Chain transmission structure, engine and vehicle

Abstract

The utility model relates to the technical field of vehicles, in particular to a chain transmission structure, an engine and a vehicle, the chain transmission structure comprises a chain and a chain wheel, the chain is used for being meshed with the chain wheel, the pitch of the chain wheel is Pa, the pitch of the chain is Pb, the ratio of the pitch of the chain wheel to the pitch of the chain is n, and n = Pa / Pb; n is greater than 0.97 and less than 1. By means of the arrangement, the pitch of the chain wheel is smaller than that of a chain wheel in the prior art, and meshing order noise in the meshing process of the chain and the chain wheel can be remarkably reduced. And moreover, the ratio of the pitch of the chain wheel to the pitch of the chain is between 0.97 and 1, so that the effect of improving the meshing order noise is relatively good.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicles, in particular to a chain drive structure, an engine and a vehicle. Background Art

[0002] Chain drives are widely used in the engine timing drive system. However, due to the existence of the polygon effect of chain drives, a large meshing order noise will be generated during the meshing process between the sprocket and the chain.

[0003] Specifically, the chain drive structure includes a chain and a sprocket. The chain is a bush chain. The radius of the pitch circle of the sprocket is R. The sprocket includes Z chain teeth evenly distributed along its circumferential direction. A tooth groove is formed between two adjacent chain teeth. As Figure 1 shown, at this time, the sleeve just meshing with the sprocket 2-1 is the first sleeve 1-11. The other sleeves downstream of the first sleeve 1-11 are the second sleeve 1-12, the third sleeve 1-13... At this time, the first sleeve 1-11 is at the highest point, that is, the center of the first sleeve 1-11 is at the highest point. The first sleeve 1-11 meshes with the tooth groove of the sprocket 2-1, and this tooth groove is also at the highest point. The center of the first sleeve 1-11 is tangent to the pitch circle of the sprocket 2-1. The distance between the center of the first sleeve 1-11 and the center of the sprocket 2-1 is equal to R. As Figure 2 shown, Figure 2 For Figure 1 the position of the sprocket 2-1 in the chain drive structure shown after rotating clockwise by (180° / Z), at this time, the second sleeve 1-12 downstream of the first sleeve 1-11 enters and meshes with the corresponding tooth groove of the sprocket 2-1. Both the first sleeve 1-11 and the second sleeve 1-12 are at the lowest point. The centers of the first sleeve 1-11 and the second sleeve 1-12 are both tangent to the pitch circle of the sprocket 2-1, and the vertical distances between the centers of the first sleeve 1-11 and the second sleeve 1-12 and the center of the sprocket 2-1 are both Rcos(180° / Z). Therefore, during the process of each sleeve from non-meshing to meshing, the center height of the sleeve changes by H = R(1 - cos(180° / Z)). The change in the center height of the sleeve during the meshing process will cause the lateral vibration of the chain 1-1 and be transmitted to other chain links downstream, generating meshing order noise.

[0004] Therefore, there is an urgent need for a chain drive structure to solve the above problems. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a chain drive structure, an engine and a vehicle to improve the polygon effect during the chain drive process and reduce the meshing order noise.

[0006] On the one hand, the present utility model provides a chain drive structure, which includes a chain and a sprocket. The chain is used to mesh with the sprocket, and the pitch of the sprocket is P a , and the pitch of the chain is P b . The ratio of the pitch of the sprocket to the pitch of the chain is n, and n = P a / P b ; the value of n is greater than 0.97 and less than 1.

[0007] As a preferred technical solution of the chain drive structure, the chain includes a plurality of chain links. Each chain link includes two parallel and spaced chain plates, a chain shaft rotatably connected to the two chain plates at the same time, and a sleeve rotatably sleeved on the chain shaft. Among two adjacent chain links, the two chain plates of one chain link are rotatably connected to the chain shaft of the other chain link.

[0008] As a preferred technical solution of the chain drive structure, a plurality of tooth grooves and a plurality of chain teeth are provided on the outer periphery of the sprocket. The plurality of chain teeth are evenly and spaced along the circumferential direction of the sprocket. A tooth groove is formed between any two adjacent chain teeth. The tooth groove has an arc-shaped tooth groove surface. The chain teeth are used to be inserted between two adjacent sleeves, and the sleeve is used to be tangentially matched with the tooth groove surface of the tooth groove.

[0009] As a preferred technical solution of the chain drive structure, the radius of the tooth groove surface is greater than the radius of the sleeve.

[0010] As a preferred technical solution of the chain drive structure, the diameter of the sleeve is D, and the radius of the tooth groove surface is R 齿沟面 , 0.528 > R 齿沟面 / D > 0.505.

[0011] On the second hand, the present utility model provides an engine, which includes an engine body, a crankshaft arranged on the engine body, an intake camshaft arranged on the engine body, an exhaust camshaft arranged on the engine body, and the chain drive structure in any of the above solutions. The chain drive structure includes three sprockets sequentially arranged on the crankshaft, the intake camshaft and the exhaust camshaft, and the chain meshes with the three sprockets respectively.

[0012] As a preferred technical solution of the engine, the engine further includes a guide rail arranged on the engine body. The guide rail is provided with a guide groove, and the chain is threaded through the guide groove.

[0013] As a preferred technical solution of the engine, along the extending direction of the guide rail, the guide rail has a first end and a second end. The first end is rotatably connected to the engine body through a pivot shaft. The engine further includes a tension driving member, and the tension driving member is used to drive the second end to rotate around the axis of the pivot shaft.

[0014] As a preferred technical solution of the engine, the engine includes two such guide rails and two such tension driving members. One of the guide rails is disposed between the crankshaft and the intake camshaft, and the other guide rail is disposed between the crankshaft and the exhaust camshaft. The two tension driving members are arranged in one-to-one correspondence with the two guide rails.

[0015] On the other hand, the present utility model provides a vehicle, including the vehicle in any of the above solutions. The vehicle further includes a gearbox, a transmission shaft, and a drive axle, and the engine, the gearbox, the transmission shaft, and the drive axle are sequentially connected for transmission.

[0016] The beneficial effects of the present utility model are as follows:

[0017] The present utility model provides a chain drive structure, an engine, and a vehicle. The chain drive structure includes a chain and a sprocket. The chain is used to mesh with the sprocket, and the pitch of the sprocket is P a , and the pitch of the chain is P b , and the ratio of the pitch of the sprocket to the pitch of the chain is n, and n = P a / P b ; the value of n is greater than 0.97 and less than 1. With such a setting, the pitch of the sprocket is reduced compared to the pitch of the sprocket in the prior art, and the meshing order noise during the meshing process of the chain and the sprocket can be significantly improved. Moreover, by making the ratio of the pitch of the sprocket to the pitch of the chain be between 0.97 and 1, the improvement effect on the meshing order noise can be relatively good. Description of the Drawings

[0018] Figure 1 is a schematic structural view of a chain drive structure in the prior art Figure 1 (the pitch of the sprocket is equal to the pitch of the chain);

[0019] Figure 2 is a schematic structural view of a chain drive structure in the prior art Figure 2 (the pitch of the sprocket is equal to the pitch of the chain);

[0020] Figure 3 is a schematic diagram for comparing the structures of a sprocket in the prior art and a sprocket in an embodiment of the present utility model;

[0021] Figure 4 is a schematic structural view of the chain drive structure in an embodiment of the present utility model Figure 1 (the pitch of the sprocket is less than the pitch of the chain);

[0022] Figure 5 Structural schematic of the chain drive structure in the embodiment of the present utility model Figure 2 (The pitch of the sprocket is smaller than the pitch of the chain).

[0023] In the figure:

[0024] 1-1, chain; 1-11, first sleeve; 1-12, second sleeve; 1-13, third sleeve; 2-1, sprocket

[0025] 1, chain; 11, chain link; 111, chain plate; 112, chain shaft; 113, sleeve; 1131, first sleeve; 1132, second sleeve; 1133, third sleeve

[0026] 2, sprocket; 21, sprocket tooth; 22, tooth groove; 221, tooth groove surface Specific implementation manners

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0028] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0029] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.

[0031] In the prior art, due to the existence of the polygon effect of chain drive, a relatively large meshing order noise will be generated during the meshing process between the sprocket and the chain. Among them, the polygon effect means that when the chain winds around the sprocket, it forms a regular polygon. When the driving sprocket rotates at a constant angular velocity, the running speed of the chain will show a periodic change. That is, during the operation of the sprocket, every time the sprocket rotates one tooth, the chain speed in the horizontal direction changes from small to large and then from large to small once, causing the linear speed of the chain and the angular velocity of the sprocket to change, and the instantaneous transmission ratio is not constant; at the same time, the rise and fall of the center point of the chain sleeve cause the lateral vibration of the chain, which will be transmitted to the free link, resulting in greater vibration and noise when the free link sleeve contacts the sprocket.

[0032] In response to this, the present embodiment provides a chain drive structure to solve the above problems. This chain drive structure can be applied to the timing drive system of an engine and is applied to a vehicle.

[0033] Specifically, please refer to Figures 3 to 5 , in which the chain drive structure includes a chain 1 and a sprocket 2, and the chain 1 is used to mesh with the sprocket 2.

[0034] Optionally, the chain 1 is a bush chain. Specifically, the chain 1 includes a plurality of chain links 11. The chain link 11 includes two parallel and spaced-apart chain plates 111, a chain shaft 112 rotatably connected to both chain plates 111 at the same time, and a sleeve 113 rotatably sleeved on the chain shaft 112. Among two adjacent chain links 11, the two chain plates 111 of one chain link 11 are rotatably connected to the chain shaft 112 of the other chain link 11. This chain 1 meshes with the sprocket 2 through the sleeve 113, which can effectively reduce the frictional resistance. Of course, in other embodiments, the chain 1 can also be set as a silent chain or a roller chain according to needs.

[0035] Optionally, a plurality of tooth grooves 22 and a plurality of chain teeth 21 are provided on the outer periphery of the sprocket 2. The plurality of chain teeth 21 are evenly and spaced apart along the circumferential direction of the sprocket 2. A tooth groove 22 is formed between any two adjacent chain teeth 21. The tooth groove 22 has an arcuate tooth groove surface 221. The chain teeth 21 are used to be inserted between two adjacent sleeves 113, and the sleeves 113 are used to be tangentially engaged with the tooth groove surface 221 of the tooth groove 22.

[0036] Optionally, in this embodiment, the pitch of the sprocket 2 is P a , and the pitch of the chain 1 is P b , and the ratio of the pitch of the sprocket 2 to the pitch of the chain 1 is n, and n = P a / P b ; the value of n is greater than 0.97 and less than 1. With such a setting, the pitch of the sprocket 2 is reduced compared to the pitch of the sprocket in the prior art, and the meshing order noise during the meshing process of the chain 1 and the sprocket 2 can be significantly improved. Moreover, by making the ratio of the pitch of the sprocket 2 to the pitch of the chain 1 between 0.97 and 1, the improvement effect on the meshing order noise can be relatively good. Exemplarily, the value of n can be 0.971, 0.972, 0.973, 0.974, 0.975, 0.976, 0.977, 0.978, 0.979, 0.980, 0.981, 0.982, 0.983, 0.984, 0.985, 0.986, 0.987, 0.988, 0.989, 0.990, 0.991, 0.992, 0.993, 0.994, 0.995, 0.996, 0.997, 0.998 or 0.999. Specifically, through experimental analysis, the chain drive structure provided in this embodiment has a noise ratio of 44 / 51.5 when the sprocket 2 operates under the condition of 1500 revolutions per minute compared with the existing chain drive structure; and has a noise ratio of 55.3 / 67.4 when the sprocket 2 operates under the condition of 2500 revolutions per minute.

[0037] Optionally, in this embodiment, the radius of the tooth groove surface 221 is greater than the radius of the sleeve 113. As Figure 3 shown, d1 is the pitch circle diameter of the sprocket 2 in the existing chain drive structure, and the pitch of the sprocket in the existing chain drive structure is equal to the pitch of the chain and both are P1; d2 is the pitch circle diameter of the sprocket 2 in the chain drive structure provided in this embodiment, and the pitch of the sprocket 2 is P2. Since the radius of the tooth groove surface 221 is greater than the radius of the sleeve 113, compared with the existing chain drive structure, the pitch circle of the sprocket 2 in this embodiment is closer to the center of the sprocket 2. Therefore, d2 < d1 and P2 < P1.

[0038] As Figure 4As shown, the sleeve 113 that has just engaged with the sprocket 2 at this time is the first sleeve 1131, and the other sleeves 113 downstream of the first sleeve 1131 are the second sleeve 1132, the third sleeve 1133... respectively. At this time, the first sleeve 1131 is at the highest point, that is, the center of the first sleeve 1131 is at the highest point. The first sleeve 1131 engages with the tooth groove 22, and this tooth groove 22 is also at the highest point. The distance between the center of the first sleeve 1131 and the center of the sprocket 2 is R1. Correspondingly, as Figure 1 shown, in the existing chain drive structure in the same state as Figure 4 , the distance between the center of the first sleeve and the center of the sprocket is equal to R. In this embodiment, since the radius of the tooth groove surface 221 is greater than the radius of the sleeve 113, thus R1 < R.

[0039] As Figure 5 shown, Figure 5 is the position after the sprocket 2 in the chain drive structure shown in Figure 4 rotates clockwise by (180° / Z), where Z is the number of chain teeth 21 included in the sprocket 2. At this time, the second sleeve 1132 downstream of the first sleeve 1131 enters and engages with the corresponding tooth groove 22 of the sprocket 2. At this time, the vertical distances between the center of the second sleeve 1132 and the center of the first sleeve 1131 and the center of the sprocket 2 are equal, and the vertical distances between the center of the first sleeve 1131 and the center of the second sleeve 1132 and the center of the sprocket 2 are both R2. And for the chain drive structure provided in this embodiment, since the pitch of the chain 1 is greater than the pitch of the sprocket 2, thus the centers of the second sleeve 1132 and the first sleeve 1131 will not drop to the position tangent to the pitch circle like the existing chain drive structure. Therefore, R2 > R1cos(180° / Z). In this embodiment, the vertical fluctuation distance of the center height of the first sleeve 1131 is H1 = R1 - R2. Since R2 > R1cos(180° / Z), thus H1 < R1(1 - cos(180° / Z)). Correspondingly, as Figure 2 shown, in the existing chain drive structure in the same state as Figure 5 , the vertical distance between the center of the first sleeve and the center of the sprocket is equal to Rcos(180° / Z). When the first sleeve changes from the state shown in Figure 1 to the state shown in Figure 2 , the vertical fluctuation distance of the center height of the first sleeve is H = R(1 - cos(180° / Z)). Since R1 < R, thus, H1 < R1(1 - cos(180° / Z)) < H. Therefore, in this embodiment, by making the radius of the tooth groove surface 221 greater than the radius of the sleeve 113, the vertical fluctuation distance of the center of the sleeve 113 of the chain 1 during meshing can be significantly reduced, thereby reducing the lateral vibration of the chain 1 and improving the meshing noise generated at the moment when the chain sleeve 113 engages.

[0040] Specifically, in this embodiment, the diameter of the sleeve 113 is D, and the radius of the tooth groove surface 221 is R 齿沟面 , 0.528 > R 齿沟面 / D > 0.505. Exemplarily, the value of R 齿沟面 / D can be 0.506, 0.507, 0.508, 0.509, 0.510, 0.510, 0.511, 0.512, 0.513, 0.514, 0.515, 0.516, 0.517, 0.518, 0.519, 0.520, 0.521, 0.522, 0.523, 0.524, 0.525, 0.526 or 0.527. By making 0.528 > R 齿沟面 / D > 0.505, it can ensure that the ratio of the pitch of the sprocket 2 to the pitch of the chain 1 is between 0.97 and 1, thereby ensuring a relatively good improvement effect on the meshing order noise.

[0041] This embodiment also provides an engine, which includes an engine body, a crankshaft disposed on the engine body, an intake camshaft disposed on the engine body, an exhaust camshaft disposed on the engine body, and the above chain drive structure. The chain drive structure includes three sprockets 2 sequentially disposed on the crankshaft, the intake camshaft, and the exhaust camshaft. The chain 1 meshes with the three sprockets 2 respectively. When the crankshaft rotates, it drives the intake cam and the exhaust cam to rotate synchronously. Since the meshing order noise of the chain drive structure is small, it can effectively improve the NVH (Noise, Vibration, Harshness) performance of the engine.

[0042] Optionally, the engine further includes a guide rail disposed on the engine body. The guide rail is provided with a guide groove, and the chain 1 is threaded through the guide groove. By providing the guide rail, the movement path of the chain 1 can be constrained to a certain extent, avoiding interference between the chain 1 and other components on the engine body. Further optionally, the guide rail has a first end and a second end. The first end is rotatably connected to the engine body through a pivot shaft. The engine further includes a tensioning drive member for driving the second end to rotate around the axis of the pivot shaft. Among them, the tensioning drive member can be an electric push rod, a cylinder or an oil cylinder, etc. By driving the guide rail to rotate with the tensioning drive member, the tension of the chain 1 can also be adjusted, thereby ensuring the stability of the operation of the chain 1. Specifically, taking the tensioning drive member as an electric push rod as an example, a drive block is provided on the output shaft of the electric push rod, and a slot is provided on the guide rail. The drive block is inserted into the slot, and the aperture of the slot is larger than the aperture of the drive block. Thus, when the electric push rod drives the drive block to reciprocate in a straight line direction, the drive block has a certain movement space relative to the slot and can contact the bottom wall of the slot and drive the guide rail to rotate without interference between the drive block and the slot wall. Preferably, the engine includes two guide rails and two tensioning drive members. One guide rail is disposed between the crankshaft and the intake camshaft, and the other guide rail is disposed between the crankshaft and the exhaust camshaft. The two tensioning drives are arranged in one-to-one correspondence with the two guide rails. In this way, separate adjustment of the part of the chain 1 between the crankshaft and the intake camshaft and the part between the crankshaft and the exhaust camshaft can be achieved.

[0043] This embodiment also provides a vehicle, which includes the above engine. The vehicle further includes a gearbox, a transmission shaft and a drive axle. The engine, the gearbox, the transmission shaft and the drive axle are sequentially connected for transmission. Since the meshing order noise of the chain drive structure is small, the NVH performance of the engine of this vehicle can be effectively improved.

[0044] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A chain drive structure, comprising a chain (1) and a sprocket (2), wherein the chain (1) is used to engage with the sprocket (2), and is characterized in that, The pitch of the sprocket (2) is P a , and the pitch of the chain (1) is P b . The ratio of the pitch of the sprocket (2) to the pitch of the chain (1) is n, and n = P a / P b ; the value of n is greater than 0.97 and less than 1.

2. The chain drive structure according to claim 1, characterized in that The chain (1) comprises a plurality of chain links (11), wherein the chain links (11) comprise two chain plates (111) arranged in parallel and at intervals, a chain shaft (112) rotatably connected to the two chain plates (111), and a sleeve (113) rotatably sleeved on the chain shaft (112); in two adjacent chain links (11), the two chain plates (111) of one chain link (11) are rotatably connected to the chain shaft (112) of the other chain link (11).

3. The chain drive structure according to claim 2, wherein The outer periphery of the sprocket (2) is provided with a plurality of tooth grooves (22) and a plurality of chain teeth (21); the plurality of chain teeth (21) are evenly and spacedly arranged along the circumferential direction of the sprocket (2); a tooth groove (22) is formed between any two adjacent chain teeth (21); the tooth groove (22) has a tooth groove surface (221) in the form of an arc; the chain tooth (21) is used for being inserted between two adjacent sleeves (113); and the sleeve (113) is used for being tangentially matched with the tooth groove surface (221) of the tooth groove (22).

4. The chain drive structure according to claim 3, wherein The radius of the tooth groove surface (221) is greater than the radius of the sleeve (113).

5. The chain drive structure according to claim 4, characterized in that, The diameter of the sleeve (113) is D, and the radius of the tooth groove surface (221) is R 齿沟面 , 0.528 > R 齿沟面 / D > 0.505 6. An engine, characterized in that, It comprises an engine body, a crankshaft arranged on the engine body, an intake camshaft arranged on the engine body, an exhaust camshaft arranged on the engine body, and a chain transmission structure as described in any one of claims 1 to 5, wherein the chain transmission structure comprises three sprockets (2) arranged on the crankshaft, the intake camshaft and the exhaust camshaft in sequence, and the chain (1) is respectively engaged with the three sprockets (2).

7. The engine according to claim 6, characterized in that, The engine further comprises a guide rail arranged on the engine body, the guide rail being provided with a guide groove, and the chain (1) is passed through the guide groove.

8. The engine according to claim 7, characterized in that, Along the extension direction of the guide rail, the guide rail has a first end and a second end, the first end is rotatably connected to the engine body via a pivot shaft, and the engine also includes a tensioning drive component, which is used to drive the second end to rotate around the axis of the pivot shaft.

9. The engine according to claim 8, characterized in that, The engine includes two guide rails and two tensioning drives, one of the guide rails is arranged between the crankshaft and the intake camshaft, and the other guide rail is arranged between the crankshaft and the exhaust camshaft, and the two tensioning drives are arranged in a one-to-one correspondence with the two guide rails.

10. A vehicle, characterized in that, The vehicle comprises the engine as claimed in any one of claims 6 to 9, and further comprises a gearbox, a transmission shaft and a drive axle, wherein the engine, the gearbox, the transmission shaft and the drive axle are sequentially connected in a transmission manner.

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