JPH07224904A - Engine balancer equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce frictional resistance when the counterweight slides while stably supporting the counterweight that reduces engine vibration. The counterweight 22 is connected to a second crankpin 23 formed on the crankshaft 8 via a second connecting rod 24. Counterweight 22
Is slidably supported by the counterweight guide portion 21 ₂ of the first swinging link 21 pivotally supported via the first swinging shaft 21 ₁ , and the second connecting rod 24 and the counterweight 22 are pivotally supported. A second end whose one end is pivotally supported by the supporting counterweight pin 25 via a second swing shaft 26.
The other end of the swing link 27 is pivotally supported.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine balancer device for reducing vibration by reciprocating a counterweight in conjunction with rotation of a crankshaft.

[0002]

2. Description of the Related Art As a balancer device for such an engine,
The one disclosed in Japanese Utility Model Publication No. 5-45876 and the one disclosed in JP-A-1-316542 are known.

In the former type, a guide pin is planted on the opposite side of the cylinder with the crankshaft sandwiched so as to be positioned on the axis of the cylinder, and a counterweight slidably supported by the guide pin is connected to a connecting arm. It is connected to the eccentric journal of the crankshaft via the. The counterweight reciprocates in the opposite phase of the piston as the crankshaft rotates.

Further, in the latter one, a counterweight is pivotally supported on the opposite side of the cylinder with a crankshaft interposed therebetween via a rotating pin, and the counterweight is eccentric to the crankshaft via a link. It is connected to a member, and the counterweight is reciprocally rocked in a phase opposite to that of the piston as the crankshaft rotates.

[0005]

In the former case, since the guide pin for slidably supporting the counterweight is fixed to the crankcase, the counterweight driven by the swinging connecting arm. There is a problem that a large lateral pressure is generated between the fixed guide pin and the fixed guide pin, and the sliding resistance of the counterweight increases.

Further, in the latter one, since the counterweight is pivotally supported by one rotating pin so that the counterweight is swingable, the support of the counterweight is unstable and easily wobbles, and the rotating pin is quickly worn. I have a problem to do.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to reduce frictional resistance when the counterweight reciprocates while stably supporting the counterweight.

[0008]

In order to achieve the above-mentioned object, the invention described in claim 1 is such that a first crank pin of a crank shaft is slidably fitted to a first crank pin of a crank shaft.
The second crankpin of the crankshaft is connected to the counterweight via the second connecting rod in order to cancel the vibration caused by the reciprocating motion of the piston connected via the connecting rod, and this counterweight is linked to the rotation of the crankshaft. In a balancer device for reciprocating the engine, a counterweight is slidably supported on a first swing link pivotally supported by a crankcase via a first swing shaft, and one end of the second swing shaft is a second swing shaft. It is characterized in that the other end of the second swinging link pivotally supported on the crankcase via the shaft is pivotally supported on the counterweight of the second connecting rod via the counterweight pin.

In addition to the structure of claim 1, the invention described in claim 2 is characterized in that the axis connecting the center of the crankshaft and the center of the first swing shaft intersects the axis of the cylinder. And

In addition to the structure of claim 1, the invention described in claim 3 defines an axis connecting the center of the crankshaft and the center of the first crankpin with the center of the crankshaft and the center of the second crankpin. The inferior angle formed by the connecting axis is α, and the inferior angle formed by the axis connecting the center of the crankshaft and the center of the first swing shaft with the axis of the cylinder is β, and the reciprocating mass of the piston and the first connecting rod is M
e, the reciprocating mass of the counterweight and the second connecting rod is Mb, the distance between the center of the crankshaft and the center of the first crankpin is Re, and the distance between the center of the crankshaft and the center of the second crankpin. Is defined as Rb, the following equations and equations are established. α = 2β−180 ° Me × Re = Mb × Rb In addition to the configuration of claim 1, the invention described in claim 4 has a single counterweight, a second connecting rod and a second swing link. It is characterized in that they are mutually pivoted by counterweight pins.

According to a fifth aspect of the present invention, in addition to the structure of the first aspect, the crankcase includes a crankcase main body and a side cover connected to a side surface of the crankcase main body, and the crankcase is provided in a horizontal direction and in a mutual direction. Both ends of the crankshaft, the first swing shaft, and the second swing shaft, which are arranged parallel to each other, are supported by the crankcase body and the side cover, respectively.

According to a sixth aspect of the present invention, in addition to the structure of the first aspect, the crankcase includes a crankcase main body and an oil pan connected to a lower surface of the crankcase main body, and the crankcase is arranged in a vertical direction. Both ends of the crankshaft, the first swing shaft, and the second swing shaft, which are arranged parallel to each other, are supported by the crankcase body and the oil pan, respectively.

According to a seventh aspect of the present invention, in addition to the configuration of the second aspect, an oil pan is provided below a crank chamber that horizontally supports the crankshaft, and
It is characterized in that the center of the first swing shaft is biased upward from the axis of the cylinder.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an engine equipped with a balancer device, FIG. 2 is a sectional view taken along line 2-2 of FIG. [Fig. 6] is an explanatory view of an action.

[0016] As shown in FIGS. 1 and 2, a crankcase 1 of the single-cylinder Horizontal type engine E includes a cylinder 1 ₁ and the crankcase body 1 ₂ that is integrally formed,
It is composed of a side cover 2 which covers the side opening of the crankcase body 1 ₂ . Oil pan 4 is formed in the bottom of the crank chamber 3 defined by the crank case body 1 ₂ and the side cover 2. Cylinder 1 ₁ extends obliquely upward from the crankcase 3, the cylinder head 5 is coupled to the deck surface of its upper end.

The both end portions of the crank case body 1 ₂ and the crankshaft 8, respectively in side cover 2 through a ball bearing 6, 7 are supported. The first crankpin 9 provided at the center of the crankshaft 8 is attached to the cylinder 1 ₁
A piston 10 slidably fitted into the inside of the cylinder is connected via a first connecting rod 11. A flywheel 12 is provided at one end of a crankshaft 8 extending from the crankcase 1 to the outside. Flywheel 12
A starter gear 12 _{1 with} which a pinion (not shown) provided on the output shaft of the starter motor 13 meshes is formed on the outer circumference of the.

The cam gear 14 provided on the journal portion of the crankshaft 8 is the cam gear 1 provided on the camshaft 15.
6 meshes with a tappet 18 that reciprocates slidably supported by the cylinder 1 ₁ in contact with the cam 17 provided on the camshaft 15, valve-operating mechanism provided in the cylinder head 5 (not shown) Connected to. Reference numerals 19 and 20 are a governor drive gear and a governor gear of the governor for keeping the rotation speed of the engine E constant.

The first swing link 21 is provided with a first pivot shaft 21 _1, 21 ₁ which is swingably pivoted to the crankcase main body 1 ₂ and the side cover 2 at both ends,
A counterweight guide portion 21 ₂ extending in a direction perpendicular to the first swing shafts 21 ₁ and 21 ₁ is provided at the center thereof. Counterweight guide portion 2 of the first swing link 21
The counterweight 22 is slidably supported by 1 ₂ .

The crankshaft 8 is provided with a second crankpin 23 which is eccentric with respect to its center O.
The crank pin 23 supports the large end of the second connecting rod 24. The small end portion of the second connecting rod 24 is pivotally supported by a counterweight pin 25 provided on the counterweight 22. One end second swing link 27 is pivotally supported swingably to the crank case body 1 ₂ and the side cover 2 via a second pivot shaft 26 is pivotally supported on the counterweight pin 25 at the other end.

The counterweight guide portion 21 ₂ and the second connecting rod 24 of the first swing link 21 is disposed substantially on a straight line so as to face each other, the second swing link 27 is counterweight guide portion 21 ₂ and 2
The counterweight pin 25 connecting the connecting rod 24 extends in a substantially right angle direction.

The axis L ₁ connecting the center O of the crankshaft 8 and the center of the first crankpin 9 and the crankshaft 8
Axis L connecting the center O of the crankshaft and the center of the second crankpin 23
_An inferior angle α formed with ₂ is, for example, 150 °, and an axis L ₃ connecting the center O of the crankshaft 8 and the centers of the first swing shafts 21 ₁ and 21 ₁ and the axis L ₄ of the cylinder 1 ₁ . The formed inferior angle β is, for example, 165 °. That is, α and β
Is set to satisfy α = 2β−180 °.

Further, the mass of the reciprocating portion of the piston 10 and the first connecting rod 11 is Me, the mass of the reciprocating portion of the counterweight 22 and the second connecting rod 24 is Mb, the center O of the crankshaft 8 and the first crankpin 9 When the distance between the centers of the crankshaft 8 and the center of the second crankpin 23 is Rb, the following formula is satisfied.
e, Mb, Le, and Lb are set.

Me × Re = Mb × Rb ... The crankshaft 8, the first oscillating shafts 21 ₁ and 21 ₁ and the second oscillating shaft 27 are arranged in parallel with each other, and both ends thereof are cranked. Since it is supported by the case body 1 ₂ and the side cover 2, respectively, the number of man-hours for processing the crank case body 1 ₂ and the side cover 2 is reduced, and the crankshaft 8, the first swing shafts 21 ₁ , 21 ₁ and the second swing shaft 2 are also supported. It is possible to improve the assemblability of the moving shaft 27.

Further, it crossed the axis L ₃ connecting the center O and the first pivot shaft 21 _1, 21 ₁ of the center of the crankshaft 8 to the axis L ₄ of the cylinder 1 _1, the cylinder 1 ₁ counterweight 22 Since it is located above the axis L _{4 of} the engine E, while keeping the overall height of the engine E low, the counterweight 22 is located above the oil surface 28 of the oil in the oil pan 4 to prevent unnecessary agitation of the oil. Can be prevented.

Next, the operation of the first embodiment of the present invention having the above construction will be described.

When the second crank pin 23 rotates eccentrically as the crank shaft 8 rotates, the counter weight 22 connected to the second crank pin 23 via the second connecting rod 24 causes the second swing link 27 to move. It is reciprocated by being guided by the upper end of the and the counterweight guide portion 21 ₂ of the first swing link 21. That is, the second swing link 27 swings back and forth at the angle a between FIGS. 3 (a) and 3 (c),
The counterweight pin 25 of the counterweight 22 reciprocates on an arc which is a locus of the upper end of the second swing link 27. The arcuate locus is substantially coincident with an axis L ₃ connecting the center O of the crankshaft 8 and the centers of the first swing shafts 21 ₁ and 21 ₁ , and the counterweight 22 is substantially on the axis L ₃ . Can be regarded as reciprocating.

Further, the reciprocating counterweight 22
Is guided not only by the second swing link 27 but also by the counterweight guide portion 21 ₂ of the first swing link 21, so that it can smoothly reciprocate without rattling. This prevents wear of the first swing shafts 21 ₁ and 21 ₁ , the second swing shaft 26, and the counterweight pin 25 due to bending. When the counterweight 22 slides while being guided by the counterweight guide part 21 ₂ , the counterweight guide part 21 ₂ slides.
_{Since 2} can freely swing within the range of the angle b shown in FIGS. 3B and 3D, no lateral pressure is generated between the counterweight 22 and the counterweight guide portion 21 ₂ , and as a result, the counterweight is generated. The sliding resistance of 22 is reduced.

Thus, the engine E of this embodiment satisfies the above equations and equations so that the primary inertial force caused by the reciprocating movement of the piston 10 and the first connecting rod 11 is counterweight 22 and the second connecting rod 24.
It is possible to reduce the vibration of the engine E by canceling it out by the primary inertial force associated with the reciprocating movement of.

That is, if the counterweight 22 reciprocally driven by the second crankpin 23 of the crankshaft 8 via the second connecting rod 24 is regarded as a second piston, this engine E is a V-type two-cylinder engine. Can be assumed. And, the above formula and formula are V
It is nothing but a well-known conditional expression representing the condition for reducing the primary inertial force of a two-cylinder engine. Therefore, by laying out the counterweight 22 and the second connecting rod 24 so as to satisfy the above formula and the formula,
Vibration of the engine E can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS.

The engine E of the second embodiment is a vertical type engine in which the crankshaft 8 is arranged vertically,
The crank chamber 3 is defined by a crankcase body 1 ₂ and an oil pan 29 connected to an opening on the lower surface of the crankcase body 1 ₂ . The crankshaft 8, the first swing shafts 21 ₁ and 21 ₁ and the second swing shaft 26 are arranged vertically and parallel to each other, and both ends of them are supported by the crankcase body 1 ₂ and the oil pan 29. As a result, the processing man-hours and the assembly man-hours can be reduced.

The axis L ₃ connecting the center O of the crankshaft 8 and the centers of the first swing shafts 21 ₁ and 21 ₁ is the cylinder 1 ₁
Are aligned with the axis L ₄ of
Is at the top dead center or the bottom dead center, the center of the first connecting rod 11, the first crank pin 9, the center O of the crank shaft 8, the center of the second crank pin 23, the second connecting rod 24, the counter weight pin. 25, the center of the counterweight guide portion 21 ₂ of the first swing link 21 and the first swing shafts 21 ₁ , 21 ₁ of the first swing link 21 are aligned on a straight line.

Also in this second embodiment, the piston 1
0, the first connecting rod 11, the crankshaft 8, the second connecting rod 24, and the counterweight 22 satisfy the above equations and relationships (α = 180 °, β = 180 ° in the equation), and The vibration can be reduced by canceling the primary inertial force as in the first embodiment.

Further, similarly to the first embodiment, the counterweight 22 is smoothly guided by the first swing link 21 and the second swing link 27, and the first swing shafts 21 ₁ , 21 ₁ ,
It is possible to prevent wear of the second swing shaft 26 and the counterweight pin 25 due to a twist. Moreover, free to oscillate the counterweight guide portion 21 ₂ for guiding the counterweight 22 slidably, counterweight 22
Sliding resistance can be reduced.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments, and various design changes can be made.

For example, in the embodiment, the second connecting rod 24 and the second swinging link 27 are pivotally supported on the counterweight 22 by the common counterweight pin 25, thereby reducing the number of parts, but coaxially. Placed 2
The second connecting rod 24 and the second swing link 27 can be separately pivoted by the counter weight pins 25, 25 of the book.

[0038]

As described above, according to the invention described in claim 1, the counterweight is slidable on the first swing link pivotally supported by the crankcase via the first swing shaft. Since the other end of the second swing link, which is supported and whose one end is pivotally supported by the crankcase through the second swing shaft, is pivotally supported by the second connecting rod and the counterweight through the counterweight pin, It is possible to smoothly guide the counterweight that reciprocates with the rotation of the crankshaft by the first swing link and the second swing link, and prevent wear of the first swing shaft and the second swing shaft due to bending. In addition to being possible, the first swing link that slidably supports the counterweight is freely swung around the first swing to reduce the lateral pressure between the counterweight and the first swing link. to this Ri the sliding resistance of the counterweight can be reduced.

According to the invention described in claim 2,
Since the axis connecting the center of the crankshaft and the center of the first swing axis intersects the axis of the cylinder, the counterweight can be freely laid out so as not to interfere with the auxiliary devices, and the engine design flexibility can be increased. Is improved.

According to the invention described in claim 3,
Angle α, β, reciprocating mass of Me, Mb and distance Re, R
Since b is set so as to satisfy α = 2β−π and Me × Re = Mb × Rb, it is possible to effectively cancel the primary inertial force of the engine and reduce the vibration.

According to the invention described in claim 4,
Counterweight, second connecting rod and second
Since the swing links are pivotally supported by a single counterweight pin, the number of counterweight pins can be minimized to reduce the number of parts.

According to the invention described in claim 5,
The crankcase is composed of a crankcase body and a side cover joined to a side surface of the crankcase body,
Crankshafts arranged horizontally and parallel to each other,
Since both ends of the first swing shaft and the second swing shaft are supported by the crankcase body and the side cover, respectively, the man-hours for processing the crankcase body and the side cover, the crankshaft, the first swing shaft, and the second swing shaft are increased. The man-hours for assembling the drive shaft can be reduced.

According to the invention described in claim 6,
The crankcase is composed of a crankcase body and an oil pan connected to the lower surface of the crankcase body, and the crankshaft is arranged vertically and in parallel with each other, and both ends of the first swing shaft and the second swing shaft. Since these are supported by the crankcase body and the oil pan, respectively, the man-hours for processing the crankcase body and the oil pan, and the man-hours for assembling the crankshaft, the first swing shaft, and the second swing shaft can be reduced.

According to the invention described in claim 7,
Since the oil pan is provided below the crank chamber that horizontally supports the crankshaft, and the center of the first swing shaft is biased upward from the axis of the cylinder, the counterweight stirs the oil in the oil pan. The overall height of the engine can be kept low while preventing the above.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an engine including a balancer device according to a first embodiment.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is an explanatory diagram of operation

FIG. 4 is a vertical sectional view of an engine including a balancer device according to a second embodiment.

5 is a sectional view taken along line 5-5 of FIG.

[Explanation of symbols]

1 Crankcase 1 ₁ Cylinder 1 ₂ Crankcase body 2 Side cover 3 Crank chamber 4 Oil pan 8 Crankshaft 9 1st crankpin 10 Piston 11 1st connecting rod 21 1st swinging link 21 ₁ 1st swinging shaft 21 ₂ Counter weight guide part 22 Counter weight 23 Second crank pin 24 Second connecting rod 25 Counter weight pin 26 Second swing shaft 27 Second swing link 29 Oil pan

Claims (7)

[Claims] 1. A piston (10) slidably fitted in a cylinder (1 ₁ ) and connected to a first crankpin (9) of a crankshaft (8) via a first connecting rod (11). The second crankpin (23) of the crankshaft (8) is connected to the counterweight (22) through the second connecting rod (24) in order to cancel the vibrations caused by the reciprocating motion of the counterweight (22).
A balancer device for an engine that reciprocates in conjunction with the rotation of a crankshaft (8), comprising a first swinging link (21) pivotally supported by a crankcase (1) via a first swinging shaft (21 ₁ ). The counterweight (22) is slidably supported by the second swing link (27) whose one end is pivotally supported by the crankcase (1) via the second swing shaft (26). An engine balancer device characterized by being pivotally supported by the second connecting rod (24) and the counterweight (22) through a weight pin (25). 2. The center of the crankshaft (8) and the first
Pivot shaft (21 ₁₎ the axis (L ₃₎ and the cylinder (1 _1), characterized in that the axis of the (L ₄₎ crossed the balancer device of claim 1, wherein the engine connecting the centers of. 3. The center of the crankshaft (8) and the first
The axis (L ₁ ) connecting the centers of the crankpins (9) and the center of the crankshaft (8) and the second crankpin (23)
Axis connecting the centers of the minor angle formed by the (L ₂₎ and alpha, the center and the first pivot shaft (21 ₁₎ axis connecting the centers of the crankshaft (8) (L ₃₎ and the cylinder (1 ₁₎ Axis of (L
_The inferior angle formed with ₄ ) is β, and the piston (10) and the first
The mass of the reciprocating part of the connecting rod (11) is Me, the mass of the reciprocating part of the counterweight (22) and the second connecting rod (24) is Mb, and the center of the crankshaft (8) and the first crankpin (9). The following formulas and formulas are satisfied, where Re is the distance between the centers and Rb is the distance between the center of the crankshaft (8) and the center of the second crankpin (23). 1. The engine balancer device according to 1. α = 2β−180 ° Me × Re = Mb × Rb 4. The counterweight (22), the second connecting rod (24) and the second rocking link (27) are pivoted to each other by a single counterweight pin (25). A balancer device for an engine according to item 1. 5. The crankcase (1) comprises a crankcase body (1 ₂ ) and a side cover (2) connected to a side surface of the crankcase body (1 ₂ ), and is arranged in a horizontal direction and in parallel with each other. Both ends of the installed crankshaft (8), the first swing shaft (21 ₁ ) and the second swing shaft (26) are supported by the crankcase body (1 ₂ ) and the side cover (2), respectively. The balancer device for an engine according to claim 1. 6. The crankcase (1) comprises a crankcase main body (1 ₂ ) and an oil pan (29) connected to the lower surface of the crankcase main body (1 ₂ ), and is arranged vertically and in parallel with each other. Both ends of the installed crankshaft (8), the first swing shaft (21 ₁ ) and the second swing shaft (26) are supported by the crankcase body (1 ₂ ) and the oil pan (29), respectively. The balancer device for an engine according to claim 1. 7. A crankcase supporting the crankshaft (8) in the horizontal direction together with the provision of the oil pan (4) at the bottom (3), the center of the first pivot shaft (21 ₁₎ the cylinder (1 ₁₎ 3. The balancer device for the engine according to claim 2, wherein the balancer device is biased upward from the axis (L ₄ ) of the above.