Buffer type variable flow valve and hydraulic tensioner

Abstract

The buffer type variable flow valve comprises a valve body, a valve element and two elastic components, the valve body is provided with an installation hole, the installation hole comprises a large-diameter section and a small-diameter section, the valve element is installed in the installation hole in a sliding mode, the peripheral wall of the valve element is attached to the inner wall of the small-diameter section, the interior of the large-diameter section is an inlet cavity, and the interior of the small-diameter section is an outlet cavity. The valve element is axially balanced under the action of the elastic component, a control flow channel is arranged on the peripheral wall of the valve element, in the axial balance state, the control flow channel is communicated with the inlet cavity and the outlet cavity, when the valve element moves close to the outlet cavity, the effective length of the control flow channel is gradually increased, and when the control flow channel is completely located in the small-diameter section, the effective length of the control flow channel is gradually increased. The control flow channel is isolated from the inlet cavity. According to the buffer type variable flow valve, the valve element can move along with the change of inlet oil pressure, the flow control and opening and closing functions of a control flow channel are achieved, the hydraulic rigidity and the damping characteristic of a hydraulic tensioner adopting the buffer type variable flow valve can be automatically adjusted, and different engine working conditions are considered.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic power, in particular to a buffer type variable flow valve and a hydraulic tensioner. Background Art

[0002] As the core component of the chain system, the hydraulic tensioner is responsible for tensioning the chain, compensating for chain wear and elongation, suppressing chain vibration, and reducing the dynamic impact of the system.

[0003] The hydraulic tensioner mainly includes a tensioner housing, a one-way valve, a piston, a spring and a throttle valve, etc. Figure 1 and Figure 2 As shown, a simple gear train of an engine is taken as an example. Under the condition of engine operation, the oil from the engine flows into the housing 13' through the oil inlet 11' and the one-way valve 12' of the hydraulic tensioner 1', and fills the high-pressure chamber formed by the piston 14'. Under the combined action of the oil pressure in the high-pressure chamber and the thrust of the spring 15', the piston 14' pushes the tensioning rail 2' in the axial direction, and the tensioning rail 2' presses the chain 3', thereby realizing the synchronous rotation and torque transmission of the driving wheel 4' and the driven wheel 5'. In this gear train, the fixed guide rail 6' is located at the tight side of the chain 3', playing a guiding role to avoid large shaking of the chain section 3'.

[0004] Because the chain 3' is also affected by the speed fluctuation of the driving wheel 4' and the periodic load change of the driven wheel 5' during operation, dynamic jitter and tension change occur, which in turn affects the phase accuracy of the driven wheel 5'. In severe cases, it may also cause abnormal noise or even dynamic problems such as tooth skipping. Therefore, the hydraulic tensioner 1' also needs to generate appropriate hydraulic damping by controlling the outflow speed of the oil in the high-pressure chamber to ensure that the chain system can operate stably under various engine operating conditions. For ordinary hydraulic tensioners, when compressed by force, the volume change of its high-pressure chamber depends on the diameter and displacement of the piston 14'. When the same displacement occurs, the larger the diameter of the piston 14', the more the oil in the high-pressure chamber needs to be compressed or discharged. At this time, the hydraulic stiffness of the hydraulic tensioner 1' is higher. In fact, the volume of the oil is difficult to be compressed. Therefore, the part of the oil whose volume in the high-pressure chamber is reduced needs to be discharged in time through the oil drain channel 16' and the oil return channel 17'. The size of these channels determines the oil outlet speed and damping characteristics of the hydraulic tensioner 1'.

[0005] In the structure of the hydraulic tensioner of the prior art, the size and length of the oil drain channel 16' and the oil return channel 17' are fixed after the design is locked. However, in practice, when the engine is in different speed ranges and operating conditions, the working conditions and load levels of the chain system are very different. The hydraulic stiffness and damping characteristics determined by the diameter of the piston 14' and the oil outlet speed of the hydraulic tensioner 1' are fixed. Therefore, its design must be hard enough to ensure that the chain 3' can be effectively tightened under high speed and high load of the engine and certain extreme conditions, and there will be no system instability and dynamic problems. However, such a design is not optimal for the medium and low speed partial load conditions that are more commonly used by users, because the tension and jitter of the chain 3' are not large under these conditions. If the hydraulic tensioner 1' can be made appropriately softer, the peak tension of the chain 3' can be reduced, smaller friction loss and noise can be obtained, and the reliability of parts can be improved.

[0006] Therefore, how to provide a buffered variable flow valve and a hydraulic tensioner so that the hydraulic stiffness and damping characteristics of the hydraulic tensioner can be automatically adjusted according to the actual working state, so as to better adapt to different operating conditions, and ensure that the chain system remains stable and reliable under extreme working conditions. The dynamic tension of the chain under normal working conditions can be significantly reduced, thereby reducing the friction loss of the chain system and improving its noise and reliability. This is a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0007] The purpose of the utility model is to provide a buffer type variable flow valve and a hydraulic tensioner, so that the hydraulic stiffness and damping characteristics of the hydraulic tensioner can be automatically adjusted according to the actual working state, so as to better adapt to different operating conditions, and on the premise of ensuring that the chain system remains stable and reliable under extreme working conditions, the dynamic tension of the chain under common working conditions is significantly reduced, thereby reducing the friction loss of the chain system and improving its noise and reliability.

[0008] In order to solve the above technical problems, the utility model provides a buffer type variable flow valve, comprising a valve body, a valve core and two elastic components, the valve body has an axially through mounting hole, the mounting hole comprises a large diameter section and a small diameter section, the valve core is slidably mounted inside the mounting hole, the peripheral wall of the valve core and the inner wall of the small diameter section are fitted, an inlet cavity is formed inside the large diameter section, an outlet cavity is formed inside the small diameter section at one end of the valve core, the two elastic components are mounted at the axial ends of the valve core, the valve core is in an axially balanced state under the action of the two elastic components, the peripheral wall of the valve core is provided with a control flow channel, and the valve core is configured as follows:

[0009] In the axial balanced state, the control flow channel connects the inlet chamber and the outlet chamber. When the valve core moves toward the outlet chamber, the effective length of the control flow channel gradually increases. When the valve core moves until the control flow channel is entirely located in the small-diameter section, the control flow channel is isolated from the inlet chamber.

[0010] The utility model buffer type variable flow valve has a special structural design of the valve core and the valve body, and the valve core can produce axial movement with the change of the inlet oil pressure, so as to realize the flow control and switching function of the control flow channel. For the hydraulic tensioner adopting the buffer type variable flow valve, its hydraulic stiffness and damping characteristics will be automatically adjusted according to the displacement of the piston and the actual operating state of the chain system, so as to better take into account different engine operating conditions, realize better chain system performance, and improve the NVH and mechanical efficiency of the engine.

[0011] Optionally, one of the elastic components is a control spring, the control spring is located inside the small-diameter section, and two axial ends of the control spring are respectively in contact with the valve core and an inner end wall of the small-diameter section.

[0012] Optionally, one of the elastic components is a return spring, the return spring is located inside the large diameter section, and two axial ends of the return spring are respectively in contact with the valve core and an inner end wall of the large diameter section.

[0013] Optionally, the valve core includes a valve core body and a protrusion, the protrusion is located at one end of the valve core body close to the large diameter section, a step surface is formed between the protrusion and the valve core body, and the corresponding end of the return spring is sleeved on the protrusion and abuts against the step surface.

[0014] Optionally, the valve body includes a valve seat and a valve bonnet, wherein one end of the valve seat close to the large diameter section is an open end, the valve bonnet is installed on the open end, and the inner end wall of the valve bonnet forms an abutment wall for abutting against the corresponding elastic component.

[0015] Optionally, the valve seat and the valve cap are fixed by interference fit or threaded connection.

[0016] Optionally, the control flow channel is a spiral flow channel arranged around the valve core.

[0017] Optionally, an oil leakage channel is further provided on the outer end wall of the valve body close to the small diameter section, the radial outer end of the oil leakage channel penetrates the peripheral wall of the valve body, and the radial inner end of the oil leakage channel is connected to the mounting hole.

[0018] Optionally, the oil leakage channel is in a spiral shape.

[0019] The utility model also provides a hydraulic tensioner, comprising a housing and a piston, wherein the piston is installed inside the housing, a high-pressure chamber is formed between the housing and the piston, and the piston is also provided with an oil drain hole.

[0020] It also includes the aforementioned buffer type variable flow valve, which is installed inside the piston, the outer peripheral wall portion of the buffer type variable flow valve is in contact with the inner wall of the piston, the inlet chamber of the buffer type variable flow valve is connected to the high pressure chamber, and the outlet chamber of the buffer type variable flow valve is connected to the oil drain hole.

[0021] The hydraulic tensioner of the utility model includes the aforementioned buffer type variable flow valve, and thus has the same technical effect as the aforementioned buffer type variable flow valve, which will not be described in detail herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the working principle of the hydraulic tensioner in the prior art;

[0023] Figure 2 for Figure 1 A simplified diagram of the application status of the hydraulic tensioner;

[0024] Figure 3 This is a structural schematic diagram of a specific embodiment of the buffer type variable flow valve provided by the utility model;

[0025] Figure 4 for Figure 1 Split diagram of the buffer type variable flow valve;

[0026] Figure 5 for Figure 1 Schematic diagram of the structure of the buffer variable flow valve in low tension and low damping mode;

[0027] Figure 6 for Figure 1 Schematic diagram of the structure of the buffer variable flow valve in variable damping transition mode;

[0028] Figure 7 for Figure 1 Schematic diagram of the structure of the buffer variable flow valve in high tension and high damping mode;

[0029] Figure 8 A structural schematic diagram of a specific embodiment of the hydraulic tensioner provided by the utility model;

[0030] Fig. 9 for Figure 8 Structural diagram of hydraulic tensioner;

[0031] Fig.10 for Figure 8 A simplified diagram of the application status of the hydraulic tensioner;

[0032] in, Figure 1-Figure 2 The reference numerals in the figures are described as follows:

[0033] 1'-hydraulic tensioner; 11'-oil inlet; 12'-check valve; 13'-housing; 14'-piston; 15'-spring; 16'-oil drain channel; 17'-oil return channel; 2'-tensioning rail; 3'-chain; 4'-driving wheel; 5'-driven wheel; 6'-fixed guide rail;

[0034] in, Figure 3-Figure 10 The reference numerals in the figures are described as follows:

[0035] 01-hydraulic tensioner; 1-buffered variable flow valve; 11-valve body; 111-valve seat; 112-valve bonnet; 11a-installation hole; 11a1-large diameter section; 11a2-small diameter section; 11b-oil drain channel; 12-valve core; 121-valve core body; 122-protrusion; 12a-control channel; I-inlet chamber; O-outlet chamber; 13-control spring; 14-reset spring; 2-housing; 3-piston; 3a-oil drain hole; A-high pressure chamber; 01a-oil inlet; 4-check valve; 5-spring;

[0036] 02-Tension rail;

[0037] 03-Chain. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0039] The “plurality” mentioned herein generally means more than two; and when “plurality” is used to indicate the number of certain components, it does not indicate the relationship between the quantities of these components.

[0040] Please refer to Figure 3-Figure 10 , Figure 3 This is a structural schematic diagram of a specific embodiment of the buffer type variable flow valve provided by the utility model; Figure 4 for Figure 1 Split diagram of the buffer type variable flow valve; Figure 5 for Figure 1 Schematic diagram of the structure of the buffer variable flow valve in low tension and low damping mode; Figure 6 for Figure 1 Schematic diagram of the structure of the buffer variable flow valve in variable damping transition mode; Figure 7 for Figure 1 Schematic diagram of the structure of the buffer variable flow valve in high tension and high damping mode; Figure 8 A structural schematic diagram of a specific embodiment of the hydraulic tensioner provided by the utility model; Fig. 9 for Figure 8Structural diagram of hydraulic tensioner; Fig.10 for Figure 8 Schematic diagram of the hydraulic tensioner in use.

[0041] The utility model provides a buffer type variable flow valve, comprising a valve body 11, a valve core 12 and two elastic components, the valve body 11 has an axially through mounting hole 11a, the mounting hole 11a comprises a large diameter section 11a1 and a small diameter section 11a2, the valve core 12 is slidably mounted inside the mounting hole 11a, the peripheral wall of the valve core 12 and the inner wall of the small diameter section 11a2 are fitted, an inlet cavity I is formed inside the large diameter section 11a1, an outlet cavity O is formed inside the small diameter section 11a2 at one end of the valve core 12, two elastic components are mounted at both axial ends of the valve core 12, the valve core 12 is in an axially balanced state under the action of the two elastic components, a control flow channel 12a is provided on the peripheral wall of the valve core 12, and the control flow channel 12a is configured as follows:

[0042] In the axially balanced state, the control flow channel 12a connects the inlet chamber I and the outlet chamber O. When the valve core 12 moves toward the outlet chamber O, the effective length of the control flow channel 12a gradually increases. When the valve core 12 moves until the control flow channel 12a is entirely located in the small-diameter section 11a2, the control flow channel 12a is isolated from the inlet chamber I.

[0043] When the buffer variable flow valve 1 of the utility model is applied to the hydraulic tensioner 01, Figure 8 As shown, the hydraulic tensioner 01 includes a housing 2 and a piston 3. The piston 3 is installed inside the housing 2. A high-pressure chamber A is formed between the housing 2 and the piston 3. The piston 3 is also provided with an oil drain hole 3a. The buffered variable flow valve 1 is installed inside the piston 3. The outer peripheral wall portion of the buffered variable flow valve 1 fits the inner wall of the piston 3. The inlet chamber I of the buffered variable flow valve 1 is connected to the high-pressure chamber A, and the outlet chamber O of the buffered variable flow valve 1 is connected to the oil drain hole 3a. That is, the oil in the high-pressure chamber A of the hydraulic tensioner 01 can enter the inlet chamber I of the buffered variable flow valve 1 under the action of pressure, and then enter the outlet chamber O of the buffered variable flow valve 1 through the control flow channel 12a, and finally directly flow out of the hydraulic tensioner 01 from the oil drain hole 3a.

[0044] Please combine Fig. 9 and Fig.10Understand, taking a simple gear train as an example, the engine oil from the engine flows into the housing 2 through the oil inlet 01a of the hydraulic tensioner 01 and the one-way valve 4, and pushes the piston 3 out together with the spring 5, and presses the tensioning rail 02 and the chain 03. During the operation of the chain system, with the dynamic change of the tension of the chain 03 and the swing of the tensioning rail 02, the piston 3 will also have a certain reciprocating motion. The hydraulic tensioner 01 using the buffered variable flow valve 1 of the utility model does not show a single hydraulic stiffness and damping characteristics. On the contrary, the buffered variable flow valve 1 can automatically change the damping characteristics of the hydraulic tensioner 01 according to the operating conditions of the chain system. Specifically:

[0045] like Figure 5 As shown, when the engine is running at a medium and low speed and partial load, the chain system runs smoothly, the average tension of the chain 03 is low, the oil pressure in the high-pressure chamber A of the hydraulic tensioner 01 is also low, the effective length of the control flow channel 12a is short, and the oil in the high-pressure chamber A of the hydraulic tensioner 01 can flow out quickly through the control flow channel 12a. At this time, the oil outlet speed is fast, the hydraulic stiffness of the hydraulic tensioner 01 is low, and the hydraulic tensioner 01 works in a low tension and small damping mode, which is conducive to reducing the dynamic tension of the chain 03, so that the chain system has better noise performance and lower friction loss;

[0046] like Figure 6 As shown, as the rotation speed and load of the chain system increase, the average tension of the chain 03 increases, the vibration of the chain 03 and the swing amplitude of the tensioning rail 02 increase. At this time, the oil pressure of the high-pressure chamber A of the hydraulic tensioner 01 is also higher, and the valve core 12 will move to the outlet side under the push of the oil pressure. As the control spring 13 is compressed more, the spring force of the control spring 13 also increases rapidly, and the effective length of the control flow channel 12a will also increase. The oil outlet speed of the hydraulic tensioner 01 slows down accordingly, and the volume change of the high-pressure chamber A caused by the piston 3 being continuously pressed in increases. The hydraulic stiffness of the hydraulic tensioner 01 is higher, thereby providing stronger supporting force. The hydraulic tensioner 01 is in a variable damping transition mode, which can better balance the dynamic tension and vibration of the chain 03 and optimize the performance of the chain system.

[0047] like Figure 7As shown, when the chain system runs at high speed and high load or encounters other extreme working conditions, the average tension of the chain 03 is extremely high, and the jitter increases significantly, the oil pressure in the high-pressure chamber A of the hydraulic tensioner 01 will also be very high, and the control spring 13 will be greatly compressed, and then the valve core 12 moves to when the control flow channel 12a is completely located in the small diameter section 11a2, the control flow channel 12a is separated from the inlet chamber I, and the control flow channel 12a is closed. At this time, the oil outlet speed of the hydraulic tensioner 01 will be greatly reduced, and the hydraulic tensioner 01 works in a high tension, large damping mode, so that it can more effectively support the tensioning rail 02, avoid the jitter of the chain 03 and the excessive phase deviation of the driven object, as well as the occurrence of other chain system dynamic problems such as abnormal noise and tooth jumping.

[0048] In summary, the buffered variable flow valve 1 of the utility model has a special structural design of the valve core 12 and the valve body 11, and the valve core 12 can produce axial movement with the change of the inlet oil pressure, thereby realizing the flow control and switching function of the control flow channel 12a. For the hydraulic tensioner 01 using the buffered variable flow valve 1, its hydraulic stiffness and damping characteristics will be automatically adjusted according to the displacement of the piston 3 and the actual operating state of the chain system, so that when the hydraulic tensioner 01 is subjected to the dynamic impact of the chain system, its supporting force is initially soft, and gradually becomes harder with the displacement of the piston 3, thereby providing effective support, controlling the swing amplitude of the tensioning rail 02 and the shaking of the chain 03, and playing a certain buffering role, effectively reducing the peak value of the dynamic tension of the chain 03, and then the hydraulic tensioner 01 using the buffered variable flow valve 1 can better take into account different engine operating conditions, achieve better chain system performance, and improve the engine's NVH and mechanical efficiency.

[0049] The aforementioned “effective length of the control flow channel 12a” refers to the flow path of the oil when it flows through the control flow channel 12a. Figure 5-Figure 7 It can be seen that as the valve core 12 moves toward the outlet cavity O, the flow path of the engine oil flowing through the control flow channel 12a gradually increases until the control flow channel 12a is disconnected from the inlet cavity I.

[0050] Among them, Figure 5 As shown, among the two elastic components mentioned above, one of the elastic components is a control spring 13, which is located inside the small diameter section 11a2, and the axial ends of the control spring 13 respectively abut against the valve core 12 and the inner end wall of the small diameter section 11a2; the other elastic component is a return spring 14, which is located inside the large diameter section 11a1, and the axial ends of the return spring 14 respectively abut against the valve core 12 and the inner end wall of the large diameter section 11a1.

[0051] In this way, under the action of the control spring 13 and the return spring 14, the valve core 12 can be in an axially balanced state. By reasonably designing the stiffness of the control spring 13 and the return spring 14, the hydraulic stiffness and damping characteristics of the hydraulic tensioner 01 can be adjusted to adapt to the actual operating conditions of the engine.

[0052] like Figure 5 It can be seen that the diameter of the control spring 13 can be substantially equal to the inner diameter of the small diameter section 11a2, and the small diameter section 11a2 can guide and limit the control spring 13, so that the control spring 13 can only be compressed in the axial direction.

[0053] like Figure 4 and Figure 5 As shown, in this embodiment, the valve core 12 includes a valve core body 121 and a protrusion 122. The protrusion 122 is located at one end of the valve core body 121 close to the large diameter section 11a1. A step surface is formed between the protrusion 122 and the valve core body 121. The corresponding end of the return spring 14 is sleeved on the protrusion 122 and abuts against the step surface.

[0054] As configured above, the protrusion 122 can guide and limit the return spring 14, so that the return spring 14 is stably installed between the valve core 12 and the inner end wall of the large diameter section 11a1, so that the return spring 14 only expands and contracts axially, reducing the possibility of other structural deformation of the return spring 14.

[0055] The diameter of the protrusion 122 gradually decreases in a direction away from the valve core body 121 , so that the corresponding end of the return spring 14 can be more conveniently fitted onto the protrusion 122 .

[0056] In practice, the valve core 12 is not limited to the above-mentioned structural form. For example, it is also feasible to set a mounting groove at one end of the inner end wall of the valve core 12 facing the large diameter section 11a1, and the reset spring 14 is partially installed inside the mounting groove, and the mounting groove plays a guiding and limiting role for the reset spring 14.

[0057] Please continue to refer to Figure 4 and Figure 5 The valve body 11 includes a valve seat 111 and a valve bonnet 112. The end of the valve seat 111 close to the large diameter section 11a1 is an open end. The valve bonnet 112 is installed at the open end. The inner end wall of the valve bonnet 112 forms an abutment wall, which is used to abut against the corresponding elastic component.

[0058] Thus, during the assembly of the buffer type variable flow valve 1, the valve cap 112 can be disassembled first, and then the control spring 13, the valve core 12 and the return spring 14 are sequentially installed inside the mounting hole 11a, and then the valve cap 112 is installed on the open end of the valve seat 111. It can be seen that the valve body 11 adopts a split structure of the valve seat 111 and the valve cap 112, which facilitates the assembly of the buffer type variable flow valve 1.

[0059] There is no limitation on the connection method between the valve seat 111 and the valve cap 112 , for example, the two can be connected by interference fit or threaded connection.

[0060] like Figure 5 As shown, the valve cap 112 includes an axially connected first connecting section and a second connecting section, the diameter of the first connecting section at the connection with the second connecting section is larger than the diameter of the second connecting section, an abutment wall is formed between the first connecting section and the second connecting section, and the diameter of the first connecting section gradually decreases in a direction away from the second connecting section. In the installed state, the second connecting section is inserted into the inside of the valve seat 111, and the opening end wall of the valve seat 111 and the abutment wall abut against each other.

[0061] like Figure 4 As shown, in this embodiment, the control flow channel 12 a is a spiral flow channel arranged around the valve core 12 .

[0062] It is understandable that in actual applications, the number of control channels 12a can be one or more, and the path and shape of the control channel 12a are not limited, as long as the effective length and on-off of the control channel 12a can change with the position of the valve core 12.

[0063] In addition, in this embodiment, the flow areas of the control channel 12a in different cross sections are roughly equal. In actual applications, when the valve core 12 moves toward the outlet cavity O, it is also feasible to gradually reduce the minimum flow area of ​​the control channel 12a, which can further reduce the oil outlet speed of the high-pressure cavity A.

[0064] Please continue to refer to Figure 3 In this embodiment, an oil leakage channel 11b is further provided on the outer end wall of the valve body 11 near the small diameter section 11a2, the radial outer end of the oil leakage channel 11b penetrates the peripheral wall of the valve body 11, and the radial inner end of the oil leakage channel 11b is connected to the mounting hole 11a.

[0065] In this way, when the buffered variable flow valve 1 of the utility model is applied to the hydraulic tensioner 01, the engine oil inside the high-pressure chamber A can also flow to one end close to the oil drain hole 3a through the fitting clearance between the buffered variable flow valve 1 and the piston 3, and then drain to the outside through the oil drain channel 11b.

[0066] In practical applications, whether the oil drain channel 11 b needs to be provided can be determined based on the design calculation and dynamic performance test results of the chain system.

[0067] Depend on Figure 3 It can be seen that in this embodiment, the shape of the oil leakage channel 11b is a spiral line. It can be understood that in actual applications, the path and shape of the oil leakage channel 11b are not limited as long as the oil leakage can be achieved.

[0068] The utility model also provides a hydraulic tensioner 01, comprising a housing 2 and a piston 3, wherein the piston 3 is installed inside the housing 2, a high-pressure chamber A is formed between the housing 2 and the piston 3, and the piston 3 is also provided with an oil drain hole 3a.

[0069] It also includes the aforementioned buffer type variable flow valve, the buffer type variable flow valve 1 is installed inside the piston 3, the outer peripheral wall portion of the buffer type variable flow valve 1 is in contact with the inner wall of the piston 3, the inlet chamber I of the buffer type variable flow valve 1 is connected to the high pressure chamber A, and the outlet chamber O of the buffer type variable flow valve 1 is connected to the oil drain hole 3a.

[0070] The hydraulic tensioner 01 of the utility model includes the aforementioned buffer type variable flow valve 1, and thus has the same technical effect as the aforementioned buffer type variable flow valve 1, which will not be described in detail herein.

[0071] In addition, the hydraulic tensioner 01 can also decide whether to set up an oil return channel to achieve bypass oil return based on the design calculation and dynamic performance test results of the chain system.

[0072] The above is a detailed introduction to a buffered variable flow valve and a hydraulic tensioner provided by the utility model. This article uses specific examples to illustrate the principle and implementation of the utility model. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A buffer type variable flow valve, characterized in that: The invention comprises a valve body (11), a valve core (12) and two elastic components, wherein the valve body (11) has an axially through-going mounting hole (11a), the mounting hole (11a) comprises a large-diameter section (11a1) and a small-diameter section (11a2), the valve core (12) is slidably mounted inside the mounting hole (11a), the peripheral wall of the valve core (12) and the inner wall of the small-diameter section (11a2) are in contact with each other, an inlet cavity (I) is formed inside the large-diameter section (11a1), and an outlet cavity (O) is formed inside the small-diameter section (11a2) at one end of the valve core (12), the two elastic components are mounted at two axial ends of the valve core (12), the valve core (12) is in an axially balanced state under the action of the two elastic components, the peripheral wall of the valve core (12) is provided with a control flow channel (12a), and the valve core (12) is configured as follows: In the axially balanced state, the control flow channel (12a) connects the inlet chamber (I) and the outlet chamber (O); when the valve core (12) moves in a direction close to the outlet chamber (O), the effective length of the control flow channel (12a) gradually increases; when the valve core (12) moves until the control flow channel (12a) is completely located in the small-diameter section (11a2), the control flow channel (12a) is isolated from the inlet chamber (I).

2. The buffer type variable flow valve according to claim 1, characterized in that: One of the elastic components is a control spring (13), the control spring (13) is located inside the small-diameter section (11a2), and two axial ends of the control spring (13) are respectively in contact with the valve core (12) and the inner end wall of the small-diameter section (11a2).

3. The buffer type variable flow valve according to claim 1, characterized in that: One of the elastic components is a return spring (14), the return spring (14) is located inside the large diameter section (11a1), and the axial ends of the return spring (14) are respectively in contact with the valve core (12) and the inner end wall of the large diameter section (11a1).

4. The buffer type variable flow valve according to claim 3, characterized in that: The valve core (12) comprises a valve core body (121) and a protrusion (122), wherein the protrusion (122) is located at one end of the valve core body (121) close to the large diameter section (11a1), a step surface is formed between the protrusion (122) and the valve core body (121), and a corresponding end of the return spring (14) is sleeved on the protrusion (122) and abuts against the step surface.

5. The buffer type variable flow valve according to any one of claims 1 to 4, characterized in that: The valve body (11) comprises a valve seat (111) and a valve bonnet (112); an end of the valve seat (111) close to the large diameter section (11a1) is an open end; the valve bonnet (112) is mounted on the open end; an inner end wall of the valve bonnet (112) forms an abutment wall, and the abutment wall is used to abut against the corresponding elastic component.

6. The buffer type variable flow valve according to claim 5, characterized in that: The valve seat (111) and the valve cap (112) are fixed by interference fit or threaded connection.

7. The buffer type variable flow valve according to any one of claims 1 to 4, characterized in that: The control flow channel (12a) is a spiral flow channel arranged around the valve core (12).

8. The buffer type variable flow valve according to any one of claims 1 to 4, characterized in that: An oil leakage channel (11b) is also provided on the outer end wall of the valve body (11) close to the small diameter section (11a2); the radial outer end of the oil leakage channel (11b) penetrates the peripheral wall of the valve body (11), and the radial inner end of the oil leakage channel (11b) is connected to the mounting hole (11a).

9. The buffer type variable flow valve according to claim 8, characterized in that: The oil leakage channel (11b) is in the shape of a spiral line.

10. A hydraulic tensioner, comprising a housing (2) and a piston (3), wherein the piston (3) is mounted inside the housing (2), a high-pressure chamber (A) is formed between the housing (2) and the piston (3), and the piston (3) is further provided with an oil drain hole (3a), characterized in that: It also includes the buffer type variable flow valve as described in any one of claims 1 to 9, wherein the buffer type variable flow valve (1) is installed inside the piston (3), the outer peripheral wall portion of the buffer type variable flow valve (1) is in contact with the inner wall of the piston (3), the inlet chamber (I) of the buffer type variable flow valve (1) is connected to the high pressure chamber (A), and the outlet chamber (O) of the buffer type variable flow valve (1) is connected to the oil drain hole (3a).

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