Centrifugal self-opening and closing fan clutch

Abstract

The present invention provides a centrifugal self-opening and closing fan clutch, including an oil storage chamber, an engagement chamber and a drive shaft connected to the end of an engine shaft, the drive shaft is connected to an active plate, the active plate is provided with an oil passage for connecting the oil storage chamber and the engagement chamber, and also includes a valve core assembly and a counterweight block arranged in a split manner, the counterweight block rotates synchronously with the drive shaft and can move radially along the drive shaft, the counterweight block is provided with an elastic member for driving the counterweight block to slide toward the inner end, and the valve core assembly includes a valve core body for opening and closing the oil passage and an elastic unit for driving the valve core body to open the oil passage. The opening and closing of the valve core is achieved by the sliding of the counterweight block, and the counterweight block is driven to slide by centrifugal force, and the valve core can only be opened when the centrifugal force completely overcomes the elastic force of the elastic member, so that the valve core will not be opened when the engine is cold started or the speed is low, and the silicone oil in the oil storage chamber cannot flow into the engagement chamber.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile engine cooling, and in particular relates to a fan clutch on an automobile engine. Background Art

[0002] The general working principle of the silicone oil fan clutch on the automobile engine is: the engine is connected to the active plate in the clutch, driving the active plate to rotate with the engine. When the valve plate mechanism receives the PWM pulse opening signal, the valve plate opens the oil outlet port connecting the oil storage chamber and the working tank. The silicone oil in the oil storage chamber of the active plate will enter the working tank through the oil outlet hole under the action of centrifugal force. Due to the high viscosity of silicone oil, the viscous shear force of silicone oil prompts the clutch active plate to drive the front cover plate and rear housing of the clutch through silicone oil to rotate with the active plate, thereby driving the fan fixed on the rear housing to rotate. The more silicone oil there is in the maze groove of the working chamber, the greater the torque transmitted by the clutch, the smaller the slip of the clutch, the higher the speed of the corresponding fan, and the increase in air volume; when the valve mechanism receives the PWM pulse closing signal, the valve closes the oil outlet, and the silicone oil in the oil storage chamber no longer enters the working groove. At the same time, the silicone oil in the working groove flows back to the oil storage chamber through the oil return channel under the action of centrifugal force. In this way, the silicone oil in the working groove is reduced, the torque transmitted by the clutch becomes smaller, the slip increases, the fan speed decreases, and the air volume decreases.

[0003] Generally, when the engine is in the parked state, the oil outlet port of the electronically controlled silicone oil clutch oil storage chamber is generally in an open state, because such a setting can ensure that when the vehicle's circuit system fails and there is no power, the electronic control components will not work. However, the silicone oil outlet through-hole is open, and the silicone oil is in a working state, ensuring that the fan rotates at high speed to cool the engine. At this time, the silicone oil is in the lower part of the oil storage chamber due to gravity. If the oil outlet port happens to be in the lower part of the oil storage chamber, the silicone oil in the oil storage chamber will flow from the oil storage chamber to the working groove of the clutch through the oil outlet port and the oil outlet through-hole. When the engine is started from a cold car, there is no need for the fan to rotate to cool the engine. However, the silicone oil that leaks into the working tank when the car is parked causes the clutch to be in a working state that drives the fan to rotate at high speed, that is, a high engagement state with relatively small slip. In addition, when the cold car is started, the engine speed is not high, and the corresponding speed of the clutch active plate is also relatively low. The silicone oil in the clutch working tank lacks power to return oil, and the return amount is not large. Therefore, oil leakage when the car is parked not only consumes the energy of the engine unnecessarily, but more importantly, the unnecessary cold car heat dissipation of the engine increases the normal preheating time of the engine, thereby increasing the cold car wear of the engine, unnecessarily consuming energy, and increasing the energy consumption of the whole vehicle. The extended engine preheating time also seriously affects the working performance of the engine.

[0004] Chinese patent CN113503208A discloses a dual-valve electronically controlled silicone oil fan clutch, which has a main valve plate and an auxiliary valve plate for controlling the opening and closing of the oil circuit. When the main valve plate is not under stress, it opens the passage from the oil storage chamber to the meshing chamber, and the auxiliary valve plate closes the passage from the oil storage chamber to the meshing chamber. When the auxiliary valve plate is under stress, it connects the passage from the oil storage chamber to the meshing chamber. It realizes the opening and closing of the oil circuit in the fan clutch under different working conditions of the vehicle through two groups of valve plates. However, too many valve plate structures will inevitably lead to the complication of the fan clutch. At the same time, it must be ensured that the two groups of valve plates will not interfere with each other. The eccentrically arranged auxiliary valve plate will also affect the mass distribution of the fan clutch and easily cause the fan clutch to be unbalanced. Its auxiliary valve plate is a swing valve structure, which needs to ensure the closure of the oil channel when the engine crankshaft is in a specific position, and it also needs to close the oil channel and disconnect the clutch when the engine is at a low speed, so as to ensure that the engine heats up quickly and reduce energy consumption.

[0005] In addition, there is a solution in the prior art that uses centrifugal force as a driving force to open the oil channel. A flower-shaped valve core that can block the oil outlet and oil return ports is set on the oil storage chamber oil outlet and oil return ports, and a reset elastic member and a centrifugal member act on the valve core. The centrifugal force is used to overcome the reset force of the reset elastic member on the valve core so that the valve core moves to a position that avoids the oil channel and opens the oil channel. However, the valve core and the centrifugal member are basically an integrated structure, and the centrifugal member is even the valve core itself, which is opened and closed by the sliding of the valve core on the active plate surface. In this way, the sliding surface of the valve core must be parallel to the radial direction of the active plate, and a flat plane parallel to the radial direction of the active plate needs to be found on the radial direction of the active plate to arrange the valve core and the oil port. However, for the active plate of some fan clutches, due to fluid mechanics or to facilitate the arrangement of surrounding components, its shape is not a complete flat plate structure, and even a relatively flat plane cannot be found on it. The valve core structure that slides radially must be arranged on a complete plane parallel to the radial direction to simultaneously form a sliding fit and a sealing fit. In other words, the valve core structure scheme in the comparative application can only be applied to a flat active plate. At the same time, since the valve core structure directly serves as or is directly connected to the centrifugal acting part, that is, the valve core needs to have a certain weight while serving as a sealing part, so the material selection of the valve core has higher requirements, and due to the limited position of the valve core, it is impossible to arrange a larger size of the reset elastic part and the centrifugal acting part. In the case of a smaller size, the valve core also needs to be adapted for sliding fit and sealing fit at the same time, and the relevant adjustment parameters of the two matching relationships interfere with each other. Summary of the invention

[0006] The object of the present invention is to provide a centrifugal self-opening and closing fan clutch, which avoids the restriction of the active disk structure itself on the shape and opening and closing direction of the valve core.

[0007] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0008] A centrifugal self-opening and closing fan clutch comprises an oil storage chamber, an engagement chamber and a driving shaft for connecting to the end of an engine shaft, an active plate is connected to the driving shaft, the inner ring plate surface of the active plate is the oil storage chamber wall, the outer ring plate surface of the active plate is the engagement chamber wall, an oil passage for connecting the oil storage chamber and the engagement chamber is arranged on the active plate, and also comprises a valve core assembly and a counterweight block arranged in a split manner, the counterweight block rotates synchronously with the driving shaft and can move along the radial direction of the driving shaft, an elastic member for driving the counterweight block to slide toward the inner end is arranged on the counterweight block, the valve core assembly comprises a valve core body for opening and closing the oil passage and an elastic unit for driving the valve core body to open the oil passage, when the counterweight block moves toward the driving shaft, the counterweight block presses the valve core body, so that the valve core body can overcome the elastic force of the elastic unit and gradually close the oil passage; when the counterweight block moves toward the direction away from the driving shaft, the elastic force of the elastic unit causes the valve core body to gradually open the oil passage.

[0009] In the above scheme, the opening and closing of the valve core is realized by the sliding of the counterweight block, and the counterweight block is driven to slide by centrifugal force. The valve core can only be opened when the centrifugal force completely overcomes the elastic force of the elastic member. In this way, the valve core will not be opened when the engine is cold started or the speed is low, and the silicone oil in the oil storage chamber cannot flow into the meshing chamber. Both of these working conditions are working conditions where the engine does not need excessive heat dissipation, thereby improving the cold start performance of the engine. Therefore, the fan clutch of the present application can prevent the silicone oil in the oil storage chamber from leaking into the meshing chamber when the car is parked or idling. After the cold car is started, the clutch will not engage to drive the cooling fan to cool the engine unnecessarily, thereby minimizing the cold car wear and the overall energy consumption of the car, and making the clutch completely engaged, responsive, and shortening the reaction time, greatly improving the performance and efficiency of the clutch and the engine. At the same time, the valve core and the counterweight are designed separately. The opening and closing of the valve core is achieved by the pressure between the counterweight and the valve core. The counterweight that slides radially is not directly arranged on the active plate, so the stroke, size, and shape of the counterweight are not overly restricted by the shape of the active plate. The counterweight and the elastic parts on the counterweight are easier to adapt and adjust according to the engine speed. The valve core and the oil channel can be arranged within the stroke range of the counterweight, and the axial or radial opening and closing of the valve core can be set only by changing the pressure position of the counterweight and the valve core. Similarly, since there is no need to limit the opening and closing direction of the valve core, the valve core can adapt to various shapes of the active plate, and is no longer limited to the valve core arranged to slide along the active plate surface, nor is it limited to flat-type active plates.

[0010] Preferably, a plurality of counterweights are evenly spaced apart along the circumference of the drive shaft.

[0011] Preferably, the oil passage is a radial hole arranged on the wall of the meshing cavity, the valve core is an annular structure which is sleeved on the driving shaft and rotates coaxially therewith, the annular structure and the end of the radial hole located in the oil storage cavity form an opening and closing cooperation, the annular structure is arranged between the counterweight block and the active plate, the elastic unit makes the annular structure have a tendency to detach from the end of the radial hole located in the oil storage cavity, the annular structure includes an inclined surface arranged downward from the inside to the outside, and the upper surface of the inclined surface abuts against the lower end surface of the counterweight block.

[0012] Preferably, the outer end of the inclined surface is provided with a downwardly bent flange forming a valve disc, and the position of the active plate corresponding to the flange is provided with an annular surface, and one end of the radial hole located in the oil storage chamber is located on the annular surface. When the counterweight block moves toward the drive shaft and presses against the circular ring structure, the flange fits the annular surface and blocks the radial hole. When the counterweight block moves away from the drive shaft, the flange separates from the annular surface and opens the radial hole.

[0013] Preferably, an annular groove is provided on the upper end surface of the active plate, the outer side wall of the annular groove is an annular surface, a vertical guide wall is provided on the upper end of the annular surface, the upper surface of the oil storage cavity wall protrudes upward to form an annular boss, the outer peripheral wall of the annular boss constitutes the inner side wall of the annular groove, and the annular surface is a structure inclined outward from bottom to top.

[0014] Preferably, the elastic unit is a vertically arranged compression spring, the inner ring of the annular structure is provided with an annular edge, and the compression spring is connected between the annular edge and the wall of the oil storage chamber.

[0015] Preferably, the annular boss presses against the circular ring structure to form an elastic deformation area on the circular ring structure, and the elastic deformation area constitutes the elastic unit.

[0016] Preferably, there are multiple inclined surfaces, each of which is fan-shaped, and the multiple inclined surfaces are evenly spaced axially. The inner ends of the inclined surfaces are connected to the annular edges. There are multiple radial holes and counterweight blocks, and the multiple radial holes and counterweight blocks are evenly spaced axially. The flanges at the outer ends of each inclined surface correspond to the positions of one of the radial holes and counterweight blocks, and the restoring forces of the elastic parts on at least two of the counterweight blocks are different in magnitude.

[0017] Preferably, an even number of the inclined surfaces are provided, and the elastic forces of the elastic members on the two counterweight blocks symmetrically arranged relative to the axis core of the drive shaft are the same.

[0018] Preferably, the oil channel is a through hole axially penetrating the oil storage chamber wall, the valve core is a spring piece connected to the upper surface of the oil storage chamber wall, the outer end of the spring piece is connected to the oil storage chamber wall, the inner end of the spring piece is a free end, the spring piece is arranged downwardly inclined from the inside to the outside, the upper surface of the spring piece is pressed against the lower end surface of the counterweight block and an elastic deformation area is formed on the spring piece, the spring piece and one end of the through hole located in the oil storage chamber form an opening and closing fit, and the elastic deformation area constitutes the elastic unit.

[0019] Preferably, there are multiple spring sheets, which are evenly spaced circumferentially, there are multiple through holes and counterweight blocks, which are evenly spaced axially, each of the spring sheets corresponds to a through hole and a counterweight block, and the restoring forces of the elastic parts on at least two of the counterweight blocks are different in magnitude.

[0020] Preferably, the spring pieces are arranged in an even number, and the elastic forces of the elastic members on the two counterweight blocks symmetrically arranged relative to the axis core of the drive shaft are the same.

[0021] Preferably, the guide wall is arranged to protrude upward along the axial direction, and a shell is provided on the outer side of the guide wall to separate the oil storage chamber and the engagement chamber. The elastic member is connected between the shell and the counterweight block, and the elastic member applies radial elastic force to the counterweight block.

[0022] Preferably, a guide rod is radially arranged on the driving shaft, a radial guide groove or guide hole is opened on the counterweight block, the guide groove or guide hole and the guide rod form a plug-in sliding fit, the counterweight block is arranged above the valve core, and the lower end face of the counterweight block is arranged in contact with the upper surface of the valve core.

[0023] Preferably, the counterweight block is an arc-shaped section structure, and when the drive shaft is stationary, the ends of adjacent counterweight blocks fit together, and the counterweight blocks together form a ring structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the three-dimensional structure of the valve core in the closed state of this application;

[0025] Figure 2 This is a three-dimensional structural diagram of the valve core in the open state of this application;

[0026] Figure 3 It is a schematic diagram of a counterweight block sleeved on a guide rod;

[0027] Figure 4 This is a top view of this application;

[0028] Figure 5 , 6 It is a three-dimensional structural schematic diagram of a circular ring structure;

[0029] Figure 7 This is a cross-sectional view of a valve core in a closed state in Embodiment 1 of the present application;

[0030] Figure 8 This is a cross-sectional view of the valve core in the open state of the first embodiment of the present application;

[0031] Fig. 9 This is a cross-sectional view of the valve core in the closed state of the second embodiment of the present application;

[0032] Fig.10 This is a cross-sectional view of the valve core in the open state of the second embodiment of the present application;

[0033] Explanation of the reference numerals: 10, driving shaft; 11, guide rod; 20, oil storage chamber; 30, meshing chamber; 40, active plate; 41, oil storage chamber wall; 42, meshing chamber wall; 43, radial hole; 44, guide wall; 45, through hole; 46, annular surface; 50, circular ring structure; 51, flange; 52, annular edge; 53, compression spring; 54, inclined surface; 60, counterweight; 61, lower surface; 62, elastic member; 70, shell; 80, spring. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0035] In the description of the present application, it should be noted that the orientation or position relationship indicated by the terms "bottom", "outside", "front and back", etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0036] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] like Figure 1 , 2As shown, a centrifugal self-opening and closing fan clutch comprises an oil storage chamber 20, a meshing chamber 30 and a drive shaft 10 for connecting to the end of the engine shaft, the drive shaft 10 is connected to an active plate 40, the inner plate surface of the active plate 40 is an oil storage chamber wall 41, the outer plate surface of the active plate 40 is a meshing chamber wall 42, the active plate 40 is provided with an oil passage for connecting the oil storage chamber 20 and the meshing chamber 30, and also comprises a valve core assembly and a counterweight block 60 arranged in a split manner, the counterweight block 60 rotates synchronously with the drive shaft 10 and can rotate along the drive shaft The moving shaft 10 moves radially, and the counterweight block 60 is provided with an elastic member 62 for driving the counterweight block 60 to slide toward the inner end. The valve core assembly includes a valve core body for opening and closing the oil passage and an elastic unit for driving the valve core body to open the oil passage. When the counterweight block 60 moves toward the direction close to the driving shaft 10, the counterweight block 60 will press the valve core body, so that the valve core body can overcome the elastic force of the elastic unit and gradually close the oil passage; when the counterweight block 60 moves away from the driving shaft 10, the elastic force of the elastic unit causes the valve core body to gradually open the oil passage.

[0038] In the above scheme, the inner circle of the active plate 40 refers to the position close to the drive shaft 10, and the outer circle refers to the position away from the drive shaft 10. When the engine rotates, the drive shaft 10 will be driven to rotate, so that the counterweight 60 will move to the position away from the axis of the drive shaft 10 under the action of centrifugal force, thereby avoiding the open position of the valve core, and then the valve core can reach the open position under the action of the elastic unit to open the oil channel port, and then the silicone oil in the oil storage chamber 20 can enter the meshing chamber 30 through the oil channel. In this way, the active plate 40 can drive the fan to rotate through the silicone oil, thereby achieving the closure of the clutch. When the engine is stopped, the counterweight 60 will approach the drive shaft 10 under the elastic force of the elastic member 62, and then press the valve core to close the oil channel port when it is close to the drive shaft 10, thereby closing the oil channel, so that when the engine is stopped, the silicone oil in the oil storage chamber 20 cannot flow into the meshing chamber 30, so that the fan clutch is in a disengaged state when the engine is started, thereby improving the cold start performance of the engine. The opening and closing of the valve core is realized by the sliding of the counterweight 60, and the counterweight 60 is driven to slide by the centrifugal force. The valve core can only be opened when the centrifugal force completely overcomes the elastic force of the elastic member 62. In this way, the valve core will not be opened when the engine is cold started or the speed is low, and the silicone oil in the oil storage chamber 20 cannot flow into the meshing chamber 30. Both of these working conditions are working conditions where the engine does not need excessive heat dissipation. Therefore, the electronically controlled silicone oil fan clutch of the present application can prevent the silicone oil in the oil storage chamber 20 from leaking into the meshing chamber 30 when the car is parked, and the silicone oil in the original meshing chamber 30 will return to the oil storage chamber 20 through the return oil pipe. After the cold car is started, the clutch will not engage to drive the cooling fan to cool the engine unnecessarily, which minimizes the wear of the cold car and the overall energy consumption of the car, and makes the clutch completely engaged, sensitive, and shortened. The performance and efficiency of the clutch and the engine are greatly improved. At the same time, the present application provides a linear sliding counterweight 60 structure, which is easier to arrange and more convenient to inspect and maintain, and avoids the use of a complex swing block and ring valve structure. The linear sliding counterweight 60 is easier to adapt to the elastic force of the elastic member 62, and its elastic force changes linearly. When the centrifugal force is between the maximum elastic force and the minimum elastic force when the elastic member 62 is stretched, the opening of a single oil channel can be controlled according to the change in the centrifugal force, so that the silicone oil outflow speed changes according to the speed, and the clutch engagement performance can be gradually improved according to the heat dissipation requirements. The elastic unit of the valve core can be its own elastic force or a compression spring or other structure.

[0039] At the same time, the valve core and the counterweight 60 are designed separately, and the opening and closing of the valve core is achieved by the pressure between the counterweight 60 and the valve core. The counterweight 60 that slides radially is not directly arranged on the active plate 40, so the stroke, size, and shape of the counterweight 60 will not be excessively restricted by the shape of the active plate 40, and the counterweight 60 and the elastic member on the counterweight 60 are more easily adapted and adjusted according to the engine speed. The valve core and the oil channel can be arranged within the stroke range of the counterweight 60, and the axial or radial opening and closing of the valve core can be set only by changing the pressure position of the counterweight 60 and the valve core. Similarly, since there is no need to limit the opening and closing direction of the valve core, the valve core can adapt to various shapes of the active plate 40, and is no longer limited to the valve core arranged to slide along the plate surface of the active plate 40, nor is it limited to the flat active plate 40.

[0040] For example, the subsequent scheme in this application provides two completely different valve core and oil channel structures, which can be installed and adapted on active plates 40 of various non-planar structures, rather than only being adapted to active plates 40 of planar structures. For example, the active plate 40 in this application is a structure with a protrusion in the middle. In this way, there is no need to make too many changes to the existing fan clutch mold and fluid mechanics properties. The counterweight block 60 and the valve core structure can be directly added to the original fan clutch. At the same time, the sliding fit and the sealing fit are adapted by two components respectively, and the two fitting relationships can be adjusted separately. The counterweight block 60 only needs to adjust the parameters of the sliding fit, and the valve core only needs to adjust the parameters of the sealing fit. The two parameters correspond to two independent components to avoid mutual interference when adjusting parameters such as size, weight, and elasticity.

[0041] like Figure 1 , 2 As shown in FIGS. 3 and 4, a plurality of the counterweight blocks 60 are evenly spaced and arranged along the circumference of the drive shaft 10. This makes the mass of the counterweight blocks 60 evenly distributed, preventing the center of gravity from deviating and causing the active plate 40 and the drive shaft 10 to shake when rotating.

[0042] Embodiment 1, as Figure 7 , 8As shown, preferably, the oil passage is a radial hole 43 arranged on the meshing cavity wall 42, and the valve core is a circular ring structure 50 which is sleeved on the drive shaft 10 and rotates coaxially therewith. The circular ring structure 50 and the end of the radial hole 43 located in the oil storage cavity 20 form an opening and closing cooperation. The circular ring structure 50 is arranged between the counterweight block 60 and the active plate 40. The elastic unit makes the circular ring structure 50 have a tendency to break away from the end of the radial hole 43 located in the oil storage cavity 20. The circular ring structure 50 includes an inclined surface 54 arranged downwardly from the inside to the outside, and the upper surface of the inclined surface 54 abuts against the lower end surface 61 of the counterweight block 60. In the above scheme, when the counterweight 60 slides horizontally, since the inclined surface 54 is arranged obliquely, when the counterweight 60 slides to the outer end, the inclined surface 54 will move up until it contacts the counterweight 60 to open the radial hole 43. At the same time, the valve core of this structure has a uniform mass distribution and is not easy to lose balance when rotating. It is also convenient to arrange an electromagnet to attract it, and the electromagnet can receive the opening and closing signal sent by the vehicle. In this way, the fan clutch has two control modes, self-opening and electric opening and closing, to correspond to various working conditions respectively and reduce energy consumption. At the same time, the outer ring of the circular ring structure 50 after being bounced can support the counterweight 60 located at the outermost end to prevent the counterweight 60 from being misplaced and falling. When the counterweight 60 slides radially, its height remains unchanged, and the inclined surface 54 is arranged obliquely, so that when the counterweight 60 is close to the middle of the valve core, it can squeeze the valve core to move down and close the port of the oil channel.

[0043] like Figure 7 , 8 As shown, the outer end of the inclined surface 54 is provided with a downwardly bent flange 51 constituting a valve flap, and the position corresponding to the flange 51 on the active plate 40 is provided with an annular surface 46, and one end of the radial hole 43 located in the oil storage chamber 20 is located on the annular surface 46. When the counterweight 60 moves toward the direction close to the drive shaft 10 to press the annular structure 50, the flange 51 fits the annular surface 46 and blocks the radial hole 43. When the counterweight 60 moves away from the drive shaft 10, the flange 51 is separated from the annular surface 46 and opens the radial hole 43. The radial hole 43 is opened and closed by fitting the flange 51 with the annular surface 46, and the radial hole 43 can be opened as long as the flange 51 is separated from the annular surface 46.

[0044] Preferably, the upper end face of the active plate 40 is provided with an annular groove, the outer side wall of the annular groove is an annular surface 46, the upper end of the annular surface 46 is provided with a vertical guide wall 44, the upper surface of the oil storage chamber wall 41 protrudes upward to form an annular boss, the outer peripheral wall of the annular boss constitutes the inner side wall of the annular groove, and the annular surface 46 is a structure inclined outward from bottom to top. The guide wall 44 can play the role of circumferential limit and axial guidance for the valve core, preventing the valve core from being misplaced and causing damage to system components. At the same time, the lower surface of the oil storage chamber wall 41 forms an annular groove corresponding to the shape of the upper surface, and the electromagnet is conveniently arranged in the circular groove, so that when the electromagnet is powered off and the counterweight block 60 is located away from the drive shaft 10, the valve core will be in an open state.

[0045] Preferably, the elastic unit is a vertically arranged compression spring 53, the inner ring of the annular structure 50 is provided with an annular edge 52, and the compression spring 53 is connected between the annular edge 52 and the oil storage cavity wall 41. The upper end of the compression spring 53 abuts against the annular edge 52, and the lower end abuts against the active plate 40, so that the annular structure 50 can be moved closer to the active plate 40 by overcoming the elastic force.

[0046] Preferably, the annular boss and the annular structure 50 are pressed against each other and an elastic deformation area is formed on the annular structure 50, and the elastic deformation area constitutes the elastic unit. In the above scheme, the elasticity of the material between the annular structure 50 and the annular boss constitutes an elastic unit, so there is no need to arrange an additional elastic member structure, and it is only necessary to ensure that the flange 51 can be tilted and pressed down to ensure the opening and closing of the radial hole 43. The compression spring 53 is sleeved on the drive shaft 10 or a plurality of compression springs 53 are evenly distributed in the circumference of the drive shaft 10.

[0047] Preferably, there are multiple inclined surfaces 54, each of which is fan-shaped, and multiple inclined surfaces 54 are evenly spaced in the axial direction. The inner end of the inclined surface 54 is connected with the annular edge 52. There are multiple radial holes 43 and counterweights 60, and multiple radial holes 43 and counterweights 60 are evenly spaced in the axial direction. The flange 51 at the outer end of each inclined surface 54 corresponds to a radial hole 43 and a counterweight 60, and the elastic members 62 on at least two counterweights 60 have different restoring forces. Due to the difference in the restoring force of the elastic members 62 on the counterweights 60, when the drive shaft 10 is in a specific speed range, only the radial holes 43 corresponding to the counterweights 60 with smaller restoring forces will be opened. At this time, the meshing performance is low, corresponding to the heat dissipation condition required by the engine at a low speed. When the speed of the drive shaft 10 increases, the centrifugal force increases, and all radial holes 43 can be opened at this time, and silicone oil is quickly filled into the meshing cavity 30 to improve the meshing performance, so that the fan can be driven to rotate at a high speed.

[0048] like Figure 5As shown, the inclined surface 54 is provided with an even number, and the elastic force of the elastic members 62 on the two counterweight blocks 60 arranged symmetrically with respect to the axis center of the drive shaft 10 is the same. In this way, the two corresponding counterweight blocks 60 can be closed and opened synchronously, avoiding vibration caused by the displacement of the center of gravity due to the sliding of the counterweight blocks 60.

[0049] Embodiment 2, as Fig. 9 , 10 As shown, the oil passage is a through hole 45 that axially penetrates the oil storage cavity wall 41, and the valve core is a spring piece 80 connected to the upper surface of the oil storage cavity wall 41. The outer end of the spring piece 80 is connected to the oil storage cavity wall 41, and the inner end of the spring piece 80 is a free end. The spring piece 80 is arranged downwardly tilted from the inside to the outside. The upper surface of the spring piece 80 presses against the lower end surface 61 of the counterweight block 60 and forms an elastic deformation area on the spring piece 80. The spring piece 80 and one end of the through hole 45 located in the oil storage cavity 20 form an opening and closing fit, and the elastic deformation area constitutes the elastic unit. In the above scheme, the spring piece 80 is in a warped shape. When the counterweight block 60 slides, since the spring piece is in a warped shape, the warping can be smoothed when the counterweight block 60 is located at the innermost end so that the spring piece 80 fits the orifice of the through hole 45. The bottom of the oil storage chamber wall 41 is also connected to the meshing chamber 30, so that the through hole 45 penetrating the oil storage chamber wall 41 can connect the meshing chamber 30 and the oil storage chamber 20. At the same time, the structure of the spring piece 80 is relatively small, which is convenient for distribution on the original active plate 40, and it has little effect on the mass distribution of the original active plate 40.

[0050] Preferably, there are multiple spring pieces 80, and the multiple spring pieces 80 are evenly spaced in the circumferential direction. There are multiple through holes 45 and counterweights 60, and the multiple through holes 45 and counterweights 60 are evenly spaced in the axial direction. Each spring piece 80 corresponds to a through hole 45 and a counterweight 60, and the restoring force of the elastic members 62 on at least two counterweights 60 is different. The essence of the above scheme is to set up multiple valve structures. Due to the difference in the elastic force of the elastic members 62 on the counterweights 60, when the drive shaft 10 is in a specific speed range, only the through holes 45 corresponding to the counterweights 60 with smaller elastic force will be opened. At this time, the meshing performance is low, corresponding to the heat dissipation condition required by the engine at a low speed. When the speed of the drive shaft 10 increases, the centrifugal force increases, and all the through holes 45 can be opened at this time. Silicone oil is quickly filled into the meshing cavity 30 to improve the meshing performance, so that the fan can be driven to rotate at a high speed.

[0051] Preferably, the spring pieces 80 are arranged in an even number, and the elastic force of the elastic members 62 on the two counterweights 60 arranged symmetrically with respect to the axis of the drive shaft 10 is the same. In this way, the two corresponding counterweights 60 can be closed and opened synchronously, avoiding vibration caused by the displacement of the center of gravity due to the sliding of the counterweights 60.

[0052] Preferably, the guide wall 44 is arranged to protrude upward in the axial direction, and a housing 70 is provided on the outer side of the guide wall 44 to separate the oil storage chamber 20 and the meshing chamber 30. The elastic member 62 is connected between the housing 70 and the counterweight 60, and the elastic member 62 applies radial elastic force to the counterweight 60. For the second embodiment, the elastic member 62 can also be provided between the drive shaft 10 and the counterweight 60.

[0053] Preferably, a guide rod 11 is radially arranged on the driving shaft 10, and a radial guide groove or guide hole is opened on the counterweight 60, and the guide groove or guide hole forms a plug-in sliding fit with the guide rod 11. The counterweight 60 is arranged above the valve core, and the lower end face 61 of the counterweight 60 is arranged in close contact with the upper surface of the valve core. For the second embodiment, a guide hole structure is preferred, and the guide rod 11 can support the counterweight 60 located at the outermost end to prevent the counterweight 60 from being misplaced and falling. Among them, it is preferred that the counterweight 60 is sleeved on the guide rod 11 in the spring-type 80 valve core. The structure of the lower end face 61 is convenient for fitting the valve core to prevent scratching the valve core.

[0054] Preferably, the counterweight 60 is an arc-shaped section structure. When the drive shaft 10 is stationary, the ends of adjacent counterweights 60 fit together, and the counterweights 60 together form a ring structure. In this way, the counterweights 60 can form a limit position with each other. The innermost end refers to the position close to the axis core of the drive shaft 10, and the position close to the axis core of the drive shaft 10 is the inner end, and the position away from the axis core of the drive shaft 10 is the outer end.

[0055] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of this application.

Claims

1. A centrifugal self-opening and closing fan clutch, comprising an oil storage chamber (20), a meshing chamber (30) and a drive shaft (10) for connecting to the end of an engine shaft, wherein an active plate (40) is connected to the drive shaft (10), an inner plate surface of the active plate (40) is an oil storage chamber wall (41), an outer plate surface of the active plate (40) is a meshing chamber wall (42), and an oil passage for connecting the oil storage chamber (20) and the meshing chamber (30) is provided on the active plate (40), characterized in that: It also includes a valve core assembly and a counterweight (60) which are arranged in a split manner. The counterweight (60) rotates synchronously with the drive shaft (10) and can move radially along the drive shaft (10). The counterweight (60) is provided with an elastic member (62) for driving the counterweight (60) to slide toward the inner end. The valve core assembly includes a valve core body for opening and closing the oil passage and an elastic unit for driving the valve core body to open the oil passage. When the counterweight (60) moves in a direction close to the drive shaft (10), the counterweight (60) presses against the valve core body, so that the valve core body can overcome the elastic force of the elastic unit and gradually close the oil passage. When the counterweight (60) moves in a direction away from the drive shaft (10), the elastic force of the elastic unit causes the valve core body to gradually open the oil passage. A plurality of the counterweight blocks (60) are evenly spaced along the circumference of the drive shaft (10); a guide rod (11) is radially arranged on the drive shaft (10); a radial guide groove or guide hole is opened on the counterweight block (60); the guide groove or guide hole and the guide rod (11) form a plug-in sliding fit; the counterweight block (60) is arranged above the valve core body; the lower end surface (61) of the counterweight block (60) is arranged in contact with the upper surface of the valve core body; the counterweight block (60) is an arc-shaped structure; when the drive shaft (10) is stationary, the ends of adjacent counterweight blocks (60) are in contact, and the counterweight blocks (60) together form a ring structure.

2. The centrifugal self-opening and closing fan clutch according to claim 1 is characterized in that: The oil passage is a radial hole (43) arranged on the meshing cavity wall (42); the valve core body is a circular ring structure (50) sleeved on the drive shaft (10) and coaxially rotating therewith; the circular ring structure (50) and one end of the radial hole (43) located in the oil storage cavity (20) form an opening and closing cooperation; the circular ring structure (50) is arranged between the counterweight block (60) and the active plate (40); the elastic unit makes the circular ring structure (50) have a tendency to break away from the end of the radial hole (43) located in the oil storage cavity (20); the circular ring structure (50) includes an inclined surface (54) arranged downwardly from the inside to the outside; the upper surface of the inclined surface (54) is in contact with the lower end surface (61) of the counterweight block (60).

3. The centrifugal self-opening and closing fan clutch according to claim 2 is characterized in that: The outer end of the inclined surface (54) is provided with a downwardly bent flange (51) constituting a valve flap, and an annular surface (46) is provided on the active plate (40) at a position corresponding to the flange (51), and one end of the radial hole (43) located in the oil storage chamber (20) is located on the annular surface (46); when the counterweight (60) moves toward the driving shaft (10) to press against the annular structure (50), the flange (51) fits against the annular surface (46) and blocks the radial hole (43); when the counterweight (60) moves toward the direction away from the driving shaft (10), the flange (51) separates from the annular surface (46) and opens the radial hole (43).

4. The centrifugal self-opening and closing fan clutch according to claim 3 is characterized in that: The upper end surface of the active plate (40) is provided with an annular groove, the outer side wall of the annular groove is an annular surface (46), the upper end of the annular surface (46) is provided with a vertical guide wall (44), the upper surface of the oil storage cavity wall (41) protrudes upward to form an annular boss, the outer peripheral wall of the annular boss constitutes the inner side wall of the annular groove, and the annular surface (46) is in a structure inclined outward from bottom to top.

5. The centrifugal self-opening and closing fan clutch according to claim 4 is characterized in that: The elastic unit is a vertically arranged compression spring (53); the inner ring of the circular ring structure (50) is provided with an annular edge (52); the compression spring (53) is connected between the annular edge (52) and the oil storage cavity wall (41); the annular boss is pressed against the circular ring structure (50) to form an elastic deformation area on the circular ring structure (50); the elastic deformation area constitutes the elastic unit.

6. The centrifugal self-opening and closing fan clutch according to claim 5, characterized in that: There are a plurality of inclined surfaces (54), each of which is fan-shaped. The plurality of inclined surfaces (54) are evenly spaced apart in the axial direction. The inner end of the inclined surface (54) is connected to the annular edge (52). There are a plurality of radial holes (43) and counterweight blocks (60). The plurality of radial holes (43) and counterweight blocks (60) are evenly spaced apart in the axial direction. The flange (51) at the outer end of each inclined surface (54) corresponds to the position of one radial hole (43) and counterweight block (60). The elastic members (62) on at least two of the counterweight blocks (60) have different restoring forces. There are an even number of inclined surfaces (54), and the elastic members (62) on two counterweight blocks (60) symmetrically arranged relative to the axis center of the drive shaft (10) have the same elastic force.

7. The centrifugal self-opening and closing fan clutch according to claim 1 is characterized in that: The oil passage is a through hole (45) axially penetrating the oil storage chamber wall (41); the valve core body is a spring sheet (80) connected to the upper surface of the oil storage chamber wall (41); the outer end of the spring sheet (80) is connected to the oil storage chamber wall (41); the inner end of the spring sheet (80) is a free end; the spring sheet (80) is arranged to tilt downward from the inside to the outside; the upper surface of the spring sheet (80) is pressed against the lower end surface (61) of the counterweight (60) and an elastic deformation area is formed on the spring sheet (80); the spring sheet (80) and one end of the through hole (45) located in the oil storage chamber (20) form an opening and closing fit; and the elastic deformation area constitutes the elastic unit.

8. The centrifugal self-opening and closing fan clutch according to claim 7, characterized in that: There are a plurality of spring sheets (80), and the plurality of spring sheets (80) are evenly spaced in the circumferential direction; there are a plurality of through holes (45) and counterweight blocks (60), and the plurality of through holes (45) and counterweight blocks (60) are evenly spaced in the axial direction; each spring sheet (80) corresponds to a position of a through hole (45) and a counterweight block (60); and the elastic members (62) on at least two of the counterweight blocks (60) have restoring forces of different magnitudes; the spring sheets (80) are arranged in an even number, and the elastic members (62) on two counterweight blocks (60) that are symmetrically arranged relative to the axis center of the drive shaft (10) have the same elastic force magnitude.

9. The centrifugal self-opening and closing fan clutch according to any one of claims 4 to 6, characterized in that: The guide wall (44) is arranged to protrude upward in the axial direction, and a shell (70) is provided on the outer side of the guide wall (44) for separating the oil storage chamber (20) and the meshing chamber (30). The elastic member (62) is connected between the shell (70) and the counterweight (60), and the elastic member (62) applies a radial elastic force to the counterweight (60).

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