WO2015188603A1

WO2015188603A1 - Engine timing wheel train

Info

Publication number: WO2015188603A1
Application number: PCT/CN2014/093979
Authority: WO
Inventors: 陈友祥; 邱若友; 何月涛; 邹凯; 张亚洲; 刘俊; 叶志伟; 王英杰; 朱浩杰; 穆芳影; 王友成; 惠昭晨
Original assignee: 安徽江淮汽车股份有限公司
Priority date: 2014-06-13
Filing date: 2014-12-16
Publication date: 2015-12-17
Also published as: CN104005807B; CN104005807A

Abstract

An engine timing wheel train comprises an oil pump belt wheel (4, 4'), an air exhaust timing belt wheel (2), an air intake timing belt wheel (1) of an air intake variable valve timing apparatus, and an elliptic crankshaft timing belt wheel (5). The crankshaft timing belt wheel (5) drives the air intake timing belt wheel (1), the air exhaust timing belt wheel (2) and the oil pump belt wheel (4, 4') to rotate by means of a timing belt (7). The oil pump belt wheel (4, 4') and the crankshaft timing belt wheel (5) have a same shape, size and initial assembly direction. The engine timing wheel train can ensure that the oil pump belt wheel (4, 4') and the crankshaft timing belt wheel (5) always keep synchronous rotation in a same direction when the crankshaft timing belt wheel (5) drives the oil pump belt wheel (4, 4') by means of the timing belt (7) to rotate, so that a part, located between the crankshaft timing belt wheel (5) and the oil pump belt wheel (4, 4'), of the timing belt (7) is always in a tensioned state which is the same as that during initial assembly, thereby extending the service life of the timing belt (7) and improving the NVH performance of a whole engine timing system.

Description

Engine timing train

Technical field

The present invention relates to an engine timing system, and more particularly to a timing train of an engine timing system.

Background technique

The engine timing train is an important part of the engine timing system, which acts to transmit the high-speed rotating crankshaft motion to the intake camshaft and the exhaust camshaft in strict phase relationship to accurately achieve the timing opening and closing. The corresponding intake and exhaust valves ensure that the engine has normal and good power output performance. At the same time, the engine timing train can also be used to drive auxiliary devices such as oil pumps and pumps. At present, the engine timing train mainly includes belt drive, chain drive and gear transmission, and the belt drive is widely used in the engine timing train wheel due to its low noise, low transmission resistance and low transmission inertia.

1 shows an existing engine timing train structure using a belt drive, the engine timing train includes an intake timing pulley 1 mounted on one end of an intake camshaft, and is mounted on an exhaust cam. An exhaust timing pulley 2 at one end of the shaft 2, a crank timing pulley 5 mounted on one end of the crankshaft, and an oil pump pulley 4 mounted on the input shaft of the oil pump, here, due to the intake timing pulley 1 Between the crankshaft timing pulley 5 and the center distance between the exhaust timing pulley 2 and the oil pump pulley 4, therefore, in order to solve the span of the timing belt 7 at the above two sections Large problem of timing belt jitter and resonance, usually a mechanical tensioning pulley 6 is provided between the intake timing pulley 1 and the crankshaft timing pulley 5, and the exhaust timing pulley 2 and the oil pump are provided. The idler 3 is disposed between the pulleys 4, and the engine timing train operates in such a manner that the crankshaft timing pulley 5 drives the associated train wheel in the clockwise direction as shown in FIG. 2 by the timing belt 7.

In order to improve the combustion efficiency of the engine, variable valve timing (VVT) technology is currently used, and the variable valve timing technology is mainly applied to the control of the intake camshaft, that is, the advancement in FIG. The gas timing pulley 1 corresponds to the intake timing pulley of the intake variable valve timing device.

In the engine timing system in which the intake variable valve timing device is provided, the presence of the intake timing pulley 1 causes potential high excitation and high dynamic performance, which in turn causes the timing belt 7 to jump. The momentum is large and the swing of the mechanical tensioning wheel 6 is too large, causing the mechanical tensioning wheel 6 to fail, which usually causes a timing error due to the occurrence of the jumping tooth phenomenon, and eventually the engine cannot work normally. In order to solve the above problem, in the engine timing system in which the intake variable valve timing device is provided, an elliptical crankshaft timing pulley 5 is generally employed, as shown in FIGS. 2 and 3, the crankshaft timing pulley 5 The difference between the diameter of the long side a and the diameter of the short side b is usually 2 mm to 5 mm. With the elliptical crank wheel timing pulley 5, the timing belt 7 can be used in the intake timing pulley 1 and the crank timing pulley. The amount of runout between 5 is greatly reduced, and the swing of the mechanical tensioning pulley 6 can be greatly reduced. However, the technical problem of the crankshaft timing pulley 5 having such a structure is that the number of timing belt sections (or the number of belt teeth) between the crankshaft timing pulley 5 and the oil pump pulley 4 does not change. When the crankshaft timing pulley 5 rotates once, as shown in FIG. 2 and FIG. 3, the partial timing belt 71 between the crank timing pulley 5 and the oil pump pulley 4 is generated (specifically The length of the timing belt 7 between the joint point P1 combined with the crankshaft timing pulley 5 and the separation point P2 separated from the oil pump pulley 4 is in accordance with the tension-relaxation-tensioning-relaxation The ground cycle changes, this aspect will directly affect the service life of the timing belt, on the other hand, it will cause the timing belt 7 to have a large jitter at that place, and because the part of the timing belt 71 is on the crankshaft timing pulley 5 and The smaller span between the oil pump pulleys 4 will increase the jitter frequency of the part of the timing belt 71. The high frequency jitter of the timing belt 71 will generate a large noise, which will affect the noise of the entire engine timing system. , vibration and harshness (Noise, Vibration, Harshness, NVH) performance, and then shadow Engine and vehicle driving comfort, using the above-described problem also exists in the engine timing chain drive gear train and the use of oval-crankshaft timing pulley.

Summary of the invention

The purpose of embodiments of the present invention is to solve the above problems caused by the use of an elliptical crankshaft timing pulley, and to provide an engine timing train that can reduce the high frequency jitter of the timing belt.

In order to achieve the above object, the technical solution adopted by the present invention is: an engine timing train, including an oil pump pulley, an exhaust timing pulley, an intake timing pulley of an intake variable valve timing device, and An elliptical crankshaft timing pulley, wherein the crankshaft timing pulley drives the intake timing pulley, the exhaust timing pulley and the oil pump pulley to rotate by a timing belt; the oil pump pulley and The crankshaft timing pulleys have the same shape, size, and initial assembly orientation.

Preferably, the first timing of the engine timing train on the crankshaft timing pulley Memorizing on a first straight line passing through the center of the crankshaft timing pulley, the engine timing train is disposed on a second line of the oil pump pulley opposite to the position of the first straight line Second timing mark;

The engine timing train is provided on the engine block with a fourth timing mark that matches the second timing mark, the fourth timing mark and the engine block The third timing marks that match a timing mark have the same orientation.

Preferably, the first timing mark is disposed on a short side or a long side of the crankshaft timing pulley.

Preferably, the angle between the third timing mark and the fourth timing mark and the vertical direction is greater than or equal to -5 degrees and less than or equal to 5 degrees.

Preferably, the engine timing train further includes a mechanical tensioner disposed between the intake timing pulley and the crank timing pulley.

Preferably, the engine timing train further includes an idler pulley disposed between the exhaust timing pulley and the oil pump pulley.

The beneficial effects of the present invention are that the engine timing wheel train of the present invention can make the oil pump pulley have the same structure, size and initial assembly orientation as the crankshaft timing pulley, so that the crankshaft timing pulley can pass through the positive When the belt drive oil pump belt rotates, it ensures that the oil pump pulley always maintains the synchronous rotation with the crankshaft timing pulley, which can make the timing belt combine with the crankshaft timing pulley and The portion between the separation points of the oil pump pulleys is always maintained in the same tension state as in the initial assembly, thereby extending the service life of the timing belt on the one hand and reducing the jitter frequency of the timing belt on the other hand. And reduce the noise of the engine timing system and improve the NVH performance of the entire engine timing system.

DRAWINGS

1 is a schematic structural view of a conventional engine timing train;

Figure 2 is a view showing the maximum tension state of the timing belt shown in Figure 1 when the crankshaft timing pulley is rotated to the short side and the center line between the crankshaft timing pulley and the oil pump pulley is vertical;

The solid line in Fig. 3 shows the maximum relaxed state of the timing belt shown in Fig. 1 when the crankshaft timing pulley is rotated until the long side is perpendicular to the center line, and the broken line in Fig. 3 shows the positive in Fig. 2. The maximum tension of the belt when it is in;

4 is a schematic structural view showing an embodiment of an engine timing train according to the present invention;

Fig. 5 is a partially enlarged schematic view showing the crank wheel timing pulley and the oil pump pulley portion of Fig. 4.

Description of the reference signs:

1-intake timing pulley; 2-exhaust timing pulley;

3- idler; 4, 4'-oil pump pulley;

5-crankshaft timing pulley; 6-mechanical tensioner;

7- timing belt; a, c-long side;

b, d- short side; T1-first timing mark;

T2-second timing mark; T3-third timing mark;

T4-fourth timing mark; 71, 71'- the part timing belt;

P1-binding point; P2-separation point.

detailed description

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.

The engine timing train of the present invention includes a crankshaft timing pulley 5 of an existing engine timing train as shown in FIG. 1, an oil pump pulley 4, an exhaust timing pulley 2, and an intake variable valve positive The intake timing pulley 1 of the device, the crank timing pulley 5 drives the intake timing pulley 1, the exhaust timing pulley 2 and the oil pump pulley 4 through the timing belt 7 to solve the engine The timing wheel train is a problem caused by the intake timing variable valve timing device of the engine timing system, and the crank timing belt pulley 5 is an elliptical pulley. In order to solve the separation of the engine timing wheel train due to the use of the elliptical crankshaft timing pulley 5, the timing belt 7 is combined with the crankshaft timing pulley 5 and separated from the oil pump pulley 4 The portion between the points presents a problem of periodic variation from tension to slack, and then from slack to tension. The engine timing train of the present invention replaces the conventional circular oil pump pulley 4 with the conventional circular oil pump pulley 4 as shown in FIG. The elliptical oil pump pulley 4' is shown to have the same shape as the crankshaft timing pulley 5, and the oil pump pulley 4' and the crankshaft timing pulley 5 should have the same The size and the initial assembly orientation, therefore, the major axis a and the minor axis b of the crankshaft timing pulley 5 are equal to the major axis c and the minor axis d of the oil pump pulley 4', respectively, where the crankshaft timing pulley The long axis a of 5 determines the initial assembly orientation of the crankshaft timing pulley 5, and the angle between the major axis a of the crankshaft timing pulley 5 and the vertical direction is required to be equal to the long axis c and vertical of the oil pump pulley 4'. The angle of the direction, so that when the crankshaft timing pulley 5 drives the oil pump pulley 4' through the timing belt 7, the oil pump pulley 4' can always be kept in synchronization with the crankshaft timing pulley 5 Rotation, in this case, since the oil pump pulley 4' has the same size as the crank timing pulley 5, the joint point of the timing belt 7 and the crank timing pulley 5 can be combined and The portion between the separation points at which the oil pump pulley 4' is separated (hereinafter simply referred to as the portion timing belt 71') is always maintained in the same tension state as in the initial assembly, so that the portion timing belt 71' can be provided. Minimum swing and vibration frequency.

As shown in FIG. 5, since the crankshaft timing pulley 5 is initially assembled, the first timing mark T1 on the crank timing pulley 5 is required to be aligned with the third timing mark T3 on the engine block, Ensure that the piston of the engine block is in the initial position of the compression stroke top dead center. In order to ensure that the crankshaft timing pulley 5 and the oil pump pulley 4' have the same initial assembly orientation, as shown in FIG. The first timing mark T1 of the engine timing wheel train on the crankshaft timing pulley 5 is disposed on the first straight line of the crankshaft timing pulley 5 at the center of the crankshaft timing pulley 5, and the engine of the present invention is positive. The hour wheel train may also be provided with a second timing mark T2 on a second line of the oil pump pulley 4' opposite to the first straight line, wherein the timing mark is set on the straight line including the timing mark along The limit corresponding to the direction of the line. Since the crankshaft timing pulley 5 and the oil pump pulley 4' are both elliptical pulleys, the first timing mark T1 can be set to the crankshaft in order to facilitate determination of the first straight line and the second straight line of the relative position. The second timing mark T2 is disposed on the long side c of the oil pump pulley 4'; similarly, the first timing mark T1 and the second timing mark T2 can also be They are respectively disposed on the short side b of the crankshaft timing pulley 5 and the short side d of the oil pump pulley 4'. Correspondingly, the engine timing train of the present invention should also be provided with a fourth timing mark T4 for matching the second timing mark T2 on the engine block, and the fourth timing mark T4 should be the third positive The time stamp T3 has the same orientation to ensure that the crankshaft timing pulley 5 and the oil pump pulley 4' have the same initial assembly orientation.

In order to make the portion of the timing belt 71' have better dynamic performance, as shown in FIG. The angle between the third timing mark T3 and the fourth timing mark T4 and the vertical direction P is preferably -5 degrees or more and 5 degrees or less, wherein the third timing mark T3 and the fourth timing mark T4 are opposite. The angle in which the vertical direction P is deflected in the counterclockwise direction is a negative angle, and the angle of the vertical direction P deflected in the clockwise direction is a positive angle, the third timing mark T3 and the fourth timing mark T4 and the vertical direction P The angle is selected especially between -5 degrees and less than or equal to 0 degrees.

Like the existing engine timing train, as shown in FIG. 4, the engine timing train of the present invention may also include a mechanical tensioner disposed between the intake timing pulley 1 and the crank timing pulley 5. 6. An idler pulley 3 disposed between the exhaust timing pulley 2 and the oil pump pulley 4'.

In addition, the partial presentation of the timing belt 7 of the present invention by the elliptical oil pump pulley 4' improves the point of engagement between the timing belt 7 in combination with the crankshaft timing pulley 5 and the separation point from the oil pump pulley 4. Tightening to slack, and then the cyclical variation of slack to tension is also suitable for chain-driven engine timing trains, which should be considered equivalent technical solutions, so if only the above-mentioned crankshaft timing belt The wheel 5, the oil pump pulley 4', the exhaust timing pulley 2, the intake timing pulley 1 of the intake variable valve timing device, the timing belt 7 and the partial timing belt 71' are replaced by Crankshaft timing sprocket, oil pump sprocket, exhaust timing sprocket, intake timing sprocket of intake variable valve timing device, timing chain and the part timing chain, wherein the part timing chain It is the same as the definition of the partial timing belt 71', that is, the portion between the timing point of the timing chain combined with the crankshaft timing sprocket and the separation point separated from the oil pump sprocket, which should be considered as Within the scope of protection of the present invention.

Furthermore, for convenience of explanation, the present invention defines the crankshaft timing pulley 5 as an elliptical shape, but the solution of the present invention is equally applicable to the non-circular structure in which the crankshaft timing pulley 5 is an elliptical shape, as long as the oil pump pulley 4' has the same structure, shape and initial assembly orientation as the crankshaft timing pulley 5. For example, the crankshaft timing pulley 5 may be a combination of two semicircles and two arcs between two semicircles. The shape of the two arcs is symmetrically arranged with respect to the line connecting the centers of the two semicircles. Therefore, the technical scheme of adopting an elliptical-like non-circular structure for the crankshaft timing pulley 5 should be considered to be an elliptical structure. The equivalent technical solution should be considered to be within the scope of the present invention.

The structure, features and effects of the present invention are described in detail above with reference to the embodiments shown in the drawings. The above description is only a preferred embodiment of the present invention, but the present invention is not limited by the drawings. The scope of the present invention is intended to be limited to the scope of the invention and the scope of the invention.

Claims

An engine timing train includes an oil pump pulley, an exhaust timing pulley, an intake timing pulley of an intake variable valve timing device, and an elliptical crank timing belt pulley The hour pulley drives the intake timing pulley, the exhaust timing pulley and the oil pump pulley to rotate by a timing belt; wherein the oil pump pulley has the same function as the crank timing pulley The shape, size and initial assembly orientation.
The engine timing train of claim 1 wherein said first timing mark of said engine timing train on said crankshaft timing pulley is disposed at a center of said crankshaft timing pulley In a straight line, the engine timing train is provided with a second timing mark on a second straight line of the oil pump pulley opposite to the position of the first straight line;

The engine timing train is provided on the engine block with a fourth timing mark that matches the second timing mark, the fourth timing mark and the engine block The third timing marks that match a timing mark have the same orientation.
The engine timing train according to claim 2, wherein said first timing mark is disposed on a short side or a long side of said crank timing pulley.
The engine timing train according to claim 2, wherein an angle between the third timing mark and the fourth timing mark and the vertical direction is -5 degrees or more and 5 degrees or less.
The engine timing train according to any one of claims 1 to 4, wherein the engine timing train further includes a timing timing pulley and the crank timing pulley Mechanical tensioning wheel between.
The engine timing train according to any one of claims 1 to 4, wherein the engine timing train further includes a discharge timing pulley and the oil pump pulley The idler between the two.