JP2013189958A - Engine working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and easily align an intake pipe of an internal combustion engine with an insulator.SOLUTION: An engine working machine includes an engine 12 and a carburetor 13 connected via an elastic insulator 15. The engine working machine includes: a flange part 26a disposed at an end of an intake pipe 26 protruding from a cylinder outer wall of the engine 12; and a cover part 43 disposed at one end of the insulator 15 and receiving the flange part 26a of the intake pipe 26. A projection 46 is formed on an inner face 44 of the cover 43, while a recess 29 to which the projection 46 is to be fitted, is formed on an end face 27 of the flange part 26a covered with the inner face 44.

Description

  The present invention relates to an engine working machine using an internal combustion engine as a drive source, and more particularly to an engine working machine in which an internal combustion engine and a carburetor are connected via an elastic insulator.

  Chain saws and cutters are known as examples of engine working machines that use an internal combustion engine as a drive source. For example, in a cutter (engine cutter) using an internal combustion engine as a drive source, a frame or a base on which a handle gripped by an operator is formed includes an internal combustion engine and a carburetor that supplies an air-fuel mixture to the internal combustion engine. Yes. Specifically, the internal combustion engine is mounted on a frame or base via an elastic body such as a rubber bush or a spring, and the carburetor is fixed to the frame or base.

  Further, in order to block vibration and heat transfer from the internal combustion engine to the carburetor, the internal combustion engine and the carburetor are connected via an elastic insulator (generally a rubber insulator). Specifically, the other end of the insulator, one end of which is connected to the carburetor, is connected to the end of the intake pipe that protrudes from the cylinder outer wall of the internal combustion engine. More specifically, the end portion of the insulator is put on the end portion of the intake pipe and both are connected. In other words, the end of the intake pipe is inserted inside the end of the insulator (Patent Document 1).

JP-A-11-280573

  When the internal combustion engine and the carburetor are connected via a rubber insulator, various problems occur if the intake pipe and the insulator of the internal combustion engine are not accurately aligned. For example, as a result of twisting of the insulator, unnecessary stress may act on the insulator and the insulator may be torn.

  In a piston valve type internal combustion engine, it is preferable that the intake port has a quadrangular shape or a shape close to a quadrangular shape in order to secure an opening area of the intake port formed on the inner wall surface of the cylinder. It is preferable for the intake port to be square in order to accurately set the intake timing and time. On the other hand, in order to manufacture a cylinder using a mold that can be manufactured at low cost, it is not preferable that the cross-sectional shape of the intake pipe communicating with the intake port changes rapidly. For this reason, when the intake port has a quadrangular shape or a shape close to a quadrangle for the reasons described above, the cross-sectional shape of the intake pipe is also preferably a quadrangular shape or a shape close to a quadrangular shape. However, when the cross-sectional shape of the intake pipe is a quadrangle or a shape close to a quadrangle, if the intake pipe and the insulator are not accurately aligned, a step is generated on the attachment surfaces of the two. If there is a step on the attachment surface between the intake pipe and the insulator, liquefied fuel accumulates at the step, and when the engine is tilted, the accumulated fuel may flow into the engine and stall the engine.

  An object of the present invention is to enable accurate and easy alignment between an intake pipe and an insulator of an internal combustion engine.

  The engine working machine of the present invention is an engine working machine in which an internal combustion engine as a drive source and a carburetor for supplying a mixture to the internal combustion engine are connected via an elastic insulator, and the cylinder of the internal combustion engine An intake pipe projecting from an outer wall, a flange portion provided at an end of the intake pipe forming a flow path communicating with an intake port provided in an inner wall of the cylinder, and provided at one end of the insulator; A cover portion that receives the flange portion of the pipe, and a concave portion is formed on one of the inner surface of the cover portion and the outer surface of the flange portion covered by the inner surface, and a convex portion that fits in the concave portion is formed on the other side. And the rotation of the circumferential direction of the said flange part and the said insulator is controlled because the said recessed part and a convex part mutually fit.

  In the engine work machine according to the present invention, one of the concave portion and the convex portion is formed on an end surface of the flange portion, and the other is formed in a region of the inner surface of the cover portion that overlaps the end surface of the flange portion. Yes.

  In the engine working machine of the present invention, either one of the concave portion and the convex portion is formed on a side surface of the flange portion, and the other is formed in a region overlapping with the side surface of the flange portion on the inner surface of the cover portion. Yes.

  In the engine working machine of the present invention, two or more sets of the concave portion and the convex portion are provided.

  In the engine working machine of the present invention, a bellows portion is provided between one end of the insulator where the cover portion is provided and the other end opposite to the one end.

  In the engine working machine according to the present invention, a reinforcing member made of a material having rigidity higher than that of the insulator is embedded in the cover portion of the insulator.

  According to the present invention, it is possible to accurately and easily align the intake pipe and the insulator of the internal combustion engine.

It is sectional drawing of the engine cutter to which this invention was applied. It is a partial expanded sectional view of the engine cutter shown by FIG. It is a perspective view of a cylinder. It is an expansion perspective view of an insulator. It is a disassembled sectional view which shows the connection part of an insulator and an engine. It is a schematic diagram which shows the state which the opening part of the insulator and the intake pipe shifted.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an engine cutter 1 to which the present invention is applied. The illustrated engine cutter 1 includes a main body 2, a blade (rotary blade) 4 rotatably attached to the tip of an arm 3 extending from the main body 2, and a guard 5 that covers a part of the blade 4. The main body 2 includes a rear handle 10 and a front handle 11, and an internal combustion engine 12 (hereinafter referred to as "engine 12") and a carburetor 13 are mounted thereon. Further, the arm 3 extending from the main body 2 incorporates a transmission mechanism for transmitting the driving force output from the engine 12 to the blade 4, and the blade 4 is driven by the driving force transmitted through this transmission mechanism. Driven by rotation.

  The engine 12 is fixed to the main body 2 via an elastic body 14 such as a rubber bush or a spring. The carburetor 13 is fixed to the main body 2 behind the engine 12 (on the rear handle side). Further, the engine 12 and the carburetor 13 are connected via an insulator 15.

  As shown in FIG. 2, the engine 12 has an integrated cylinder case 20 (hereinafter referred to as “cylinder 20”) and a crankcase 21, and a piston 22 is disposed inside the cylinder 20 so that the piston 22 can be raised and lowered. Has been. The illustrated piston 22 is at the top dead center position. An ignition plug 23 is provided in the upper part of the cylinder 20, and an intake port 24 and an exhaust port 25 that are opened and closed by a piston 22 that moves up and down are formed on the inner wall of the cylinder 20. As shown in FIG. 3, an intake pipe 26 that forms a passage communicating with the intake port 24 (FIG. 2) extends from the outer wall of the cylinder 20. The intake pipe 26 is cast integrally with the cylinder 20.

  On the other hand, as shown in FIG. 2, a crank weight 34 that is rotatably supported by a crank shaft 33 is disposed in the crank case 21, and the crank weight 34 and the piston 22 are connected via a connecting rod 35. ing. A scavenging passage 36 is formed between the crankcase 21 and the cylinder 20.

  The insulator 15 is made of an elastic body (rubber in this embodiment). As shown in FIG. 4, one end of a tubular main body 40 having a bellows portion 40a is connected to the vaporizer 13 (FIG. 2). A fixed portion 42 is integrally formed, and a cover portion 43 connected to the intake pipe 26 (FIG. 3) of the engine 12 is integrally formed at the other end. Two notches 42 a are formed in the fixed portion 42, and the insulator 15 is attached to the vaporizer 13 by fitting the notches 42 a to protrusions formed on a bracket (not shown). Positioned and fixed.

  The cover portion 43 includes an extended portion 43a that extends in parallel with the opening surface from the periphery of the opening portion 40b of the main body portion 40, and an annular portion 43b that extends in a direction substantially orthogonal to the opening surface from the periphery of the extension portion 43a. When connecting the insulator 15 to the intake pipe 26 of the engine 12, as shown in FIG. 5, the cover portion 43 of the insulator 15 is put on a circular flange portion 26 a formed at the end of the intake pipe 26. In other words, the flange portion 26 a formed at the end portion of the intake pipe 26 is inserted into (inserted into) the cover portion 43. That is, the cover portion 43 of the insulator 15 receives the flange portion 26 a formed at the end portion of the intake pipe 26.

  When the insulator 15 and the intake pipe 26 are connected as described above, it is obvious that the outer surface of the flange portion 26a of the intake pipe 26 is covered by the inner surface of the cover portion 43 of the insulator 15. Specifically, the end surface 27 of the flange portion 26 a is covered with the inner surface 44 of the extended portion 43 a of the cover portion 43, and the side surface 28 of the flange portion 26 a is covered with the inner surface 45 of the annular portion 43 b of the cover portion 43.

  As shown in FIGS. 4 and 5, a pair of convex portions 46 are formed on the inner surface 44 of the extended portion 43 a of the cover portion 43 so as to face each other with the opening 40 b interposed therebetween. On the other hand, as shown in FIGS. 3 and 5, a pair of concave portions 29 are formed on the end surface 27 of the flange portion 26 a that is covered by the inner surface 44 of the expansion portion 43 a so as to face each other with the opening portion 26 b of the intake pipe 26 interposed therebetween. ing.

  4 and 5, a ring-shaped protrusion 47 is formed on the inner surface 45 of the annular portion 43b of the cover portion 43 over the entire circumference. On the other hand, as shown in FIGS. 3 and 5, a ring-shaped groove 30 is formed on the side surface 28 of the flange portion 26 a covered by the inner surface 45 of the annular portion 43 b over the entire circumference.

  When connecting the insulator 15 to the intake pipe 26, the convex portion 46 formed on the cover portion 43 of the insulator 15 is fitted into the concave portion 29 formed on the flange portion 26 a of the intake pipe 26, and the insulator 15 The protrusion 47 formed on the cover portion 43 is fitted into the groove 30 formed on the flange portion 26 a of the intake pipe 26.

  Here, when the convex part 46 formed in the cover part 43 of the insulator 15 and the concave part 29 formed in the flange part 26a of the intake pipe 26 are fitted together, the opening part of the main body part 40 is formed. The position and dimensions are set so that 40b and the opening 26b of the intake pipe 26 are abutted with no gap and no step is generated between them. Therefore, by fitting the concave portion 29 and the convex portion 46 to each other, the insulator 15 and the intake pipe 26 are aligned accurately and easily, and the circumferential rotation of the insulator 15 and the intake pipe 26 is restricted. . Therefore, the assemblability is improved, and the position difference between the opening 40b of the insulator 15 and the opening 26b of the intake pipe 26 as shown in FIG. Further, since no step is generated between the opening 40b of the insulator 15 and the opening 26b of the intake pipe 26, the opening 40b of the insulator 15 and the opening 26b of the intake pipe 26 are formed in the same shape having a substantially rectangular shape. Thus, the cylinder 20 (FIG. 3) can be cast using an inexpensive mold.

  The insulator 15 and the intake pipe 26 connected as described above are fastened by a hose band 50 shown in FIG. Specifically, it is fastened by a hose band 50 wound around an annular portion 43b of a cover portion 43 that covers the side surface 28 of the flange portion 26a. Therefore, a positioning groove 48 for positioning the hose band 50 is formed on the outer surface of the annular portion 43b of the cover portion 43 over the entire circumference.

  By connecting the carburetor 13 and the engine 12 via the insulator 15 as described above, a flow path for supplying an air-fuel mixture is formed between the carburetor 13 and the engine 12. At this time, since the insulator 15 is made of rubber and includes the bellows portion 40a, vibration and heat of the engine 12 are prevented from being transmitted to the vaporizer 13.

  Further, the insulator 15 includes a fixing portion 42 and a cover portion 43 that are integrally formed at both ends of the main body portion 40 including the bellows portion 40a. For this reason, even if the insulator 15 is made of a single material, the rigidity of the main body portion 40 is substantially lower than that of the fixed portion 42 and the cover portion 43. Therefore, the main body 40 is easily bent or deformed, and a gap is hardly generated between the insulator 15 and the engine 12. In addition, in order to increase the difference in rigidity between the main body portion 40 and the fixing portion 42 and the cover portion 43, a reinforcing member made of a material having higher rigidity than the material of the insulator 15 may be embedded in the fixing portion 42 or the cover portion 43. For example, a metal reinforcing member may be cast into the cover portion 43.

  Further, as a result of the carburetor 13 being pulled away from the engine 12 while the engine cutter 1 is in use, even if the insulator 15 is pulled in the same direction, the convex portion 46 on the insulator side fits into the concave portion 29 on the engine side. As a result, the gap volume generated between the insulator 15 and the engine 12 is reduced, and the occurrence of fuel accumulation is suppressed.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the convex portion is formed on the insulator side and the concave portion is formed on the engine side. However, there is an embodiment in which the concave portion is formed on the insulator side and the convex portion is formed on the engine side. There is also an embodiment in which a convex portion or a concave portion is formed on the inner surface of the annular portion of the cover portion of the insulator and a concave portion or a convex portion is formed on the side surface of the flange portion of the intake pipe. Moreover, one set may be sufficient as the group of the recessed part and convex part which mutually fit, and three or more sets may be sufficient as it. The present invention can be applied to engine working machines other than the engine cutter, and in that case, the same effects as described above can be obtained.

1 Engine cutter 2 Body 12 Engine (Internal combustion engine)
DESCRIPTION OF SYMBOLS 13 Vaporizer 15 Insulator 20 Cylinder 24 Intake port 26 Intake pipe 26a Flange part 27 End surface 28 Side surface 29 Concave part 40 Main part 40a Bellows part 43 Cover part 43a Expansion part 43b Annular part 44, 45 Inner face 46 Convex part

Claims (6)

An engine working machine in which an internal combustion engine as a drive source and a carburetor for supplying an air-fuel mixture to the internal combustion engine are connected via an elastic insulator,
An intake pipe projecting from the cylinder outer wall of the internal combustion engine, and a flange portion provided at an end of the intake pipe forming a flow path communicating with an intake port provided in the cylinder inner wall;
A cover portion provided at one end of the insulator and receiving the flange portion of the intake pipe;
A concave portion is formed on one of the inner surface of the cover portion and the outer surface of the flange portion covered by the inner surface, a convex portion that fits into the concave portion is formed on the other side, and the concave portion and the convex portion are fitted to each other. An engine working machine characterized in that circumferential rotation of the flange portion and the insulator is restricted.   One of the concave portion and the convex portion is formed on an end surface of the flange portion, and the other is formed in a region of the inner surface of the cover portion that overlaps the end surface of the flange portion. The engine working machine according to 1.   One of the concave portion and the convex portion is formed on a side surface of the flange portion, and the other is formed in a region of the inner surface of the cover portion that overlaps the side surface of the flange portion. The engine working machine according to 1.   The engine working machine according to any one of claims 1 to 3, wherein two or more sets of the concave portion and the convex portion are provided.   The bellows portion is provided between one end of the insulator where the cover portion is provided and the other end opposite to the one end, according to any one of claims 1 to 4. The engine working machine described.   The engine working machine according to any one of claims 1 to 5, wherein a reinforcing member made of a material having rigidity higher than that of the insulator is embedded in the cover portion of the insulator.

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