CN110185756B

CN110185756B - Engine transmission system tensioner and engine

Info

Publication number: CN110185756B
Application number: CN201910474639.6A
Authority: CN
Inventors: 张超; 杨林强; 王军; 穆立侠; 常耀红; 赵真真; 卓丽颖; 陈庚; 雷蕾; 倪成鑫; 李渊
Original assignee: Anhui Jianghuai Automobile Group Corp
Current assignee: Anhui Jianghuai Automobile Group Corp
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2021-03-30
Anticipated expiration: 2039-05-31
Also published as: CN110185756A

Abstract

The invention discloses an engine transmission system tensioner and an engine, wherein the engine transmission system tensioner comprises a base, a pivot, a swing arm and a damping component, wherein the lower end of the pivot is fixedly connected with the base; the swing arm is rotatably sleeved on the pivot, and an annular cavity is formed in the swing arm to divide the lower section of the swing arm into an outer ring and an inner ring; the damping assembly is at least partially sleeved on the inner ring, the damping assembly interferes with the pivot in the rotating process of the swing arm, and the interference amount of the damping assembly and the pivot is gradually increased in the reverse rotating process of the swing arm and is gradually reduced in the forward rotating process of the swing arm. According to the invention, different interference amounts can be formed between the swing arm and the pivot under different rotation states by arranging the damping assembly, and when the swing arm rotates in the reverse direction, the interference amount is gradually increased, so that the continuous rotation of the swing arm is inhibited; on the contrary, when the swing arm rotates along the forward direction, the interference amount is gradually reduced, so that the quick adjustment of the swing arm is facilitated, and the sufficient rotation response capability is provided.

Description

Engine transmission system tensioner and engine

Technical Field

The invention relates to the technical field of vehicle engines, in particular to the technical field of transmission equipment of vehicle engines, and particularly relates to an engine transmission system tensioner and a vehicle.

Background

Timing systems are typically provided in internal combustion engine configurations of modern vehicles. A crankshaft in the timing system controls the opening and closing of an intake valve and an exhaust valve by driving a camshaft to rotate, realizes the cooperation of the crankshaft and the camshaft, and coordinates with the intake stroke and the exhaust stroke to organize the inlet and the outlet of working media and exchange, thereby providing guarantee and conditions for the working cycle of the engine. Timing systems can be classified into three types, i.e., chain systems, toothed belt systems, and gear systems, depending on the connection method. With the requirements of light weight and vibration noise of engines, gear and gear transmission is gradually eliminated, and chains and toothed belts become mainstream. The belt is one of the mainstream transmission forms of the timing system, and is widely applied to modern engine products due to small abrasion, small elongation and low working noise after long-term working.

In order to realize accurate phase control and ensure that a crankshaft and a camshaft can be synchronous in work, a belt on each span is required to be properly tensioned, and the phenomenon that the working cycle of an engine is influenced due to the fact that a belt section is loosened is avoided. The tensioner is a mechanism capable of automatically balancing belt tension, can compensate when the belt tension is low, and can unload when the belt tension is high, so that the belt can maintain a stable tensioning level under different working conditions.

A conventional tensioner generally includes a base, a swing arm, and a spring positioned between the base and the swing arm, the spring having one end connected to the base and the other end connected to the swing arm, and applying a torque to the swing arm to enable the swing arm to deflect the swing arm. Generally, the direction of increasing the belt tension is defined as the reverse direction and the direction of decreasing the belt tension is defined as the forward direction during the swing arm rotates around the base.

The tensioner utilizes a spring to generate rotational motion against the swing arm. To achieve an effective damping effect, the stiffness of the spring may be increased, but this may cause the system to withstand a high-strength resisting torque under small fluctuations or near-static conditions, affecting the system life and durability; the friction surface and the friction plate can be added in the automatic tensioner, a damping effect is generated by using the friction device, the relative rotation between the swing arm and the base can be well inhibited, but the forward rotation response capability of the tensioner is reduced due to overlarge working damping, and the rebound after compression is delayed; the insufficient or small damping causes the reverse rotation response of the tensioner to be increased, the stroke of the swing arm is increased, and meanwhile, the resistance to system fluctuation can be reduced, and the performance of stabilizing the belt tension is insufficient.

Disclosure of Invention

The invention mainly aims to provide an engine transmission system tensioner and an engine, and aims to solve the problems that a traditional automatic tensioner is low in forward rotation response capability of a swing arm and poor in reverse rotation inhibition effect.

To achieve the above object, the present invention provides an engine transmission system tensioner, comprising:

a base;

the lower end of the pivot is fixedly connected to the base;

the swing arm is rotatably sleeved on the pivot, and an annular cavity which is arranged to the lower end of the swing arm in a consistent mode is formed in the swing arm so as to divide the lower section of the swing arm into an outer ring and an inner ring; and the number of the first and second groups,

the damping assembly is at least partially sleeved on the inner ring, the damping assembly interferes with the pivot in the rotating process of the swing arm, and the interference amount of the damping assembly and the pivot is gradually increased in the reverse rotating process of the swing arm and is gradually reduced in the forward rotating process of the swing arm.

Optionally, the damping assembly comprises:

the upper section of the pivot friction ring is sleeved on the inner ring, and the lower section of the pivot friction ring extends out of the annular cavity and is sleeved on the pivot;

the elastic bowl ring is arranged on the base, is arranged below the pivot friction ring and is sleeved on the pivot;

the first elastic piece is sleeved on the inner ring, and the upper end of the first elastic piece is connected with the swing arm; and the number of the first and second groups,

the pivot friction ring is sleeved with the second elastic piece, the upper end of the second elastic piece is connected with the lower end of the first elastic piece, and the lower end of the second elastic piece is connected with the elastic bowl ring;

wherein the first elastic member has a stiffness less than a stiffness of the second elastic member.

Optionally, the stiffness of the first elastic member and/or the stiffness of the second elastic member are/is arranged in a gradient increasing manner from top to bottom.

Optionally, the rigidity of the material of the first elastic member is less than the rigidity of the material of the second elastic member.

Optionally, the damping assembly includes three springs, the three springs have equivalent stiffness, one of the three springs constitutes the first elastic member, and the remaining two of the three springs constitute the second elastic member after being connected in parallel.

Optionally, the damping assembly further includes a connecting sleeve, the connecting sleeve is rotatably sleeved on the inner ring, an annular step is formed on a side surface of a lower section of the connecting sleeve in an outward protruding manner, and a lower end surface of the annular step abuts against an upper end surface of the pivot friction ring;

the first elastic piece is sleeved on the upper section of the connecting sleeve, and the lower end of the first elastic piece and the upper end of the second elastic piece are fixedly connected to the annular step respectively.

Optionally, the inner diameter of the first elastic element is larger than the outer diameter of the upper section of the connecting sleeve; and/or the presence of a gas in the gas,

the inner diameter of the second elastic element is equivalent to the outer diameter of the pivot friction ring.

Optionally, one of the swing arm and the first elastic piece is provided with a positioning structure, and the other is provided with a matching structure; and/or the presence of a gas in the gas,

one of the first elastic piece and the connecting sleeve is provided with a positioning structure, and the other one is provided with a matching structure; and/or the presence of a gas in the gas,

one of the connecting sleeve and the second elastic piece is provided with a positioning structure, and the other one is provided with a matching structure; and/or the presence of a gas in the gas,

one of the second elastic piece and the elastic bowl ring is provided with a positioning structure, and the other elastic piece and the elastic bowl ring are provided with a matching structure;

wherein, the positioning structure and the matching structure are mutually connected and matched.

Optionally, one of the positioning structure and the mating structure is a positioning concave part, and the other is a positioning convex part.

Furthermore, the present invention also provides an engine, characterized by comprising an engine drive system tensioner, the engine drive system tensioner comprising:

a base;

the lower end of the pivot is fixedly connected to the base;

According to the technical scheme provided by the invention, different interference amounts can be formed between the swing arm and the pivot under different rotation states of the swing arm by arranging the damping assembly, and when the swing arm rotates in the reverse direction, the interference amount is gradually increased, so that a restraining effect is generated on the continuous rotation of the swing arm; on the contrary, when the swing arm rotates in the forward direction, the interference amount is gradually reduced, so that the quick adjustment of the swing arm is facilitated, and the rotation response capability is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic perspective view of one embodiment of an engine drive system tensioner provided by the present invention;

FIG. 2 is a schematic illustration of the explosive structure of FIG. 1;

FIG. 3 is a schematic view from another perspective of the explosive structure of FIG. 1;

FIG. 4 is a schematic longitudinal sectional view of FIG. 1;

fig. 5 is a schematic structural view of the elastic bowl ring in fig. 1.

The reference numbers illustrate:

the implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" appearing throughout includes three juxtapositions, exemplified by "A and/or B" including either A or B or both A and B. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

In view of the above, the present invention provides an engine including a conventional system tensioner of an engine, and fig. 1 to 5 show an embodiment of a tensioner of an engine transmission system, and since the main inventive point of the present invention is to improve the tensioner 100 of the engine transmission system, the tensioner 100 of the engine transmission system will be mainly described with reference to the specific drawings.

Referring to fig. 1, 2 and 4, the tensioner 100 of the present invention for an engine transmission system comprises a base 2, a pivot 3, a swing arm 4 and a damping assembly 5, wherein the lower end of the pivot 3 is fixedly connected to the base 2; the swing arm 4 is rotatably sleeved on the pivot 3, and an annular cavity 41 penetrating to the lower end of the swing arm 4 is formed in the swing arm 4 to divide the lower section of the swing arm 4 into an outer ring 421 and an inner ring 422; the damping assembly 5 is at least partially disposed in the annular cavity 41 and sleeved on the inner ring 422, the damping assembly 5 interferes with the pivot 3 in the rotation process of the swing arm 4, and the interference amount of the damping assembly 5 and the pivot is gradually increased in the reverse rotation process of the swing arm 4 and gradually decreased in the forward rotation process of the swing arm 4.

In the technical scheme provided by the invention, different interference amounts can be formed between the damping assembly 5 and the pivot shaft 3 in different rotation states of the swing arm 4, and when the swing arm 4 rotates in the reverse direction, the interference amount is gradually increased, so that a restraining effect is generated on the continuous rotation of the swing arm 4; on the contrary, when the swing arm 4 rotates in the forward direction, the interference amount is gradually reduced, thereby facilitating the quick adjustment of the swing arm 4 and having sufficient rotation response capability.

The up-down direction in this embodiment refers to the length extending direction of the pivot 3, wherein the side of the pivot 3 close to the base 2 is the lower side, and the side far away from the base 2 is the upper side. The shape of the pivot 3 is not limited to a straight tube shape, and may be adaptively adjusted according to other structures related to the assembly thereof.

In addition, engine transmission system tensioner 100 also generally includes belt pulley 1, belt pulley 1 is the tube-shape, belt pulley 1 is used for supplying the belt to wind, belt pulley 1's inside is formed with and holds the chamber, hold the chamber and be used for holding at least swing arm 4 with pivot 3. The swing arm 4 is in a step shape with a small upper part and a large lower part to form a shoulder, and the belt pulley 1 is sleeved on the shoulder through a bearing 11 to realize the transmission of torque between the belt pulley 1 and the swing arm 4. At this time, the central axis of the pivot 3 is defined as a first axis a1, and the central axis of the swing arm 4 is defined as a second axis a2, so that the first axis a1 coincides with the central axes of the base 2 and the pulley 1 and deviates from the second axis a2, thereby enabling the swing arm 4 to deflect relative to the base 2. Wherein the annular cavity 41 is centered on the first axis a 1. In the engine transmission system tensioner 100, the specific structure and installation manner of the base 2, the pivot shaft 3, the swing arm 4, the pulley 1 and other cooperating mechanisms can refer to the prior art and will not be described in detail herein.

The damping assembly 5 for achieving the above-mentioned functions can specifically refer to fig. 2 to 3, the damping assembly 5 includes a pivot friction ring 51, an elastic bowl ring 52, a first elastic member 53 and a second elastic member 54, an upper section of the pivot friction ring 51 is disposed in the annular cavity 41 and sleeved on the inner ring 422, and a lower section of the pivot friction ring 51 extends out of the annular cavity 41 and is sleeved on the pivot 3; the elastic bowl ring 52 is disposed on the base 2, the elastic bowl ring 52 is disposed below the pivot friction ring 51 and is sleeved on the pivot 3, and the elastic bowl ring 52 is shaped like an inverted bowl, and thus has an elastically deformable inclined section 521. The pivot friction ring 51 and the elastic bowl ring 52 are both existing products, and the specific structure can refer to the prior art. The first elastic member 53 is disposed in the annular cavity 41 and sleeved on the inner ring 422, and the upper end of the first elastic member 53 is connected to the swing arm 4; the second elastic element 54 is disposed in the annular cavity 41 and sleeved on the pivot friction ring 51, the upper end of the second elastic element 54 is connected to the lower end of the first elastic element 53, and the lower end of the second elastic element 54 is connected to the elastic bowl ring 52; wherein the first elastic member 53 has a rigidity lower than that of the second elastic member 54. The first elastic member 53 and the second elastic member 54 may be embodied in a spring member or a rubber member, for example, without limitation. Taking the first elastic member 53 and the second elastic member 54 as spring members as an example, during the operation of the tensioner 100 of the engine transmission system, since the stiffness of the first elastic member 53 is small, the rotation compression amount and the rotation angle after being stressed are large, the first elastic member 53 mainly bears the stiffness response of the moment fluctuation on the swing arm 4, and when the moment is sequentially transmitted to the pivot friction ring 51 and the elastic bowl ring 52, the damping effect on the pivot 3 is enhanced, and the damping effect can be used for adjusting and responding to the external load change of the swing arm 4; the second elastic part 54 mainly plays a role in damping the moment fluctuation acting on the swing arm 4, and is helpful to sequentially reduce the moment on the elastic bowl ring 52 and the pivot friction ring 51, so as to reduce the damping effect on the pivot 3, and can be used for generating system damping. Since the second elastic member 54 is used for controlling the positive pressure of the pivot friction ring 51 and the elastic bowl ring 52, an excessive deformation may cause an excessive variation of the positive pressure, and even cause the swing arm 4 to be stuck, and the like, and therefore, the second elastic member 54 needs to have a larger rigidity. So configured, the cooperation of the first elastic member 53 and the second elastic member 54 helps to improve the stability of the engine transmission system tensioner 100 against belt tension adjustment.

Further, in the present embodiment, the stiffness of the first elastic member 53 and/or the stiffness of the second elastic member 54 are set to increase from top to bottom in a gradient manner. On the premise of ensuring that the rigidity of the first elastic member 53 is less than the rigidity of the second elastic member 54, the number of divisions of the steps is not limited, for example, the whole first elastic member 53 may be provided with only one step, or the first elastic member 53 may be divided into a plurality of steps from top to bottom, so that the rigidity of the first elastic member 53 is gradually changed; the second elastic element 54 has the same structure and will not be described in detail. When the first elastic member 53 and the second elastic member 54 are divided into a plurality of steps, respectively, the maximum stiffness of the first elastic member 53 is set to be smaller than the minimum stiffness of the second elastic member 54. Under the incremental step, when the swing arm 4 rotates reversely, the first elastic member 53 forms a gradually increasing rotational deformation from bottom to top, and then outputs a stably changing torque, so that the reverse rotation response is stably enhanced; on the contrary, when the swing arm 4 rotates in the forward direction, the second elastic member 54 forms a gradually decreasing rotational deformation from top to bottom, and the damping acting on the swing arm 4 is stably decreased, so that the forward rotational response is stably enhanced.

In the present invention, there are various technical solutions for changing the stiffness, wherein the most convenient technical solution for the user is to set the stiffness of the material of the first elastic member 53 to be smaller than the stiffness of the material of the second elastic member 54. It should be noted that the first elastic member 53 and the second elastic member 54 may be made of the same material, for example, the first elastic member 53 and the second elastic member 54 are made of metal material, and different stiffness can be obtained by adjusting different dimensions or other parameters of the metal material, which may refer to the prior art; alternatively, the first elastic member 53 and the second elastic member 54 are made of different materials, such as a metal material and a rubber material, respectively, and have different rigidities correspondingly, and the specific correspondence relationship can refer to the prior art. With such an arrangement, the installation manner of the damping assembly 5 can be simplified, and when the damping assembly 5 is abnormal, a user only needs to detach and replace the corresponding first elastic member 53 and the second elastic member 54, so that the operation is simple and convenient.

Of course, the rigidity of the first elastic member 53 and the second elastic member 54 may be equivalent rigidity. Specifically, for example, the damping assembly 5 includes three springs (not shown in the drawings), the three springs have equivalent stiffness, the upper end of one of the three springs is connected to the swing arm 4 to form the first elastic member 53, the remaining two springs of the three springs are connected in parallel, that is, the two springs are connected end to end, respectively, then the upper ends of the two springs connected in parallel are connected to the lower end of the spring of the first elastic member 53, and the lower ends of the two springs connected in parallel are connected to the elastic bowl ring 52. The stiffness is comparable, meaning that the stiffness is not very different but approximately the same, or the stiffness is the same. As can be seen from the mechanical properties of the spring, if the stiffness of the spring is K, when the length L is stretched, the total force F of the second elastic member 54 is KL + KL, that is, the equivalent stiffness K1 of the second elastic member 54 is F/L2K, which is greater than the stiffness K of the first elastic member 53, which proves that the stiffness of the first elastic member 53 and the second elastic member 54 can be set as described above. Of course, the three springs do not limit the first elastic element 53 and the second elastic element 54, and other numbers of springs or elastic members similar to the deformation principle of the springs may be used, and the desired stiffness relationship may be obtained by combining the springs in series and in parallel, which is within the scope of the present invention.

In addition, the first elastic element 53 and the second elastic element 54 can be directly connected in series, for example, by welding, but in order to facilitate the independent dismounting and replacing of the first elastic element 53 or the second elastic element 54, please refer to fig. 2 and fig. 4, in this embodiment, the damping assembly 5 further includes a connecting sleeve 55, the connecting sleeve 55 is rotatably sleeved on the inner ring 422, a side surface of a lower section of the connecting sleeve 55 is protruded outward to form an annular step 551, and a lower end surface of the annular step 551 abuts against an upper end surface of the pivot friction ring 51; the first elastic member 53 is sleeved on the upper section of the connecting sleeve 55, the lower end of the first elastic member 53 is fixedly connected to the annular step 551, for example, is fixedly connected to the upper end surface of the annular step 551, and the upper end of the second elastic member 54 is fixedly connected to the annular step 551, for example, is fixedly connected to the lower end surface of the annular step 551. The arrangement is such that the connection sleeve 55 can realize the series connection between the first elastic member 53 and the second elastic member 54 to transmit the torque therebetween, and can ensure the independence of installation of the first elastic member 53 and the second elastic member 54, thereby facilitating the independent assembly and disassembly.

Because the rigidity of the first elastic part 53 is small, the rotational deformation after the stress is large, and the inner diameter of the first elastic part 53 is larger than the outer diameter of the upper section of the connecting sleeve 55, a sufficient space can be reserved for the deformation of the first elastic part 53, so that the mutual abrasion between the first elastic part 53 and the connecting sleeve 55 is reduced, and the service life of the first elastic part 53 is prolonged; in addition, after the second elastic member 54 is deformed by force, the pivot friction ring 51 is pressed radially by applying force to the pivot friction ring 51 so as to deform, thereby increasing the sliding friction of the pivot friction ring 51 on the inner ring 422, and achieving the purpose of increasing the rotational damping of the swing arm 4, therefore, the inner diameter of the second elastic member 54 can be set to be equal to the outer diameter of the pivot friction ring 51, and the equal refers to that the two are not greatly different but approximately the same or the same. With this arrangement, the second elastic member 54 can abut against the pivot friction ring 51 and apply a force to the pivot friction ring 51 after being deformed to an appropriate degree, that is, after being reduced in diameter and stretched in length to a small degree, thereby increasing the rotational response speed. Of course, both of the above-described solutions may be employed simultaneously to enhance the belt tightness adjustment effect of the engine driveline tensioner 100.

Next, referring to fig. 2, fig. 3 and fig. 5, in the present embodiment, one of the swing arm 4 and the first elastic element 53 is provided with a positioning structure, and the other is provided with a matching structure; and/or, one of the first elastic piece 53 and the connecting sleeve 55 is provided with a positioning structure, and the other is provided with a matching structure; and/or, one of the connecting sleeve 55 and the second elastic element 54 is provided with a positioning structure, and the other is provided with a matching structure; and/or one of the second elastic element 54 and the elastic bowl ring 52 is provided with a positioning structure, and the other is provided with a matching structure, wherein the positioning structure and the matching structure are connected and matched with each other. It should be noted that the positioning structure and the matching structure between the swing arm 4 and the first elastic member 53, between the first elastic member 53 and the connecting sleeve 55, between the connecting sleeve 55 and the second elastic member 54, and between the second elastic member 54 and the elastic bowl ring 52 may be the same, which is equivalent to forming a standard component, so as to facilitate direct replacement; at least part of the components may be arranged differently to adapt to different structural shapes and stress conditions of the components, which will not be described in detail herein.

Of course, there are various technical solutions for the positioning structure and the matching structure to achieve the above functions, such as a screwed connection fixing, etc., but considering that the movement form inside the engine transmission system tensioner 100 is single and basically only rotates in the forward direction or the reverse direction, preferably, one of the positioning structure and the matching structure may be configured as a positioning concave portion, and the other is configured as a positioning protrusion, and the positioning concave portion and the positioning protrusion have the advantages of simple structure and convenient forming, and the limit between the two connected members can be achieved through the concave-convex matching between the positioning concave portion and the positioning protrusion. The positioning structure may be embodied as, for example, a first bayonet 611 disposed on the swing arm 4, a second bayonet 612 disposed on the upper end surface of the connecting sleeve 55, a third bayonet 613 disposed on the lower end surface of the connecting sleeve 55, and a fourth bayonet 614 disposed on the elastic bowl ring 52, where the positioning structure includes at least two limiting blocks, and the two limiting blocks are disposed at an interval to define a slot at the interval; when the first elastic member 53 and the second elastic member 54 are both springs, correspondingly, the matching structure may be embodied as a first bending portion 621 protruding from the upper end of the first elastic member 53, a second bending portion 622 protruding from the lower end of the first elastic member 53, a third bending portion 623 protruding from the upper end of the second elastic member 54, and a fourth bending portion 624 protruding from the lower end of the second elastic member 54. At this time, the matching structure can be limited after being inserted into the slot of the positioning structure.

In a specific application, at the beginning of assembling the engine transmission system tensioner 100, the swing arm 4 rotates around the first axis a1, and the first elastic element 53 is driven to rotate by the insertion of the first bayonet 611 and the first bending part 621; then, the second bayonet 612 is inserted into the second bending portion 622 to drive the connecting sleeve 55 to rotate; then, the second elastic element 54 is driven to rotate by the insertion of the third bayonet 613 and the third bending portion 623; finally, through the insertion of the fourth bayonet 614 and the fourth bending portion 624, the torque is transmitted to the elastic bowl ring 52, and the elastic bowl ring 52 and the base 2 cannot rotate relatively due to the constraint assembly, so that the second elastic member 54 and the first elastic member 53 deform, and finally the torque of the swing arm 4 deflection is formed.

And when the engine drive system tensioner 100 is operating, the tension in the belt begins to fluctuate. When the swing arm 4 rotates in the opposite direction, that is, in the direction of increasing the belt tension, the first elastic member 53 is forced to twist, so that a large rotational deformation is generated, and the output torque is increased; after the transmission of the connection sleeve 55, the second elastic member 54 is driven to twist, so that the diameter of the second elastic member 54 is reduced, and the pivot friction ring 51 penetrating the inner side of the second elastic member 54 is deformed by bearing radial pressure, and then abuts against and applies pressure to the inner ring 422 of the swing arm 4. The swing arm 4 has a rotation speed relative to the pivot friction ring 51, so that sliding friction is formed between the pivot friction ring 51 and the inner ring 422, and as the radial pressure is increased, the sliding friction force is also increased correspondingly, and the damping effect is enhanced. Meanwhile, the second elastic part 54 is stretched in length after being stressed and downwards presses the elastic bowl ring 52, so that the inclined section 521 of the elastic bowl ring 52 is elastically deformed due to stress and expanded, at the moment, the outer wall surface of the elastic bowl ring 52 compresses the outer ring 421 of the swing arm 4, the normal load on the friction pair is increased, the friction force is increased, and the damping effect is further enhanced. In this way, by enhancing the damping effect after the belt tension increases, the swing of the swing arm 4 is suppressed, and the working swing angle of the engine transmission system tensioner 100 is reduced.

On the contrary, when the swing arm 4 rotates in the forward direction, that is, rotates in the direction of reducing the belt tension, the external load borne by the first elastic member 53 is reduced, the resultant torque does not reach the balance, and the first elastic member 53 is urged to rebound and unscrew; after the transmission of the connection sleeve 55, the tightening torque of the second elastic member 54 is also reduced, which causes the second elastic member 54 to rotate moderately and the diameter to increase, so that the pivot friction ring 51 penetrating the inner side of the second elastic member 54 is reset, the normal load between the friction pairs is reduced, and the damping effect is weakened. Meanwhile, as the length of the second elastic member 54 is shortened, the elastic bowl ring 52 is released from being pressed to rebound, the load part of the outer ring 421 of the swing arm 4 pressed by the outer wall surface of the elastic bowl ring 52 is released, the friction force is reduced, and the damping effect is further weakened. With such an arrangement, after the belt tension is reduced, the rebound of the engine transmission system tensioner 100 can be accelerated by weakening the damping effect of the engine transmission system tensioner 100, and the forward rotation response of the engine transmission system tensioner 100 is improved.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. An engine drive system tensioner, comprising:

a base;

the lower end of the pivot is fixedly connected to the base;

the swing arm is rotatably sleeved on the pivot, and an annular cavity which is arranged to the lower end of the swing arm in a consistent mode is formed inside the swing arm so as to divide the lower section of the swing arm into an outer ring and an inner ring; and the number of the first and second groups,

the damping assembly is at least partially sleeved on the inner ring, interferes with the pivot in the rotation process of the swing arm, and the interference amount of the damping assembly and the pivot is gradually increased in the reverse rotation process of the swing arm and gradually decreased in the forward rotation process of the swing arm;

wherein the damping assembly comprises:

the rigidity of the first elastic part is smaller than that of the second elastic part, and the rigidity of the first elastic part and/or the rigidity of the second elastic part are/is arranged in an increasing mode from top to bottom in a gradient mode.

2. The engine transmission system tensioner as set forth in claim 1, wherein the first resilient member is made of a material having a stiffness less than a stiffness of the second resilient member.

3. The engine driveline tensioner of claim 1, wherein the damping assembly comprises three springs, the three springs being of comparable stiffness, one of the three springs comprising the first resilient member, the remaining two of the three springs connected in parallel comprising the second resilient member.

4. The tensioner as claimed in claim 1, wherein the damping assembly further comprises a connecting sleeve rotatably sleeved on the inner ring, a side surface of a lower section of the connecting sleeve is provided with an annular step in a protruding manner, and a lower end surface of the annular step abuts against an upper end surface of the pivot friction ring;

5. The engine transmission system tensioner of claim 4, wherein the first elastic member has an inner diameter greater than an outer diameter of the upper section of the coupling sleeve; and/or the presence of a gas in the gas,

6. The engine transmission system tensioner as set forth in claim 4, wherein one of said swing arm and said first elastic member is provided with a positioning structure, and the other is provided with a mating structure; and/or the presence of a gas in the gas,

7. The engine transmission system tensioner as set forth in claim 6, wherein one of said positioning structure and said mating structure is a positioning recess and the other is a positioning projection.

8. An engine comprising an engine driveline tensioner as claimed in any one of claims 1 to 7.