Locking device of variable compression ratio engine

Abstract

The utility model discloses a locking device of a variable compression ratio engine, and relates to the technical field of engines. Comprising a machine body, a crankshaft and a plurality of eccentric bearing assemblies, the eccentric bearing assemblies are rotationally arranged in main bearing holes of the machine body, main journals of the crankshaft are rotationally connected with inner holes of the eccentric bearing assemblies, and the inner holes of the eccentric bearing assemblies and the axis of an outer ring are parallel but not collinear; the movable end covers, the unlocking mechanisms and the pressing mechanisms are in one-to-one correspondence with the eccentric bearing assemblies; the inner ring of the movable end cover is matched with the outer ring of the eccentric bearing assembly; the unlocking mechanism is used for keeping the inner ring of the movable end cover away from the outer ring of the eccentric bearing assembly; the pressing mechanism is used for enabling the inner ring of the movable end cover to press the outer ring of the eccentric bearing assembly to the main bearing hole of the machine body. According to the utility model, the controllability of the compression ratio is improved, the vibration and noise of an engine are reduced, the requirements of related parts on materials and processing precision are reduced, the reliability of the related parts is improved, and the production cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of engine technology, and in particular to a locking device for a variable compression ratio engine. Background Technology

[0002] Chinese patent application number 202410162914.1 discloses a compact, high-reliability, fully variable engine, including: a block, piston, connecting rod, crankshaft, eccentric bearing assembly, eccentric planetary gear mechanism, control unit, and eccentric bearing drive assembly. The eccentric bearing assembly is rotatably mounted in the main bearing bore of the block. The control unit controls the eccentric bearing drive assembly to rotate, thereby changing the compression ratio. However, during engine operation, the eccentric bearing assembly is subjected to forces from the piston-connecting rod-crankshaft, causing it to move within the main bearing bore of the block. On the one hand, this results in significant forces on the eccentric bearing assembly, the block, and the eccentric bearing drive assembly, leading to poor reliability of related components and significant vibration and noise during engine operation. On the other hand, maintaining the phase of the eccentric bearing drive assembly requires not only a sufficiently large force from the assembly but also extremely small clearances between its components, resulting in high precision requirements. Utility Model Content

[0003] The main objective of this invention is to provide a locking device for a variable compression ratio engine to solve the aforementioned problems.

[0004] To achieve the above objectives, this utility model provides a locking device for a variable compression ratio engine, comprising a body, a crankshaft, and multiple eccentric bearing assemblies. The eccentric bearing assemblies are rotatably disposed within the main bearing bore of the body. The main journal of the crankshaft is rotatably connected to the inner bore of the eccentric bearing assembly. The axes of the inner bore and outer ring of the eccentric bearing assembly are parallel but not collinear. The device also includes multiple movable end caps, an unlocking mechanism, and a pressing mechanism, each corresponding to one of the eccentric bearing assemblies. The inner ring of the movable end cap engages with the outer ring of the eccentric bearing assembly. The unlocking mechanism is used to move the inner ring of the movable end cap away from the outer ring of the eccentric bearing assembly. The pressing mechanism is used to press the inner ring of the movable end cap against the outer ring of the eccentric bearing assembly onto the main bearing bore of the body.

[0005] Furthermore, one end of the movable end cap is hinged to the machine body, and the other end is provided with an unlocking mechanism and a pressing mechanism.

[0006] Furthermore, it also includes a hinge shaft, which is fixedly mounted on the machine body, and one end of the movable end cover is rotatably connected to the hinge shaft.

[0007] Furthermore, the two ends of the movable end cap are provided with an unlocking mechanism and a clamping mechanism.

[0008] Furthermore, the unlocking mechanism includes a first camshaft and a plurality of first cams corresponding one-to-one with the movable end cover. The first camshaft is rotatably mounted on the machine body, and the first cams are disposed on the first camshaft. The first cams are used to move the inner ring of the movable end cover away from the outer ring of the eccentric bearing assembly. The pressing mechanism includes a spring, which is used to press the inner ring of the movable end cover against the outer ring of the eccentric bearing assembly onto the main bearing hole of the machine body.

[0009] Furthermore, the first cam has at least a high-lift region and a low-lift region, wherein the high-lift region of the first cam is used to move the inner ring of the movable end cover away from the outer ring of the eccentric bearing assembly, and the low-lift region of the first cam is used to create a small gap between the movable end cover and the first cam.

[0010] Furthermore, the unlocking mechanism also includes multiple unlocking rockers that correspond one-to-one with the movable end cover. The unlocking rockers are rotatably connected relative to the body, and the lower part of one end of the unlocking rocker abuts against the movable end cover. The first cam abuts against the lower part of the unlocking rocker.

[0011] Furthermore, one end of the spring abuts against the upper part of one end of the movable end cover, and the other end abuts against the support block, adjusting screw, or telescopic rod of the first telescopic mechanism; the first telescopic mechanism is a cylinder, electric cylinder, or hydraulic cylinder.

[0012] Furthermore, the clamping mechanism also includes a second cam mechanism; the second cam mechanism includes a second camshaft, a plurality of second cams corresponding one-to-one with the movable end cover, and a follower; the second camshaft is rotatably mounted on the machine body, the second cams are fixedly mounted on the second camshaft, the second cams drive the upper end of the follower, one end of the spring abuts against the upper part of one end of the movable end cover, and the other end abuts against the lower end of the follower; the follower is slidably or rotatably connected relative to the machine body; the second cam has at least a high-lift region and a low-lift region, wherein the high-lift region of the second cam is used to shorten the length of the spring; the low-lift region of the second cam is used to increase the length of the spring.

[0013] Furthermore, the clamping mechanism also includes a second telescopic mechanism, wherein the telescopic rod of the second telescopic mechanism abuts against the upper part of one end of the movable end cap; the second telescopic mechanism is a pneumatic cylinder, an electric cylinder, or a hydraulic cylinder.

[0014] Furthermore, limiting structures are set on both sides of the movable end cap to prevent it from tipping over to the sides.

[0015] This utility model has the following beneficial effects:

[0016] This invention can lock the eccentric bearing assembly to the engine block when the engine compression ratio does not need to be adjusted, thereby reducing the forces on the eccentric bearing assembly, engine block, and eccentric bearing drive assembly while ensuring the compression ratio remains constant. This reduces engine vibration and noise, while also lowering the requirements for materials and machining precision of related components, improving the reliability of related components, and reducing production costs. When the engine compression ratio needs to be adjusted, the eccentric bearing assembly can be unlocked from the engine block almost simultaneously, quickly, and completely. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a locking device for a variable compression ratio engine proposed in this utility model;

[0018] Figure 2 This is a cross-sectional view of a locking device for a variable compression ratio engine proposed in this utility model.

[0019] In the diagram: 1-body; 2-eccentric bearing assembly; 3-crankshaft; 4-hinge shaft; 5-bolt; 6-movable end cover; 7-support block; 8-spring; 9-unlocking rocker arm; 10-first rocker arm shaft; 11-first cam; 12-first camshaft; 13-adjusting screw. Detailed Implementation

[0020] To achieve the above objectives and effects, the technical means and structure adopted by this utility model are described in detail with reference to the accompanying drawings, focusing on the features and functions of the preferred embodiments of this utility model.

[0021] As attached Figure 1-2 As shown, this utility model provides a locking device for a variable compression ratio engine, including a body 1, a crankshaft 3, and multiple eccentric bearing assemblies 2. The eccentric bearing assemblies 2 are rotatably disposed within the main bearing bore of the body 1. The main journal of the crankshaft 3 is rotatably connected to the inner bore of the eccentric bearing assembly 2. The axes of the inner bore and outer ring of the eccentric bearing assembly 2 are parallel but not collinear. The device also includes multiple movable end caps 6 corresponding to each eccentric bearing assembly 2, an unlocking mechanism, and a pressing mechanism. The inner ring of the movable end cap 6 engages with the outer ring of the eccentric bearing assembly 2. The unlocking mechanism is used to move the inner ring of the movable end cap 6 away from the outer ring of the eccentric bearing assembly 2. The pressing mechanism is used to press the inner ring of the movable end cap 6 against the outer ring of the eccentric bearing assembly 2 onto the main bearing bore of the body 1. It should be noted that the engine body includes an upper body and a lower body, which are fixedly connected. (The image shows the piston, connecting rod, eccentric bearing assembly, and locking device components.) Figure 1 and Figure 2 The upper body was not shown.

[0022] In another embodiment, one end of the movable end cap 6 is hinged to the body, and the other end is provided with an unlocking mechanism and a pressing mechanism.

[0023] It also includes a hinge shaft 4, which is fixed to the machine body. One end of the movable end cover 6 is rotatably connected to the hinge shaft 4, forming a hinge connection. The hinge shaft 4 can be fixed to the machine body in various ways. Figure 1 A scheme is given for fixing the hinge shaft 4 to the body 1 by bolts 5.

[0024] In another embodiment, the two ends of the movable end cap 6 are provided with an unlocking mechanism and a pressing mechanism.

[0025] In another embodiment, the unlocking mechanism includes a first camshaft 12 and a plurality of first cams 11 corresponding one-to-one with the movable end cover 6. The first camshaft 12 is rotatably mounted on the machine body, and the first cams 11 are disposed on the first camshaft 12. The first cams 11 are used to move the inner ring of the movable end cover 6 away from the outer ring of the eccentric bearing assembly 2. The pressing mechanism includes a spring 8, which is used to press the inner ring of the movable end cover 6 against the outer ring of the eccentric bearing assembly 2 onto the main bearing hole of the machine body.

[0026] The first cam mechanism is preferred as the unlocking element because, for the engine, multiple movable end caps 6 need to be unlocked substantially simultaneously and rapidly. A single first camshaft 12 can drive the corresponding first cams 11 of each movable end cap 6. Firstly, this ensures that the eccentric bearing assembly 2 can be unlocked substantially simultaneously, rapidly, and completely. Secondly, the unlocking time of the eccentric bearing assembly 2 is entirely determined by the phase of the first camshaft 12, making it easy to determine the operating time of the eccentric bearing drive assembly based on the phase of the first camshaft 12, thus simplifying the control strategy. If a hydraulic mechanism is used as the unlocking element, it is difficult to guarantee that each hydraulic piston can unlock the eccentric bearing assembly 2 rapidly and substantially synchronously. The hydraulic delay characteristics and the asynchronous operation of each hydraulic piston will increase the time required for the eccentric bearing assembly 2 to be completely unlocked, resulting in the eccentric bearing assembly 2, the engine block, and related components such as the eccentric bearing drive assembly being subjected to significant forces for a considerable period. This will deteriorate the reliability of engine components and engine vibration and noise. If a rack and pinion mechanism is used as the unlocking component, although a single drive shaft can be used to drive the gears corresponding to each movable end cover 6, on the one hand, the mounting positions of the racks corresponding to each movable end cover 6 on the machine body and the rack and pinion mechanism itself require precision machining, which will significantly increase the machining cost; on the other hand, the relative movement of the movable end covers 6 in the locked and unlocked states is very small, making the use of a rack and pinion mechanism very unnecessary. Instead, it would increase the complexity of the device and the stress between the various components of the rack and pinion mechanism, and easily reduce the control accuracy of each movable end cover 6.

[0027] Spring 8 is preferred as the clamping component because it is the most reliable and cost-effective solution compared to hydraulic mechanisms or cam mechanisms alone. If a hydraulic mechanism is used alone, hydraulic oil leakage may occur after prolonged engine shutdown, making it difficult to reliably lock the eccentric bearing assembly 2. If a cam mechanism is used alone, due to machining and assembly errors in each component, it is difficult to guarantee that each movable end cap 6 can reliably lock the corresponding eccentric bearing assembly 2.

[0028] In another embodiment, the first cam 11 has at least a high lift region and a low lift region, wherein the high lift region of the first cam 11 is used to move the inner ring of the movable end cover 6 away from the outer ring of the eccentric bearing assembly 2, and the low lift region of the first cam 11 is used to create a small gap between the movable end cover 6 and the first cam 11 so as to press the movable end cover 6 against the eccentric bearing assembly 2.

[0029] In another embodiment, the unlocking mechanism further includes a plurality of unlocking rocker arms corresponding one-to-one with the movable end cover 6. The unlocking rocker arms are rotatably connected relative to the body, and abut against the lower part of one end of the movable end cover 6. The first cam 11 abuts against the lower part of the unlocking rocker arm. By setting the unlocking rocker arms, a force-saving lever is formed to reduce the required driving force of the first camshaft 12.

[0030] The unlocking rocker arm can be connected to the machine body in several ways, such as... Figure 1 and Figure 2 The first rocker arm shaft 10 is mounted on the machine body, and the unlocking rocker arm 9 is rotatably connected to the first rocker arm shaft 10 to form a hinge. Alternatively, the machine body may have a ball head for ball joints, and the unlocking rocker arm may have a corresponding recess on the ball head to form a ball joint.

[0031] In another embodiment, one end of the spring 8 abuts against the upper part of one end of the movable end cover 6, and the other end abuts against the support block, the adjusting screw 13, or the telescopic rod of the first telescopic mechanism; the first telescopic mechanism is a cylinder, an electric cylinder, or a hydraulic cylinder.

[0032] When the other end of spring 8 abuts against the support block, the support block is mounted on the engine block. There is a certain gap in the height direction between the spring support end of the support block and the spring support end of the movable end cover 6 to accommodate spring 8. This solution is mainly for situations where the driving force required by the first camshaft is relatively small, the machining and assembly errors of engine-related parts are small, and the wear of parts is slow, and it has excellent cost advantages.

[0033] When the other end of spring 8 abuts against adjusting screw 13, as Figure 1 and Figure 2Adjusting screw 13 is screwed onto support block 7. The preload of spring 8 can be adjusted by changing the position of adjusting screw 13. During installation, adjusting screw 13 can be first adjusted to the position where the preload of spring 8 is minimized. Figure 1 To reduce the installation force required to install spring 8 and related components, adjust screw 13 to its highest position. Then, adjust the position of screw 13 so that the spring force of spring 8 meets the requirement of pressing the inner ring of movable end cover 6 against the outer ring of eccentric bearing assembly 2 to the main bearing hole of the engine block. Alternatively, spring 8 can be installed first, followed by installing and adjusting the adjusting screw. This solution is primarily for situations where the first camshaft requires relatively low driving force, and the machining and assembly errors of engine components are difficult to reduce, especially in cases of rapid component wear. By setting the adjusting screw, the difference in spring force experienced by each movable end cover 6 due to machining and assembly errors of various components and subsequent component wear can be reduced. This solution reduces the requirements for machining and assembly errors of engine components, extends the service life of related components, and ultimately reduces engine production and operating costs.

[0034] When the other end of spring 8 abuts against the telescopic rod of the first telescopic mechanism, the first telescopic mechanism is mounted on the support block, and the telescopic rod of the first telescopic mechanism extends downward to abut against the other end of spring 8. During installation, the telescopic rod of the first telescopic mechanism can be retracted first, which reduces the installation force when installing spring 8 and related components. Alternatively, spring 8 can be installed first, followed by the first telescopic mechanism. This solution is mainly for situations where the first camshaft requires a large driving force and the engine vibration and noise are also significant. In addition, the position of the first telescopic mechanism relative to the support block can be adjusted to reduce the difference in spring force on each movable end cap 6 caused by factors such as machining and assembly errors of various components and subsequent wear of components. When it is necessary to adjust the compression ratio, retracting the telescopic rod of the first telescopic mechanism increases the length of spring 8, reduces the spring force, and ultimately reduces the driving force of the first camshaft 12; after the compression ratio is adjusted, extending the telescopic rod of the first telescopic mechanism shortens the length of spring 8, increasing the spring force. Throughout the entire engine operation, the first telescopic mechanism increases the damping force of the device, further reducing engine vibration and noise.

[0035] In another embodiment, the clamping mechanism further includes a second cam mechanism; the second cam mechanism includes a second camshaft, second cams corresponding one-to-one with multiple movable end caps 6, and a follower; the second camshaft is rotatably mounted on the machine body, the second cams are fixedly mounted on the second camshaft, the aforementioned follower is slidably connected to or rotatably connected to the machine body, and the second cam abuts against the upper part of the follower; one end of the spring 8 abuts against the upper part of one end of the movable end cap 6, and the other end abuts against the lower part of the follower; the second cam has at least a high-lift region and a low-lift region, wherein the high-lift region of the second cam is used to shorten the length of the spring 8 and increase the spring force; the low-lift region of the second cam is used to increase the length of the spring 8 and decrease the spring force. This solution is mainly for situations where the first camshaft requires a large driving force. When the compression ratio needs to be adjusted, rotating the second camshaft increases the length of the spring 8, reduces the spring force, and ultimately reduces the driving force of the first camshaft 12; after the compression ratio is adjusted, rotating the second camshaft again shortens the length of the spring 8 and increases the spring force.

[0036] The second cam can also have a lower lift region, which makes the length of the spring 8 compressed smaller when the spring 8 is installed, resulting in a smaller spring force and a reduced installation force.

[0037] For the second camshaft with a lower lift range, the rotation phase of the second camshaft can also be limited to prevent the situation where the compressed length of the spring 8 is too short during engine operation, resulting in insufficient clamping force of the movable end cover on the eccentric bearing assembly.

[0038] In another embodiment, the clamping mechanism includes not only the spring 8 but also a second telescopic mechanism. The telescopic rod of the second telescopic mechanism abuts against the upper part of one end of the movable end cover 6. The second telescopic mechanism is a pneumatic cylinder, an electric cylinder, or a hydraulic cylinder. When the compression ratio needs to be adjusted, the telescopic rod of the second telescopic mechanism retracts, thereby reducing the driving force of the first camshaft 12. After the compression ratio is adjusted, the telescopic rod of the second telescopic mechanism extends downward, increasing the clamping force and the damping force of the device. This solution is mainly for situations where the controllability of the engine compression ratio needs to be further enhanced, especially for situations where a significant reduction in engine vibration and noise is required.

[0039] In another embodiment, limiting structures are provided on both sides of the movable end cap 6 to prevent the movable end cap 6 from tipping over to the sides. Preferably, the support block 7 has a gate-shaped structure to limit the movement of the movable end cap 6 on both sides.

[0040] It should be noted that the support block described in this invention can also be part of the body structure.

[0041] The above description is only a preferred embodiment of the present utility model and not all embodiments. Anyone should know that structural changes made under the guidance of the present utility model are protected by the present utility model. All technical solutions that are the same as or similar to the present utility model are within the scope of protection of the present utility model.

Claims

1. A locking device for a variable compression ratio engine, comprising an engine block, a crankshaft (3) and a plurality of eccentric bearing assemblies (2) rotatably arranged in main bearing holes of the engine block, a main journal of the crankshaft (3) being rotatably connected to a bore of the eccentric bearing assembly (2), the bore of the eccentric bearing assembly (2) and the axis of the outer ring being parallel but not collinear; characterized in that: Further comprising a plurality of movable end covers (6) corresponding to the eccentric bearing assemblies (2), an unlocking mechanism and a pressing mechanism; the inner ring of the movable end cover (6) is matched with the outer ring of the eccentric bearing assembly (2); the unlocking mechanism is used for moving the inner ring of the movable end cover (6) away from the outer ring of the eccentric bearing assembly (2); the pressing mechanism is used for pressing the outer ring of the eccentric bearing assembly (2) onto the main bearing hole of the body by the inner ring of the movable end cover (6).

2. A locking device for a variable compression ratio engine as claimed in claim 1, characterized in that: One end of the movable end cover (6) is hinged to the body, and the other end is provided with an unlocking mechanism and a pressing mechanism.

3. A locking device for a variable compression ratio engine as claimed in claim 2, characterized in that: Further comprising a hinge shaft (4) fixedly arranged on the body, and one end of the movable end cover (6) is rotatably connected to the hinge shaft (4).

4. A locking device for a variable compression ratio engine as set forth in claim 1, characterized in that: Both ends of the movable end cover (6) are provided with an unlocking mechanism and a pressing mechanism.

5. A locking device for a variable compression ratio engine according to any one of claims 1 to 4, characterized in that: The unlocking mechanism comprises a first camshaft (12) and a plurality of first cams (11) corresponding to the movable end cover (6); the first camshaft (12) is rotatably arranged on the body; the first cam (11) is arranged on the first camshaft (12); the first cam (11) is used for moving the inner ring of the movable end cover (6) away from the outer ring of the eccentric bearing assembly (2); the pressing mechanism comprises a spring (8), which is used for pressing the outer ring of the eccentric bearing assembly (2) onto the main bearing hole of the body by the inner ring of the movable end cover (6).

6. A locking device for a variable compression ratio engine as claimed in claim 5, characterized in that: The first cam (11) has at least one high-lift region and one low-lift region, wherein the high-lift region of the first cam (11) is used for moving the inner ring of the movable end cover (6) away from the outer ring of the eccentric bearing assembly (2), and the low-lift region of the first cam (11) is used for allowing a small gap between the movable end cover (6) and the first cam (11).

7. A locking device for a variable compression ratio engine as claimed in claim 5, characterized in that: The unlocking mechanism further comprises a plurality of unlocking rocker arms corresponding to the movable end cover (6); the unlocking rocker arms are rotatably connected to the body; one end of the unlocking rocker arm abuts against the lower part of the movable end cover (6); and the first cam (11) abuts against the lower part of the unlocking rocker arm.

8. A locking device for a variable compression ratio engine as claimed in claim 6 or 7, characterized in that: One end of the spring (8) abuts against the upper part of one end of the movable end cover (6), and the other end abuts against the supporting block, the adjusting screw (13) or the telescopic rod of the first telescopic mechanism; the first telescopic mechanism adopts a pneumatic cylinder, an electric cylinder or a hydraulic cylinder.

9. A locking device for a variable compression ratio engine as claimed in claim 6 or 7, characterized in that: The pressing mechanism further comprises a second cam mechanism; the second cam mechanism comprises a second camshaft, a plurality of second cams corresponding to the movable end cover (6) and a driven part; the second camshaft is rotatably arranged on the body; the second cam is fixedly arranged on the second camshaft; the second cam drives the upper end of the driven part; one end of the spring (8) abuts against the upper part of one end of the movable end cover (6), and the other end abuts against the lower end of the driven part; the driven part is slidably or rotatably connected to the body; the second cam has at least one high-lift region and one low-lift region, wherein the high-lift region of the second cam is used for shortening the length of the spring (8); and the low-lift region of the second cam is used for increasing the length of the spring (8).

10. A locking device for a variable compression ratio engine as claimed in claim 6 or 7, characterized in that: The pressing mechanism further comprises a second telescopic mechanism, a telescopic rod of the second telescopic mechanism abutting against an upper end of the movable end cover (6); the second telescopic mechanism adopts a pneumatic cylinder, an electric cylinder or a hydraulic cylinder.

11. A locking device for a variable compression ratio engine according to any one of claims 1 to 4, characterized in that: Limiting structures are arranged on both sides of the movable end cover (6), so that the movable end cover (6) cannot overturn to both sides.

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