JPS62203928A - Opposed piston engine - Google Patents

Abstract

PURPOSE:To obtain the good balance while to promote the smallness of size and the lightness of weight, by connecting both pistons mainly through a four- side equilateral link and a Z-type crankshaft, in the case of an engine formed by arranging a pair of pistons to be opposed. CONSTITUTION:An engine arranges a pair of cylinders C1, C2 to be opposed on the same axial line, and pistons P1, P2, mounted to be fitted into each cylinder C1, C2, are connected by two pairs of links L1, L3, L2, L4 equilateral in a diamond shape. While a crossing arm A1 is crossed in an X-shape with two crossing arms A2 in a crossing point of diagonal lines of the paired links in such a manner that the arms A2 hold the arm A1 from the upper and the bottom. Both ends of each crossing arm A1, A2 are pivotally mounted to the middle points of each link L1-L4, while a swivel shaft 1 is secured to the crossing arm A1 in the crossing point with the crossing arms A1, A2 at a right angle with their working surface, and a yoke 2 is provided in the other end of said swivel shaft. And the engine, which provides a Z-shaped crankshaft 3 so that its center line crosses at a right angle with the swivel shaft 1, supports the yoke 2 to a diagonally crossing crank pin 5 of said crankshaft 3 through a bearing 6 crossing at a right angle.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is an engine in which a pair of pistons move symmetrically in opposition to each other, which improves the balance of the engine compared to an ordinary crank and connecting rod. This invention relates to a device that is small and lightweight, utilizes the change in volume of the space on the back side of the piston, which corresponds to the conventional crank chamber, and uses this as a supercharger.

[Prior art and problems to be solved by the invention] Conventional two-cylinder four-stroke engines mainly include parallel type, horizontally opposed type, and V-type twin cylinders. Engines with relatively large displacements require an extra mechanism such as a primary balancer to counter the fattening, and the benefits cannot be taken advantage of.

In addition, in the horizontally opposed type, the pistons move symmetrically, so vibrations like the parallel type do not occur, but the central axes on which the pistons move are not on the same straight line and are offset, making it visually strange and causing unnecessary vibrations. A large engine room is required. Furthermore, there is a restriction that the direction of the output shaft is perpendicular to the direction of movement of the piston, and for example, when used in motorcycles, most of the applications are limited to shaft drives.

On the other hand, a V-type two-cylinder engine has a higher degree of freedom in layout than a horizontally opposed engine, but requires a larger engine space.

The present invention is completely different from conventional cranks and conrods, and is mainly composed of four isosceles links and two crank axes, thereby eliminating the drawbacks of the above-mentioned types, such as balance and space. .

Engines using isosceles links generally have an even number of pistons that move symmetrically, such as U, S, P
2,050,603 and the American Kamine cam engine (History of Internal Combustion Engines (Published by Sanei Shobo, December 25, 1964) P260), these have both types of cams that are internally or externally connected to the rollers. It is a type of engine that rolls at high speed, which may be superior in terms of balance and vibration, but it also has problems with durability as an engine due to wear and tear on the contact parts.

In addition, in an engine such as that disclosed in Japanese Patent No. 236540, which transmits the reciprocating motion of the piston to the rocking swash plate and converts it into rotational motion, the joint part when transmitting the linear motion of the piston to the rocking swash plate is complicated. There is. These are the above
The history of internal combustion engines is explained in detail on pages 266 to 273.

The present invention has been made with attention to these points, and the aforementioned Japanese Patent Application No. 60-259336, which was invented by the same person, describes the use of isosceles links connected in a diamond shape when used as an engine or compressor. Instead of placing pistons in all the connecting parts, the present invention preferentially utilizes only one pair of opposing connecting parts to reduce the size and weight of the cylinder lock, simplify the valve mechanism, and reduce the displacement. The advantages of this mechanism can also be applied to relatively small engines.

[Means to solve the problem]

The technical means of the present invention is that the piston pin (p,) (p2)
and equilateral links (L+) (L2) (L2) (L call) connected in a diamond shape with joint pins (jl) (jz)
Opposed links (L+) (L3) and (Lz) (L
Cross arms (A1) (
A2) are connected to each other, and a swing shaft (1) is fixed perpendicular to the operating plane of the cross arm (A1) at the intersection point of the center of the cross arm, and a yoke (2) is fixed to the other end. .

Also, the Z crankshaft (
3) Arrange the center lines of the major axis (4a) and minor axis (4b).

A crank pin (5) is provided so as to connect the main shaft (4a) and the sub-shaft (4b) obliquely to the center line.

The orthogonal bearing (6) that allows the crank pin (5) to play freely is provided with swing pins (to 6) (6~) on both sides perpendicular to its center line, and the swing shaft (1) and the main shaft (4a ) The center lines of the subshaft (4b), the crank pin (5), the swing pin (6L), and (6~) are arranged so that they always intersect at one point.

[Effect]

With the above configuration, when the pistons (P 1 ) (P2) move forward or backward, the cross arms (A
t) (AZ) swing with respect to each other, and the yoke (the yoke) at the end of the swing shaft (1) fixed to the cross arm (A1) swings to produce a nutation movement (missosliction) in the orthogonal bearing (6). movement),
The orthogonal bearing (6) and the idler crank pin (5) also move in a similar manner and serve to rotate the two crankshafts (3) consisting of a main shaft (4a), a counter shaft (4b), etc. At this time, the pair of pistons and the equilateral link mechanism move symmetrically about the intersection of the diagonal lines of the rhombus that they constitute, so they are perfectly balanced.

Also, the Z crankshaft (3) is the main shaft (4a) and the M shaft (4b).
The balance weights (4'a) (4"b) provided in the
) is decomposed into a component of nutation movement around the crank pin and a component of rocking movement near the swing pins (6a) (6a), and each component is separated by the balance weight (4°a) (4'b).
By balancing the cross arm (A2) (AZ) arranged so as to sandwich the cross arm (A1) and the cross arm (A1) with swinging balance weights added as necessary, the overall structure can be extremely well-balanced. However, the occurrence of angular vibration due to unbalanced rocking can be relatively easily reduced by modifying the engine mount, and is often unnecessary in small engines.

(Example) Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional plan view of the main part, and FIG. 2 is a side view thereof. Figure 3 I (a) - TV (a) mainly shows the piston CP+) (P2) and the equilateral links (L7) to (L
Cow) Cross arm (Az) and intake valve ('J15
) (V2Sl exhaust valve (VteJ (Vze) <7)
Figure 3 I (b) - 17 (b) shows the operating state of the Z crankshaft (3) viewed from the cross section of the swing shaft (1) downward, and Figure 3 I (C) - 1V (C) is the main shaft (4a
) shows the rotational phase angle using the arrow as a guide.

A pair of cylinders (C/) arranged oppositely on the same axis
(CZ) and cylinder head (H/) (H2),
The cylinder head (H/) (Hz) has an intake valve (V/s)
(Vra) (V2a) and spark plug (11
)(Iz) is provided. Each cylinder (C1) (
The piston (P/) (P2) inserted into the piston (P/) (Cz) is connected to the links (L/)-(L+) by the piston pin (P/) (pz), and the other end of each link is connected to the joint pin (jl) (
j7) and are connected in a diamond shape as a whole. Opposing parallel equilateral links CLI ) (L3) each 2 trees and (L
, 2) The ends of the cross arms (A1) (A2) that intersect in an X shape at each midpoint of (L4-) are arm pins (7).
(7) and (8) The piston (
The rhombus formed by the link deforms in response to the reciprocation of P+) (Pλ), and the cross arms (A1) (Az) accordingly swing around their intersection, changing their intersecting angle.

A swing shaft (1) is fixed at the midpoint of the cross arm (A/) perpendicular to its operating surface and rotatably supported by a journal flange (9). Part (1
゛) is loosely fitted to the boat flange (1o).

Next, a yoke (2) is fixed to the lower part of the swing shaft (1), and swing pins (6a ) (6a
) is swingably supported, and the bearing part of the orthogonal bearing (6) supports the crank pin (5) of the two crankshafts (3), which are disposed perpendicular to the center line of the swing shaft (1). are doing.

Here, the swing axis (1), swing pins (6a) (6a), Z
The center lines of the main shaft (4a), sub-shaft (4b), and crank pin (5) of the crankshaft (3) intersect at one point.

Next, the valve mechanism will be described.

A bevel gear (11) is fixed to the countershaft (4b), while a bevel gear (13) is fixed to the camshaft I (12).
They are meshed to rotate synchronously at the rotational speed of station 4a). Camshaft I (12) and camshaft II (14) are each provided with a sprocket (15) and a sprocket (16), and are connected to each other by a chain or a timing belt so as to rotate at a constant speed. Furthermore, timing is taken by cams protruding from camshaft I (12) and camshaft II (14), and rocker arms (17) (18) (19) (
20) drives the intake valve or exhaust valve provided in the cylinder head CHI) (Hυ).

This valve mechanism is simple as an OHC mechanism.
The HC mechanism normally requires a chain to be provided for each cylinder in multiple rows, but compared to those systems, it is an extremely well-organized mechanism.

In the valve train described above, if it is necessary to arrange a clutch with a large diameter on the same axis as the main shaft (4a) due to the positional relationship between the engine and the transmission, the swing shaft (1) should be made longer than in Fig. 2. 2. Is it possible to install the crankshaft (3) further down? In that case, instead of fixing the bevel gear (11) directly to the subshaft (4b), the bevel gear (11) is decelerated by one step using a cylindrical gear mechanism, and then the bevel gear is By decelerating the mechanism one more step, the clutch is placed in the lower right space (Ql) in Figure 2, and the clutch is placed in the lower left space (Ql).
It is possible to place accessories such as a generator in the QZ), and the engine room can be used effectively without wasting space.

Next, the shape of the piston is shown in Figure 3 I (a), m (a)
In this state, part of the link mechanism is wedged into the piston skirt, and the journal flange (9) and bow I
・A notch is provided for the body of the flange (1o). In addition, the cylinder (C/) (C2) has a space (Sl) (S/) where the link escapes at the bottom dead center of the piston.
), and a piston skirt (R
5) CP, s) are provided.

This structure was originally invented in patent application No. 60-2593.
In No. 36, when one pair of pistons comes near the bottom dead center, the piston tilts against the side thrust because the 4-cylinder cylinder is structurally unable to extend the cylinder to the piston skirt part, but the other pair of pistons tilts against the side thrust. This differs from the fact that the piston receives site thrust near top dead center and compensates for tilting.

Next, the operation of the engine as a whole will be explained.

Figure 3 I (a) shows the cylinder (C/) or the end of inhalation;
The cylinder (C2) indicates the end of explosion, and the air-fuel mixture is sucked through the intake valve (V/s). I (b) shows the state of the two-crank mechanism in I (a) as seen from the swing axis (1). The cross arm (A1) and yoke (2) are directly connected, and both are in the leftmost phase. It's a corner.

At this time, the arrow of the main axis (4a) is directed upward.

As you go down in Figure 3, regarding the cylinder (C1), II (a) Compression - + U1 (a) Explosion - IV
(a) Exhaust, cylinder (Cz) II (a) Exhaust → III (a) Intake → IV (a) Compression, yoke (
Regarding 2), 11 (b) right tilt 4 m (b) left tilt - rV (b
) Right tilt, about the main axis (4a), II (c) left half rotation → I
II (c) Half rotation to the left → ■ (C) Half rotation to the left and repeat to complete one cycle of the engine as a whole. During this time, the left and right cylinders each generate one concave plate, which becomes piston pressure → thrust of the link → rocking torque of the cross arm (A1) → couple of the yoke (2) → via the orthogonal bearing → Z crank This will be converted into the rotational torque of the shaft (3).

Regarding the operating states of I (a) to ■(a) in Figure 3, the piston (PH) (P2), the parallel opposing link (L1)
(L3) 2 each and (LZ) (Lto), cross arm (
A1) (Az) operates symmetrically around the intersection of the diagonal lines of the rhombus formed by the links, so its inertial force is canceled out.
Also, regarding the angular vibration due to the swinging of the yoke (2), the swing axis (
The inertia factor around the center line of 1] is quite small compared to other operating parts, so it is not a problem in practical use. Also, since a normal rocking swash plate mechanism obtains rotational torque by thrust in the axial direction parallel to the output shaft, is a thrust bearing necessary?1.As in the present invention, the rotational torque due to the couple of the yoke (2) is radial. This can occur depending on the bearing, so depending on the lubrication conditions,
It is extremely advantageous in terms of durability, structure, etc.

The structure described above provides a very well-organized structure as a whole, and solves the balance and space problems of conventional two-cylinder engines.

As shown in FIG. 2, the present invention can be arranged so that the interlocking direction of the piston is parallel to the center line of the two crankshafts (3), or it can be arranged so that it is rotated 90 degrees with respect to the direction of movement of the piston.
There is a great deal of freedom in the layout of the engine as a whole.

The space behind the piston (P+) (P2) is I(a),
It is minimum when III (a), and II (a), IT
It is maximum in case (a).

Scavenging is performed using the conventional engine mechanism consisting of the crank and connecting rod, but when the piston reaches bottom dead center, the volume of the crank chamber, that is, the clearance volume, is occupied by the space behind the piston and while the connecting rod is rotating. The volume is considerably larger than the stroke volume of the piston, and the compression ratio of the crank chamber, that is, (gap volume + piston stroke volume)/(gap volume) = 1.3 to 1.4. [“Automotive Engineering Course – Internal Combustion Engine (Structural Lines)” Meigensha, March 30, 1984, P.
, 104) This is a structural characteristic of a normal engine, and it is difficult to increase the compression ratio of the crank chamber any further. Therefore, it is impossible to use it as an air compressor, and the pressure of the gas handled here is limited to approximately atmospheric pressure.

On the other hand, in the present invention, when a pair of opposing pistons CPt) (Pz) reaches the bottom dead center as shown in Fig. 3 I (a) and m (a), the space occupied by the back side of the pistons (referred to as the clearance volume) is mainly a slight gap in the link mechanism and a space (SZ) immediately behind the piston head.

Regarding the space (SZ) (SZ), as shown in Figure 4, there are projections (9') on the journal flange (9) and boat flange (10).
) (9") (10") (10') to create a space (SZ)
By filling (SZ), the volume of the gap can be further reduced.

Therefore, the efficiency of the compressor can be increased by increasing the compression ratio (referred to as clearance compression ratio) of the crank chamber of a normal engine. In other words, by sealing the space behind the piston (called a sealed chamber), providing a communication hole in a part of it, and installing an appropriate valve mechanism nearby, it can be used as a relatively low-pressure air compressor. .

The boat flange (10) in Fig. 4 has several communication holes (21) (21) between it and the sealed chamber, and a suction reed valve (22) (22) and a discharge reed valve (23) are connected to the link-shaped space.
(23), and an inlet (24) and an outlet (23), respectively.
5) It communicates with.

Now, inhale air from the suction port (24) and move to the discharge port (25).
The air-fuel mixture is connected to the engine intake boats (26) and (27) via a carburetor and branch pipes (not shown), and the mixture is sent to the cylinders (C1) and (Cz), as shown in Figure 3 I.
In the case of (a), the air-fuel mixture obtained by changing the volume of the piston stroke volume x 2 is transferred from the suction boat (26) to the cylinder (C
In addition, in m (a), the same air-fuel mixture is sent into the cylinder (Cz) from the intake bow) - (27), which causes a larger amount of air-fuel mixture than in the natural intake type, which draws air at atmospheric pressure. It will be necessary to send the mixture. That is, the change in volume of the sealed chamber is used as a supercharger, and this is an extremely simple mechanism compared to providing a supercharger separately from the engine body. Furthermore, since the present invention relies on the engine itself to deal with mechanical friction loss and durability, which are problems when a supercharger is provided, it is an extremely practical mechanism in terms of reliability.

FIG. 5 is an operational diagram of the reed valve mechanism provided on the boat flange (10), and FIG. ) when changing to
Suction reed valve (22) (22) Glue (22°) (2
2°) is opened and air is sucked into the sealed chamber through the communication holes (21) (21).
) or rV When changing from (a) to I (a), the reed (22') (22°) is closed and the reed (23°) (23°) is opened and discharged as shown in Figure 5. Exit (25)
The air coming out of the tank is turned into a mixture by a vaporizer, etc., and the mixture is divided into branch pipes and connected to the suction boats (26) and (27).

Regarding the lubrication of the sliding parts of the sealed chamber, when considering the route from the suction port (24) to the suction boats (26) and (27), it is necessary to install a carburetor before reaching the suction port (24) like in a two-stroke engine. There is a method in which the mixture mixed with lubricating oil is sent into a sealed chamber, or the lubricating oil alone is mixed with air using a meter link pump or the like before the suction port (24), and the carburetor is used after the discharge port (25). There are methods such as providing a lubricating oil and directly lubricating the mechanism of the sealed chamber.In some cases, it is possible to attach an oil separator to the discharge port (25) and collect the lubricating oil that leaks out.

Note that the present invention can also be used as a diesel engine with a supercharger by feeding only air into the cylinder without installing a carburetor or an injection nozzle midway to create a mixture. Furthermore, various methods are possible regarding the position of the communication hole and the structure of the valve.

These are not limited to this embodiment.

〔Effect of the invention〕

As can be seen from the above description, the present invention is a 4-stroke, 2-cylinder engine that is superior to conventional types in terms of balance, engine space, flexibility in the direction of the output shaft, and specific output relative to engine weight. In addition, compared to the various types of new engines described in the above [History of Internal Combustion Engines], the elements that make up the engine have severe lubrication conditions that pose problems in terms of durability. or,
It is highly practical because it combines proven elements without using a structure that is difficult to airtight. In addition, superchargers that utilize a sealed chamber on the backside of the piston are cost-effective and space-saving, compared to their adoption in small-displacement engines, where practical use is currently delayed in terms of durability and mechanical efficiency. , it is extremely excellent in terms of durability.

In addition, the present invention takes advantage of the good balance and uses two cylinders instead of three or four cylinders in the past for small-displacement diesel engines where it is difficult to control the injection amount of the fuel injection pump. By increasing the stroke volume per cylinder to increase combustion efficiency and also providing a supercharger, it is possible to create an engine with extremely high specific output.

Next, regarding the valve mechanism, the rocker arm (17
) (18), (19), and (20), it is possible to easily increase the number of valves per cylinder to 3 or 4, making it possible to support higher speed and higher output engines. It is a mechanism.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a plan view with a cross section of the main part, FIG. 2 is a side view with a cross section of the main part, and FIGS. 3 I (a), II (a), m(a),
IV (a) is a plan view showing the operation of the main parts, I (b), II (b), m (b), IV
(b) is a plan view of the two-crank mechanism looking downward from the swing axis (1), I (c), II (c), m (c),
IV (c) is the main axis 4 of I (b) to rv (b) (
Figure 4 shows the rotational phase of journal flange (9) and boat flange (a).
Figure 5 is an explanatory diagram of the operation of the reed valve mechanism of the boat flange (10), 1; Swing shaft 2: Yoke 3; Z crankshaft 4
a: Main shaft 4b; Sub-shaft 4'a, 4°b; Balance weight 5; Crank pin 6; Orthogonal bearing 6a:
Swing pins 7, 8: Arm pin 9; Journal flange 9゛; Projection of journal flange 10
; Boat flange 10°: Boat flange protrusion 11.13; Bevel gear 12: Camshaft 114; Camshaft l
115, 16; Sprocket 17, 18, 19
, 20; Rocker arm 21; Communication hole 22: Suction reed valve 23: Discharge reed valve 22', 23°
;Lead 24;Suction port 25:Discharge port 26, 2
7; Suction boat AI+A2; Cross arm p
,, p2; Piston 1)1. p2; piston pin
C1, C2; Cylinder Hl, H2; Cylinder head t, l, L2. L3. L4; Link jl
, jz; Joint pin St: Link escape space
Q,, Q2; Space at both ends of Z crankshaft 11. I
z; Spark plug PS: Piston skirt v, s, v25
;Intake valve Vte, V2e;Exhaust valve.

Claims (3)

[Claims] (1) A pair of cylinders (C_1) facing each other on the same axis
) (C_2) and the piston pin (p_1) of each piston (P_1) (P_2) inserted into each cylinder.
(p_2) and joint pins (j_1) (j_2), connect equilateral links (L_2) (L_4) to (L_1)(
L_3) Two each are connected in a rhombic shape by sandwiching them from above and below, and at the intersection of their diagonals, the cross arm (A_1) is crossed in an X shape by two cross arms (A_2) (A_2) sandwiching it from above and below. , its ends are connected to arm pins (7) (7) and (
8) In (8), (L_2) (L_4) and (L_
1) (L_3) at each midpoint, fix the swing shaft (1) to the cross arm (A_1) perpendicular to its operating surface at the intersection of the cross arms, and attach the yoke (2) to the other end. Prepare,
A Z crankshaft (3) is provided so that its center line is orthogonal to the swing axis (1), and a crank pin (5) that is obliquely intersected with the center line between its main shaft (4a) and sub-shaft (4b) is supported. An orthogonal bearing (6) is provided so that the swing pins (6a) (6a) are connected to the pair of arms (2a) of the yoke (2) on the center line on both sides perpendicular to the axis of the orthogonal bearing (6). ) (2a), the swinging motion of the yoke (2) is extracted from the reciprocating motion of the piston, and the Z crankshaft (
3) An opposed piston engine characterized in that it can be converted into rotational motion. (2) The cylinder head (H_1) (H_2) has a swing shaft (
A camshaft (12) (14) is provided parallel to the subshaft (4).
The rotation reduced by 1/2 from b) is transmitted to the camshaft (12) via a reduction gear mechanism, and the sprockets (15) and (16) provided on each camshaft are connected with a chain or a timing belt to mutually maintain constant speed. The rocker arm (
17) (18) (19) (20) through the intake valve (V_
1_s) (V_2_s) Exhaust valve (V_1_e) (V_2
_e) The opposed piston engine according to claim 1, comprising a valve mechanism configured to open the valve mechanism. (3) The space behind the pair of opposing pistons (P_1) (P_2) is sealed, a suction valve and a discharge valve are attached close to the sealed chamber, and the pistons (P_1) (P_2) reciprocate to seal the space. The opposed piston according to claim 1 or 2, characterized in that the compressed air or mixture obtained by changing the volume of the chamber is sent to the cylinders (C_1) (C_2) and used as a supercharger. engine.