Bidirectional tensioner with damping compensation function

Abstract

The bidirectional tensioner with the damping compensation function comprises a pivot structure, the pivot structure comprises an end cover, a spiral compression spring, a pivot and a friction ring, the spiral compression spring comprises a part A and a part B, the end cover comprises a conical transition part and a cylindrical part, a transition conical face is arranged on the inner side of the conical transition part, and a protruding ring is arranged at the bottom of the cylindrical part. A pivot connecting face and a spring abutting face are arranged on the protruding ring, the tensioning arm is hinged to the base through a pivot, and a friction ring is arranged between the tensioning arm and the base. The spiral compression spring is arranged between the pivot and the end cover in a sleeved mode, the end cover is in interference fit with the pivot through the pivot connecting face, the A portion abuts against the friction ring, the B portion abuts against the spring abutting face, the spiral compression spring is kept in a compressed state all the time, and the outer side of the B portion makes contact with the friction face of the end cover. Along with the increase of the abrasion loss of the friction ring, the spiral compression spring automatically extends, the axial friction force of the spring is reduced through the form change of the spring before and after abrasion, and damping force loss caused by abrasion is automatically compensated.

Description

Technical Field

[0001] The utility model relates to the technical field of tensioners, in particular to a bidirectional tensioner with a damping compensation function. Background Art

[0002] like Figure 1 As shown, in the automotive hybrid power system (hybrid system), the bidirectional tensioner 100 of the generator 200 is a specific device for the automotive generator. The design of the bidirectional tensioner 100 allows the tension of the transmission belt 300 to be automatically adjusted in two directions, as shown by the red arrows in the figure. When the engine is working, the tension of the transmission belt will also vary due to changes in engine load and speed. The bidirectional tensioner automatically adjusts its tension according to the state of the transmission belt on both sides of the generator through an elastic device and two tensioning arms, which can prevent the transmission belt from being loose or too tight, thereby extending the life of the transmission belt and ensuring the stable operation of the power system. This design is very common in modern cars because it can improve the reliability and efficiency of the generator system while reducing maintenance requirements.

[0003] Existing bidirectional tensioners such as Figure 2 As shown, it mainly includes two movable tensioning arms 1, 2, a base 3, a linear spring 5, and two pulleys 4a and 4b. The base 3 is fixed on the car, and the two movable tensioning arms 1, 2 are respectively hinged on the base 3 through pivot structures 6, 7. The other ends of the two tensioning arms are respectively hinged to pulleys 4a and 4b, and the linear spring 5 connects the other ends of the two tensioning arms 1, 2. When the tension of the transmission belt changes or vibrates due to changes in the engine working conditions, the working torque applied by the transmission belt to the tensioner (i.e., the torque of the pulley on the way relative to the pivot structure) changes significantly, and the linear spring will automatically compress or extend, causing the tensioning arm to rotate around the pivot structure, and automatically adjusting the belt tension at both ends of the generator pulley.

[0004] In order to suppress the swing amplitude and frequency of the tension arm, the existing bidirectional tensioner generally sets a damping component in the pivot structure. The damping component provides friction reaction force during the swing of the tension arm, moderately constrains the rotation of the tension arm, and makes the operation of the transmission belt more stable. However, during the operation of the transmission belt, due to reasons such as engine torsional vibration and accessory load changes, the tension arm is in a state of continuous swing. After long-term operation, the damping component will be significantly worn by the tension arm, resulting in a significant decrease in the damping force provided by the damping component.

[0005] The above-mentioned damping assembly has a utility model patent with the authorization announcement number CN218118507U, and its name is a bidirectional tensioner and pulley structure. In this patent, the butterfly spring applies pressure between the damping ring, the damping plate, the tensioning arm, and the shaft, so that the tensioning arm continuously rubs the damping ring and the damping plate during the swinging process, thereby generating friction damping. However, after long-term operation, the thickness of the damping ring and the damping plate will be reduced due to repeated friction, which will reduce the compression of the disc spring, reduce the pressure applied downward by the butterfly spring to the damping ring, the damping plate, and the tensioning arm, and reduce the friction between the three, thereby causing the friction damping to decrease, affecting the working state of the tensioner. Utility Model Content

[0006] The technical problem to be solved by the utility model is: in order to overcome the deficiency of the prior art that the friction damping decreases due to wear, the utility model provides a bidirectional tensioner with a damping compensation function.

[0007] The technical solution to be adopted by the utility model to solve its technical problems is: a bidirectional tensioner with a damping compensation function, comprising a base, two tensioning arms, two pulleys, a linear spring, and a pivot structure, wherein the base is fixed on the car, the two tensioning arms are respectively arranged on the left and right sides of the base, and one end of the tensioning arm is hinged to the base through the pivot structure, and the other end is hinged to the pulley, and the linear spring is connected between the ends of the tensioning arms close to the base side, characterized in that: the pivot structure comprises an end cover, a helical compression spring, a pivot, an upper friction ring and a lower friction ring, wherein the helical compression spring comprises an A part and a B part which are integrally connected, the outer diameter of the A part is larger than the outer diameter of the B part, the end cover is a hollow cylinder, and the upper end is a conical transition part, and the lower end is a cylindrical part , the inner side of the conical transition part is provided with a transition cone surface, the inner wall of the bottom of the cylindrical part is provided with a convex ring, the inner side surface of the convex ring is a pivot connection surface, the upper end surface of the convex ring is a spring abutment surface, the tensioning arm is hinged on the base through a pivot, and an I-shaped friction ring is provided between the tensioning arm and the pivot contact surface; the helical compression spring is sleeved on the end of the pivot away from the base, and the outer side is sealed by an end cover, the end cover is interference fit with the pivot through the pivot contact surface, the end face of the A part of the helical compression spring abuts on the friction ring, and the end face of the B part abuts on the spring abutment surface of the convex ring, so that the helical compression spring always maintains a compressed state, the A part is located in the conical transition part of the end cover, and its outer side does not contact the transition cone surface, the B part is located in the cylindrical part of the end cover, and its outer side contacts the friction surface of the end cover. Among them, the friction ring, the helical compression spring and the end cover together constitute a damping assembly, and the friction ring is a damping member.

[0008] During operation, the wear conditions at both ends of the friction ring may not be synchronized, one end may be severely worn, and the other end may be lightly worn. Therefore, in order to reduce maintenance costs, the friction ring further includes a first friction ring and a second friction ring which are separately arranged, the second friction ring is close to one side of the base, the first friction ring is close to one side of the end cover, and the outer end of the first friction ring forms a first flange-shaped friction part, the outer end of the second friction ring forms a second flange-shaped friction part, one end of the spiral compression spring is against the first flange-shaped friction part, and the second flange-shaped friction part is clamped between the pivot and the end face of the tensioning arm facing the base. When the wear conditions at both ends are different, the friction ring at the severely worn end can be replaced first, and the friction ring at the other end can continue to be used, which saves maintenance costs, and also disperses the torsional force on the friction ring, extending the service life.

[0009] Preferably, the first friction ring and the second friction ring are made of engineering plastics.

[0010] Specifically, the pivot and the base are interference fit.

[0011] The beneficial effect of the utility model is that the utility model provides a bidirectional tensioner with a damping compensation function. As the wear of the damping component, i.e., the friction ring, increases, the helical compression spring in the damping assembly automatically extends, and the axial friction force of the outer wall of the spring is reduced by utilizing the change in the shape of the spring before and after wear, thereby automatically compensating for the damping force loss caused by the wear of the damping component. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0013] Figure 1 It is a structural diagram of a hybrid power system of an automobile.

[0014] Figure 2 It is a structural schematic diagram of a bidirectional tensioner in the prior art.

[0015] Figure 3 It is a structural schematic diagram of the bidirectional tensioner of the utility model.

[0016] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure at the pivot structure of AA.

[0017] Figure 5 yes Figure 4 Schematic diagram of the enlarged structure of the second pivot structure.

[0018] Figure 6 It is a schematic diagram of the three-dimensional structure of the end cover.

[0019] Figure 7 It is a schematic diagram of the cross-sectional structure of the end cover.

[0020] Figure 8 It is a schematic diagram of the structure of a helical compression spring.

[0021] Fig. 9 This is a schematic diagram of the state of the helical compression spring before the friction ring wears.

[0022] Fig.10 It is a schematic diagram of the state of the helical compression spring after the friction ring is worn.

[0023] Fig.11 It is a schematic diagram of the stress state.

[0024] In the figure: 100, bidirectional tensioner, 200, generator, 300, transmission belt, 400, crankshaft, 500, other accessory pulleys; 1, first tensioning arm, 2, second tensioning arm, 3, base, 4a, first pulley, 4b, second pulley, 5, linear spring, 6, first pivot structure, 7, second pivot structure, 8, end cover, 8.1, conical transition portion, 8.2, cylindrical portion, 8.3, transition cone surface, 8.4, convex ring, 8.5, pivot connection surface, 8.6, spring abutment surface, 8.7, friction surface, 9, helical compression spring, 10, pivot, 11, first friction ring, 12, second friction ring. DETAILED DESCRIPTION

[0025] The present invention is now described in further detail in conjunction with the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not adopted in a restrictive sense, and the scope of the subject matter for which protection is sought is limited only by the attached claims and their equivalents.

[0026] like Figure 3 As shown, the utility model is a bidirectional tensioner with damping compensation function, comprising a base 3, two tensioning arms, two pulleys, a linear spring 5, and a pivot structure, wherein the two tensioning arms are respectively a first tensioning arm 1 and a second tensioning arm 2, the two pulleys are respectively a first pulley 4a and a second pulley 4b, the pivot structure comprises a first pivot structure 6 and a second pivot structure 7, the base 3 is fixed on the car, the first tensioning arm 1 and the second tensioning arm 2 are respectively arranged on the left and right sides of the base 3, and one end of the first tensioning arm 1 is hinged to the base 3 through the first pivot structure 6, the other end of the first tensioning arm 1 is hinged to the first pulley 4a, one end of the second tensioning arm 2 is hinged to the base 3 through the second pivot structure 7, the other end of the second tensioning arm 2 is hinged to the second pulley 4b, and the linear spring 5 is connected between the ends of the first tensioning arm 1 and the second tensioning arm 2 close to the side of the base 3.

[0027] like Figure 4 As shown, the structures of the first pivot structure 6 and the second pivot structure 7 are the same, so the specific connection relationship thereof will be described in detail below by taking the second pivot structure 7 as an example.

[0028] like Figure 5 As shown, the second pivot structure 7 includes an end cap 8, a helical compression spring 9, a pivot 10, an upper friction ring and a lower friction ring, wherein Figure 8 As shown, the helical compression spring 9 includes an A portion and a B portion connected in one piece, and the outer diameter of the A portion is larger than the outer diameter of the B portion. Figure 6 and Figure 7 As shown, the end cover 8 is a hollow cylinder, and the upper end is a conical transition portion 8.1, and the lower end is a cylindrical portion 8.2. The inner side of the conical transition portion 8.1 is provided with a transition cone surface 8.3, and the inner wall of the bottom of the cylindrical portion 8.2 is provided with a convex ring 8.4. The inner side surface of the convex ring 8.4 is a pivot connection surface 8.5, and the upper end surface of the convex ring 8.4 is a spring abutment surface 8.6. Figure 5 As shown, the second tensioning arm 2 is hinged on the base 3 through the pivot 10, and the pivot 10 and the base 3 are interference fit. An I-shaped friction ring is provided between the second tensioning arm 2 and the pivot connection surface 8.5; the helical compression spring 9 is sleeved on the end of the pivot 10 away from the base 3, and the outer side is sealed by the end cover 8, and the end cover 8 is interference fit with the pivot 10 through the pivot connection surface 8.5, and the end face of the A part of the helical compression spring 9 abuts on the friction ring, and the end face of the B part abuts on the spring abutment surface 8.6 of the convex ring 8.4, so that the helical compression spring 9 always maintains a compressed state, the A part is located in the conical transition part 8.1 of the end cover 8, and its outer side does not contact the transition cone surface 8.3, and the B part is located in the cylindrical part 8.2 of the end cover 8, and its outer side contacts the friction surface 8.7 of the end cover 8. Among them, the friction ring, the helical compression spring 9 and the end cover 8 together constitute a damping assembly, and the friction ring is a damping member. For the B part of the helical compression spring 9 that contacts the friction surface 8.7 of the inner wall of the end cover 8, it always remains in a compressed state in radial direction, and the radial compression amount is the largest in the area corresponding to the friction surface 8.7. The other part of the outer wall of the helical compression spring 9, part A, that is, the end of the spring shown in the figure does not contact the transition cone surface 8.3 of the inner wall of the end cover 8, and its radial direction is not compressed. During the expansion and contraction process of the helical compression spring 9, the transition cone surface 8.3 of the end cover 8 plays a guiding role to prevent the radial jump of the B part during the expansion and contraction process. If the spring is extended, a certain area of ​​the B part will be out of contact with the friction surface 8.7 of the inner wall of the end cover 8.

[0029] Preferably, the friction ring in this embodiment includes a first friction ring 11 and a second friction ring 12 which are separately arranged, wherein the second friction ring 12 is close to one side of the base 3, and the first friction ring 11 is close to one side of the end cover 8, and the outer end of the first friction ring 11 forms a first flange-shaped friction portion, and the outer end of the second friction ring 12 forms a second flange-shaped friction portion, one end of the spiral compression spring 9 is against the first flange-shaped friction portion, and the second flange-shaped friction portion is clamped between the pivot 10 and the end face of the tensioning arm facing the base 3. When the wear conditions of the two ends are different, the friction ring at one end with severe wear can be replaced first, and the friction ring at the other end can continue to be used, which saves maintenance costs, and also disperses the torsional force on the friction rings, thereby extending the service life. Preferably, the first friction ring 11 and the second friction ring 12 are made of engineering plastics.

[0030] Working principle:

[0031] As shown in 11, N is the radial pressure of the outer wall of the B part of the helical compression spring 9 on the friction surface 8.7, F f is the friction force generated by the pressure N on the friction surface 8.7, F is the pressure applied by the end face of the A part of the helical compression spring 9 on the end face of the friction ring, and F' is the pressure released by the free expansion and contraction of the helical compression spring 9.

[0032] During the swinging process of the tensioning arm, the helical compression spring 9 always applies pressure F on the end surface, so that the tensioning arm, the friction ring and the pivot 10 are compressed, and the swinging of the tensioning arm is subjected to friction damping in the opposite direction. The end surface pressure F determines the magnitude of the friction damping. In the traditional structure, due to the long-term wear and thinning of the friction ring, the compression amount of the spring or butterfly spring relative to the initial state is reduced, resulting in a decrease in the pressure applied by the spring or butterfly spring on the friction ring, which in turn causes a decrease in friction damping.

[0033] like Fig. 9 As shown, in the utility model, the B part of the outer wall of the helical compression spring 9 has three turns which are radially compressed in the friction surface 8.7 of the end cover 8. Under the action of elastic potential energy, the three turns of the spring are always in close contact with the friction surface 8.7. The three turns of the spring apply an outward radial pressure N to the friction surface 8.7. At the same time, the three turns of the spring are subjected to the friction force in the opposite direction of the extension direction as shown in the figure. F f The pressure exerted by the helical compression spring 9 on the friction ring at the end face is always restricted by the friction force. In this patent, the pressure exerted by the helical compression spring 9 on the friction ring at the end face after overcoming the outer wall friction force can be expressed as F=F'- F f , F' is the pressure of the helical compression spring 9 released on the end face of the friction ring after being compressed in theory without the action of the outer wall friction force.

[0034] like Fig.10 As shown, after long-term operation, the friction ring becomes thinner, the helical compression spring 9 stretches, its compression amount decreases, F' decreases, and the friction damping in the traditional structure will decrease. In this patent, the B area of ​​the helical compression spring 9 is reduced, the A area is expanded, and the helical compression spring 9 in the B area that contacts the friction surface 8.7 of the end cover 8 is reduced from 3 turns to 2 turns. Compared with the initial state, the radial pressure exerted by these two turns of spring on the friction surface 8.7 is reduced, so the friction force on the helical compression spring 9 is reduced. F f Reduced. According to the formula F=F'- F f It can be seen that after the helical compression spring 9 is stretched, F' and F f By adjusting the size of the inner wall of the end cover 8, the number of spring coils of the helical compression spring 9 in contact with the friction surface 8.7 before and after the extension can be indirectly adjusted, thereby controlling F f The reduction in friction ring speed is reduced to maintain the F value stable, thereby ensuring that the tensioner can still provide the same level of friction damping after the friction ring wears.

[0035] Fig. 9 and Fig.10 The structure in the red frame is to indicate the state of the friction ring and the helical compression spring 9 before and after the friction ring is worn. Fig.11 The colored arrows in the middle are used to distinguish different forces. The same color represents the same force, and different colors represent different forces.

[0036] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the scope of the utility model through the above description. The technical scope of this utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A bidirectional tensioner with damping compensation function, comprising a base, two tensioning arms, two pulleys, a linear spring, and a pivot structure, wherein: The base is fixed on the car, and the two tensioning arms are respectively arranged on the left and right sides of the base, and one end of the tensioning arm is hinged on the base through a pivot structure, and the other end is hinged to the pulley, and the linear spring is connected between the ends of the tensioning arms close to the base side, characterized in that: the pivot structure includes an end cover, a helical compression spring, a pivot, an upper friction ring and a lower friction ring, wherein the helical compression spring includes an A part and a B part connected as one body, the outer diameter of the A part is larger than the outer diameter of the B part, the end cover is a hollow cylinder, and the upper end is a conical transition part, and the lower end is a cylindrical part, the inner side of the conical transition part is provided with a transition cone surface, the inner wall of the bottom of the cylindrical part is provided with a convex ring, and the convex ring The inner side surface of the ring is the pivot connection surface, the upper end surface of the convex ring is the spring abutment surface, the tensioning arm is hinged on the base through a pivot, and an I-shaped friction ring is provided between the tensioning arm and the pivot contact surface; the helical compression spring is sleeved on the end of the pivot away from the base, and the outer side is sealed by an end cover, the end cover is interference fit with the pivot through the pivot contact surface, the end face of part A of the helical compression spring abuts on the friction ring, and the end face of part B abuts on the spring abutment surface of the convex ring, so that the helical compression spring always keeps a compressed state, part A is located at the conical transition part of the end cover, and its outer side does not contact the transition conical surface, and part B is located at the cylindrical part of the end cover, and its outer side contacts the friction surface of the end cover.

2. The bidirectional tensioner with damping compensation function according to claim 1, characterized in that: The friction ring includes a first friction ring and a second friction ring which are separately arranged, wherein the second friction ring is close to one side of the base, and the first friction ring is close to one side of the end cover, and the outer end of the first friction ring forms a first flange-shaped friction portion, and the outer end of the second friction ring forms a second flange-shaped friction portion, one end of the helical compression spring is against the first flange-shaped friction portion, and the second flange-shaped friction portion is clamped between the pivot and the end surface of the tensioning arm facing the base.

3. The bidirectional tensioner with damping compensation function as claimed in claim 2, characterized in that: The first friction ring and the second friction ring are made of engineering plastics.

4. The bidirectional tensioner with damping compensation function according to claim 1, characterized in that: The pivot and the base are interference fit.

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