JP2003120317A - Horizontally opposed cylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a dimension in a cylinder axial direction in a horizontally opposed cylinder engine provided with two crankshafts. SOLUTION: The horizontally opposed cylinder engine E transversally mounted on a vehicle V at a front part of a vehicle body is provided with a first crankshaft 14a and a second crankshaft 14b. A second cylinder 11b in which a second piston 12b connected to the second crankshaft 14b slides is arranged above the first crankshaft 14a and a first cylinder 11a in which a first piston 12a connected to the first crankshaft 14a slides is arranged below the second crankshaft 14b. A first crank case 9a housing the first crankshaft 14a is oppositely arranged below the second cylinder 11b and a second crank case 9b housing the second crankshaft 14b is oppositely arranged below the first cylinder 11a.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a horizontally opposed cylinder type engine having a first crankshaft and a second crankshaft.

[0002]

2. Description of the Related Art Two crankshafts respectively provided in two banks arranged to face each other in a horizontal direction are connected to each other by a gear, and outputs of the two crankshafts are taken out from any one of the crankshafts. An engine whose vibration is thus reduced is known from JP-A-10-141082.

[0003]

By the way, in the above-mentioned conventional engine, the two banks corresponding to the two crankshafts extend in the directions in which they are separated from each other with the two crankshafts interposed therebetween. There was a problem in that the engine size in the axial direction (the axial direction of the cylinder) was increased.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the axial dimension of a cylinder in a horizontally opposed cylinder type engine having two crankshafts.

[0005]

In order to achieve the above object, according to the invention described in claim 1, in a horizontally opposed cylinder type engine provided with a first crankshaft and a second crankshaft, A second cylinder on which a second piston connected to the second crankshaft slides is arranged above the crankshaft, and a first cylinder connected to the first crankshaft is arranged below the second crankshaft.
A first cylinder in which a piston slides is arranged, a first crankcase accommodating a first crankshaft is opposed to a lower side of a second cylinder, and a second crankcase accommodating a second crankshaft is disposed above the first cylinder. A horizontally opposed cylinder type engine is proposed which is characterized by being opposed to each other.

According to the above construction, since the second cylinder is arranged above the first crankshaft and the first cylinder is arranged below the second crankshaft, the lower first crankshaft and the first cylinder are arranged above. Second
The size of the engine in the axial direction of the first and second cylinders can be reduced by the amount of overlap with the crankshaft and the second cylinder. In addition, the first crankcase to the second
Since the second crankcase is opposed to the upper side of the first cylinder while facing the lower side of the cylinder, the first and second crankcases are opposed to each other.
The dimensional difference in the radial direction between the cylinder and the first and second crankcases can be reasonably absorbed to reduce the size of the engine in the vertical direction.

Further, according to the invention described in claim 2,
In addition to the structure of claim 1, the first and second crankshafts are arranged in the vehicle width direction at the front of the vehicle body of the vehicle, and the first cylinder head connected to the first cylinder is arranged toward the front of the vehicle body. A horizontally opposed cylinder type engine is proposed in which a second cylinder head connected to the second cylinder is arranged toward the rear of the vehicle body.

According to the above construction, the engine is horizontally arranged in the front part of the vehicle body, the lower first cylinder head is arranged forward of the vehicle body, and the upper second cylinder head is arranged rearward of the vehicle body. Since it is arranged, the bonnet line that covers the upper part of the engine can be lowered.

According to the invention described in claim 3,
In addition to the configuration of claim 1 or claim 2, the output shaft arranged between the first crankshaft and the second crankshaft, the lower end of the first cylinder, and the lower end of the second cylinder are on the same plane. A horizontally opposed cylinder type engine characterized by the arrangement is proposed.

According to the above construction, since the output shaft and the lower ends of the first and second cylinders are arranged on the same plane, there is a dead space between the first and second crankcases connected to the first and second cylinders. It can be effectively used to arrange the output shaft compactly and suppress the increase in size of the engine.

According to the invention described in claim 4,
In addition to the structure according to any one of claims 1 to 3, two main galleries extending in the axial direction of the output shaft supported by the engine block are opposite to the output shaft with the first and second cylinders interposed therebetween. A horizontally opposed cylinder type engine is proposed which is formed in the engine block on the side.

According to the above construction, since the two main galleries extending in the axial direction of the output shaft are formed in the engine block on the side opposite to the output shaft with the first and second cylinders interposed, the engine in the vicinity of the output shaft is formed. The rigidity of the block can be improved to firmly support the output shaft.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

1 and 2 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of the engine as seen from the side of the front part of the vehicle, and FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a figure.

A horizontally opposed cylinder type four-cylinder engine E horizontally mounted on the front part of a vehicle V is provided with a front side and a lower first bank Ba and a rear side and an upper second bank Bb. . Since the structures of the first and second banks Ba and Bb are substantially point symmetric with respect to the axis O of the output shaft 31, the structure of the first bank Ba will be mainly described. The reference numerals of the constituent elements of the second bank Bb are the subscripts "a" of the corresponding constituent elements of the first bank Ba changed to "b". In the engine E of the first embodiment, the cylinder axis La of the first bank Ba and the cylinder axis Lb of the second bank Bb are parallel to each other and arranged in the vehicle front-rear direction.

The engine E has a cylinder block 9 and an oil pan 10 which are common to the first bank Ba and the second bank Bb, and the first bank Ba has two first cylinders arranged inside the cylinder block 9. Cylinders 11a, 1
1a, two first pistons 12a, 12a slidably fitted to them, and a first crankshaft 14a connected to them via two first connecting rods 13a, 13a.

A first cylinder head 15a and a first head cover 16a are fixed to the front surface of the cylinder block 9, and a first valve operating chamber 17a is defined between the first cylinder head 15a and the first head cover 16a. First
The cylinder head 15a is formed with an intake port 19a and an exhaust port 20a connected to the first combustion chamber 18a, and an intake valve 21a that opens and closes the intake port 19a and an exhaust valve 22a that opens and closes the exhaust port 20a.
Book camshafts 23a, 23a 'are arranged. A fuel injection valve 42a is provided in the intake manifold 41a connected to the intake port 19a.

Two rocker arm shafts 24a, which are arranged adjacent to the two cam shafts 23a, 23a '.
An intake rocker arm 25a and an exhaust rocker arm 26a are swingably supported by 24a ',
The intake rocker arm 25a connects the intake cam 27a to the intake valve 21a, and the exhaust rocker arm 26a connects the exhaust cam 28a to the exhaust valve 22a. Exhaust passage 29 connected to the exhaust port 20a
An exhaust gas purification catalyst 30a is provided at a.

A first main gallery 38a for supplying oil from an oil pump (not shown) to the engine block 9 below the lower deck portion (lower end of the first cylinder 11a) of the first bank Ba has an axis O of the output shaft 31. The lower deck portions (second cylinder 11) of the second bank Ba are formed in parallel.
A second main gallery 38b is formed parallel to the axis O of the output shaft 31 in the engine block 9 below the lower end (b).

First and second crankshafts 14a, 14
The output shaft 31 is supported by the engine block 9 between b, and the driven gear 32 provided on the output shaft 31 is provided on the shaft ends of the first and second crankshafts 14a and 14b.
It meshes with the drive gears 33a and 33b. First and second crankshafts 14a and 14b and first and second drive gears 33
a and 33b, first and second one-way clutches 34a,
34b is provided. The housing 35 of the generator or the electric motor GM is sandwiched between the engine E and the transmission T, and the stator 36 fixed inside the housing 35 and the rotor 37 fixed to the output shaft 31 constitute the generator or the electric motor GM. To be done.

The first crankshaft 1 of the first bank Ba
The second cylinder 11b of the second bank Bb is arranged above 4a, and the second crankshaft 14b of the second bank Bb is arranged.
Of the first bank Ba, the first cylinder 11a of the first bank Ba is arranged below the first cylinder 11a of the second bank Bb, and the first crankcase 9a of the first bank Ba faces the second cylinder 11b of the second bank Bb. Crankcase 9b is in first bank B
It faces above the first cylinder 11a of a.

As a result, the second cylinder is provided above the first cylinder 11a of the first bank Ba and the first crankcase 9a.
Since the second cylinder 11b of the bank Bb and the second crankcase 9b are arranged in an overlapping manner, the size of the engine E in the cylinder axis La, Lb direction of the first and second banks Ba, Bb can be reduced. it can. Moreover, the first cylinder 11a and the second crankcase 9b face each other in the vertical direction, and the second cylinder 11b and the first crankcase 9a
Are opposed to each other in the vertical direction, the first and second cylinders 11a and 11b having a small diameter and the first and second crankcases 9 having a large diameter.
The vertical dimension of the engine E can be reduced by reasonably absorbing the dimensional difference between the a and 9b.

Then, the engine E operates to operate the first and second
First and second crankshafts 14 of banks Ba and Bb
When both a and 14b rotate in the direction of arrow R, the first and second
The one-way clutches 34a, 34b are engaged to transmit the rotations of the first and second drive gears 33a, 33b to the driven gear 32, and the output shaft 31 integrated with the driven gear 32 rotates in the R'direction. When the cylinder of the first bank Ba is deactivated and only the second bank Bb is operated, the rotation of the second crankshaft 14b of the second bank Bb is rotated via the second one-way clutch 34b, the second drive gear 33b and the driven gear 32. It is transmitted to the output shaft 31. At this time, the first one-way clutch 34a of the first bank Ba slips and the first crankshaft 14a of the first bank Ba is maintained in a stopped state. On the other hand, when the cylinders of the second bank Bb are deactivated and only the first bank Ba is operated, the first crankshaft 14a of the first bank Ba
Rotation of the first one-way clutch 34a, the first drive gear 33
It is transmitted to the output shaft 31 via a and the driven gear 32. At this time, the second one-way clutch 3 of the second bank Bb
4b slips and the second crankshaft 14b of the second bank Bb is maintained in a stopped state.

In this way, the first and second banks Ba, Bb
When one of the cylinders is deactivated, the first and second crankshafts 14a and 14b of the bank on the deactivated side do not rotate, so the rotation resistance of the first and second crankshafts 14a and 14b, the first and second cylinders 11a. , 11b and the sliding resistance between the first and second pistons 12a, 12b, the first,
Generation of pumping resistance and the like due to the reciprocating movement of the second pistons 12a and 12b is prevented, and the effect of reducing the fuel consumption of the engine E due to cylinder deactivation is further enhanced.

First and second banks of the first and second banks Ba and Bb
The one-way clutches 34a and 34b are opposite to the side on which the timing chains (not shown) that drive the first and second camshafts 23a and 23b are arranged, that is, the transmission T side end of the cylinder block 9. Since the space is provided by utilizing the space, it is possible to prevent the engine E from increasing in size.

When only one of the first and second banks Ba and Bb is deactivated, the temperature of the exhaust gas purifying catalysts 30a and 30b provided in the exhaust passages 29a and 29b of the deactivated bank is activated. There is a risk that the temperature will drop below the temperature and the emission will increase. However, in the present embodiment, the cylinders of the first and second banks Ba and Bb are alternately deactivated at predetermined intervals, so that the exhaust gas purifying catalyst 30 provided in the exhaust passages 29a and 29b of the banks Ba and Bb, respectively.
It is possible to prevent the temperatures of a and 30b from dropping below the activation temperature, and to avoid an increase in emissions.

When the engine E is cold started, the cylinder of the first bank Ba on the front side is deactivated and the second bank Bb on the rear side is operated for a predetermined time. In this way, by operating the second bank Bb on the rear side, which has a low cooling effect due to the running wind of the vehicle, the exhaust gas purifying catalyst 30b provided in the exhaust passage 29b is quickly heated to contribute to the reduction of emissions. can do.

When the generator or the electric motor GM is an electric motor, when the cylinders of both the first and second banks Ba and Bb are deactivated, that is, when the engine E is stopped, the electric motor is driven to drive the vehicle. be able to. If the generator or the electric motor GM is a generator, the kinetic energy of the vehicle body can be recovered as electric energy by performing regenerative braking by the generator when the vehicle is decelerated.

In addition, the output shaft 31 is arranged on a straight line connecting the first and second crankshafts 14a and 14b, and this position is located at the lower deck portion of the lower first bank Ba and the upper second bank. Since the position is sandwiched by the lower deck portion of Bb, the support rigidity of the output shaft 31 can be increased. Moreover, the lower deck portion of the lower first bank Ba, the lower deck portion of the upper second bank Bb, and the output shaft 3
Since 1 and 1 are arranged on the same plane P, the output shaft 31 is arranged by effectively utilizing the dead space between the first crankcase 9a and the second crankcase 9b, and it is possible to suppress the enlargement of the engine E. it can. Further, the first bank Ba on the lower side has the first cylinder head 15a serving as the projecting portion facing forward, and the second bank Bb on the upper side has the second cylinder head 15b serving as the projecting portion facing rearward. Therefore, the hood line 43 of the vehicle body can be lowered.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, constituent elements corresponding to those of the first embodiment are designated by the same reference numerals as in the first embodiment.

In the first embodiment described above, the first bank Ba
Is formed in the engine block 9 below the lower deck portion (the lower end of the first cylinder 11a), and the second main gallery 38b of the second bank Ba is
Is formed in the engine block 9 (near the output shaft 31) below the lower deck portion (lower end of the second cylinder 11b), but in the second embodiment, the first main gallery 39a is formed.
The location has not changed, but the 2nd Main Gallery 3
The position of 9b is formed in the engine block 9 above the lower deck portion (the lower end of the second cylinder 11b) of the second bank Ba. That is, the first and second main galleries 39
The points a and 39b are point-symmetrical with respect to the axis O of the output shaft 39, and are separated from the periphery of the output shaft 31. As a result, the rigidity of the engine block 9 near the output shaft 31 can be improved and the support strength of the output shaft 31 can be increased.

Although the embodiments of the present invention have been described in detail above, the present invention can be modified in various ways without departing from the scope of the invention.

For example, only one of the first and second banks Ba and Bb is configured so that the cylinders can be deactivated, and the power transmission cutoff means (the first and second one-way clutches 34a and 34b) is provided only to the bank in which the cylinders are deactivated. ) Can be provided.

The power transmission cutoff means is not limited to the first and second one-way clutches 34a and 34b, but may be a hydraulic clutch or an electromagnetic clutch.

[0035]

As described above, according to the invention described in claim 1, the second cylinder is arranged above the first crankshaft and the first cylinder is arranged below the second crankshaft.
Since the cylinders are arranged, the size of the engine in the axial direction of the first and second cylinders can be reduced by the amount that the lower first crankshaft and the first cylinder overlap the upper second crankshaft and the second cylinder. it can. Further, since the first crankcase is opposed to the lower side of the second cylinder and the second crankcase is opposed to the upper side of the first cylinder, the first and second cylinders and the first and second crankcases are arranged in the radial direction. The vertical dimension of the engine can be reduced by reasonably absorbing the dimensional difference.

According to the invention described in claim 2,
Since the engine is arranged horizontally at the front of the vehicle, the lower first cylinder head is arranged toward the front of the vehicle, and the upper second cylinder head is arranged toward the rear of the vehicle, the upper part of the engine is covered. The bonnet line can be lowered.

According to the invention described in claim 3,
Since the output shaft and the lower ends of the first and second cylinders are arranged on the same plane, the dead space between the first and second crankcases connected to the first and second cylinders is effectively used to make the output shaft compact. It is possible to prevent the engine from increasing in size.

According to the invention described in claim 4,
Since two main galleries extending in the axial direction of the output shaft are formed in the engine block on the opposite side of the output shaft with the first and second cylinders sandwiched between them, the rigidity of the engine block near the output shaft is improved and the output shaft is improved. Can be firmly supported.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an engine according to a first embodiment.

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

FIG. 3 is a vertical sectional view of an engine according to a second embodiment.

[Explanation of symbols]

9 engine block 9a 1st crankcase 9b Second crankcase 11a first cylinder 11b 2nd cylinder 12a First piston 12b Second piston 14a First crankshaft 14b Second crankshaft 15a First cylinder head 15b Second cylinder head 31 Output shaft 39a First Main Gallery 39b Second Main Gallery P same plane V vehicle

Claims (4)

[Claims] 1. A horizontally opposed cylinder type engine having a first crankshaft (14a) and a second crankshaft (14b), which is connected to a second crankshaft (14b) above the first crankshaft (14a). The second piston (12
The second cylinder (11b) on which b) slides is arranged,
Below the crankshaft (14b), a first piston (12a) connected to the first crankshaft (14a)
A first cylinder (11a) that slides is arranged, and a first crankcase (9a) accommodating the first crankshaft (14a) is made to face below the second cylinder (11b),
A horizontally opposed cylinder type engine characterized in that a second crankcase (9b) accommodating a second crankshaft (14b) is opposed to above the first cylinder (11a). 2. A first cylinder head (15a) having first and second crankshafts (14a, 14b) arranged in a vehicle width direction at a front portion of a vehicle body of a vehicle (V) and connected to a first cylinder (11a). ) Is arranged toward the front of the vehicle body and is connected to the second cylinder (11b).
5b) is arranged toward the rear of the vehicle body,
The horizontally opposed cylinder type engine according to claim 1. 3. An output shaft (31) arranged between the first crankshaft (14a) and the second crankshaft (14b), a lower end of the first cylinder (11a), and a lower end of the second cylinder (11b). And (2) are arranged on the same plane (P), The horizontally opposed cylinder type engine according to claim 1 or 2, characterized in that 4. The two main galleries (39a, 39b) extending in the axial direction of the output shaft (31) supported by the engine block (9) are provided with first and second cylinders (11a,
11b) is formed on the engine block (9) on the opposite side of the output shaft (31).
The horizontally opposed cylinder type engine according to claim 3.