JPS6115255Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an internal combustion engine, and more specifically relates to a mounting structure for a recoil starter in an internal combustion engine in which the recoil starter is attached to a fan case. The purpose of this invention is to provide an internal combustion engine in which tilting or displacement can be regulated within an allowable range, thereby promoting thinner and lighter fan cases and reducing the cost of the engine as a whole. It is something.

Hereinafter, the internal combustion engine of the present invention will be explained based on the embodiment shown in FIGS. 1 to 9. FIG. 1 shows a vertical water-cooled diesel engine Z according to the embodiment of the present invention. In Fig. 1, reference numeral 1 indicates a piston, an engine main body 4 consisting of a cylinder block 2 and a cylinder head 3, 5 an engine shaft, and 6 an engine shaft 5 with its blades 7, 7, . . . directed toward the end 5a of the engine shaft 5. The centrifugal cooling fan is fixed in place and doubles as a flywheel. Reference numeral 8 indicates a camshaft. A fan case 20 is attached to the outside of the cooling fan 6 so as to surround the cooling fan 6.

The fan case 20 is composed of an inner fan case 21 that is attached to the engine body 1 side and an outer fan case 22 that is attached to the outside. It is supported in an anti-vibration manner. That is, the fan case 20 is
As shown in FIG. 4, an annular air inlet 24 is formed around the engine shaft insertion hole 23 of the side plate 21a of the inner fan case 21, and the engine body 1 is formed at the outer peripheral edge 24a of the air inlet 24. Three bolt receivers 26, 26, . These bolt receiving parts 26, 26... are formed by making a part of the inner fan case side plate 21a protrude outward in a cylindrical shape, as shown in FIG.
A cylindrical anti-vibration rubber 2 is provided inside the bolt receiving portions 26, 26...
7, 27... (corresponding to the vibration isolating member within the scope of the utility model registration claim) are inserted. This anti-vibration rubber 2
7 is a flange-shaped annular projection 2 formed on the inner circumferential surface of the bolt receiving part 26 in an annular groove 27a formed on the outer circumferential surface thereof.
By fitting 6a, the vibration isolating rubber 27
This prevents it from slipping out in the axial direction. Therefore, the fan case 20 has its bolt receiving portion 2
6, 26... are the side walls 2a of the cylinder block 2.
By abutting the fan case mounting bases 9, 9, . The reference numeral 25 indicates a wire mesh attached to the air inlet 24 to prevent foreign matter from entering, 28 indicates a sleeve, and 29 indicates a washer. Further, a gap 32 formed between the side wall 2a of the cylinder block 2 and the side plate 21a of the inner fan case 21 acts as a passage for the intake air of the cooling fan 6. In addition, code 6
A cooling fan 7 is formed on the side wall 2c of the crank chamber so as to project into the cavity 32, and serves to cool the lubricating oil within the crank chamber.

On the other hand, a recoil starter 18 is attached to a side plate 22a of the outer fan case 22 facing the outer end side of the cooling fan 6 so as to be coaxial with the engine shaft 5. The recoil starter 18 includes a rope pulley 19 around which a starter rope 36 is wound, a crank pulley 19 that is removably engaged with the rope pulley 19 via a dog 30, and a recoil starter cover 65 that connects the crank pulley 19 to an outer fan case. The brake spring 16 is rotatably mounted on a shaft 10 fixed to the side plate 22a, and is provided through the shaft 10 in the axial direction by a threaded center shaft 13 and a brake spring 16. Movement in the axial direction is restricted. Inner end 13a of this central shaft 13
, there is a cylindrical portion 17 with an appropriate inner diameter that opens toward the engine shaft 5 side.
are integrally formed. A cylindrical liner 39 made of sintered alloy or the like is fitted into the cylindrical portion 17 under strong pressure. This liner 39 is attached to the engine shaft 5
The recoil starter 18 acts as a steady rest member for restricting movement of the recoil starter 18 in the radial direction, and its inner circumferential surface serves as an engagement surface for the engine shaft 5. The liner 39 has the distal end 5b of the engine shaft 5 protruding further outward from the boss portion 6a of the cooling fan 6 fitted into the liner 39 in a loose and overlapping state with each other in the radial direction. On the other hand, the crank pulley 12 is formed into a cylindrical shape with a bottom, and is fastened to the boss portion 6a of the cooling fan 6 with its open end facing the rope pulley 19 side. This crank pulley 12 and rope pulley 19 are
When the shafts 9 rotate in the engine starting direction (in the direction of arrow A in FIG. 6), they are engaged with each other by the docks 30 and act to rotate the engine shaft 5 together with the crank pulley 12. On the other hand, after the engine is started, the engagement by the dock 30 is removed, and only the crank pulley 12 continues to rotate together with the cooling fan 6, and the rope pulley 19 is moved in the opposite direction by the return spring 15 to the position before starting (Fig. 6, arrow direction B).

In the illustrated embodiment, the rope pulley 19 of the recoil starter 18 and the exhaust valve tappet 66 (sixth
A decompression device X is provided between the internal combustion engine and the internal combustion engine to make the combustion chamber in a non-compressed state at the time of starting the internal combustion engine to facilitate rotation at the time of starting.

This decompression device X, as shown in FIG.
By rotating the tappet 66 at an appropriate angle,
A decompression shaft 50 that acts to lift the
and a decompletion reel 40 coaxially fixed to the rope pulley 19 are connected by an intermediate member Y having a link 59 and a decompression yoke shaft 60, which will be described in detail later.

The decompression shaft 50 is constituted by a rotatably supported straight rod of an appropriate length, and one end 50a of the decompression shaft 50 is
has a corner sliding surface 53 close to the decompression shaft axis.
A corner sliding protrusion 53 is formed having a peripheral surface 53b spaced apart from the axis a by an appropriate distance.

This decompression shaft 50 has a corner sliding surface 53a on one end 50a of the decompression shaft 50, which is connected to the tappet 66 at the lowest position.
are placed close to and facing each other on the lower surface of the.

Therefore, when the decompression shaft 50 is rotated so that the peripheral surface 58b of the square projection 53 faces the lower surface of the tappet 66, the tappet 66 is lifted upward by the peripheral surface 53b, and the exhaust valve is opened. In other words, when the corner sliding surface 53a of the tappet 66 is opposed to the lower surface of the tappet 66, the decompression action on the exhaust valve is released.
On the other hand, a lever member 51 is fixed to the other end 50b of the decompression shaft 50. This lever member 51
is always urged by a return spring 52 to rotate in the direction of arrow H (decompression release direction). Note that this decompression shaft 50 has a tappet 66.
The rotational position during decompression is maintained by the frictional force between the lower surface of the tappet 66 and the circumferential surface 53b of the corner sliding protrusion. When the angular sliding protrusion circumferential surface 53b is spaced apart from each other, the decompression shaft 5
0 is rotated in the direction of arrow H by the spring force of the return spring 52 and returns to the decompression release position.

Next, the guide groove 41 is shown in FIGS. 7 to 9.
The detailed configuration and operation of the starter rope 36 (sixth
The rotation of the rope pulley 19 and decomp reel 40 that rotate based on the pull-out operation in Figure 6 is referred to as forward rotation, and the direction of rotation (direction of arrow A in Figure 6) is referred to as forward rotation, and the opposite rotation direction.
That is, the rotation of the rope pulley 19 and the decomp reel 40 in the direction of winding the starter rope 36 is called a reverse rotation, and the direction of rotation (direction of arrow B in FIG. 6) is called a reverse rotation direction.

Also, when the decomp reel 40 rotates in the forward direction, the apparent travel of the actuator 33 relative to the decomp reel guide groove 41 is referred to as forward travel, and its travel direction (direction of arrow A' in FIGS. 8 and 9). )
is called the forward running direction, and the apparent running of the actuator 33 relative to the decomp reel guide groove 41 when the decomp reel 40 rotates in the reverse direction is called the reverse running direction. In FIGS. 8 and 9, the direction of arrow B') is referred to as the reverse running direction.

The structure and function of the decomp reel guide groove 41 will be explained below according to the above definition. FIG. 8 shows a developed view of the decomp reel guide groove 41.

In FIG. 8, thick black arrows indicate the (apparent) forward running locus of the actuator 33 with respect to the guide groove 41, and thick white arrows indicate the (apparent) reverse locus of the actuator 33 with respect to the guide groove 41. ing. In addition, in Fig. 8, the white groove portion is a low-bottom groove portion with a low groove bottom, the double diagonal line groove portion is a high-bottom groove portion with a high groove bottom, and the single diagonal line groove portion is formed between a low-bottom groove portion and a high-low groove portion. The slope grooves are shown respectively.

First, the planar configuration of this guide groove 41 will be explained. As shown in FIGS. A second circumferential groove 43 and a third circumferential groove formed on both sides of the first circumferential groove 42 sandwich the first circumferential groove 42.
The circumferential groove 44, and the first groove when the decomp reel rotates forward
A first diagonal groove 45 that connects the circumferential groove 42 and the second circumferential groove 43, and a second circumferential groove 43 when the decomp reel rotates forward.
and a second diagonal groove 46 that connects the third circumferential groove 44 across the first circumferential groove 42, and a third diagonal groove 47 that connects the third circumferential groove 44 and the first circumferential groove 42 during forward rotation of the decomp reel. have. In this case, the second
The length of the circumferential groove 43 and the third circumferential groove 44 and the relative positional relationship between them in the rotational direction are such that the third diagonal groove 47 is the first diagonal groove 47 between the first diagonal groove 45 and the second diagonal groove 46
It is appropriately set in the circumferential groove 42 so as to be able to communicate in the forward running direction of the actuator.

Next, the cross-sectional structure of the guide groove 41 will be explained with reference to FIGS. In the first diagonal groove 45
The decomp reel 40 is positioned so that it is at a position a between the second oblique groove 46 and the second oblique groove 46 .

In this case, the position a is such that the actuator 33 is in the guide groove 4.
The first circumferential groove 42 starts from this start position a and sequentially extends forward in the forward running direction (arrow A') of the actuator 33 into a low-bottom groove part 42a, One side wall 42h (upright wall) of the first diagonal groove 45, a high bottom groove portion 42k, a slope groove portion 42e that slopes downward toward the front, a low bottom groove portion 42d, one side wall 42f of the second diagonal groove 46
(upright wall), a high-bottomed groove portion 42c, and a sloped groove portion 42b that slopes downward toward the front, and is shaped to return to the starting position a.

The two circumferential grooves 43 have a low bottom groove 43a that is continuous with the first diagonal groove 45, and sequentially in front of the low bottom groove 43a, an upward slope slope groove 43b, a high bottom groove 43C, and a second diagonal groove 46.
one side wall 43d (upright wall), a non-grooved portion 43e,
It has a low bottom groove portion 43f and a non-groove portion 43g, and is shaped to return to the first oblique groove 45.

The third circumferential groove 44 has a low bottom groove 44a that continues to the second diagonal groove 46, and in front thereof an upwardly sloped slope groove 44b that continues to the third diagonal groove 47, and a high bottom that is the main part of the third diagonal groove 47. It has a groove portion 44c, one side wall 44d (upright wall) of the third oblique groove 47, a non-grooved portion 44e, a low bottom groove portion 44f, and a non-grooved portion 44g, and is shaped to return to the low bottom groove portion 44a.

High bottom groove part 43c of second circumferential groove 43 and first circumferential groove 42
The boundary between the third oblique groove 47 and the low bottom groove 42d of the first circumferential groove 42 is an upright wall 42m, and the boundary between the third oblique groove 47 and the low bottom groove 42d of the first circumferential groove 42 is also an upright wall 42n.

Note that the low-bottom groove portion 43f of the second circumferential groove 43 and the low-bottom groove portion 44f of the third circumferential groove 44 do not have a guiding function for the actuator 33, and are simply formed to balance the rotation of the decomp reel 40.

Next, the movement path of the actuator 33 within the guide groove 41 will be explained based on FIGS. 4
The relative position with respect to the decomp reel 40 is appropriately set so as to be at the start position a in FIG. From this state, the starter rope 36 of the recoil starter 18 is pulled out to rotate the decomp reel 40 together with the rope pulley 19 in the forward rotation direction (direction of arrow A). When the decomp reel 40 rotates in the normal direction, the actuator 33 moves (apparently) within the guide groove 41 in the normal running direction shown by arrow A' in FIGS. 8 and 9. During one rotation of the decomp reel 40, the actuator 33 enters the second circumferential groove 43 from the start position a of the first circumferential groove 42 via the first oblique groove 45, and then enters the second circumferential groove 43.
The low bottom groove portion 44a of the third circumferential groove 44 via the oblique groove 46
reach. At this time, the actuator 33 is guided by the vertical side wall 42h of the first diagonal groove 45 and moves from the first circumferential groove 42 into the second circumferential groove 43, and also moves into the second circumferential groove 43.
When passing, there is a high bottom groove 43 at 42m of the upright wall.
c to the low bottom groove 46a. When the decomp reel 40 makes one more rotation, the actuator 33 enters the low bottom groove 42d of the first circumferential groove 42 from the position d of the low bottom groove 44a of the third circumferential groove 44 via the third oblique groove 47, and further It returns to the position d of the third circumferential groove 44 via the low-bottom groove portion 46a of the second oblique groove 46 (the travel path of the actuator 33 in the second rotation will be hereinafter referred to as a circulation path x). After this, Decomp Reel 40
No matter how many times the actuator 33 rotates, the actuator 33 always follows the circulation path
It circulates within the body and does not migrate into other routes. At this time, when the actuator 33 passes through the third diagonal groove 47, it moves from the high-bottom groove portion 44c to the first circumferential groove 4 at the upright wall 42n.
At the same time, it falls into the second low-bottom groove 42d, and is guided by the vertical side wall 42f of the second oblique groove, and moves from the first circumferential groove 42 into the third circumferential groove 44. That is, the actuator 33
moves from the first circumferential groove 42 into the second circumferential groove 43 only once during the recoil starter starting operation, and thereafter circulates along the circulation path x.

On the other hand, when the decomp reel 40 is reversely rotated in the direction of arrow B as the recoil starter 18 returns, the actuator 33 moves inside the guide groove 41 in the direction shown by arrow B' in FIGS. 8 and 9. Drive in the opposite direction (apparently). In this case, the actuator 33 is
When it is in the circumferential groove 44, it is guided by the vertical side wall 46b of the second oblique groove 46, and it is also in the first circumferential groove 42.
If it is within the first circumferential groove 42, it directly reaches the low bottom groove 42d of the first circumferential groove 42, and further passes through the slope groove 42e and the high bottom groove 42k of the first circumferential groove 42 to reach the start point in the first circumferential groove 42. Reach position a. When the decomp reel 40 further rotates in the reverse direction in the direction of arrow B from the state in which the actuator 33 has returned to the starting position a,
The actuator 33 has a first circumferential groove 42 formed in a straight line.
When the decomp reel 40 finally stops, it returns to the starting position a.

Note that when the decomp reel 40 rotates in reverse, the rotation speed of the decomp reel 40 becomes faster than when it rotates forward (starting rotation), so the ability of the actuator 33 to follow the guide groove 41 deteriorates. In the device, during return rotation, the actuator 33
By running the guide groove 4 in the linear first circumferential groove 42 with the least running resistance, the guide groove 4
The influence of the running resistance of the actuator 33 on the actuator 1 is minimized to improve its followability.

The intermediate member Y has a link 59 whose one end 59a is hooked to the lever member 51 of the decompression shaft 50, and an actuator 33 formed at one end thereof in the guide groove 41 of the decompression reel 40, which is slidably fitted into the link 59. The decompression yoke shaft 60 and the decompression yoke shaft 60 are engaged with each other through elongated holes.

The decompression yoke shaft 60 is composed of a straight rod that is rotatably and slidably supported, and one end of the decompression yoke shaft 60 is
A short shaft-shaped actuator 3 is connected to 0a via an eccentric lever 61.
3 is fixed, while the other end 60b is provided with an arcuate elongated hole 6.
A substantially fan-shaped decompression yoke lever 63 having a diameter of 2 is fixed thereto. This decompression yoke shaft 60 has its eccentric actuator 33 slidably fitted into the guide groove 41 of the decompression reel 40, and
Another type 59b of the link 59 is hooked into the elongated hole 62 of the decompression yoke lever 63.
At this time, the decompression yoke shaft 60 is biased toward the guide groove 41 of the decompression reel 40 by a compression spring 64 fitted into its intermediate portion. Therefore, when the decomp reel 40 is rotated, the eccentric actuator 33 is guided by the guide groove 41 and moves in the direction of the arrow C-
The decompression yoke shaft 60 rotates in the direction D, and the decompression yoke shaft 60 also rotates in the direction of arrow CD. At this time, only when the decompression yoke shaft 60 rotates in the direction of arrow C, the elongated hole 6 of the decompression yoke lever 63
One end 62a of the link 59 and the end 59b of the link 59 are engaged with each other, so that the decompression shaft 50 can be rotated in the direction of the arrow G.

Next, to explain the function of this decompression device X, when starting the internal combustion engine, first, the starter rope 36 of the recoil starter 18 is pulled out vigorously, and the decompression reel 40 is rotated together with the engine shaft 5 in the direction of arrow A. When the decompression reel 40 rotates, the decompression yoke shaft 60 is guided by the guide groove 41 of the decompression reel 40 and first rotates in the direction of the arrow C, and then the decompression shaft 50 is rotated in the direction of the arrow G via the link 59. The decompression shaft 50 is set to the decompression position. Therefore, in this state, the exhaust valve is held open, so the working chamber of the internal combustion engine is in a non-compressed state, and the engine shaft 5 can be easily rotated.

When the starter rope 36 is further pulled out from this state, the decompression yoke shaft 60 moves into the guide groove 4.
1, the decompression shaft 50 rotates in the direction of arrow D and returns to the predetermined position before starting. When the tappet 66 is further lifted upward by the valve operating cam of the camshaft 8, the return spring 5 is released.
It is returned to the direction of arrow H, that is, to the decompression release position, by the spring force No. 2.

When the decompression shaft 50 is returned to the decompression release position, the working chamber becomes compressed and the engine starts. After pulling out the starter rope 36 to start the engine, the tensile force of the starter rope 36 is released and the recoil starter 18 and decomp reel 40 are returned to their state before the starting operation by the spring force of the return spring 52.

This completes the engine starting operation.

When starting this engine, the starter rope 3
Since a considerably large force is applied in the radial direction of the recoil starter 18 due to the pulling force of The recoil starter is caused to swing in the radial direction together with the recoil starter 18. However, in the internal combustion engine of the illustrated embodiment, the tip 5b of the engine shaft 5 is placed within the inner circumferential surface of the liner 39 attached to the end of the central shaft 13 of the recoil starter 18, with an appropriate play gap in the radial direction. Since the recoil starter 18 is loosely aligned, when the swing width of the recoil starter 18 with respect to the axis of the engine shaft 5 reaches a preset dimension or more, the liner 39 engages with the engine shaft tip 5b, and the recoil starter 18 swings with a swing width greater than that. It can be regulated to prevent movement.
In addition, since the radial tilting of the recoil starter 18 with respect to the engine shaft 5 is restricted within an allowable range, the actuator 33 attached to the engine body 1 side is connected to the decomp reel 40 attached to the rope pulley 19 of the recoil starter 18. In an internal combustion engine having a decompression device X as shown in the figure which is made to abut and follow a guide groove, the mutual positional relationship between the actuator 33 and the decompression reel 40 changes greatly even during the recoil starter starting operation. Therefore, the actuator 33 does not come off from the guide groove 41, and the ability of the actuator 33 to follow the guide groove 41 is improved, making it possible to perform the decompression action more reliably when starting the internal combustion engine. .

In the illustrated embodiment, a radiator device 34 for cooling the engine is disposed in a space 31 formed above the cooling fan 6 in the fan case 20. The radiator device 34 is sandwiched and supported between the inner fan case 21 and the outer fan case 22 with its upper part inclined toward the inner fan case side plate 21a. The engine cooling water W is cooled by the cooling air A generated by the cooling fan 6 while passing through the radiator device 34 .

Next, to explain the effects of the internal combustion engine of the present invention, the internal combustion engine of the present invention supports the fan case against the engine body in a vibration-proof manner via a vibration isolating member. A steady rest member is attached to the inner surface of the engine shaft that engages with one end of the engine shaft in its radial direction and acts to restrict the tilting or displacement of the fan case within an allowable range, so that when the recoil starter is started, the starter rope It is possible to prevent troubles in which the fan case tilts significantly due to the pulling force of the fan case and the recoil starter etc. attached to the fan case collide with the cooling fan attached to the engine shaft and are damaged.

In addition, since the amount of displacement of the fan case relative to the engine body is regulated by the steady rest member attached to the recoil starter, the vibration isolating member interposed between the engine body and the fan case should be made of a soft material with more elasticity. Various parts (e.g. radiator equipment) that can be used with a fan case and are attached to the fan case.
It is possible to improve the vibration-proofing effect of the vibration-proofing member, and the durability of the vibration-proofing member itself can be improved since no unreasonable force is applied to the vibration-proofing member itself.

Furthermore, since the reaction force from the starter rope when operating the recoil starter is distributed and transmitted to the fan case and the engine shaft, the rigidity of the fan case itself can be reduced accordingly, thereby promoting thinning of the fan cover. This provides practical effects such as being able to reduce the size and weight of the device.

[Brief explanation of the drawing]

FIG. 1 is a structural explanatory diagram of an internal combustion engine according to an embodiment of the present invention, FIG. 2 is an enlarged view of a portion of FIG. 1, FIG. 3 is an enlarged view of FIG. 1, and FIG. 5 is a cross-sectional view of FIG. 1, FIG. 6 is an exploded perspective view of essential parts of the decompression device shown in FIG. 5, FIG. 7 is a perspective view of the decomp reel shown in FIG. 6, and FIG. The figure is a developed view of the guide groove of the decomp reel shown in FIG. 6, and FIGS. 9A, B, and C are cross-sectional views taken along line AA, line B-B, and line C-C in FIG. 8, respectively. DESCRIPTION OF SYMBOLS 1... Engine body, 5... Engine shaft, 5a... Engine shaft end, 5b... Tip of engine shaft, 6... Cooling fan, 13... Center shaft, 18... Recoil starter, 20... Fan Case, 27... Vibration isolating member,
39... Steady rest member.

Claims (1)

[Scope of utility model registration request] The fan case 20 surrounding the outside of the cooling fan 6 attached to the end 5a of the engine shaft 5 is connected to the engine body 1 through vibration isolating members 27, 27, . . . made of an elastic material having an appropriate elastic restoring force. At the same time, a recoil starter 18 is mounted on the fan case 20 at a position close to and facing the outer end of the cooling fan 6, and a recoil starter 18 is mounted on the inner end of the center shaft 13 of the recoil starter 18. , an internal combustion engine characterized in that a steady rest member 39 having an engagement surface that can engage with the tip 5b of the engine shaft 5 in the radial direction is provided so as to overlap the tip 5b of the engine shaft in the radial direction. institution.