JP2816608B2 - Engine with balancer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine with a balancer.

[0002]

2. Description of the Related Art As a conventional technology of an engine with a balancer,
There is one shown in FIG. This prior art is as follows. A shaft insertion hole is made in one of the front and rear walls of the crankcase 101, and the crankcase 101 is inserted through the shaft insertion hole.
The crankshaft 105 and the balancer shafts 106 are inserted in parallel into the crankshaft 105 and the balancer shaft 1.
And 06, 106 and <br/> rack set laterally parallel form to the crank case 101, the lateral peripheral portions of the balancer weight 109 in the lateral peripheral portions 108 and the balancer shaft 106, 106 of the counterweight 107 of the crankshaft 105 Interference avoidance gaps 111 are provided between the shaft 110 and the shaft 110 when the shaft is inserted.

According to the above configuration, the counter weight 10
7 and the balancer weight 109 without causing interference.
The crankshaft 105 and the balancer shaft 106 can be inserted into the crankcase 101 in parallel.

In the prior art, the peripheral surface of the counterweight 107 and the peripheral surface of the balancer weight 109 are each formed in an arc shape having a constant curvature.

[0005]

The above prior art has the following problems. Since the peripheral surface of the counterweight 107 and the peripheral surface of the balancer weight 109 are each formed in an arc shape having a constant curvature, the horizontal peripheral portion 108 of the counterweight 107 has the same radius as the lower peripheral portion 112 thereof. The overhanging side portion 110 of the balancer weight 109 has the same radius as the lower portion 113 thereof.
And overhangs sideways. For this reason, the axial distance between the crankshaft 105 and the balancer shafts 106, which are arranged in a side-by-side configuration to avoid mutual interference, becomes longer, the lateral width of the crankcase 101 accommodating them increases, and the engine becomes larger. Become

[0006] The present invention is to reduce the distance between the crankshaft and the balancer shaft, and to reduce the size of the engine.
Is a technical issue.

[0007]

According to the present invention , as shown in FIG. 1 (B), a shaft insertion hole 4 is formed in one of the front and rear walls of the crankcase 1 and the crankcase 1 is inserted through the shaft insertion hole 4. The crankshaft 5 and the balancer shafts 6.6 are inserted in parallel into the inside, and the crankshaft 5 and the balancer shafts 6.6 are laid in the crankcase 1 in a side-by-side manner, as shown in FIG. As shown in the figure, the interference avoidance gaps 11 when inserting the shaft between the horizontal peripheral surface portion 8 of the counter weight 7 of the crankshaft 5 and the horizontal peripheral surface portion 10 of the balancer weight 9 of the balancer shafts 6 are formed. The provided engine with balancer has the following features.

As shown in FIG. 1A, the horizontal peripheral surface portion 8 of the counter weight 7 is retracted inward from the lower peripheral surface portion 12, and the horizontal peripheral surface portion 10 of the balancer weight 9 is the Rukoto was <br/> retracted is also inwardly from the lower peripheral surface portion 13 thereof, the crank shaft 5 and the balancer shaft 6.6
And the distance between the crankshaft 5 and the balancer shaft 6
Shorten the separation.

[0009] As shown in FIG. 1 (A) (B), the crank
The balancer weight passage gap 14 between the counterweight 7, 7 of the front and rear parallel設状axis 5 is provided, so as to face to the balancer weight passing gap 14 is positioned above the balancer weight 9, balancer weights 9 rotational phase difference With this configuration, it passes through the balancer weight passage gap 14. In addition, at least the anti-balance
The gate side portion is recessed to form a large end passage recess 9a,
With this large end passage recess 9a facing the crank pin 19
Position the connecting rod large end 19a and
The large end 19a is moved to the large end passage recess 9a by the rotational phase difference.
Is configured to pass through.

[0010] Then, as shown in FIG. 1 (A), of the transverse walls 36 the crank case 1, the balancer weights 9
The concave ribs 35a are formed by denting the front and rear adjacent portions of the lateral wall portion 35a facing the. Next to this crankcase 1
The meat of the side wall portion 35a facing the balance weight 9 of the wall 36
The thickness of the concave rib 35b is made substantially equal to the thickness.
It is characterized by having done.

[0011]

According to the present invention , as shown in FIG. 1A, the horizontal peripheral surface portion 8 of the counterweight 7 is retracted inward from the lower peripheral surface portion 12, and the balancer weight 9 Since the crank shaft 5 and the balancer shafts 6.6 are made closer to each other by retracting the horizontal peripheral surface portion 10 inward from the lower peripheral surface portion 13, the distance between the crank shaft 5 and the balancer shaft 6.6 is reduced. The distance can be shortened. For this reason, the width of the crankcase 1 accommodating them is reduced, and the engine can be downsized.

Further, as shown in FIG. 1 (B), the crank
A balancer weight passage gap 14 is provided between the counterweights 7, 7 arranged side by side with the shaft 6, and the balancer weight 9 is positioned so as to face the balancer weight passage gap 14, and the balancer weight 9 is rotated by a balance phase difference. Since the configuration is made so as to pass through the weight passage gap 14, the balancer weight 9 and the counterweight 7 do not interfere with each other during rotation, even though the crankshaft 5 and the balancer shafts 6, 6 are brought close to each other.

In addition, the balancer shaft 6 has at least the
Depress the sensor weight side part to form the large end passage recess 9a.
And the crank pin
Position the connecting rod large end 19a connected to
Rod large end 19a is concave through the large end due to rotational phase difference
Because it is configured to pass through the section 9a, the
The distance between the shafts of the link shaft 5 and the balancer shafts 6, 6 can be reduced,
The width of the crankcase 1 has become smaller, and
Can be downsized.

Further , in the present invention, the crankcase 1
Concave portions 35b and 3 are formed by recessing the front and rear adjacent portions of the horizontal wall portion 35a facing the balancer weight 9 in the horizontal wall 36 of FIG.
Since the side wall 5b is formed, the side wall 36 of the crankcase 1 does not protrude significantly laterally, and the side wall portion 35a and the concave rib 35b function as an uneven reinforcing rib. Thus, the mechanical strength of the side wall 36 of the crankcase 1 can be increased while reducing the size of the engine. Furthermore, the cover of the side wall 36 of the crankcase 1
For the thickness of the side wall portion 35a facing the lance weight 9
The thickness of the concave rib 35b was formed to be substantially equal.
The concave rib 35 is used as a reinforcing rib for the crankcase.
In order to increase the mechanical strength of the concave rib 35b,
Is not thicker than the thickness of the lateral wall portion 35a.
However, it is possible to reduce the weight and resources of the crankcase.
Wear.

[0015]

An embodiment of the present invention will be described with reference to the drawings.
Figure 1 is a diagram for explaining a balancer with engine according to an embodiment of the present invention, FIG. 1 (A) is a vertical DanTadashi view of the lower engine is of the crank angle of 0 °. FIG. 1 (B) is FIG.
Line B-B arrow cross planar sectional view of (A), it is of the crank angle of 90 °.

In FIG. 1, reference numeral 15 denotes an in-line two-cylinder engine. As shown in FIG. 1A, the engine 15 has a structure in which the crankcase 1 is integrally formed below a cylinder block 16 and an oil pan 17 is assembled below the crankcase 1. FIG. 1 (B)
As shown in FIG. 1, a crankshaft 5 and two balancer shafts 6, 6 are installed in the crankcase 1 in a side-by-side manner.

The crankshaft 5 is as follows. As shown in FIG. 1 (B), two pairs of crank arms 18.1
The two crank pins 19
The angle of 19 is 360 °. Two pairs of counterweights 7 are provided on opposite sides of the two pairs of crank arms 18. Adjacent central counterweights 7, 7 are integrated. A crank gear 20 and a crank pulley 21 are fitted to the front end of the crankshaft 1. A flywheel 22 is attached to the rear end of the crankshaft 5.
A dynamo 23 is arranged in the flywheel 22.

Each balancer shaft 6 is provided with a balancer weight 9 at each of two front and rear positions, and a balancer gear 24 is fitted to the front end of each balancer shaft 6. Each balancer gear 24 meshes with the crank gear 20.
The gear ratio between the crank gear 20 and the balancer gear 24 is made equal. As shown in FIG. 1A, the crankshaft 5 rotates clockwise, and each balancer shaft 6 rotates counterclockwise at the same speed as the crankshaft 5.

The assembled state of the crankshaft 5 and each balancer shaft 6 to the crankcase 1 is as follows. FIG.
As shown in (B), the front journal portion 26 of the crankshaft 5 is inserted into a front wall center bearing hole 25 at the center of the front wall 2 of the crankcase 1 and is bearing it. Front wall left and right bearings 27 at right and left positions of front wall 2 of crankcase 1
Each of the front journal portions 28 of the balancer shafts 6 is inserted therethrough, bearings them, and is prevented from coming off by a retaining nut 29.

A shaft insertion hole 4 is formed in the rear wall of the crankcase 1 and is covered with a removable bearing cover 30.
A bearing case 31 is attached to the inside of the center of the bearing cover 30, and a rear journal portion 32 of the crankshaft 5 is inserted into the bearing case 31 and bearings the bearing. Left and right bearing lids 33 are provided inside the left and right positions of the bearing lid 30.
And the rear journal 3 of each balancer shaft 6
4 is inserted and bearing this. FIG.
As shown in FIG. 1A, interference avoidance gaps 11 at the time of shaft insertion are provided between the horizontal peripheral surface portion 8 of the counterweight 7 and the horizontal peripheral surface portion 10 of each balancer weight 9.

The assembly of the crankshaft 5 and the balancer shafts 6 to the crankcase 1 is performed as follows. FIG.
As shown in (B), each balancer shaft 6 is inserted into the crankcase 1 from the shaft insertion hole 4 in the rear wall of the crankcase 1, and the front journal 28 of each balancer shaft 6 is inserted into the front wall left and right bearing hole 27. The balancer gear 24 is fitted to the front end of the front journal 28 projecting from this, and the retaining nut 29 is screw-fitted. At this time, each balancer shaft 6 has a balancer weight 9 turned downward in FIG.
The state is as shown in FIG.

Next, as shown in FIG. 1 (B), the crankshaft 5 with the bearing cover 30 integrally attached thereto via the bearing case 31 is inserted through the shaft insertion hole 4 in the rear wall of the crankcase 1 into the crankcase 1. Insert At this time, the crankshaft 5
1A is inserted into the crankcase 1 from the back side of the paper toward the front side of the paper with the counterweight 7 facing downward as shown in FIG. When this insertion, the interference circuit
Since the clearance gaps 11 are provided, the horizontal peripheral surface portion 8 of the counterweight 7 does not interfere with the horizontal peripheral surface portion 10 of the balancer weight 9.

Next, as shown in FIG. 1 (B), the front journal 26 of the crankshaft 5 is inserted into the center bearing hole 25 of the front wall, and each balancer shaft 6 The rear journal 34 is inserted, and the bearing cover 30 is attached to the shaft insertion hole 4 to close the shaft insertion hole 4. next,
Front journal part 2 protruding from front wall center bearing hole 25
6 has a crank gear 20 and a crank pulley 21 at the front end.
And fit.

In the engine 15, in order to shorten the distance between the crankshaft 5 and each balancer shaft 6, the following measures are taken. As shown in FIG. 1A, the lower peripheral surface portion 12 of the counterweight 7 is formed in an arc shape, and both lateral peripheral surface portions 8 are retracted more inward than the lower peripheral surface portion 12. It has a flat shape. Further, the lower peripheral surface portion 13 of the balancer weight 9 is formed in an arc shape, but both lateral peripheral surface portions 10 are formed in a flat shape which is retracted from the lower peripheral surface portion 13. Then, the crankshaft 5 and each balancer shaft 6 are brought closer to each other by the amount of retreat.

In this engine 15, in order to avoid interference between the approaching crankshaft 5 and the counterweight 7 and the balancer weight 9 of each balancer shaft 6 during rotation,
The following innovations have been made. As shown in FIG. 1 (B), a counterweight 7, the front and rear parallel設状of the crankshaft 5
7, a balancer weight passage gap 14 is provided , and the balancer weight 9 is disposed so as to face the balancer weight passage gap 14 , so that the rotating balancer weight 9 has a rotational phase.
It passes through the balancer weight passage gap 14 due to the difference .

The balancer weight 9 of the balancer shaft 6
Concave recess on the opposite side of the weight, opposite to the large end
9a is formed, and the large end passage recess 9a is faced.
Position the connecting rod large end 19a connected to the link pin 19
The connecting rod large end 19a is
It is configured to pass through the part passage recess 9a. This point
However, the distance between the crankshaft 5 and the balancer shafts 6, 6 is short.
And the width of the crankcase 1 becomes smaller,
The engine can be downsized.

In FIG. 1, reference numeral 35a denotes a horizontal wall portion facing the balancer weights 9.9. This side wall part 3
Concave ribs 35b are formed in the front and rear adjacent portions of 5a. A balancer weight passage space 37 is formed inside the horizontal wall portion 35a, and the rotating balancer weight 9 passes through the balancer weight passage space 37. With the configuration described above, the lateral wall 36 of the crankcase 1 does not protrude significantly laterally, and the lateral wall portion 35 a
And the concave rib 35b function as an uneven reinforcing rib. Thus, the mechanical strength of the side wall 36 of the crankcase 1 can be increased while reducing the size of the engine. Reference numeral 38 denotes a lubricating oil supply pump, 3
9 is a governor device. As shown in FIGS. 1A and 1B
The balance way of the side wall 36 of the crankcase 1
The concave ribs 35 are provided for the thickness of the side wall portion 35a facing the
b is formed to have substantially the same thickness. With this configuration
The concave rib 35 is used as a reinforcing rib
In order to increase the mechanical strength of the concave rib 35b,
Is not thicker than the thickness of the lateral wall portion 35a.
However, it is possible to reduce the weight and resources of the crankcase.
Wear.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an engine with a balancer according to an embodiment of the present invention. FIG. 1A is a vertical sectional front view of a vertical section of a lower portion of the engine, and has a crank angle of 0 °. FIG. 1B is a cross-sectional view taken along line BB of FIG.
The crank angle is 90 °.

FIG. 2 shows an engine with a balancer according to the prior art.
(A) It is an equivalent figure.

[Explanation of symbols]

1 ... crankcase, 4 ... shaft insertion hole, 5 ... crankshaft,
6 ... balancer axis, 7 ... counter weight, 8 ... counter
Horizontal peripheral surface portion of the weight, 9 ... balancer weight, 9a ...
Large end passage concave portion , 10: lateral peripheral portion of balancer weight , 11: interference avoidance gap, 12: lower peripheral portion of counter weight , 13: lower peripheral portion of balancer weight , 14
... Balancer weight passage gap, 19 ... Crank pin, 1
9a: Large end of connecting rod, 36: Next to crankcase
Wall, 35a: Side wall portion facing the balancer weight, 35b
... Concave ribs at the front and rear adjacent parts of the side wall .

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16F 15/26 F02B 77/00

Claims (1)

(57) [Claims] 1. A shaft insertion hole (4) is formed in one of front and rear walls of a crankcase (1), and a crankshaft (5) and a balancer shaft are inserted into the crankcase (1) through the shaft insertion hole (4). (6) ・
(6) are inserted in parallel, and the crankshaft (5) and the balancer shafts (6) and (6) are installed in the crankcase (1) in a side-by-side manner in the crankcase (1). (8) of the counterweight (7) and the balancer weight of the balancer shafts (6) and (6)
In the engine with a balancer, in which interference avoidance gaps (11) and (11) at the time of shaft insertion are provided between the outer peripheral surface portion (10) and the lateral peripheral surface portion (10) of the counterweight (7). 8) is retracted inward from the lower peripheral portion (12), and the horizontal peripheral portion (10) of the balancer weight (9) is retracted inward than the lower peripheral portion (13). Thereby, the crankshaft (5) and the balancer shafts (6) and (6) are brought closer to each other, and the counterweights are arranged in parallel with the front and rear of the crankshaft (5).
A balancer weight passage gap (14) is provided between (7) and (7), and the balancer weight (9) is positioned so as to face the balancer weight passage gap (14).
(9) is the gap passing through the balancer weight due to the rotational phase difference
(14), and at least a portion of the balancer shaft (6) opposite to the balancer weight side is recessed to form a large-end passage recess (9a), and the large-end passage recess (9a) is formed. And the connecting rod large end (19a) connected to the crank pin (19) is positioned.
(19a) is configured to pass through the large end passage recess by the rotational phase difference (9a), before Symbol of the lateral wall of the crankcase (1) (36), the balancer weights (9) faces the lateral wall portion ( by recessing the front and rear abutment of 35a) to form a concave ribs (35b) (35b), the balance-way lateral wall (36) of the crankcase (1)
The concave rib is provided for the thickness of the side wall (35a) facing the
The thickness of (35b) formed in the substantially equal thickness, characteristics and to Luba lancer motorized that.