CN111120598B

CN111120598B - Engine and belt tensioner thereof

Info

Publication number: CN111120598B
Application number: CN201811296103.1A
Authority: CN
Inventors: 邢东仕; 丁凯; 李岩; 贺融冰; 侯明阳; 江旭光
Original assignee: SAIC Motor Corp Ltd
Current assignee: SAIC Motor Corp Ltd
Priority date: 2018-11-01
Filing date: 2018-11-01
Publication date: 2021-12-07
Anticipated expiration: 2038-11-01
Also published as: CN111120598A

Abstract

The invention discloses an engine and a belt tensioner thereof, wherein the belt tensioner comprises a tension arm assembly and a base, the tension arm assembly can rotate relative to the base, the belt tensioner also comprises at least two springs, one end of each spring along the axial direction is fixed on the base, and the other end of each spring is used for being matched with the tension arm assembly; when the tensioning arm assembly is in a working condition with a small swing angle, at least one spring is matched with the tensioning arm assembly, and when the tensioning arm assembly is in a working condition with a large swing angle, the number of the springs matched with the tensioning arm assembly is increased to at least two. The belt tensioner can meet the tension force required by the engine under the working conditions of high rotating speed and low rotating speed, and meanwhile, when the engine is under the working conditions of high rotating speed, the tension force provided by the belt tensioner is the same as or close to the tension force required by the engine, so that the oil consumption of the engine under the working conditions of high rotating speed and small swing angle of the tension arm assembly can be reduced.

Description

Engine and belt tensioner thereof

Technical Field

The invention relates to the technical field of automobile parts, in particular to an engine and a belt tensioner thereof.

Background

The automobile engine accessory gear train generally comprises a belt, a crankshaft belt pulley, an engine belt pulley, a water pump belt pulley, an oil pump belt pulley, a compressor belt pulley, an idler pulley and other parts, and the belt is easy to loosen due to extension after working for a period of time, and meanwhile, the original size of the belt is changed due to the fact that the coefficient of thermal expansion of an engine body is different from that of the belt, so that the tension of the belt is reduced, severe shaking is caused, and the working performance is reduced accordingly. Therefore, in order to ensure that the belt can reliably transmit motion, prevent the belt from slipping during operation, compensate for the elongation of the belt due to aging, wear, etc., and reduce the vibration of the belt under various conditions, tensioners are widely used in automobile accessory gear trains.

Typically, a tensioner includes a tensioner arm, a base, and a spring coupled therebetween, and a system tension of an engine accessory system is determined by the spring of the tensioner. Because the tensioner is only provided with one spring, in order to meet the requirement of a large tensioning force required by the engine under a low-rotation-speed working condition (700-2000 rpm), the spring capable of providing the large tensioning force is usually arranged, and when the engine is at a high rotation speed (2000-7000 rpm) and the required tensioning force is small, the tensioner still has the large tensioning force, so that the oil consumption of the engine under the high-rotation-speed working condition is high.

In view of this, how to provide a belt tensioner for an engine, which can provide a larger tension force when the engine is in a low-speed operating condition, and which can provide a smaller tension force when the engine is in a high-speed operating condition, so as to reduce oil consumption when the engine is in a high-speed operating condition, is a technical problem to be solved by those skilled in the art.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a belt tensioner of an engine, which comprises a tensioning arm component, a base and at least two springs, wherein the tensioning arm component can rotate relative to the base;

when the tensioning arm assembly is in a working condition with a small swing angle, at least one spring is matched with the tensioning arm assembly, and when the tensioning arm assembly is in a working condition with a large swing angle, the number of the springs matched with the tensioning arm assembly is increased to at least two.

The belt tensioner comprises a plurality of springs, and when the rotating speed of an engine is higher, the tensioning arm assembly is in a working condition of a small swing angle; when the engine speed is lower, the swing angle of the tension arm assembly is increased, the number of springs matched with the tension arm assembly in the belt tensioner is increased, the provided tension force is larger, and the belt tensioner can be matched with the low-speed working condition of the engine.

Therefore, the belt tensioner can meet the tension force required by the engine under the working conditions of high rotating speed and low rotating speed, and meanwhile, when the engine is under the working condition of high rotating speed, the tension force provided by the belt tensioner is the same as or similar to the tension force required by the engine, so that the oil consumption of the engine under the working conditions of high rotating speed and small swinging angle of the tension arm assembly can be reduced.

Optionally, when the engine is in a low-rotation-speed working condition, the tensioning arm assembly rotates along the rotation direction thereof, the swing angle is increased, the tensioning arm assembly is provided with at least two stoppers, and the spring end of each spring is located in a rotation path corresponding to the stopper, so that the number of the stoppers and the spring end which are correspondingly abutted against each other is increased in the rotation process of the tensioning arm assembly along the rotation direction.

Optionally, the tensioning arm assembly includes a tensioning arm and a damping block connected to each other, the damping block is located between a tensioning wheel of the tensioning arm and the base, a friction pair is formed between the damping block and the tensioning wheel, and the tensioning arm can drive the damping block to rotate when rotating along the rotation direction.

Optionally, the base is fixed with a large spring and a small spring which are sleeved with each other, and the damping block is provided with a first stop block and a second stop block;

when the tensioning arm assembly is in a working condition of a small swing angle, the second stop block abuts against the end part of the spring of the small spring, and a preset distance is reserved between the first stop block and the end part of the spring of the large spring; when the tensioning arm assembly is in a working condition with a large swing angle, the second stop block abuts against the end part of the spring of the small spring, and the first stop block abuts against the end part of the spring of the large spring.

Optionally, the spring ends of the large spring and the small spring are located on the same radius of the damping block, the first stopper and the second stopper are located on different radii of the damping block, and the first stopper is located downstream of the second stopper along the rotation direction.

Optionally, the damping block is provided with a first annular groove and a second annular groove, the first annular groove is provided with the first stop dog, the second annular groove is provided with the second stop dog, the large spring is fixed to the base along the axial end, the other end is located in the first annular groove, the small spring is fixed to the base along the axial end, and the other end is located in the second annular groove.

Optionally, the base has a cylindrical mounting cylinder, a first annular fixing groove and a second annular fixing groove are formed in the bottom of the mounting cylinder, one end of the large spring in the axial direction is fixed in the first fixing groove, and one end of the small spring in the axial direction is fixed in the second fixing groove.

Optionally, the tensioning wheel has a fan-shaped driving block, and a matching groove adapted to the damping block is formed in the tensioning wheel, the damping block has a fan-shaped opening adapted to the driving block, the damping block is located in the matching groove, and a circumferential side wall of the opening abuts against a circumferential side wall of the driving block, so that the tensioning arm drives the damping block to rotate through the driving block.

Optionally, the tensioning arm assembly further comprises a pin shaft, the pin shaft penetrates through the tensioning arm assembly and the central hole of the base, and the tensioning arm assembly can rotate around the pin shaft;

and a bushing is arranged between the pin shaft and each central hole.

In addition, the invention also provides an engine, which comprises an engine body and a belt tensioner, wherein when the engine is in a high rotating speed working condition, the tensioning arm assembly of the belt tensioner is in a small oscillating angle working condition, and when the engine is in a low rotating speed working condition, the tensioning arm assembly is in a large oscillating angle working condition; wherein the belt tensioner is the above-described belt tensioner.

Drawings

FIG. 1 is an assembly view of an accessory tensioner in one embodiment of the present invention;

FIG. 2 is an exploded view of FIG. 1;

FIG. 3 is a schematic diagram of the construction of the tension arm assembly of FIG. 1;

FIG. 4 is a schematic diagram of the tension arm assembly of FIG. 3 with two springs mounted;

FIG. 5 is a schematic diagram of the tensioner arm of FIG. 3;

FIG. 6 is a schematic structural diagram of the damping block of FIG. 3;

FIG. 7 is a schematic structural diagram of the base in FIG. 2;

fig. 8 is a top view of fig. 7.

In FIGS. 1-8:

1 tensioning arm, 11 tensioning wheel, 111 driving block and 112 matching groove;

2 damping block, 21 first ring groove, 22 second ring groove, 23 first block, 24 second block, 25 opening;

3, a base, a 31 installation cylinder, a 32 first fixing groove, a 33 second fixing groove and a 34 bottom plate;

4 big springs, 5 small springs, 6 pin shafts and 7 bushings.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1-8, wherein fig. 1 is an assembly view of an accessory tensioner of the present invention in one embodiment; FIG. 2 is an exploded view of FIG. 1; FIG. 3 is a schematic diagram of the construction of the tension arm assembly of FIG. 1; FIG. 4 is a schematic diagram of the tension arm assembly of FIG. 3 with two springs mounted;

FIG. 5 is a schematic diagram of the tensioner arm of FIG. 3; FIG. 6 is a schematic structural diagram of the damping block of FIG. 3;

FIG. 7 is a schematic structural diagram of the base in FIG. 2; fig. 8 is a top view of fig. 7.

In one embodiment, the present invention provides a belt tensioner for an engine, as shown in fig. 1 and 2, comprising a tensioner arm assembly and a base 3, and the tensioner arm assembly is capable of rotating relative to the base 3, and during rotation, tensioning of a belt is achieved. Meanwhile, the belt tensioner further comprises at least two springs, one end of each spring in the axial direction is fixed on the base 3, and the other end of each spring in the axial direction is used for being matched with the tensioning arm assembly, so that required tensioning force is provided for an engine belt.

When the tensioning arm assembly is in a working condition with a small swing angle, at least one spring is matched with the tensioning arm assembly, and when the tensioning arm assembly is in a working condition with a large swing angle, the number of the springs matched with the tensioning arm assembly is increased and is at least two.

Therefore, the belt tensioner can meet the tension force required by the engine under the working conditions of high rotating speed and low rotating speed, and meanwhile, when the engine is under the working condition of high rotating speed, the tension force provided by the belt tensioner is matched with the belt tensioner, so that the oil consumption of the engine under the working condition of high rotating speed, namely the working condition of small swing angle of the tension arm assembly, can be reduced.

It should be noted that, in the present invention, when the tensioning arm assembly is in a small swing angle working condition, the corresponding engine speed may be 2000rpm to 7000rpm, and when the tensioning arm assembly is in a large swing angle working condition, the corresponding engine speed may be 700 rpm to 2000 rpm. Of course, in actual use, the tensioning arm assembly can be set to be in the engine rotating speed range corresponding to the working condition of the small swing angle and the working condition of the large swing angle according to requirements.

Specifically, when the engine speed is reduced to be in a low-speed working condition and the required tension force is increased, the tension arm assembly rotates along the rotating direction of the tension arm assembly, and the swing angle is increased. The tensioning arm component is provided with at least two stop blocks, and the spring end part of each spring is positioned in the rotating path of the corresponding stop block, so that the number of the stop blocks and the spring end parts which are correspondingly abutted is increased in the rotating process of the tensioning arm component along the rotating direction of the tensioning arm component. Typically, the spring is formed by a wire wrap, and thus, the spring end refers to the end of the wire that is wrapped to form the spring.

So set up, link to each other and pass the tensile force between tensioning arm subassembly and the base 3 through the spring, specifically, tensioning arm subassembly and spring pass through the dog and the spring end links to each other, and when the two offseted, the resilience force of spring provides belt tensioner's tensile force.

Further, as shown in fig. 2 and 3, the tensioner arm assembly comprises a tensioner arm 1 and a damping block 2 connected with each other, wherein the damping block 2 is located between a tensioner 11 of the tensioner arm 1 and a base 3, and when the tensioner arm 1 rotates along the above-mentioned rotation direction, the damping block 2 can be driven to rotate, and a friction pair is formed between the damping block and the base, so that the damping block 2 can play a role of friction damping, thereby damping the vibration when the tensioner arm 1 swings relative to the base 3.

Further, as shown in fig. 4, the base 3 is fixed with a large spring 4 and a small spring 5 which are sleeved with each other, i.e. the large spring 4 with a larger diameter is sleeved on the outer periphery of the small spring 5 with a smaller diameter, and as shown in fig. 6, the damping block 2 has a first stop 23 and a second stop 24.

When the engine is in a high rotating speed working condition and the tension arm assembly of the belt tensioner is in a small swing angle working condition, the second stop block 24 is abutted against the end part of the spring of the small spring 5, a preset distance is reserved between the first stop block 23 and the end part of the spring of the large spring 4, namely the first stop block and the large spring are not abutted, and at the moment, only the small spring 5 is used for providing the tension force of the belt tensioner, so that the belt tensioner is applicable to the low rotating speed working condition of the engine and saves oil consumption under the working condition.

When the engine is in the low rotational speed operating mode, when belt tensioner's tensioning arm subassembly is in big swing angle operating mode, second dog 24 offsets with little spring 5's spring tip, and first dog 23 offsets with big spring 4's spring tip, and at this moment, big spring 4 all is used for providing belt tensioner's tensile force with little spring 5 to can provide great tensile force, be applicable to the low rotational speed operating mode of engine.

In addition, when the rotating speed of the engine is reduced, the swing angle of the tension arm assembly of the belt tensioner can be automatically increased, namely the tension arm assembly of the belt tensioner can be automatically switched between the working condition with the small swing angle and the working condition with the large swing angle without additionally arranging a driving part, so that the belt tensioner also has the advantage of simple structure.

Specifically, in the embodiment shown in fig. 4 and 5, the spring ends of the large spring 4 and the small spring 5 are located on the same radius of the tension pulley 11, and meanwhile, the first stopper 23 and the second stopper 24 are located on different radii of the damping block 2, and the first stopper 23 is located downstream of the second stopper 24 along the rotation direction, so that only the second stopper 24 abuts against the spring end of the small spring 5 when the tension arm assembly is in the working condition of small swing angle, and when the tension arm assembly is in the working condition of large swing angle, the first stopper 23 abuts against the spring end of the large spring 4 in addition to the second stopper 24 abutting against the spring end of the small spring 5.

Of course, more than two springs which are mutually sleeved can be arranged in the invention, and the number of the springs which are abutted against the damping block 2 is increased along with the gradual increase of the swing angle of the tensioning arm component so as to adapt to different working conditions of the engine.

Specifically, as shown in fig. 6, the damping block 2 is provided with a first annular groove 21 and a second annular groove 22, the first annular groove 21 is provided at the periphery of the second annular groove 22, the first stopper 23 is provided in the first annular groove 21, the second stopper 24 is provided in the second annular groove 22, one end of the large spring 4 in the axial direction is fixed to the base 3, the other end of the large spring is located in the first annular groove 21, one end of the small spring 5 in the axial direction is fixed to the base 3, and the other end of the small spring is located in the second annular groove 22.

In this embodiment, the first annular groove 21 and the second annular groove 22 are provided, so that the large spring 4 and the small spring 5 can be respectively located in the two annular grooves, thereby improving the matching reliability between the two springs and the damping block 2, ensuring that the deformation direction of the springs is controllable when the swing angle of the tensioning arm assembly is changed, and improving the working reliability of the belt tensioner.

On the other hand, as shown in fig. 7 and 8, the base 3 has a cylindrical mounting cylinder 31 and a bottom plate 34, wherein the mounting cylinder 31 is used for accommodating the large spring 4 and the small spring 5, and the bottom plate 34 is used for connecting with the engine. The bottom of the installation barrel 31 is provided with a first fixing groove 32 and a second fixing groove 33 which are annular, the first fixing groove 32 is located on the periphery of the second fixing groove 33, one end of the large spring 4 in the axial direction is fixed in the first fixing groove 32, one end of the small spring 5 in the axial direction is fixed in the second fixing groove 33, and therefore the large spring 4, the small spring 5 and the base 3 are connected.

Meanwhile, in the present embodiment, similarly to the two annular grooves provided in the damping block 2, the two fixing grooves provided in the base 3 can also promote the stability of the spring deformation, thereby improving the operational stability of the belt tensioner.

In the above embodiments, as shown in fig. 5, the tensioning wheel 11 of the tensioning arm 1 has the fan-shaped driving block 111 and the fan-shaped engaging groove 112 is opened, and as shown in fig. 6, the damping block 2 has the fan-shaped opening 25 adapted to the driving block 111, the damping block 2 is located in the engaging groove 112 of the tensioning wheel 11, and the circumferential side wall of the opening 25 abuts against the circumferential side wall of the driving block 111, so that the damping block 2 is connected to the tensioning arm 1, and when the tensioning arm 1 rotates, the driving block 111 drives the damping block 2 to rotate.

Meanwhile, as shown in fig. 1 and 2, the belt tensioner further comprises a pin shaft 6, correspondingly, as shown in fig. 5-8, concentric center holes are formed in the tensioning arm 1, the damping block 2 and the base 3, the pin shaft 6 penetrates through the center holes of the tensioning arm 1, the damping block 2 and the base 3, the tensioning arm assembly can rotate around the pin shaft 6, and as shown in fig. 2, a bushing 7 is arranged between the pin shaft 6 and each center hole, and the bushing 7 can reduce the friction coefficient between the tensioning arm 1 and the pin shaft 6, so that abrasion is reduced.

In addition, the invention also provides an engine which comprises a machine body and the belt tensioner, wherein when the engine is in a high rotating speed working condition, the tension arm assembly of the belt tensioner is in a small oscillating angle working condition, and when the engine is in a low rotating speed working condition, the tension arm assembly of the belt tensioner is in a large oscillating angle working condition.

Wherein, the belt tensioner is the belt tensioner described in any of the above embodiments, and since the belt tensioner has the above technical effects, an engine including the belt tensioner should also have corresponding technical effects, and the description thereof is omitted.

The engine and belt tensioner thereof provided by the present invention have been described in detail above. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. A belt tensioner for an engine, characterized by comprising a tensioning arm assembly and a base (3), wherein the tensioning arm assembly can rotate relative to the base (3), and at least two springs, wherein one end of each spring in the axial direction is fixed on the base (3), and the other end of each spring is used for being matched with the tensioning arm assembly;

when the tensioning arm assembly is in a working condition with a small swing angle, at least one spring is matched with the tensioning arm assembly, and when the tensioning arm assembly is in a working condition with a large swing angle, the number of the springs matched with the tensioning arm assembly is increased to be at least two;

when the engine is in a low-rotation-speed working condition, the tensioning arm assembly rotates along the rotation direction of the tensioning arm assembly, the swing angle is increased, the tensioning arm assembly is provided with at least two stop blocks, and the spring end part of each spring is positioned in a rotation path corresponding to the stop blocks, so that the number of the stop blocks and the spring end parts which are correspondingly abutted against each other is increased in the rotation process of the tensioning arm assembly along the rotation direction;

the tensioning arm assembly comprises a tensioning arm (1) and a damping block (2) which are connected, the damping block (2) is located between a tensioning wheel (11) of the tensioning arm (1) and the base (3), a friction pair is formed between the damping block (2) and the tensioning wheel (11), and the tensioning arm (1) can drive the damping block (2) to rotate when rotating along the rotating direction;

a large spring (4) and a small spring (5) which are sleeved with each other are fixed on the base (3), and the damping block (2) is provided with a first stop block (23) and a second stop block (24);

when the tensioning arm assembly is in a working condition with a small swinging angle, the second stop block (24) is abutted against the spring end part of the small spring (5), and a preset distance is reserved between the first stop block (23) and the spring end part of the large spring (4); when the tensioning arm assembly is in a working condition with a large swinging angle, the second stop block (24) is abutted against the spring end part of the small spring (5), and the first stop block (23) is abutted against the spring end part of the large spring (4).

2. Belt tensioner according to claim 1, characterized in that the spring ends of both the large spring (4) and the small spring (5) are located on the same radius of the damping mass (2), the first stop (23) and the second stop (24) are located on different radii of the damping mass (2), respectively, and the first stop (23) is located downstream of the second stop (24) in the direction of rotation.

3. The belt tensioner according to claim 1, wherein the damping block (2) is provided with a first annular groove (21) and a second annular groove (22), the first annular groove (21) is internally provided with the first stop (23), the second annular groove (22) is internally provided with the second stop (24), one axial end of the large spring (4) is fixed to the base (3), the other axial end of the large spring is located in the first annular groove (21), one axial end of the small spring (5) is fixed to the base (3), and the other axial end of the small spring is located in the second annular groove (22).

4. The belt tensioner according to claim 1, wherein said base (3) has a cylindrical mounting cylinder (31), a first fixing groove (32) and a second fixing groove (33) having a ring shape are provided at the bottom of said mounting cylinder (31), one end of said large spring (4) in the axial direction is fixed in said first fixing groove (32), and one end of said small spring (5) in the axial direction is fixed in said second fixing groove (33).

5. The belt tensioner according to any of claims 1-4, characterized in that the tensioning wheel (11) has a fan-shaped driving block (111) and is provided with a fitting groove (112) adapted to the damping block (2), the damping block (2) has a fan-shaped opening (25) adapted to the driving block (111), the damping block (2) is located in the fitting groove (112), and a circumferential side wall of the opening (25) abuts against a circumferential side wall of the driving block (111), so that the tensioning arm (1) drives the damping block (2) to rotate through the driving block (111).

6. A belt tensioner according to any one of claims 1 to 4, further comprising a pin (6), said pin (6) passing through the central holes of said tensioning arm assembly and said base (3), and said tensioning arm assembly being rotatable about said pin (6);

and a bushing (7) is arranged between the pin shaft (6) and each central hole.

7. An engine comprises a machine body and a belt tensioner, and is characterized in that when the engine is in a high rotating speed working condition, a tensioning arm assembly of the belt tensioner is in a small oscillating angle working condition, and when the engine is in a low rotating speed working condition, the tensioning arm assembly is in a large oscillating angle working condition;

the belt tensioner is the belt tensioner of any one of claims 1 to 6.