Chain tensioner and vehicle

Abstract

The embodiment of the application discloses a chain tensioner and an automobile, relates to the technical field of automobile engines, and solves the problem that the pressing force provided by the chain guide plate of the chain tensioner for the timing chain is unstable due to the existence of air in the chain tensioner, and the abnormal sound of the timing chain of the engine is caused. The chain tensioner provided by the embodiment of the application comprises a shell and a plunger. The shell is provided with a hydraulic cavity with one side opening, and the other side is provided with an oil inlet, and the oil inlet is communicated to the hydraulic cavity; the plunger is arranged in the hydraulic cavity and is in sliding sealing with the hydraulic cavity, the plunger is provided with an exhaust hole, the exhaust hole is communicated to the hydraulic cavity, and the exhaust hole is used for discharging the air in the hydraulic cavity. The chain tensioner provided by the embodiment of the application is used for providing the pressing force for the timing chain of the engine.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of automobile engine, and particularly relates to a chain tensioner and an automobile. BACKGROUND

[0002] With the development of engine technology, the structure of the engine is more and more precise, in order to ensure the accuracy of the engine intake and exhaust time, generally provided with an engine timing system. The engine timing system includes a timing belt or a timing chain, the timing belt or the timing chain connects the crankshaft, the exhaust camshaft and the intake camshaft of the engine together, so that the stroke of the piston, the opening and closing of the valve and the sequence of the ignition are kept in synchronization under the action of "timing" when the engine is running. At present, the engine timing belt has been replaced by the timing chain. According to the rotation direction of the crankshaft, one side of the timing chain is in a tension state, and the other side is in a slack state. In order to ensure that the timing chain is in a tension state at all times, a chain tensioner is generally provided on the slack side of the timing chain. The commonly used chain tensioner is an oil pressure tensioner. The oil passage of the engine is connected to the inside of the chain tensioner, and the oil is introduced into the chain tensioner to make the plunger of the chain tensioner extend, so as to tighten the chain guide plate of the timing chain, and then the timing chain is in a tension state.

[0003] After the engine is stopped for a long time, most of the engine oil in the oil passage flows back to the oil pan, and the oil passage is filled with air. There is also air in the hydraulic chamber of the chain tensioner. At this time, if the engine is started, the air in the hydraulic chamber of the chain tensioner cannot be discharged. Since the volume of the air is greatly affected by external force, the plunger of the chain tensioner will fluctuate, causing abnormal noise of the timing chain of the engine. SUMMARY

[0004] In order to solve the above problems, the embodiment of the present application provides a chain tensioner, which has the following advantages: the air in the chain tensioner can be discharged, the chain tensioner can provide stable pressing force to the chain guide plate, and the abnormal noise of the timing chain of the engine can be eliminated.

[0005] In order to achieve the above purpose, the technical scheme of the embodiment of the present application is as follows:

[0006] In a first aspect, the embodiment of the present application provides a chain tensioner, which comprises: a housing and a plunger. The housing is provided with a hydraulic chamber with one side open, and the other side is provided with an oil inlet. The oil inlet is connected to the hydraulic chamber. The plunger is arranged in the hydraulic chamber and is in sliding sealing with the hydraulic chamber. The plunger is provided with an air vent hole, which is connected to the hydraulic chamber and is used for discharging air in the hydraulic chamber.

[0007] In the chain tensioner provided in the embodiment of the present application, the chain tensioner comprises a housing and a plunger. One side of the housing is provided with a hydraulic cavity, and the other side is provided with an oil inlet. The oil inlet is communicated to an oil path of engine oil, and the engine oil is introduced into the chain tensioner. The plunger is arranged in the hydraulic cavity. When the engine oil is introduced into the hydraulic cavity, the plunger slides out of the chain tensioner under the action of the oil pressure of the engine oil, and provides a pressing force to the chain guide plate. Since there is a space in the oil path of the engine oil, an exhaust hole is arranged on the plunger of the chain tensioner provided in the embodiment of the present application, and the exhaust hole is communicated to the hydraulic cavity, and is used to exhaust the air in the hydraulic cavity. Thus, the chain tensioner provided in the embodiment of the present application can exhaust the air in the chain tensioner, so that the chain tensioner can provide a stable pressing force to the chain guide plate, and the abnormal sound of the engine timing chain is eliminated.

[0008] In a possible implementation manner of the first aspect, a sealing plug is arranged on the plunger and located inside the exhaust hole. A sealing cavity is arranged in the plunger and corresponds to the sealing plug. The sealing plug can slide to the exhaust hole along the sealing cavity.

[0009] In a possible implementation manner of the first aspect, a containing cavity is arranged on the plunger and located away from the sealing cavity. The containing cavity is open to the hydraulic cavity. The exhaust hole is communicated to the hydraulic cavity through the sealing cavity and the containing cavity. The exhaust hole is arranged at the highest position of the containing cavity. A resilient member is arranged between the exhaust hole and the sealing plug. The resilient member is used to move the sealing plug away from the exhaust hole when the sealing cavity is not filled with the engine oil.

[0010] In the chain tensioner provided in the embodiment of the present application, the resilient member is arranged between the exhaust hole and the sealing plug. The resilient member can provide an elastic force to the sealing plug to move away from the exhaust hole. When the sealing cavity is filled with air and not filled with the engine oil, the engine oil compresses the air in the sealing cavity. At this time, the oil pressure in the sealing cavity is not large enough to overcome the elastic force of the resilient member to move the sealing plug to the exhaust hole. The resilient member moves the sealing plug away from the exhaust hole, and a gap is formed between the sealing plug and the sealing cavity. The air in the sealing cavity is exhausted out of the chain tensioner through the exhaust hole.

[0011] In a possible implementation manner of the first aspect, the sealing cavity is a conical frustum structure. The diameter of the sealing cavity gradually decreases towards the exhaust hole. The sealing plug is a conical frustum structure corresponding to the sealing cavity. When the sealing plug slides to the exhaust hole, the gap between the sealing plug and the sealing cavity gradually decreases to sealing.

[0012] In a possible implementation manner of the first aspect, the sealing plug and the sealing cavity are cylindrical structures. The diameter of the sealing plug is smaller than the diameter of the sealing cavity.

[0013] The sealing plug and the sealing cavity are both provided in a cylindrical structure, and the diameter of the sealing plug is smaller than the diameter of the sealing cavity, and a gap exists between the sealing plug and the sealing cavity, so that the sealing plug can slide smoothly in the sealing cavity. Meanwhile, the gap between the sealing plug and the sealing cavity forms an air circulation channel, facilitating the air to be discharged from the chain tensioner.

[0014] In a possible implementation manner of the first aspect, a sealing seat corresponding to the position of the sealing plug is arranged on the plunger, and the sealing plug and the sealing seat form a seal when the sealing plug and the sealing seat are in contact.

[0015] In a possible implementation manner of the first aspect, the sealing seat is in a boss structure, one side of the boss structure corresponding to the sealing plug is in a planar structure, and the position of the sealing plug corresponding to the sealing seat is in a planar structure, and the sealing plug and the sealing seat form a seal when the sealing plug and the sealing seat are in contact.

[0016] In a possible implementation manner of the first aspect, the sealing seat is in a concave arc structure, and the position of the sealing plug corresponding to the sealing seat is in a convex arc structure, and the sealing plug and the sealing seat form a seal when the sealing plug and the sealing seat are in contact.

[0017] In a possible implementation manner of the first aspect, the sealing plug and the sealing cavity are in a cylindrical structure, a sealing sliding fit gap is arranged between the sealing plug and the sealing cavity, a helical groove is arranged on the side surface of the sealing plug, the helical groove and the sealing cavity form a gap, a sealing seat corresponding to the position of the sealing plug is arranged on the plunger, and the sealing plug and the sealing seat form a seal when the sealing plug and the sealing seat are in contact.

[0018] In the second aspect, the embodiments of the present application provide an automobile, comprising: an engine and the chain tensioner provided in the first aspect; wherein the engine comprises a timing chain, and the chain tensioner is arranged on one side of the timing chain, so that the timing chain is kept in a tensioned state.

[0019] Since the automobile provided by the embodiments of the present application comprises the chain tensioner provided in the first aspect, the same technical effects can be achieved, that is, the air in the chain tensioner can be discharged, the chain tensioner can provide stable pressing force to the chain guide plate, and the abnormal sound of the timing chain of the engine can be eliminated. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The assembly schematic view of the chain tensioner and the timing chain provided by the embodiments of the present application;

[0021] Figure 2 The overall structure schematic view of the chain tensioner provided by the embodiments of the present application;

[0022] Figure 3 The local enlarged schematic view of the chain tensioner provided by the embodiments of the present application.

[0023] Reference signs:

[0024] 1-timing chain; 2-chain tensioner; 21-housing; 211-hydraulic cavity; 212-oil inlet; 22-plunger; 221-exhaust hole; 222-seal plug; 2221-helical groove; 223-seal cavity; 224-springback; 2241-spring; 225-seal seat; 3-chain guide plate. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the specific technical solutions of the present application will be further described in detail below with reference to the drawings in the embodiments of the present application. The following embodiments are used to explain the present application, but not to limit the scope of the present application.

[0026] In the embodiments of the present application, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0027] In addition, in the embodiments of the present application, the orientation terms such as "upper", "lower", "left" and "right" are defined with respect to the orientation of the components shown in the drawings, and it should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and they can be changed accordingly according to the change of the orientation of the components placed in the drawings.

[0028] In the embodiments of the present application, unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, "connection" can be fixed connection, or detachable connection, or integral; can be directly connected, or indirectly connected through intermediate medium.

[0029] In the embodiments of the present application, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. Without more limitation, the element defined by the sentence "including a…" does not exclude the existence of other same elements in the process, method, article or device including the element.

[0030] In the embodiments of the present application, the word "exemplary" or "for example" is used to mean serving as an example, instance, or illustration. Any embodiment or design described in the embodiments of the present application as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the embodied word "exemplary" or "for example" is intended to present concepts in a concrete manner.

[0031] The embodiments of the present application provide an automobile, which can be a sedan, a cross-country vehicle, a truck or other vehicle types. In addition to the pure electric vehicle, the automobile has an engine, and the common engine includes a gasoline engine, a diesel engine, a liquefied natural gas engine or other forms of engine. In order to ensure that the stroke of the piston, the opening and closing of the valve, and the sequence of the ignition are kept synchronous during the operation of the engine, the engine is provided with a timing system. Referring to Figure 1 and Figure 2 The common timing system includes a timing chain 1 and a chain tensioner 2, the chain tensioner 2 is arranged on one side of the timing chain 1, and the chain tensioner 2 clamps the chain guide plate 3 to keep the timing chain 1 in a tension state. However, after the engine is stopped for a long time, most of the engine oil in the oil passage of the engine will flow back to the oil pan, the oil passage will be filled with air, and the chain tensioner 2 will also contain air. At this time, if the engine is started, the air in the hydraulic chamber 211 of the chain tensioner 2 cannot be discharged, and since the volume of the air is greatly affected by the outside world, the plunger 22 of the chain tensioner 2 will fluctuate, causing the timing chain 1 of the engine to produce abnormal noise.

[0032] The embodiments of the present application provide a chain tensioner 2, referring to Figure 2The chain tensioner 2 includes a housing 21 and a plunger 22. The housing 21 has a hydraulic chamber 211 with an opening on one side and an oil inlet 212 on the other side. The oil inlet 212 is connected to the hydraulic chamber 211 and is used to supply engine oil to the hydraulic chamber 211 of the chain tensioner 2. The plunger 22 is disposed in the hydraulic chamber 211 and slides and seals with the hydraulic chamber 211. When the hydraulic chamber 211 is full of engine oil, the plunger 22 slides along the hydraulic chamber 211 under the pressure of the engine oil and extends outward along the hydraulic chamber 211. At the same time, the plunger 22 of the chain tensioner 2 provided in this embodiment is also provided with an exhaust port 221, which is connected to the hydraulic chamber 211 and is used to discharge the air in the hydraulic chamber 211. It should be noted that this application does not limit the shape of the hydraulic chamber 211 and the plunger 22 of the chain tensioner 2 provided in the embodiment. The cross-section of the hydraulic chamber 211 and the plunger 22 can be set to a circle, an ellipse, a square or other shapes. Setting the cross-section of the hydraulic chamber 211 and the plunger 22 to a circle is the easiest to achieve, and it can also make the plunger 22 and the hydraulic chamber 211 slide smoothly, and it is also easy to ensure the sealing of the plunger 22 and the hydraulic chamber 211. Furthermore, the location of the vent hole 221 is not limited in this embodiment. As long as the vent hole 221 can communicate with the external space of the hydraulic chamber 211 and the chain tensioner 2, allowing air to be discharged from the hydraulic chamber 211, it is acceptable. For example, the vent hole 221 can be located at the end of the plunger 22 near the timing chain 1, or it can be located on the side of the plunger 22 near the top. The shape of the vent hole 221 can also be varied; it can be a cylindrical hole, a square hole, a conical hole, or other shapes. The shape of the vent hole 221 is not limited in this embodiment either. (Refer to...) Figure 2 In some embodiments of this application, the vent 221 is provided at one end of the plunger 22 near the timing chain 1, and the vent 221 is provided as a cylindrical hole.

[0033] When the oil pipeline connected to the oil inlet 212 of the chain tensioner 2 contains air, due to the pressure of the engine oil, the air will gather in the chain tensioner 2 at the end of the oil pipeline. Since the volume of the air is greatly affected by external forces, during the operation of the engine, the timing chain 1 will generate impact load on the chain tensioner 2. When the chain tensioner 2 contains air, the volume of the air in the chain tensioner 2 will change greatly, which will cause the chain tensioner 2 to provide fluctuating pressure to the chain guide plate 3, thereby causing the timing chain 1 to swing and generate abnormal noise. The chain tensioner 2 provided in the embodiments of the present application can discharge the air in the hydraulic chamber 211 through the air vent hole 221 provided on the plunger 22, so that the hydraulic chamber 211 of the chain tensioner 2 is filled with engine oil. After the hydraulic chamber 211 of the chain tensioner 2 is filled with engine oil, the volume of the hydraulic chamber 211 is approximately incompressible. Therefore, the chain tensioner 2 provided in the embodiments of the present application can provide stable tension to the chain guide plate 3, thereby avoiding the swing of the timing chain 1 and eliminating the abnormal noise of the timing chain 1.

[0034] On this basis, referring to Figure 2 and Figure 3 In the embodiments of the chain tensioner 2 provided in the present application, a sealing plug 222 is arranged on the plunger 22 inside the air vent hole 221, and a sealing cavity 223 is arranged in the plunger 22 corresponding to the position of the sealing plug 222. When the hydraulic chamber 211 is filled with engine oil, the sealing plug 222 will slide towards the air vent hole 221 under the pressure of the engine oil. It should be noted that the material of the sealing plug 222 has multiple options. For example, the sealing plug 222 can be made of carbon steel or stainless steel. The sealing plug 222 made of stainless steel can resist corrosion and prevent rust particles from entering the engine oil and polluting the engine oil. The sealing plug 222 can also be made of elastic material. The sealing plug 222 made of elastic material can better contact the sealing cavity 223, so that the sealing plug 222 and the sealing cavity 223 remain sealed. For example, the sealing plug 222 can be made of polytetrafluoroethylene or rubber. Polytetrafluoroethylene has stronger oil corrosion resistance than rubber. The embodiments of the present application do not limit the material of the sealing plug 222, which can be reasonably selected according to actual conditions.

[0035] In addition, in some embodiments of the present application, a containing cavity 2231 opening towards the hydraulic chamber 211 is arranged on the side of the plunger 22 away from the air vent hole 221, which can facilitate the engine oil to provide pressure to the plunger 22. Referring to Figure 1 and Figure 2 In some embodiments of the present application, a plunger spring is further arranged in the containing cavity 2231, which can provide a pre-pressure to the plunger 22. When the chain tensioner 2 is not filled with engine oil, the plunger 22 can also provide a certain pressure to the chain guide plate 3. Referring to Figure 2The exhaust hole 221 is communicated to the hydraulic cavity 211 through the sealing cavity 223 and the containing cavity 2231, so that the exhaust hole 221 is communicated with the sealing cavity 223, the containing cavity 2231, the hydraulic cavity 211 and the oil inlet 212, and the air in the above-mentioned spaces can be exhausted. Meanwhile, in order to easily exhaust the air in the chain tensioner 2, the exhaust hole 221 is arranged at the highest position of the containing cavity 2231, and since the density of the air is less than that of the oil, the air in the chain tensioner 2 moves to the high position, so that the exhaust hole 221 is arranged at the highest position of the containing cavity 2231, and the air in the chain tensioner 2 can be easily exhausted.

[0036] A resilient member 224 is further arranged between the exhaust hole 221 and the sealing plug 222. The resilient member 224 can push the sealing plug 222 away from the exhaust hole 221 in the opposite direction when the hydraulic cavity 211 is not filled with oil, so that the air flow channel between the exhaust hole 221 and the hydraulic cavity 211 is unblocked, and the air in the hydraulic cavity 211 can be exhausted from the chain tensioner 2 through the exhaust hole 221. The resilient member 224 can be a spring 2241, a rubber pad or an O-ring, etc. The spring 2241 is used as the resilient member 224, and compared with the rubber pad or the O-ring, the spring 2241 will not decompose impurities into the oil, so that the oil is prevented from being contaminated, and the structure stability of the spring 2241 is better, so that the spring 2241 can provide resilient force to the sealing plug 222 for a long time. When the hydraulic cavity 211 is filled with oil, the oil pushes the sealing plug 222 towards the exhaust hole 221, so that the resilient member 224 is deformed under pressure, and the sealing plug 222 and the sealing cavity 223 are kept sealed. When the hydraulic cavity 211 contains air, the air with small density gathers at the position of the hydraulic cavity 211 close to the exhaust hole 221, and the oil compresses the air in the sealing cavity 223. At this time, the oil pressure in the sealing cavity 223 is not large enough to overcome the resilient force of the resilient member 224 to move the sealing plug 222 towards the exhaust hole 221, so that the sealing plug 222 is pushed away from the exhaust hole 221 in the opposite direction, and the air flow channel between the hydraulic cavity 211 and the exhaust hole 221 is kept unblocked, so that the air in the hydraulic cavity 211 is exhausted.

[0037] In some embodiments of the present application, the sealing cavity 223 is a conical structure, and the diameter of the sealing cavity 223 gradually decreases in the direction of the exhaust hole 221. Correspondingly, the sealing plug 222 is a conical structure corresponding to the sealing cavity 223, and when the sealing plug 222 slides towards the exhaust hole 221, the gap between the sealing plug 222 and the sealing cavity 223 gradually decreases to complete sealing. In this way, a separate sealing structure is not needed, and the sealing is formed by the self-structure of the sealing plug 222 and the sealing cavity 223. However, in this way, the taper of the sealing plug 222 and the sealing cavity 223 needs to be consistent, and the machining precision of the sealing plug 222 and the sealing cavity 223 is required to be high; in order to ensure sealing, the roughness of the surface of the sealing plug 222 and the sealing cavity 223 is also required to be high.

[0038] In some embodiments of the present application, the sealing cavity 223 is a conical structure, and the diameter of the sealing cavity 223 gradually decreases in the direction of the exhaust hole 221. Correspondingly, the sealing plug 222 is a conical structure corresponding to the sealing cavity 223, and when the sealing plug 222 slides towards the exhaust hole 221, the gap between the sealing plug 222 and the sealing cavity 223 gradually decreases to complete sealing. In this way, a separate sealing structure is not needed, and the sealing is formed by the self-structure of the sealing plug 222 and the sealing cavity 223. However, in this way, the taper of the sealing plug 222 and the sealing cavity 223 needs to be consistent, and the machining precision of the sealing plug 222 and the sealing cavity 223 is required to be high; in order to ensure sealing, the roughness of the surface of the sealing plug 222 and the sealing cavity 223 is also required to be high.

[0039] On this basis, referring to Figure 2 and Figure 3In the position of the plunger 22 close to the sealing plug 222, a sealing seat 225 is arranged. When the sealing plug 222 slides towards the exhaust hole 221, the sealing plug 222 and the sealing seat 225 are in contact, and the sealing plug 222 and the sealing seat 225 form a seal, so that the oil in the chain tensioner 2 cannot flow out through the exhaust hole 221. For example, the sealing seat 225 can be machined on the plunger 22 corresponding to the position of the sealing plug 222, so that the structure of the plunger 22 of the chain tensioner 2 is simple; or the sealing seat 225 can be separately machined and then installed in the plunger 22 corresponding to the position of the sealing plug 222, so that the structure of the plunger 22 of the chain tensioner 2 is complex, but the sealing seat 225 is easy to maintain, for example, when the sealing seat 225 is damaged, the sealing seat 225 can be easily replaced, and the chain tensioner 2 is easy to maintain. In addition, it should be noted that the shape of the sealing seat 225 has multiple options, for example, the sealing seat 225 can be arranged in a wedge-shaped structure, and the position of the sealing plug 222 corresponding to the sealing seat 225 is also arranged in a wedge-shaped structure. When the sealing plug 222 and the sealing seat 225 are in contact, the wedge-shaped structure between the sealing plug 222 and the sealing seat 225 forms a seal, and the wedge-shaped structure has a self-sealing effect. The greater the pressure of the oil, the tighter the contact between the sealing plug 222 and the sealing seat 225, and the better the sealing effect of the sealing plug 222 and the sealing seat 225.

[0040] In addition to arranging the sealing structure between the sealing plug 222 and the sealing seat 225 in a wedge-shaped structure, in another possible implementation of the present application, the sealing structure between the sealing plug 222 and the sealing seat 225 can also be arranged in a planar structure. Specifically, a boss structure is arranged at the position of the sealing seat 225 corresponding to the sealing plug 222, and the side of the boss structure close to the sealing plug 222 is a planar structure. The position of the sealing plug 222 corresponding to the sealing seat 225 is also a planar structure. When the sealing plug 222 and the sealing seat 225 are in contact, the planar structure between the sealing plug 222 and the sealing seat 225 forms a seal. In addition, the surface of the planar structure of the sealing plug 222 and the sealing seat 225 can be carburized. Carburizing can improve the hardness and wear resistance of the surface of the planar structure of the sealing plug 222 and the sealing seat 225, prevent small grooves from appearing on the surface of the planar structure of the sealing plug 222 and the sealing seat 225, cause the oil in the hydraulic chamber 211 to leak through the exhaust hole 221, and thus prolong the service life of the chain tensioner 2.

[0041] In addition, in some embodiments of the present application, the sealing seat 225 is provided as a concave arc structure, and the sealing plug 222 is provided as a corresponding convex arc structure corresponding to the position of the sealing seat 225. Thus, when the sealing plug 222 and the sealing seat 225 are in contact, the arc structures between the sealing plug 222 and the sealing seat 225 form a seal. The arc structures not only facilitate the formation of the seal, but also guide the sliding of the sealing plug 222. During the sliding of the sealing plug 222 to the sealing seat 225, the sealing plug 222 and the sealing seat 225 are automatically centered, preventing the leakage of oil due to the positional deviation between the sealing plug 222 and the sealing seat 225.

[0042] In addition, for the cylindrical sealing plug 222 and the sealing cavity 223, the gap between the sealing plug 222 and the sealing cavity 223 can be set very small, so that the sealing plug 222 and the sealing cavity 223 have a fitting gap, allowing the sealing plug 222 and the sealing cavity 223 to seal and slide. At the same time, the air flow gap is formed by providing a groove on the side surface of the sealing plug 222. For example, referring to Figure 2 and Figure 3 The sealing plug 222 is provided with a spiral groove 2221, and the spiral groove 2221 and the sealing cavity 223 form a gap extending along the axis of the sealing plug 222, allowing the air in the hydraulic chamber 211 to flow through the spiral groove 2221 to the exhaust hole 221, and then be discharged through the exhaust hole 221. In this way, the radial gap between the sealing plug 222 and the sealing cavity 223 can be set very small, so that the sealing plug 222 can avoid shaking when sliding in the sealing cavity 223, and further prevent the sealing plug 222 and the sealing cavity 223 from colliding, avoiding the sealing plug 222 from jamming when sliding along the sealing cavity 223, or the sealing plug 222 and the sealing cavity 223 from producing abnormal noise due to collision. Further, in addition to the gap formed by the spiral groove 2221 of the sealing plug 222 and the sealing cavity 223, the gap between the sealing plug 222 and the sealing cavity 223 can be set very small, or even the sealing plug 222 can be sealed and slid with the sealing cavity 223 except for the spiral groove 2221, so that the sealing plug 222 can only slide along the axis of the sealing cavity 223, making the sliding of the sealing plug 222 more stable. In this case, the sealing seat 225 is provided on the plunger 22 corresponding to the position of the sealing plug 222, and when the sealing plug 222 and the sealing seat 225 are in contact, a seal is formed between the sealing plug 222 and the sealing seat 225. The arrangement between the sealing plug 222 and the sealing seat 225 can be referred to the foregoing description, which will not be described here.

[0043] In summary, the chain tensioner 2 provided by the embodiment of the application can discharge the air inside the chain tensioner 2 due to the exhaust hole 221, so that the chain tensioner 2 provides stable pressing force to the timing chain 1, and eliminates the abnormal sound of the engine timing chain 1.

[0044] The above-mentioned serial numbers of the embodiments of the application are only for description, and do not represent the advantages and disadvantages of the embodiments. The above is only the preferred embodiment of the application, and does not limit the patent scope of the application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A chain tensioner characterized by, The application relates to a chain tensioner. The chain tensioner comprises a housing, a hydraulic cavity with one side open, an oil inlet on the other side, the oil inlet being communicated with the hydraulic cavity; a plunger arranged in the hydraulic cavity and being in sliding seal with the hydraulic cavity, the plunger being provided with an exhaust hole communicated with the hydraulic cavity for exhausting air in the hydraulic cavity; a containing cavity open to the hydraulic cavity is arranged on the side of the plunger far from the exhaust hole, a plunger spring is arranged in the containing cavity, one end of the plunger spring abutting against the inner wall of the hydraulic cavity along the sliding direction of the plunger, and the other end of the plunger spring abutting against the inner wall of the containing cavity; a sealing plug is arranged on the plunger inside the exhaust hole, a sealing cavity corresponding to the sealing plug is arranged in the plunger, and the sealing plug can slide to the exhaust hole along the sealing cavity; a resilient member is arranged between the exhaust hole and the sealing plug, and the resilient member is used for moving the sealing plug away from the exhaust hole when the sealing cavity is not filled with oil. The plunger is provided with a containing cavity open to the hydraulic cavity on the side far from the sealing cavity, the exhaust hole is communicated with the hydraulic cavity through the sealing cavity and the containing cavity, and the exhaust hole is arranged at the highest position of the containing cavity. The sealing cavity is in a conical frustum structure, the diameter of the sealing cavity gradually decreases towards the exhaust hole, the sealing plug is in a conical frustum structure corresponding to the sealing cavity, and the gap between the sealing plug and the sealing cavity gradually decreases to sealing when the sealing plug slides to the exhaust hole. The sealing plug and the sealing cavity are in a cylindrical structure, and the diameter of the sealing plug is smaller than that of the sealing cavity. The sealing seat is in a boss structure, one side of the boss structure corresponding to the sealing plug is in a plane structure, the position of the sealing plug corresponding to the sealing seat is in a plane structure, and the sealing plug and the sealing seat form sealing when the sealing plug and the sealing seat are in contact.

2. The chain tensioner of claim 1, wherein The sealing seat is in an arc structure concave inward, the position of the sealing plug corresponding to the sealing seat is in an arc structure convex outward, and the sealing plug and the sealing seat form sealing when the sealing plug and the sealing seat are in contact.

3. The chain tensioner of claim 2, wherein The sealing plug and the sealing cavity are in a cylindrical structure, a sealing sliding fit gap is arranged between the sealing plug and the sealing cavity, a spiral groove is arranged on the side surface of the sealing plug, the spiral groove and the sealing cavity form a gap, a sealing seat corresponding to the position of the sealing plug is arranged on the plunger, and the sealing plug and the sealing seat form sealing when the sealing plug and the sealing seat are in contact.

4. The chain tensioner of claim 2, wherein The application further relates to an engine comprising a timing chain and the chain tensioner according to any one of claims 1 to 8 arranged on one side of the timing chain to keep the timing chain in a tensioned state.

5. The chain tensioner of claim 4, wherein ​ 6. The chain tensioner of claim 5, wherein, ​ 7. The chain tensioner of claim 5, wherein ​ 8. The chain tensioner of claim 2, wherein, ​ 9. An automobile characterized by comprising: ​ ​ ​

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