JPS6335859B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a three-cylinder internal combustion engine that is compact, lightweight, and balanced.

[Conventional technology and its problems]

In a conventional three-cylinder internal combustion engine, the phase of each cylinder is set at 120° intervals at the crank angle, and the explosion and combustion intervals of each cylinder are set at equal intervals.
If it is 120°, not only will an unbalance of inertia and couple due to the reciprocating mass occur, but also an unbalance of inertia and couple due to the rotating mass.
In order to eliminate these, a fairly large balance weight must be installed on the crankshaft, and a balance shaft that rotates in conjunction with the crankshaft must be installed parallel to the crankshaft, which significantly increases the weight and size of the engine. So it was warm.

Therefore, for a three-cylinder internal combustion engine, the phases of each cylinder are set at intervals of 180° in terms of crank angle, and the mass of the reciprocating part and the mass of the rotary part of the first and third cylinders are made the same. The mass of the reciprocating part and the mass of the rotary part in the second cylinder located in the middle is made approximately twice the mass of the reciprocating part and the mass of the rotary part of the other cylinder, that is, the first cylinder or the third cylinder. It is proposed to achieve a balance by
issue). In such a three-cylinder internal combustion engine, the second cylinder corresponds to the second cylinder and third cylinder in a general inline four-cylinder internal combustion engine combined into one cylinder, so the in-line four-cylinder internal combustion engine Since the balance state is substantially the same as that of an internal combustion engine, vibration-proof design of the engine is facilitated, and the balance weight is light and a balance shaft is not required, making it possible to reduce the size and weight of the engine.

However, in this case, the mass of the reciprocating motion part and the mass of the rotary motion part in the second cylinder are approximately twice the mass of the reciprocating motion part and the mass of the rotary motion part in the other cylinders. The mass of the rod must be approximately twice the mass of the connecting rods in other cylinders, and since the connecting rods of each cylinder cannot be made into common parts with the same size and shape, connecting rods with different sizes and shapes are required. It is necessary to manufacture two types of parts, which increases the number of parts, which not only increases the manufacturing cost but also increases the complexity of parts management.

The present invention provides an in-line three-cylinder internal combustion engine in which the three cylinders are arranged at a phase interval of 180 degrees, in which the connecting rods in each cylinder have the same size and shape.
The purpose is to prevent unbalance between each cylinder when the cylinder is shaped, or in other words, to make the connecting rod a common part for each cylinder without compromising the balance between each cylinder. be.

[Means for solving problems]

In order to achieve this object, the present invention makes the phases of the three cylinders arranged in a row 180 degrees apart in terms of crank angle, while reducing the mass of the reciprocating part and the rotary part of the first and third cylinders. The masses are the same or approximately the same for both cylinders, and the mass of the reciprocating part and the mass of the rotating part in the second cylinder are
In a three-cylinder internal combustion engine configured to have double or approximately double the mass of the reciprocating portion and the rotary portion of the first or third cylinder, the connecting rods in each cylinder are configured to have the same size and shape. on the other hand,
A mass corresponding to the mass of the small end of the connecting rod is added to the reciprocating portion of the second cylinder excluding the small end of the connecting rod, and a crank arm in the first cylinder and a crank in the third cylinder are added. Balance weights each having a mass corresponding to the mass of the rotating portion of the second cylinder are distributed and provided on both arms at a phase position of 180 degrees from the crank pin of each arm.

[Effect]

In the second cylinder, the mass of the reciprocating portion must be twice or approximately twice the mass of the reciprocating portion in the first or third cylinder;
If the connecting rods in each cylinder are configured to have the same size and shape, the mass of the reciprocating part in the second cylinder is the same as the small end of the connecting rod in the second cylinder, and the mass of the reciprocating part in the second cylinder. Since the connecting rod has the same size and shape as the small end of the connecting rod, the weight becomes lighter, resulting in an unbalanced reciprocating motion. By adding to the moving part a mass equivalent to the mass of the small end of the connecting rod,
The mass of the reciprocating part in the second cylinder is 2 times the mass of the reciprocating part in the first or third cylinder.
Since it can be doubled or approximately doubled, it is possible to balance the reciprocating motion.

On the other hand, in the second cylinder, the mass of the rotating part must be twice or approximately twice the mass of the rotating part in the first or third cylinder, but the connecting rods in each cylinder have the same shape.・If the size is configured, the mass of the rotary moving part in the second cylinder is such that the large end of the connecting rod in the second cylinder has the same size as the large end of the connecting rod in the first or third cylinder.・The rotational movement becomes unbalanced as it becomes lighter due to the shape, but as mentioned above, the phase position of each of the crank arms in the 1st and 3rd cylinders is 180° from the crank pin. In other words, by distributing and providing balance weights with masses corresponding to the mass of the rotary motion part in the second cylinder at the phase positions of the crank pin in the second cylinder,
The mass of this balance weight is added to the mass of the rotary motion part in the second cylinder, and the mass of the rotary motion part in the second cylinder is increased by the mass of the rotary motion part in the second cylinder.
Twice or approximately 2 times the mass of the rotary moving part in the cylinder
Since it can be doubled, it is possible to balance the rotational movement.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
shows a three-cylinder engine arranged in series at equal intervals in the axial direction of a crankshaft 4, the crankshaft 4 is supported by four bearings 5, 6, 7, 8, and the crankshaft 4 is
A pair of crank arms 11, 21, 31 and crank pins 12, 2 are provided at corresponding locations of each cylinder.
2 and 32 are integrally provided. In addition, the pistons 13, 23, 33 each having a piston pin 14, 24, 34 in each cylinder are connected to each of the crank pins 12, 22, 32 via connecting rods 15, 25, 35 having the same size and shape, respectively. In this case, the first cylinder 1 and the third cylinder 3 are in the same phase, but the second cylinder 2 is 180° out of phase with respect to the other cylinders on both sides, that is, the first cylinder 1 and the third cylinder 3. It is located at the location of That is, each cylinder is arranged so that the phase between adjacent cylinders is 180°.

Regarding the mass of the reciprocating portion of each cylinder in this three-cylinder internal combustion engine, the mass M ₁ of the reciprocating portion of the first cylinder 1 and the mass M ₃ of the reciprocating portion of the third cylinder 3 are equal or approximately equal. At the same time, the mass M ₂ of the reciprocating part in the second cylinder 2 is equal to the mass M ₁ of the reciprocating part in the first cylinder 1.
Alternatively, the mass M ₃ of the reciprocating portion of the third cylinder 3 is twice or approximately twice.

That is, the masses of each piston 13, 23, 33 are respectively _M13 , _M23 , _M33 , each piston pin 14,
The masses of 24 and 34 are respectively M ₁₄ , M ₂₄ and M ₃₄ ,
If the mass acting on the small end of each of the connecting rods 15, 25, and 35 (hereinafter simply referred to as the mass of the small end) is M ₁₅ , M ₂₅ , and M ₃₅ , then M ₁ =M ₁₃ +M ₁₄ +M ₁₅ M ₂ =M ₂₃ +M ₂₄ +M ₂₅ M ₃ =M ₃₃ +M ₃₄ +M ₃₅ , so this can be expressed as M ₁ =M ₃ , 2M ₁ =M ₂ or
Substituting 2M ₃ = M ₂ and sorting it out, we get 2M ₁₃ + 2M ₁₄ + 2M ₁₅ = M ₂₃ + M ₂₄ + M ₂₅ … or 2M ₃₃ + 2M ₃₄ + 2M ₃₅ = M ₂₃ + M ₂₄ + M ₂₅ … so that both equations are satisfied. Set.

In addition, regarding the rotational movement portion of each cylinder in the three-cylinder internal combustion engine, both the crank arm 11 of the first cylinder 1 and the crank arm 31 of the third cylinder 3 have a 180° angle with respect to their respective crank pins 12 and 32. At the phase position of °, balance weights 9, 9
Balance is achieved by providing .

In other words, the total mass of the balance weights 9, 9 attached to the 1st cylinder and 3rd cylinder (1st cylinder, 3rd cylinder
The masses of the balance weights of the cylinders do not necessarily have to be equal; in other words, it is sufficient that the sum of both is balanced. ) m ₉ , each crank pin 12, 22, 3
The masses of crank arms 11, 21, and 31 are m ₁₂ , m ₂₂ , m ₃₂ , respectively, and the masses of crank arms 11, 21, and 31 are m ₁₁ , m ₂₁ , m _{31 ,} respectively.
If the mass acting on the large end of each connecting rod 15, 25, 35 (hereinafter simply referred to as the mass of the large end) is m ₁₅ , m ₂₅ , m ₃₅ , then the rotational movement part is In order to balance 2(m ₁₁ +m ₁₂ +m ₁₅ )−m ₉ =m ₂₁ +m ₂₂ +m ₂₅ 2(m ₃₁ +m ₃₂ +m ₃₅ )−m ₉ =m ₂₁ +m ₂₂ +m ₂₅ , from this When calculating m ₉ , m ₉ = 2 (m ₁₁ + m ₁₂ + m ₁₅ ) − (m ₂₁ + m ₂₂ + m ₂₅ ) … or m ₉ = 2 (m ₃₁ + m ₃₂ + m ₃₅ ) − (m ₂₁ + m ₂₂ + m ₂₅ ) ..., and the masses of both balance weights 9, 9 are set in this way.

In this case, in order to make the connecting rods 15, 25, and 35 in each cylinder 1, 2, and 3 the same size and shape, and to standardize the parts, M ₁₅ = M ₂₅ = M ₃₅ , m ₁₅ = Since m ₂₅ = m ₃₅ , substituting this into the above formulas and formulas and rearranging, 2 (M ₁₃ + M ₁₄ ) + M ₁₅ = M ₂₃ + M ₂₄ …' or 2 (M ₃₃ + M ₃₄ ) + M ₃₅ =M ₂₃ +M ₂₄ …' m ₉ = 2 (m ₁₁ + m ₁₂ ) + m ₁₅ − (m ₂₁ + m ₂₂ ) …’ or m ₉ = 2 (m ₃₁ + m ₃₂ ) + m ₃₅ − (m ₂₁ + m ₂₂ ) …’ becomes.

Therefore, the total mass (M 23 +M 24 ) of the piston 23 and piston pin 24 in the second cylinder 2 is calculated as the total mass (M ₂₃ +M ₂₄ ) of the piston 13 and piston pin 1 in the first cylinder 1.
4 and the total mass (M ₁₃ + M ₁₄ ) twice (including approximately twice) or the piston 3 in the third cylinder 3
3 and the piston pin 34 (M ₃₃ +
The mass of the small end of the common connecting rod (M ₁₅ , M ₂₅ or M ₃₅ ) is twice (including approximately twice) that of M ₃₄ ).
The mass of the balance weights 9, 9 provided on the crank arm 11 of the first cylinder 1 and the crank arm 31 of the third cylinder 3 is set as
By setting them as '' or ', respectively, it is possible to use a common connecting rod in each cylinder while maintaining a balance between both reciprocating motion and rotational motion.

In this way, in order to make the connecting rods in each cylinder a common part with the same size and shape, each crank pin 12, 23, 32 should have the same shaft diameter, and each piston pin 14, 24, 34 should have the same shaft diameter. The diameter must also be the same. In order to make the piston pin 24 in the second cylinder 2 the same diameter as the piston pins in other cylinders and to increase its mass compared to the piston pins in the other cylinders, the piston pin 24 in the second cylinder 2 can be made into a hollow shaft. The mass of the piston 23 in the second cylinder 2 cannot be increased compared to the mass of the pistons in the other cylinders. , piston 1 of other cylinder
3 and 33 are made of a metal with a low specific gravity such as an aluminum alloy or a magnesium alloy (including light alloys), while the piston 23 of the second cylinder 2 is made of a metal with a high specific gravity such as cast iron. can be achieved.

The balance in the equation ' or ' is the mass M ₂₃ of the piston 23 in the second cylinder 2.
and the mass M ₂₄ of the piston pin 24 is made twice or approximately twice that of those of the other cylinders, while the piston 23 and the piston pin 24 in the second cylinder 2 are
This can be achieved by adding the mass (M ₁₅ , M ₂₅ or M ₃₅ ) of the small end of the common connecting rod to either or both of the Piston pin 1 of other cylinder
4 or 34 (M ₁₄ = M ₂₄ = M ₃₄ ), and the piston 23 of the second cylinder 2.
The mass of the piston may be set to be twice or approximately twice the mass of the pistons of other cylinders plus the mass of the common piston pin and the mass of the small end of the common connecting rod. This means makes the pistons of the first and third cylinders made of metal (including light alloy) with low specific gravity,
By making the piston of the second cylinder made of cast iron, the difference in mass between the two can be increased, so this can be easily achieved by changing the material of each piston, and the connecting rod of each cylinder can be made common. In addition, the piston pins for each cylinder can also be made common, which reduces the number of parts. By making the diameter of the piston in the second cylinder different from the diameter of the pistons in other cylinders, it is possible to prevent the piston for the second cylinder from being incorrectly assembled in the first or third cylinder when assembling the engine. Prevented.

Moreover, the mass of both balance weights 9, 9 obtained from the above formula ' or ' is the mass of the crank arm 21 and crank pin 22 in the second cylinder 2,
If the dimensions and shape are the same as those in other cylinders, m ₉ = m ₁₁ + m ₁₂ + m ₁₅ or m ₉ = m ₃₁ +
m ₃₂ + m ₃₅ , and the mass should be the same as the mass of the rotating part in the first cylinder 1 or the third cylinder 3. If the crank pin and crank arm in each cylinder are made the same size and shape, the crank The shaft can be manufactured easily and costs can be reduced.

Then, the crank pin 22 of the second cylinder 2 is made the same size and shape as the crank pins of the other cylinders,
(m ₁₂ = m ₂₂ or m ₃₂ = m ₂₂ ) The mass of the crank arm 21 of the second cylinder is larger than that of the other cylinders, for example, twice the mass of the crank arm of the other cylinders (m ₂₁ = 2 m ₁₁ or m ₂₁ = 2m ₃₁ ), the mass of both balance weights 9,9 is
m ₉ = m ₁₂ + m ₁₅ or m ₉ = m ₃₂ + m ₃₅ , and if the crank arm 21 of the second cylinder 2 is made the same size and shape as the crank arms of the other cylinders (m ₁₁ +
m ₂₁ or m ₃₁ = m ₂₁ ), and the mass of the crank pin of the second cylinder is larger than the crank pin of the other cylinders, for example, twice the mass of the crank pin of the other cylinders (m ₂₂ = 2 m ₁₂ or m ₂₂ = 2m ₃₂ ), then
The mass of both balance weights 9, 9 is m ₉ = m ₁₁ =
m ₁₅ or m ₉ =m ₃₁ +m ₃₅ , both of which can reduce the mass of both balance weights 9, 9, and the two may be combined.

In this case, in order to make the crank pin 22 of the second cylinder 2 the same diameter as the crank pins of other cylinders and to increase its mass compared to the crank pins of the other cylinders, the crank pin 22 of the second cylinder 2 must be 22 is formed into a hollow shaft, and the hollow part is filled with a metal having a high specific gravity such as lead or copper.In order to increase the mass of the crank arm 21 in the second cylinder 2 compared to the crank arms in other cylinders, ,
By embedding a metal with a high specific gravity such as lead in the crank arm 21, by increasing its cross-sectional area, by lengthening the tip of the crank arm 21 on the crank pin 22 side, or by combining these as appropriate. Therefore, this can be easily achieved, and the balance weights 9, 9 are arranged as shown in FIG. It goes without saying that they may be provided separately as shown by the two-dot chain line.

〔Effect of the invention〕

As described above, the present invention has the structure described in the claims, in which a connecting rod is made common to each cylinder in an in-line three-cylinder internal combustion engine in which the phase between adjacent cylinders is 180 degrees. Since the unbalance can be corrected and the balance maintained, the number of connecting rod parts is reduced, which has the effect of reducing the manufacturing cost of the connecting rod and the complexity of parts management.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the arrangement of a three-cylinder internal combustion engine according to an embodiment of the present invention, and FIG. 2 is a left side view of FIG. 1. 1...1st cylinder, 2...2nd cylinder, 3...3rd cylinder
Cylinder, 4... Crankshaft, 11, 21, 31...
Crank arm, 12, 22, 32... Crank pin, 13, 23, 33... Piston, 14, 2
4, 34... Piston pin, 15, 25, 35...
...Connecting rod, 9...Balance weight.

Claims (1)

[Claims] 1. While the phases of the three cylinders arranged in a row are set at intervals of 180° in terms of crank angle, the mass of the reciprocating portion and the mass of the rotating portion of the first and third cylinders are both The cylinders are the same or approximately the same, and the mass of the reciprocating part and the mass of the rotary part in the second cylinder is twice or approximately 2 times the mass of the reciprocating part and the mass of the rotary part in the first or third cylinder. In a three-cylinder internal combustion engine with double the configuration,
While the connecting rods in each cylinder are configured to have the same size and shape, a mass equivalent to the mass of the small end of the connecting rod is added to the reciprocating portion of the second cylinder excluding the small end of the connecting rod. Furthermore, both the crank arm in the first cylinder and the crank arm in the third cylinder are provided with a mass corresponding to the mass of the rotary movement part in the second cylinder at a phase position of 180 degrees from the crank pin in each of them. A three-cylinder internal combustion engine characterized by distributed balance weights. 2. The three-cylinder internal combustion engine according to claim 1, wherein a mass corresponding to the mass of the small end of the connecting rod is added to one or both of the piston and the piston pin in the second cylinder. institution. 3 The piston pin in the second cylinder has the same size and shape as the piston pin in the first or third cylinder, and the piston in the second cylinder has a mass twice the mass of the piston in the first or third cylinder. 3. The three-cylinder internal combustion engine according to claim 1, wherein the three-cylinder internal combustion engine has a mass equal to or approximately twice the mass of the piston pin and the mass of the small end of the connecting rod. 4. The crank arm and crank pin in the second cylinder have the same dimensions as the crank arm and crank pin in the first or third cylinder.
A three-cylinder internal combustion engine according to claim 1 or 2, characterized in that the three-cylinder internal combustion engine is configured in a shape. 5. The three-cylinder internal combustion engine according to claim 1 or 2, wherein the piston pin in the second cylinder is a hollow shaft, and the hollow portion thereof is filled with heavy metal. 6 The piston in the second cylinder is made of a metal with a high specific gravity such as cast iron, while the piston in the first cylinder and the third cylinder
A three-cylinder internal combustion engine according to claim 1 or 2, characterized in that the pistons in the cylinders are made of metal with low specific gravity. 7. The three-cylinder according to claim 1 or 2, characterized in that the diameter of the piston in the second cylinder is different from the diameter of the piston in the first cylinder or the third cylinder. Internal combustion engine.