied. Can be notified to the operator. If the LED lamp 40 at the top is not lit when the fuel supply button 39 is pressed, it indicates that the power supply for operating the control circuit normally is insufficient, and thus the power supply of the control circuit 37 is connected. In the case where the voltage applied to the capacitor of the ignition coil 43 is insufficient, it is necessary to perform cranking by the coil starter 1007 for the subsequent application. It should be noted that the cranking at this time is an operation unrelated to the start of the engine 1 as can be seen from the point that the purpose of the power generation is to the last and the fact that the starting fuel is not put in the insulator. After performing the cranking several times, when the fuel supply button 39 is pressed again and the LED lamp 40 is turned on, it can be determined that the starting fuel has been reliably supplied.

  In addition to the fuel supply button 39, an LED lamp check button may be provided separately. In this case, the LED lamp 40 may be turned on only when the LED lamp check button is pressed, and the LED lamp 40 may not be turned on when the LED lamp check button is not pressed, thereby reducing power consumption. In this way, it is possible to confirm whether or not the control circuit is in an operable state independently of the fuel supply operation. Further, it is possible to confirm that a temperature display panel 45 described later operates normally by turning on the LED lamp 40 described above.

  After the LED lamp 40 is turned on, the fuel 24 of the fuel storage device 36 is put into the intake passage 22 communicating with the intake port 16, and thereafter the trigger is set to the half throttle state and cranking is started. Although the engine 1 starts after several crankings, the temperature of the cylinder block 3 does not increase immediately after the engine 1 starts.

  If the temperature of the cylinder block 3 at this time is equal to or higher than normal temperature, the engine 1 continues to start even when the half throttle is released, but the engine 1 tends to stop as the temperature of the cylinder block 3 becomes lower. In order to solve this problem, the operator can confirm the release timing of the half throttle by the lighting state of the temperature display panel 45 that displays the temperature of the cylinder incorporated in the control circuit 37. .

  As shown in FIG. 6, in the temperature display panel 45, when the temperature of the cylinder block 3 is 70 ° C. or higher, all of the LED 46, LED 47, LED 48, and LED 49 are lit, and at 40 ° C., three of the LED 46, LED 47, and LED 48 are lit. At 46 ° C. or higher, the LED 46 and LED 47 are turned on, and at −20 ° C., only the LED 46 is turned on. That is, as the temperature rises, the lighting display changes in order from (a) to (d) in FIG. For example, in the temperature environment of −20 ° C. to 10 ° C., only the LED 46 is lit, but if the half throttle state is continued after the engine 1 is started, the temperature of the cylinder block 3 increases in a relatively short time. It becomes possible to make it. In this state, if the half throttle is continued until the temperature reaches 70 ° C. or higher, all of the LED 46, LED 47, LED 48, and LED 49 are lit, and then the problem that the engine 1 stops can be solved by releasing the half throttle. .

  It should be noted that once the LED 46, LED 47, and LED 48 in which the temperature of the cylinder block 3 is 40 ° C. or higher are turned on, the fuel 24 of the fuel storage device 36 is newly supplied to the intake passage 22 that communicates with the intake port 16. It is not necessary to insert the fuel 24, and it is possible to determine whether or not the fuel 24 can be additionally supplied by lighting the temperature display LED 45.

  Further, when the LEDs 48 and 49 are not lit, it indicates that additional supply of the fuel 24 is required. In this case, if the primary pump 31 is pushed again and the fuel storage device 36 capable of storing about 4 cc of fuel is refilled with the fuel 24, then the fuel 24 is put into the intake passage 22 communicating with the intake port 16. good.

  The starting fuel supply is set to supply 0 cc above 40 ° C, about 1 cc above 10 ° C, and about 4 cc above -20 ° C. Especially, it is configured to supply a large amount of starting fuel at low temperatures. However, this is because the fuel 24 is difficult to vaporize at low temperatures, and the fuel necessary for combustion is insufficient. Regarding the supply amount of the starting fuel, only a predetermined amount is supplied by the fuel supply button 39. Therefore, when the operator operates while checking the temperature operation panel 45, for example, the number of times fuel supply button corresponding to the number of light extinctions A desired amount can be selected and supplied by pressing 39 or the like. Here, a plurality of fuel supply buttons 39 may be provided on the operation panel 38 and a button 39 corresponding to the temperature display panel 45 may be provided. In that case, a configuration may be adopted in which a plurality of fuel storage chambers are provided to control the open state, or adjustment may be made by controlling the opening amount of the valve.

  When the engine 1 is started at a low temperature, if excess fuel 24 remains in the crank chamber 9, there is a concern that a malfunction may occur due to the fuel becoming thick. However, if the configuration is combined with the above-described half throttle, excess fuel is discharged outside the exhaust port during the half throttle.

  7 and 8 show a configuration in which a fuel for starting is supplied by a mechanical trigger as means for supplying fuel, and a plurality of fuel storage chambers are provided. FIG. 7 is an external view, and FIG. 8 is a schematic view of a fuel supply device. The fuel sent from the first fuel passage 26 is filled in the fuel storage chamber A41 and the fuel storage chamber B42 disposed in the fuel storage device 36, and the excess fuel 24 passes through the second fuel passage 27 and the fuel tank 29. Will return. The fuel storage chamber A41 is provided with a trigger A50, an insulator through hole A51, and a trigger spring A52, and the fuel storage chamber B42 is provided with a trigger B53, an insulator through hole B54, and a trigger spring B55.

  The fuel storage device upper cover 56, the fuel storage device lower cover 57, and the rubber packing 58 are fixed by screws 59, and an O-ring 60 is attached to the trigger A51 and the trigger B54 for the purpose of preventing leakage of the fuel 24. . Further, the excess fuel 24 returns to the fuel tank 29 through the second fuel passage 27. However, since the steel ball 61 is attached as a back support valve at this position, the fuel 24 does not flow backward.

  As described above, by installing the temperature display panel 45, the operator can easily use the fuel supply button 39 and the release timing of the half throttle when using an engine tool incorporating a manual half throttle trigger. As a result, it becomes possible to supply the engine 1 with greatly improved startability.

  The engine 1 described above is not limited to a two-cycle engine, and may be a four-cycle engine. In the above-described embodiment, the engine 1 is mounted on the chain saw 1001. However, the engine 1 is not limited to being mounted on the chain saw 1001, but a cutter, a brush cutter, a blower, a hedge trimmer with relatively poor startability. It may be mounted on an engine working machine such as a generator.

DESCRIPTION OF SYMBOLS 1 Engine 2 Engine cover 3 Cylinder block 4 Crankcase 5 Cylinder bore 6 Piston 7 Axis 8 Spark plug 9 Crank chamber 10 Piston pin 11 Connecting rod 12 Crankshaft 13 Crankweight 14 Exhaust port 15 Exhaust opening 16 Intake port 17 Intake opening 18 Muffler 19 Insulator 20 air cleaner 21 carburetor 22 intake passage 23 insulator through-hole 24 fuel 25 fuel storage device 26 first fuel passage 27 second fuel passage 28 third fuel passage 29 fuel tank 30 fuel intake port 31 primary pump 32 fuel suction port 33 fuel Discharge port 34 Fourth fuel passage 35 Operation unit 36 Fuel storage device 37 Control circuit 38 Operation panel 39 Fuel supply button 40 LED lamp 41 Fuel storage chamber A
42 Fuel storage chamber B
44 Thermocouple 45 Temperature display panel 46 LED
47 LED
48 LED
49 LED
50 Trigger A
53 Trigger B
54 Insulator through-hole B
55 Trigger Spring B
62 Fuel supply unit 1001 Chain saw according to the first embodiment 2001 Chain saw according to the second embodiment

Claims (13)

A cylinder forming a combustion chamber; a crankcase attached to the cylinder; an intake opening connected to the crankcase of the crankcase; an intake passage connected to the intake opening; and fuel supplied from a fuel tank. An engine comprising a carburetor for storing and supplying fuel into the intake passage, and a starting fuel supply device for supplying a predetermined amount of fuel to a path to the combustion chamber by operation of an operation unit,
Temperature detecting means for detecting the temperature of the cylinder, and temperature notifying means whose display changes based on the output of the temperature detecting means, wherein the starting fuel supply device selects the fuel from a plurality of predetermined amounts. An engine characterized by being able to be supplied.   The starting fuel supply device includes a plurality of starting fuel storage chambers, and can supply the predetermined amount of fuel by opening any one or more of the plurality of starting fuel storage chambers. The engine according to claim 1, wherein the engine is configured as follows.   The engine according to claim 2, wherein the plurality of starting fuel storage chambers have different storage amounts of the fuel.   4. The amount of fuel supplied by operating the operating portion of the starting fuel supply device varies according to the temperature condition detected by the temperature detecting means. The engine according to any one of the above.   5. The start fuel supply device includes a second operation unit capable of supplying an amount of fuel different from that supplied by operation of the operation unit. 6. The engine according to one item.   The starting fuel supply device includes a plurality of starting fuel storage chambers, and the plurality of starting fuel storage chambers select either the output of the temperature detection means or the plurality of operation units. 6. The engine according to claim 4 or 5, wherein the number released is changed.   The engine according to claim 1, wherein the starting fuel supply device is capable of supplying fuel of 2 cc or more.   The engine according to any one of claims 1 to 7, further comprising operation availability confirmation means for notifying whether or not the starting fuel supply device is operable.   The engine according to any one of claims 1 to 8, wherein the operation unit and the temperature display unit are provided on substantially the same operation surface.   The start supply apparatus includes a start fuel storage chamber, and the start fuel storage chamber is connected between fuel paths of the fuel tank and the carburetor. Item 10. The engine according to any one of Items 9 to 9.   A control circuit, the output of the temperature detection means is input to the control circuit, the control circuit outputs a voltage according to the output of the temperature detection means to the temperature notification means, and by operating the operation unit The engine according to any one of claims 1 to 10, wherein fuel supply is controlled.   The engine according to any one of claims 1 to 11, wherein the temperature detection means is constituted by a thermocouple.   An engine working machine comprising the engine according to any one of claims 1 to 12.