JPH0223810Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention is designed to prevent heat conduction between the engine and the carburetor attached to the case that supports the engine. This relates to a heat insulating device for a vaporizer in which a rubber heat insulating tube is interposed between the vaporizer and the vaporizer.

(Prior Art and Problems to be Solved) Conventionally, in portable engines such as chainsaws, a handle is provided in the case surrounding the engine to prevent engine vibrations from being transmitted to the hands of the worker who holds the handle. In order to avoid this problem, the case was divided into an upper case to which the engine was fixed and a lower case to which the handle was fixed, and the upper case was supported by the lower case through a vibration isolator such as rubber. In addition, since the carburetor is fixed to the engine, in order to prevent the heat of the engine from being conducted to the carburetor, the engine and carburetor are connected by a vibration-proof tube made of a heat-insulating material such as synthetic resin. Something was being done. When this heat insulating cylinder is made of rubber with a high heat insulating effect, the flange provided at the end of the heat insulating body is fixed to the carburetor via a retaining plate fixed to the case, but the engine When providing a pulse passage that communicates between the crankcase and the pulse pump of the carburetor by penetrating the heat insulating cylinder, the flange protrudes at the pulse passage part and is not circular. The intake passage could not be maintained uniformly, and there was a risk that the intake passage would deform and fuel would accumulate, making engine rotation unstable at low speeds.

In addition, if the outer periphery of the heat shield is circular and a separate pulse passage is provided outside of the heat shield by penetrating the flanges at both ends, the distance between the flanges can be adjusted so that the carburetor fixed to the upper case is It changes depending on the time error, so
It was difficult to connect the pulse passage that communicated between the two flanges.

[Structure of the invention] (Means and effects for solving the problem) The invention provides one end of a rubber heat-insulating cylinder fixed to the intake port of the engine by a first flange provided with a reinforcing plate. At the same time, a rigid holding plate with a circular inner diameter part is provided to sandwich the second flange part provided at the other end between the carburetor and the pulse pump installed in the carburetor for pumping fuel. A communicating protruding pipe is provided to protrude from the holding plate, and one end of the protruding pipe is inserted and removably engaged with the other end of the pulse passage communicating with the crankcase of the engine by penetrating the first flange. This allows the flange to be fixed at a position close to the intake passage of the insulating cylinder, while the circular inner diameter part holds the outer diameter part of the insulating cylinder in a circular shape, preventing fuel from accumulating due to deformation of the intake passage. Moreover, the structure can be simplified without requiring a pulse path using a separate pipe.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the figure, numeral 1 indicates a chain saw, which is constructed as follows. That is, the main body case 3 is divided into an upper case 5 and a lower case 7. The upper case 5 houses and fixes the engine 9 and the lubricating oil tank 11, and the lower case 7 houses the rear handle 13 and the front part. A handle 15 and a fuel tank 17 are fixed. The lower case 7 is connected to the upper case 5 via a rubber vibration isolator (not shown), and is provided to prevent the vibrations of the engine 9 from propagating to the hands of the worker who grips the front handle 15 and rear handle 13. It is being A protector 19 is fixed to the upper part of the upper case 5 to protect the hand of a worker who grips the front handle 15, and a saw chain 23 is provided which rotates by hanging around the outer circumference of a guide bar 21 fixed to the side part. It is being A throttle lever 25 is attached to the rear handle 13. The spark plug 29 is in the cylinder 27 of the engine 9.
A piston 31 is connected to a crankshaft (not shown) via a connecting rod 33. A carburetor 39 is connected to the intake port 35 of the cylinder 27 via a vibration-proof cylinder 37 made of soft rubber.
An air cleaner 41 is connected to the other end of the carburetor 39, and a cover 4 is detachably fixed to the upper case 5.
3 by means of a handle 45 in a detachable manner. A first flange 48 to which a reinforcing plate 47 is baked and fixed to the end face of the insulating cylinder 37 on the side of the inlet 35 is fixed to the inlet 35 by bolts (not shown) provided on both left and right sides. . Further, a second flange portion 49 is formed on the side surface on the carburetor 39 side, and a circular inner diameter portion 51
Bolts (not shown) are clamped by rigid synthetic resin holding plates 53 and provided on both left and right sides.
It is fixed by. The presser plate 53 is provided with a projecting pipe 55 that communicates with a pulse port 54 that communicates with a pulse pump (not shown) provided in the carburetor 39, and an intake passage that passes through the center of the heat insulating cylinder 37. 57, the first flange 48 of the heat insulating cylinder 37
A pulse passage 63 is provided with one end communicating with a pulse hole 61 that communicates with the inside of the crankcase 59, and the tip of the projecting tube 55 is removably engaged with the other end of the pulse passage 63. are doing. The pulse pump pumps fuel using a diaphragm (not shown) that oscillates depending on the positive and negative pulsating pressure of the crankcase 59, and is the same as a commonly used pump, so a detailed explanation will be omitted here. The upper part of the holding plate 53 is attached to the cover 43 with a screw (not shown).
The upper part of the shielding plate 65 made of soft rubber is held between the upper part of the shielding plate 65 and the upper part of the shielding plate 65 made of soft rubber. The lower part of the shielding plate 65 is locked to the crankcase 59, and a sealing piece 67 provided in a part thereof is in contact with the lower case 7. Further, a space 69 is formed between the shielding plate 65 and the holding plate 53.

In the above embodiment, the carburetor 39 is fixed to the upper case 5 to which the engine 9 is fixed via a cover 43, and the carburetor 39 and the intake port 35 are connected by a heat insulating cylinder 37. The heat insulating cylinder 37 is held in a circular shape by the reinforcing plate 47 and the inner diameter portion 51 of the holding plate 53. The pulsating pressure inside the crankcase 59 is controlled by the pulse hole 61, the pulse passage 63, the protrusion pipe 55,
A pulse pump (not shown) is operated through the pulse port 54 to pump fuel. The heat of the cylinder 27 is blocked by the heat insulating cylinder 37 and does not propagate to the carburetor 39.
The radiant heat and heat convection of 7 are blocked by the shielding plate 65, the space 69, and the holding plate 53, and the vaporizer 39
Never heat.

[Effect of idea]

Since the present invention has the configuration as described in the claims, it is possible to fix the flange of the heat insulating cylinder while holding it in a circular shape at a position close to the intake passage, thereby preventing fuel from accumulating due to deformation of the intake passage. It does not cause engine malfunction, and by using a soft rubber insulation cylinder, the insulation effect for the carburetor is improved, preventing the temperature of the carburetor from rising, and the pulse passage can be connected to separate piping. It is not necessary and can be provided with a simple structure.

In addition, by engaging the protruding tube with the pulse passage of the first flange portion in a freely insertable and removable manner, the protruding tube inserted into the pulse passage can be adjusted in response to changes in the distance between the two flange portions due to assembly of the carburetor. The pulse path is maintained by moving in the in/out direction.

[Brief explanation of the drawing]

FIG. 1 is a side view of a chain saw equipped with a device according to the present invention, FIG. 2 is a side sectional view of one embodiment of the present invention, and FIG. 3 is an enlarged side sectional view of the main parts. 9...Engine, 35...Intake port, 37...Heat insulating tube, 39...Carburizer, 48...First flange, 49
...Second flange portion, 51...Inner diameter portion, 53...Press plate, 55...Protrusion pipe, 57...Intake passage, 59...
...Crankcase, 63...Pulse passage.

Claims (1)

[Scope of utility model registration request] A heat insulating tube 37 made of rubber is provided between the intake port 35 and the carburetor 39 of the engine to communicate the inlet port 35 and the carburetor 39, and one end of the heat insulating tube 37 is connected to a reinforcing plate 47. The first flange 48 provided with
A rigid holding plate 53 is fixedly attached to the intake port 35 of the engine 9 by means of a circular inner diameter part 51 that is fixed to the intake port 35 of the engine 9 and that holds the second flange part 49 provided at the other end between the second flange part 49 and the carburetor 39. A protruding pipe 55 is provided in the carburetor 39 and communicates with a pulse pump for pumping fuel, protruding from the holding plate 53, passing through the first flange 48 and connecting one end to the engine. A heat insulating device for a carburetor, characterized in that the tip of the protruding tube 55 is removably engaged with the other end of a pulse passage 63 that communicates with the inside of the crankcase 59.