JP3038403U - Variable compression ratio device for internal combustion engine - Google Patents

Abstract

(57) [Abstract] (Correction) [Problem] This variable compression ratio device realizes dual performance from low load to high load by freely changing the compression ratio of the internal combustion engine, and achieves compactness and lightweight fuel. It is possible to improve economy such as improvement of consumption rate and improve indicated thermal efficiency by complete combustion. SOLUTION: During low load operation in an engine equipped with this device, a worm gear shaft 7 is driven by a motor through a worm shaft.
Is driven, the outer peripheral gear 6 meshing with this is rotated, and the upper and lower bearing metal parts 4 and 5 integrated with this are rotated. The upper and lower bearing metals rotate due to the eccentric circle structure and displace the center line of the crank journal to push up the piston. When the piston reaches the re-elevation position, the electric motor stops and the piston clearance volume becomes the minimum, and the high compression ratio state is reached. When the load is high, the upper and lower bearing metals are rotated to displace the position of the crank journal and push down the piston. When the piston moves to the lowermost part, the electric motor stops and the piston clearance volume becomes maximum and the low compression ratio state is reached.

Description

[Detailed description of the invention]

[0101]

[Technical field to which the invention belongs]

 The present invention is aimed at internal combustion engines in general, and particularly for exhaust gas turbocharged vehicle engines, to achieve high output and small torque by exerting high torque from low load operation to high load operation. It aims to improve energy efficiency by changing to a quantitative engine and improving fuel efficiency and downsizing auxiliary accessories.

[0092]

[Prior art]

 Conventionally, as a method of obtaining a high output in an internal combustion engine, there is a method of mounting a large displacement engine, maintaining a high engine speed, or adopting an exhaust turbine supercharging or mechanical supercharging method.

[Problems to be solved by the present invention]

 When high output is obtained by the conventional method, if a large displacement engine is adopted, the weight of the engine itself is large and the auxiliary equipment is also large, which is not economical. If a high-speed engine with a high engine speed is used, vibration, noise, and engine life remain uncertain, and thermal efficiency does not improve in the entire load range. In a supercharged engine, increasing the supercharging ratio is advantageous during high load operation, but low load performance, which is an important factor for vehicular machinery, especially starting performance is poor, and smooth operation cannot be performed.

In an exhaust turbine supercharged internal combustion engine, if the supercharging ratio is set high in order to obtain a small size and high output, the amount of combustible mixture in the cylinder increases in the high load range, and the maximum pressure in the cylinder (hereinafter Pmax and It is necessary to keep the compression ratio low for safety. However, if this compression ratio is set low, the effect of supercharging the exhaust turbine is low in the low load region, so the amount of filling in the cylinder is small and sufficient compression pressure cannot be obtained at the end of the compression stroke, and the combustion pressure decreases and Pmax also decreases. To do. Therefore, the indicated thermal efficiency decreases, the engine torque also weakens, and the low load performance deteriorates.

The present invention is intended to provide a device capable of freely changing the compression ratio in an internal combustion engine in order to constantly maintain a high Pmax, which is remarkable for improving the indicated thermal efficiency, from low load operation to high load operation. . That is, when the load is low, the compression ratio is set to a high level to increase the compression pressure and the combustion pressure is increased, and when the load is high, the compression ratio is set to a low level and the output can be increased by high supercharging.

[0056]

[Means for Solving the Problems]

 The structure of the compression ratio variable device (1) of the present invention is divided into two in the main bearing of the internal combustion engine and can be joined by bolts and has a gear (6) at a part of the outer circumference, which has an eccentric circular structure in the upper bearing metal. (4) and lower bearing metal (5), upper back metal (2) and lower back metal (3) for supporting the upper and lower bearing metals (4) and (5), and the lower back metal (3) A worm gear shaft (7) that meshes with the outer peripheral gear (6) of the upper and lower bearing metal (4) (5), a worm shaft (8) that drives the worm gear shaft, and an electric motor (9). It has a feature.

The compression ratio variable device (1) of the present invention drives the worm shaft (8) by its power when a signal is applied to the electric motor (9), and the worm gear shaft (7) connected to the worm shaft (8). And the peripheral gear (6) meshing with this is rotated.

When the outer peripheral gear (6) rotates, the upper bearing metal (4) and the lower bearing metal (5) rotate at that position while being supported by the upper back metal (2) and the lower back metal (3).

The upper bearing metal (4) and the lower bearing metal (5) have an eccentric circle structure on the outer circumference and the inner circumference, so that the crankshaft support surface (C) is moved at the same time as the rotational movement, and thus the crankshaft support surface (C) is moved. The centerline of the axis (10) moves up and down. Therefore, the position of the piston (P) moves, the top clearance (Z) of the engine is arbitrarily changed, and the compression ratio of the engine can be freely changed.

[0099]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a perspective view of a compression ratio varying device (1) and a crankshaft (10) of the present invention. FIG. 2 is a sectional view of the compression ratio variable device (1). FIG. 3 is an exploded perspective view of the whole. FIG. 4 is a schematic configuration diagram showing a state in which the compression ratio variable device (1) of the present invention has shifted to the high compression ratio side. FIG. 5 is a schematic configuration diagram showing a state in which the present apparatus has shifted to the low compression ratio side.

The configuration of each part of the compression ratio variable device (1) of the present invention will be described. As shown in Figs. 2 and 3, the upper bearing metal (4) and the lower bearing metal (5) are divided into upper and lower halves in cross section, and at the same time, the outer peripheral gear (6) is halved at the valley of its gear profile. To Since the upper and lower bearing metals (4) and (5) are tightened from the bottom with tightening bolts (11), the upper bearing metal (4) has screw holes (12) for the tightening bolts (11) and the lower bearing metal (4). A bolt insertion hole (13) is provided in 5), and this tightening bolt is a reamer bolt.

In an engine that has an oiling hole in the crank bearing body and performs forced oiling on the crank pin bearing / piston pin bearing, an oil groove (14) and an oil hole are formed inside and outside the upper and lower bearing metal (4) (5). (18) is provided.

In the cross section of the peripheral gear (6), the diameter (D1) of the root of the gear is slightly larger than the outer diameter (D2) of the upper and lower bearing metals (4) and (5), and both side surfaces (S) So that it receives the axial thrust of the same metal.

The gap (a) between the upper / lower bearing metal (4) (5) and the upper / lower back metal (2) (3) is minimized as long as the external gear can rotate. The clearance (b) between the upper and lower bearing metals (4) and (5) and the crank journal (10) should be an appropriate value so that the same metal will not generate heat during high speed rotation of the journal.

The upper backing metal (2) and the lower backing metal (3) support the upper and lower bearing metals (4) and (5). A groove (15) is provided. The lower back metal (3) is provided with a worm gear chamber (16) that accurately supports the worm gear shaft (7) that drives the peripheral gear (6).

When the lower back metal (3) is fastened to the upper metal back (2) with the tightening bolts (17), the clearance (a) with the upper bearing metal should be minimized as long as the outer peripheral gear (6) can rotate. The adjustment liner shall not be used for adjustment.

Next, the configuration of the compression ratio variable device will be described. Attach the upper bearing metal (4) and lower bearing metal (5) to the crank journal (10) and tighten them firmly with the tightening bolts (11). At this time, the clearance (b) should be adequate to allow sufficient oil lubrication when the journal rotates at high speed, and an adjustment liner should not be used to adjust this clearance.

The outer peripheral gear (6) of the upper / lower bearing metal (4) (5) is fitted into the gear chamber (15) of the upper backing metal (2). With the worm gear shaft (7) inserted in the worm gear chamber (16) of the lower back metal (3), attach the lower back metal (3) to the upper back metal (2) and secure it with the tightening bolts (17). At this time, it is confirmed that the upper and lower bearing metals (4) and (5) in the upper and lower back metals (2) and (3) can rotate together with the peripheral gear (6) by rotating the worm gear shaft (7).

The peripheral gear (6) and the worm gear shaft (7) can be positioned by matching the alignment mark ● (x) on the lower bearing metal with the alignment mark ● (y) on the side surface of the lower backing metal (3). Is the highest piston position. The position where the peripheral gear (6) and the worm gear shaft (7) mesh with each other does not matter.

The wheel gear (7B) at the other end of the worm gear shaft (7) meshes with the worm gear (8) connected to the small motor (9).

In another embodiment, as a method of driving the outer peripheral gear (6), there is a method of using a rack with a spur gear and driving it through a hydraulic piston.

[0211]

[Effect of the invention]

 The variable compression ratio device of this invention is a device that can freely change the compression ratio in an internal combustion engine. In other words, it enables dual performance in which high compression ratio operation is performed at low load to improve the indicated thermal efficiency, and low compression ratio is set at high load to achieve high supercharging by the supercharger to reasonably increase output. Is. Therefore, when obtaining the same output, the engine can be made smaller and lighter than before, and the fuel consumption rate can be improved along with the miniaturization of auxiliary equipment, which can increase the economic efficiency in a broad sense. Furthermore, by increasing the compression ratio when the load is low, the indicated thermal efficiency is improved and exhaust gas can be cleaned by completely burning it.

[Brief description of the drawings]

FIG. 1 is a perspective view of a compression ratio varying device and a crankshaft of the present invention.

FIG. 2 is a cross-sectional view of a compression ratio variable device of this embodiment.

FIG. 3 is an exploded perspective view of a compression ratio varying device of the present embodiment.

[Figure 4]

FIG. 5 is a schematic configuration diagram showing a state in which the compression ratio variable device is displaced to a high compression ratio side and a low compression ratio side.

[Explanation of symbols]

1 compression ratio variable device c crankshaft support surface 2 upper back metal P piston 3 lower back metal Z top clearance 4 upper bearing metal D1 outer diameter gear 6 trough diameter 5 lower bearing metal D2 upper and lower bearing metal 4,5 6 outer peripheral gear Outer diameter 7 Worm gear shaft S Both side surfaces of peripheral gear 6 8 Worm shaft a Upper and lower backing metals 2, 3 and 9 Electric motor upper and lower bearing metal 4, 5 10 Crankshaft gap 11 Tightening bolt b Upper and lower bearing metal 4・ 5 12 Gap between screw hole and crankshaft 13 Bolt insertion hole x Matching mark of lower bearing metal 14 Oil groove y Matching mark of lower back metal 15 Groove for outer peripheral gear Zh High compression ratio state 16 Worm gear chamber Ph When Zh Crankshaft centerline 17 Wheel gear shaft Zl Low compression ratio state 18 Oil hole Pl Crankshaft centerline when Zl 17 Whee Crankshaft center line when the gear shaft Zl low compression ratio state 18 Oil hole Pl Zl

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[Procedure amendment]

[Submission date] December 19, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

[Fig. 2]

[Figure 3]

FIG. 4

[Figure 5]

Claims (1)

[Utility model registration claims] 1. In a main bearing portion of an internal combustion engine, the cross section having an eccentric circle structure is located between an upper back metal (2) and a lower back metal (3) and is divided into two parts which can be joined by bolts and which have an outer peripheral gear (6). A worm gear shaft (7) held by the upper bearing metal (4), the lower bearing metal (5), and the lower back metal (3) and meshing with the peripheral gear (6), and a worm shaft (7) that drives the worm gear shaft ( A compression ratio variable device comprising 8) and an electric motor (9).