A cam-type automatic clutch actuator and its implementation method

Abstract

The present invention provides a cam-type automatic clutch actuator and its implementation method. The actuator consists of a cam drive assembly, a cam actuator assembly, and a control assembly. In the cam drive assembly, the output end of the shift drive motor is coaxially connected to a worm, the worm gear meshes with the worm for transmission, and the camshaft is coaxially connected to the worm gear to transmit power. In the clutch actuator assembly, the cam is fixedly connected to the camshaft; the release bearing is sleeved on the release bearing sleeve and consists of a bearing shoulder and a thrust bearing. Under the control of the cam control assembly, the working point on the working curve of its outer contour contacts the bearing shoulder and drives the release bearing to reciprocate linearly, thereby controlling the separation or engagement of the clutch. The implementation method includes, in addition to the method for controlling the separation or engagement of the clutch, a wear compensation method for the cam and the clutch friction plate. The present invention has low requirements for the shift drive motor, is structurally compact, easy to automatically perform clearance compensation, and has a short transmission chain and good control performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of automatic clutches in mechanical automatic transmissions, and particularly relates to a cam-type automatic clutch actuator and an execution method thereof. Background Art

[0002] The mechanical automatic transmission is improved on the basis of the manual transmission. Due to its advantages of high transmission efficiency, low cost, and convenient operation, it has been widely used.

[0003] The automatic control of the clutch is a key technology in the mechanical automatic transmission. The quality of the automatic control performance will directly affect the performance of the transmission and even the whole vehicle, and the clutch actuator is the basis and key to realizing the automatic control of the clutch.

[0004] The existing clutch actuators mainly include electro-hydraulic type and electro-mechanical type. The electro-hydraulic clutch actuator has good performance, with advantages such as high control precision, fast response, and easy implementation of safety protection. However, the electro-hydraulic clutch actuator has disadvantages such as being greatly affected by temperature, high cost, and easy leakage; the electro-mechanical clutch actuator has the advantages of simple structure, strong environmental adaptability, and low cost, and has received extensive attention in recent years. The electro-mechanical clutch actuator has developed many forms based on different structural principles, such as: worm and gear type actuator, screw type actuator, lever type actuator, gear pair type actuator, etc. However, there are still the following problems:

[0005] 1. In order to reduce the capacity of the shift drive motor to reduce costs, a multi-stage reduction mechanism is often used, which inevitably makes the mechanism complex, occupies a large space, and reduces reliability;

[0006] 2. The debugging process of some mechanisms (such as lever mechanisms) is difficult and complex, and it is difficult to achieve clearance compensation after clutch wear;

[0007] 3. Due to the long transmission chain, the clearance accumulation of each transmission pair results in low control precision. Summary of the Invention

[0008] In view of the problems existing in the above-mentioned prior art, the present invention proposes a cam-type automatic clutch actuator and an execution method thereof. The present invention has low requirements for the shift drive motor, has a compact structure, is easy to automatically perform clearance compensation, and has a short transmission chain and good control performance. Combining with the accompanying drawings of the specification, the technical solutions of the present invention are as follows:

[0009] A cam-type automatic clutch actuator for an electro-mechanical clutch, which is composed of a cam drive assembly, a cam execution assembly, and a control assembly;

[0010] The cam drive assembly consists of a shift drive motor 1, a worm 2, a worm gear 3, and a camshaft 4. The output end of the shift drive motor 1 is coaxially connected to the worm 2. The worm gear 3 is in meshing transmission with the worm 2, and the camshaft 4 is coaxially connected to the worm gear 3 to transmit power.

[0011] The clutch actuator assembly consists of a cam 5, a release bearing 6, and a release bearing sleeve 14. The cam 5 is fixedly connected to the camshaft 4. The release bearing 6 is sleeved on the release bearing sleeve 14 and consists of a bearing shoulder 601 and a thrust bearing. The working point on the working curve of the outer contour of the cam 5 is in contact with the bearing shoulder 601 and drives the release bearing 6 to perform reciprocating linear motion along its axis, thereby pressing into or releasing the diaphragm spring release fingers to control the separation or engagement of the clutch.

[0012] The control assembly consists of a shift controller TCU and vehicle state sensors. The vehicle state sensors are respectively connected to the signal receiving end of the shift controller TCU. The signal output end of the shift controller TCU is connected to the shift drive motor 1. Based on the received vehicle state signals, after making a shift judgment, the shift controller TCU sends a shift control signal to the shift drive motor 1, and the shift drive motor 1 drives the cam 5 to rotate in sequence to control the separation or engagement of the clutch.

[0013] Further, the working curve of the cam 5 is divided into three sections, namely: working section I, friction plate wear compensation section II, and cam wear compensation section III.

[0014] The working section I is a curve segment starting from endpoint A, gradually moving away from the cam rotation center, and finally reaching endpoint B, which is the farthest from the cam rotation center.

[0015] The friction plate wear compensation section II is a curve segment starting from endpoint A, gradually approaching the cam rotation center, and finally reaching endpoint C, which is the closest to the cam rotation center.

[0016] The cam wear compensation section III is a curve segment starting from the endpoint B, with an unchanged curvature radius in the middle section, and finally reaching point D.

[0017] The endpoint A is the contact point between the cam 5 and the bearing shoulder 601 when the clutch is fully engaged without wear.

[0018] The endpoint B is the contact point between the cam 5 and the bearing shoulder 601 when the clutch is fully disengaged without wear.

[0019] The endpoint C is the contact point between the cam 5 and the bearing shoulder 601 when the clutch is fully engaged in the case where the clutch friction plate 17 reaches the maximum wear amount within the designed service life.

[0020] Furthermore, the working curve of the cam 5 is symmetrically arranged on both sides of the cam 5; or the working curve of the cam 5 is arranged on one side of the cam 5, and the working curve of the cam 5 is greater than 180 degrees.

[0021] Furthermore, the bearing shoulder 601 is a convex shoulder, that is, there are two symmetrically arranged protrusions on both sides of the bearing shoulder 601, and the outer contour surface of the cam 5 acts on the upper surface of the protrusions; lifting lugs are provided on both sides of the shoulder of the release bearing 6, and annular grooves are opened on the corresponding camshaft 4. A helical spring 13 is installed between the lifting lugs and the annular grooves on the same side. One end of the helical spring 13 hooks the lifting lug of the release bearing 6, and the other end hooks the annular groove on the camshaft 4. When the release bearing 6 is pressed and moves away from the camshaft 4, the helical spring 13 elongates; when the release bearing 6 is ejected and moves closer to the camshaft 4, the helical spring 13 shortens. During this process, the two helical springs 13 can keep the position of the release bearing 6 unchanged in the circumferential direction, restricting the rotation of the release bearing 6, so that the outer contour surface of the cam 5 can always act reliably on the protruding position of the bearing shoulder 601.

[0022] Even further, the bearing shoulder 601 is a flat shoulder, that is, a circular smooth tabletop is provided around the bearing shoulder 601, and the cam 5 acts on the smooth tabletop along the circumferential direction of the bearing shoulder 601.

[0023] Further, the camshaft 4 is connected to the worm gear 3 and the cam 5 respectively by means of D-shaped shaft hole fitting connection to achieve circumferential positioning between the connecting parts and ensure reliable torque transmission to each other;

[0024] The worm gear 3 is axially positioned on the camshaft 4 through the shoulder and snap ring 12 on the camshaft 4;

[0025] The cam 5 is welded to the camshaft 4.

[0026] Further, the vehicle state sensor includes an angle sensor 22 for detecting the rotation angle of the camshaft 4, the worm 2, the worm gear 3 or the output shaft of the shift driving motor 1, as well as an accelerator pedal depth sensor, a vehicle speed sensor and a brake pedal depth sensor.

[0027] Further, the shift driving motor 1 is fixedly installed on the motor support 9;

[0028] Both ends of the camshaft 4 are rotatably installed on the camshaft bracket 8;

[0029] A lubricating bronze bushing is provided between the camshaft 4 and the camshaft bracket 8;

[0030] Both the motor support 9 and the camshaft bracket 8 are fixedly installed on the transmission housing.

[0031] Further, the angle sensor 22 in the vehicle state sensor is installed at the end of the camshaft 4. The angle sensor 22 is fixed on the camshaft bracket 8. The end of the camshaft 4 is processed into a flat shape and inserted into the flat groove on the angle sensor 22, driving the rotation of the rotor of the angle sensor 22, and then detecting the rotation angle of the camshaft 4.

[0032] An execution method for an execution mechanism of a cam-type automatic clutch is as follows:

[0033] After the shift controller TCU uses the received vehicle state signal as the basis for judging shifting and makes a shifting decision, it sends an instruction signal for controlling the engagement or disengagement of the clutch to the shift driving motor 1. The shift driving motor 1 drives the worm 2, the worm gear 3, the camshaft 4, and the cam 5 in sequence. According to the outer contour working curve on the cam 5, the cam 5 regularly pushes the release bearing 6 to move linearly along the axial direction, and then presses into or releases the diaphragm spring release finger, thereby controlling the disengagement or engagement of the clutch.

[0034] The execution method further includes a compensation method for wear of the cam 5 or the clutch friction plate 17.

[0035] When the cam 5 is worn, in the clutch disengagement state, there will be a situation where the pressing-in stroke of the release bearing 6 is insufficient, resulting in incomplete clutch disengagement. At this time, under the control of the control component, the cam driving component drives the cam execution component to move, so that the acting point of the cam 5 and the bearing shoulder 601 of the release bearing 6 gradually moves to the cam wear compensation section III of the cam 5 in the clutch disengagement state until the cam 5 reaches the lift required for complete clutch disengagement, and the release bearing 6 is reliably pressed into the maximum displacement in the direction close to the clutch friction plate 17 by the cam 5, realizing compensation for the wear amount of the cam 5.

[0036] When the clutch friction plate 17 is worn, the position of the release finger during clutch engagement bulges outward compared to the original position. If the lift of the cam 5 at the clutch engagement point is the same as the initial state, then in the clutch engagement state, there will be a situation where the pressing force of the diaphragm spring is insufficient, resulting in the clutch being unable to reliably transmit power. At this time, under the control of the control component, the cam driving component drives the cam execution component to move, so that the acting point of the cam 5 and the bearing shoulder 601 of the release bearing 6 gradually moves to the friction plate wear compensation section II of the cam 5, ensuring that the clutch can reliably transmit torque during engagement. And as the friction plate gradually wears, the corresponding acting point in the clutch engagement state moves gradually from point A to point C until the friction plate is completely worn and the acting point reaches the minimum lift point C of the cam 5, realizing compensation for the wear amount of the clutch friction plate 17.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] 1. Compared with the traditional fork - type clutch actuator, the rotation angle of the camshaft during the shifting process of the cam - type automatic clutch actuator of the present invention is much larger than that of the fork - shaft. The increase in the working angle during the process reduces the torque required for shifting under the same conditions, resulting in a better operating condition of the driving motor and a lower requirement for the rated capacity of the shifting driving motor, effectively reducing costs.

[0039] 2. In the cam - type automatic clutch actuator of the present invention, due to the large working angle of the camshaft during the shifting process, the required transmission ratio of the transmission chain is relatively low. A single - stage worm - and - worm - gear reduction can meet the usage requirements, eliminating the need for the two - stage reduction of the traditional automatic clutch actuator. This makes the structure of the entire clutch actuator more compact, effectively reducing costs, having higher reliability, occupying less space, and being easy to arrange.

[0040] 3. In the cam - type automatic clutch actuator of the present invention, as described above, since there are fewer transmission links in the transmission chain, only a single - stage worm - and - worm - gear reduction mechanism, the cumulative clearance of each transmission pair is relatively small. Therefore, it effectively improves the problem of poor control accuracy caused by the clearance of multiple - stage transmission pairs. On the other hand, due to the large working angle of the cam, the influence of the error of the same - angle sensor on the control effect is small. Therefore, the control effect of the clutch actuator of the present invention is better and the accuracy is higher.

[0041] 4. The compensation for the wear of the clutch of the cam - type automatic clutch actuator of the present invention is easy to achieve. In the clutch actuator of the present invention, the separation state of the clutch depends on the pressing position of the release bearing, and the pressing position of the release bearing depends on the relationship between the lift and rotation angle of the cam. When designing the cam curve, enough compensation margin is left on the cam lift. When the friction plate wears, the release bearing protrudes. By means of a control method, the initial cam angle position can be advanced, making the position of the release bearing adapt to the position of the release finger after the friction plate wears, realizing the compensation for the wear amount.

[0042] 5. Since the cam - type automatic clutch actuator of the present invention adopts a cam structure, when the clutch is in a fully separated state, that is, when the diaphragm spring is fully pressed in, the elastic force of the diaphragm spring is transmitted to the bracket through the camshaft and finally completely provided by the housing with a reaction force. The worm - and - worm - gear transmission pair does not always bear force, reducing the burden on the worm - and - worm - gear mechanism and improving the overall service life of the actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is the overall axonometric view of the cam - type automatic clutch actuator of the present invention;

[0044] Figure 2In the cam - type automatic clutch actuator of the present invention, it is an exploded view of the parts of the connection portion between the cam and the camshaft;

[0045] Figure 3 In the cam - type automatic clutch actuator of the present invention, it is a schematic diagram of the cooperation between the boss - shoulder type release bearing and the cam;

[0046] Figure 4 In the cam - type automatic clutch actuator of the present invention, it is a schematic diagram of the cooperation between the flat - shoulder type release bearing and the cam;

[0047] Figure 5 In the cam - type automatic clutch actuator of the present invention, it is a schematic diagram of the working curve of the outer contour of the cam;

[0048] Figure 6 In the cam - type automatic clutch actuator of the present invention, it is a schematic diagram of the working state when controlling the clutch disengagement when the cam is not worn;

[0049] Figure 7 In the cam - type automatic clutch actuator of the present invention, it is a schematic diagram of the working state when controlling the clutch disengagement when the cam is worn;

[0050] Figure 8 In the cam - type automatic clutch actuator of the present invention, it is a schematic diagram of the working state when controlling the clutch engagement when the friction plate is not worn;

[0051] Figure 9 In the cam - type automatic clutch actuator of the present invention, it is a schematic diagram of the working state when controlling the clutch engagement when the friction plate is worn to the limit state.

[0052] In the figure:

[0053] 1 - Shift driving motor 2 - Worm 3 - Worm gear 4 - Camshaft 5 - Cam 6 - Release bearing 7 - Angle sensor 8 - Camshaft bracket 9 - Motor bracket 10 - Bronze bushing 11 - Bush 12 - Snap ring 13 - Helical spring 14 - Release bearing sleeve 15 - Diaphragm spring 16 - Clutch pressure plate 17 - Clutch friction plate 18 - Flywheel 601 - Bearing shoulder Detailed implementation manners

[0054] To further elaborate on the technical solution of the present invention, in combination with the accompanying drawings of the specification, the detailed implementation manners of the present invention are as follows:

[0055] As Figure 1 shown, the present invention provides a cam - type automatic clutch actuator, and the clutch actuator is composed of a cam driving component, a cam executing component, and a control component.

[0056] The cam driving component is composed of a shift driving motor 1, a motor bracket 9, a worm 2, a worm gear 3, a camshaft 4, and a camshaft bracket 8;

[0057] As Figure 1As shown, the shift drive motor 1 is fastened to the motor bracket 9 by bolts, the shift drive motor 1 is powered by the vehicle power supply, and the motor bracket 9 is fixedly mounted on the gearbox housing; the power output end of the shift drive motor 1 is coaxially connected with the worm 2, the end of the worm 2 is mounted on the gearbox housing through a sleeve 11, and can rotate freely relative to the gearbox housing; the worm wheel 3 is meshed with the worm 2 to form a worm gear transmission pair, and the worm gear transmission pair serves as a primary speed reduction and torque increase mechanism of the power transmission part;

[0058] like Figure 2 As shown, the worm wheel 3 is installed at one end of the camshaft 4, and a D-shaped through hole is processed in the center of the worm wheel 3. Matching with it, a D-shaped shaft section is processed at the end of the camshaft 4. The worm wheel 3 and the camshaft 4 are positioned in the circumferential direction by the cooperation of the D-shaped shaft / hole. The worm wheel 3 is installed on the camshaft 4 through the shoulder and the retaining spring 12 on the camshaft 4 to achieve axial positioning, thereby achieving smooth and accurate power transmission between the worm wheel 3 and the camshaft 4; camshaft brackets 8 are installed at both ends of the camshaft 4, one end of the camshaft bracket 8 is fixed on the gearbox housing, and the other end of the camshaft bracket 8 is connected to the camshaft 4. The camshaft 4 and the camshaft bracket 8 are connected by a copper sleeve 10 or a bearing, so that the camshaft 4 can rotate freely in the axial direction on the camshaft bracket 8. In addition, the axial limitation of the camshaft 4 on the camshaft bracket 8 is achieved by the cooperation of the limiting shoulder set on the camshaft 4 and the retaining spring 12.

[0059] The cam actuator assembly is composed of a cam 5, a release bearing 6 and a release bearing sleeve 14;

[0060] The two cams 5 are installed in the middle section of the camshaft 4. A D-shaped through hole is processed on the end face of the cam 5. Matching with it, D-shaped shaft sections are processed on both sides of the middle section of the camshaft 4. The cam 5 and the camshaft 4 are positioned in the circumferential direction through the D-shaped shaft / hole cooperation to ensure that a suitable relative rotation angle is obtained during assembly. The cam 5 and the camshaft 4 are fixed by welding after adjustment and positioning, so as to increase the ability to transmit torque;

[0061] The release bearing 6 is mounted on the outer end of the clutch and acts on the diaphragm spring 15 in the clutch; the release bearing 6 is sleeved on the release bearing sleeve 14, and the release bearing 6 consists of a bearing shoulder 601 and a thrust bearing. The working surface of the cam 5 directly acts on the bearing shoulder 601 of the release bearing 6, and one end of the thrust bearing directly contacts and acts on the release finger of the diaphragm spring 15. The thrust bearing is used to eliminate the speed difference between the diaphragm spring 15 of the clutch and the release bearing.

[0062] As the cam 5 rotates driven by the cam drive assembly, according to the motion law of the working curve of the outer contour of the cam 5, the release bearing 6 is pressed in or ejected along the axis direction of the release bearing 6 under the action of the working surface of the cam 5, thereby driving the pressing in or ejection of the release fingers of the diaphragm spring 15, so as to realize the engagement or separation of the clutch control;

[0063] In the release bearing 6, since there is still resistance inside the thrust bearing, when the inner end face of the thrust bearing contacts the release fingers of the diaphragm spring 15, the thrust bearing has a tendency to rotate following the friction plate, resulting in the release bearing 6 having a tendency to rotate following the friction plate. Therefore, according to whether it is necessary to limit the rotation of the release bearing 6, the structure and connection method of the release bearing 6 are divided into the following two embodiments:

[0064] Embodiment 1:

[0065] As Figure 3 shown, when the bearing shoulder 601 that directly contacts and interacts with the working surface of the cam 5 is a convex shoulder, that is, there are two symmetrically arranged protrusions on both sides of the bearing shoulder 601, and the cam 5 can only work by acting on the upper surface of the protrusion. At this time, it is necessary to limit the rotation of the release bearing 6 to keep the cam 5 in contact with the upper plane of the protrusion. Therefore, lugs are provided on both sides of the shoulder of the release bearing 6, and an annular groove is opened on the corresponding camshaft 4. A helical spring 13 is installed between the lug on the same side and the annular groove. One end of the helical spring 13 hooks the lug of the release bearing 6, and the other end hooks the annular groove on the camshaft 4. When the release bearing 6 is pressed in and away from the camshaft 4, the helical spring 13 elongates; when the release bearing 6 is ejected and close to the camshaft 4, the helical spring 13 shortens. During this process, the elastic force of the helical springs 13 on both sides always exists, keeping the circumferential position of the release bearing 6 basically unchanged, and the release bearing 6 will not rotate at a large angle, realizing the restriction of the rotation of the release bearing 6 and ensuring that the outer contour surface of the cam 5 can always act reliably on the protrusion position of the bearing shoulder 601.

[0066] Embodiment 2:

[0067] As Figure 4 shown, when the bearing shoulder 601 that directly contacts and interacts with the working surface of the cam 5 is a flat shoulder, that is, there is a circular smooth table surface around the bearing shoulder 601, and the cam 5 can work normally by acting on this smooth table surface. This enables the cam 5 to work normally at any angular position along 360 degrees around the bearing shoulder 601. Therefore, there is no need to limit the rotation of the release bearing 6; when the release bearing 6 just contacts the release fingers of the diaphragm spring 15, the release bearing 6 rotates following the drive of the release fingers. As the release fingers are continuously pressed, the thrust bearing begins to act, and the rotational speed difference between the release bearing and the diaphragm spring 15 of the clutch is eliminated by the rotation of the thrust bearing.

[0068] In the above two embodiments, the structures of the release bearing 6 are slightly different, but the outer contour curves of the cam 5 that cooperates with the release bearing 6 to work are exactly the same. Therefore, the motion law curves when the cam 5 drives the release bearing 6 to work are consistent. The outer contour working curve and the motion law of the cam 5 will be further described below, and on this basis, the wear compensation working principle of the cam-type automatic clutch actuator described in the present invention will be introduced and explained.

[0069] As Figure 5 shown, the working curve of the cam 5 is divided into three sections, namely: the friction plate wear compensation section II located at the top and relatively close to the cam rotation center, the cam wear compensation section III located at the bottom and relatively far from the cam rotation center, and the working section I located in the middle and changing from near to far from the cam rotation center.

[0070] The working section I is a curve section that starts from the end point A relatively close to the cam rotation center and gradually moves away from the cam rotation center, and finally reaches the end point B farthest from the cam rotation center; among them, the end point A corresponds to the position of the release bearing 6 corresponding to the release finger of the diaphragm spring 15 when the clutch friction plate 17 is not worn and the clutch is reliably engaged, that is, when the cam 5 rotates to the position where the end point A acts on the shoulder of the release bearing 6 in the case where the clutch friction plate 17 is not worn, the diaphragm spring 15, under the dual cooperation of its own elastic force and the release bearing 6, pushes the clutch pressure plate 16 to tightly press the clutch friction plate 17 on the flywheel disc 18, and at this time the clutch is in a reliably engaged state; the end point B corresponds to the position of the release bearing 6 corresponding to the release finger of the diaphragm spring 15 when the clutch friction plate 17 is not worn and the clutch is completely separated, that is, when the cam 5 rotates to the position where the end point B acts on the shoulder of the release bearing 6, the outer edge of the diaphragm spring 15 warps away from the clutch friction plate 17 under the pressure of the release bearing 6, so that the clutch pressure plate 16 is completely separated from the clutch friction plate 17, and at this time the clutch is in a completely separated state; therefore, when the cam drive assembly drives the cam 5 to rotate, and the acting point of the cam 5 on the release bearing 6 moves from the end point A to the end point B, the clutch completes the separation process; when the cam drive assembly drives the cam 5 to rotate, and the acting point of the cam 5 on the release bearing 6 moves from the end point B to the end point A, the clutch completes the engagement process; by controlling the angular velocity of the rotation of the cam 5, the separation or engagement speed of the clutch can be controlled, and the slip grinding process of the clutch friction plate 17 can be controlled.

[0071] The purpose of setting the friction plate wear compensation section II is as follows: As the driving mileage increases, the clutch friction plate 17 gradually wears and becomes thinner. When the clutch is reliably engaged, the clutch pressure plate 16 moves towards the direction of the clutch friction plate 17. The outer edge of the diaphragm spring 15 follows the clutch pressure plate 16 and moves towards the direction close to the clutch friction plate 17, and the release fingers of the diaphragm spring 15 bulge outwards in the direction away from the clutch friction plate 17, causing the position of the release bearing 6 when the clutch is reliably engaged to bulge outwards compared to the initial position. If the acting point of the cam 5 on the release bearing 6 is still point A when the clutch is engaged, it will cause the clamping force of the clutch pressure plate 16 to become smaller, and the clutch cannot be reliably engaged, ultimately resulting in the clutch being unable to reliably transmit torque. Therefore, when the clutch friction plate 17 wears and becomes thinner, the lift of the acting point of the cam 5 on the release bearing 6 corresponding to reliable clutch engagement should be moved downwards. Moving the lift of the cam acting point downwards means moving the acting point to a position closer to the cam rotation center. Therefore, a section of the curve located at the top of the cam and gradually closer to the cam rotation center is set as the friction plate wear compensation section II;

[0072] The friction plate wear compensation section II is a curve segment starting from the end point A and gradually approaching the cam rotation center, and finally reaching the end point C closest to the cam rotation center; among them, the end point C corresponds to the position of the release bearing 6 corresponding to the release fingers of the diaphragm spring 15 when the clutch friction plate 17 is most worn and the clutch is reliably engaged. That is, in the case where the clutch friction plate 17 is most worn, when the cam 5 rotates to act on the shoulder of the release bearing 6 at the end point C, the release fingers of the diaphragm spring 15, under the dual cooperation of its own elastic force and the release bearing 6, push the clutch pressure plate 16 to tightly press the clutch friction plate 17 on the flywheel disc 18, and at this time the clutch is in a reliably engaged state; therefore, as the clutch friction plate 17 gradually wears, under the control of the shift control unit TCU, the acting point of the cam 5 on the release bearing 6 when the clutch is reliably engaged gradually moves from the end point A to the end point C.

[0073] The design purpose of setting the cam wear compensation section III is as follows: The working section I on the cam 5 will gradually wear as the number of working times increases, and the maximum lift of the working section I will decrease, which will cause the release bearing 6 not to be pushed to the position corresponding to complete clutch separation when the clutch performs the separation action. Therefore, it is necessary to set the cam wear compensation section III to compensate for the maximum lift of the working section I on the cam 5 after the working section I on the cam 5 wears; the cam wear compensation section III is a curve segment starting from the end point B and ending at point D. The cam wear compensation section III is an arc with a constant curvature, that is, the lift of the cam 5 in the cam wear compensation section III remains unchanged, so that the cam 5 can still reliably press the release bearing 6 to the specified position after wear, and the clutch is completely separated.

[0074] The control component consists of a shift controller TCU and an angle sensor 7.

[0075] The angle sensor 7 is fixedly installed on the camshaft bracket 8 and connected to the end of the camshaft 4. The end of the camshaft 4 is machined into a flat convex shape. Correspondingly, a flat groove is formed on the angle sensor 7. The camshaft 4 inserts the flat convex at its end into the flat groove of the angle sensor 7 and drives the rotor of the angle sensor 7 to rotate synchronously to measure the rotation angle information of the camshaft 4. The signal output end of the angle sensor 7 is connected to the signal receiving end of the shift controller TCU, and the control signal output end of the shift controller TCU is connected to the signal input end of the shift driving motor 1. When the angle sensor 7 measures the rotation angle information of the camshaft 4, it feeds back the rotation angle information to the shift controller TCU in real time as the basis for shift control. After making a shift judgment, the shift controller TCU sends a control command to the shift driving motor 1, and finally controls the operation of the cam actuator assembly through the cam driving assembly.

[0076] In addition, the control component further includes vehicle state sensors for detecting the vehicle state, such as a throttle pedal depth sensor, a vehicle speed sensor, and a brake pedal depth sensor. Similar to the angle sensor 7, the vehicle state sensors are all signal-connected to the shift controller TCU. The shift controller TCU receives the signal of the angle sensor 7 for detecting the rotation angle of the camshaft, the signal of the throttle pedal depth sensor for detecting the depth of the vehicle throttle pedal, the signal of the vehicle speed sensor for detecting the vehicle speed, the signal of the brake pedal depth sensor for detecting the depth of the brake pedal, etc., uses the above vehicle state signal data as the basis for shift judgment, makes a shift decision, and finally sends a command signal to the cam driving assembly to drive the cam actuator assembly to control the engagement or separation of the clutch, specifically manifested as controlling the working voltage, current direction, and start-stop action of the shift driving motor.

[0077] According to the structural composition and connection method of the above cam-type automatic clutch actuator, the present invention also provides an execution method for the cam-type automatic clutch actuator, and the execution method is specifically as follows:

[0078] The shift controller TCU receives vehicle state signals including the signals detected by the angle sensor 7. The vehicle signals also include the signals detected by the throttle pedal depth sensor, the vehicle speed sensor, and the brake pedal depth sensor. The signals detected by the above sensors are used as the basis for judging gear shifting (i.e., controlling the clutch disengagement / engagement). After the shift controller TCU makes a gear shifting decision, it sends a command signal to the shift drive motor 1 to control the clutch engagement or disengagement, specifically manifested as a command to control the operating voltage, current direction, and start / stop action of the shift drive motor. The shift drive motor 1 drives the worm 2 to rotate, and the worm 2 meshes with the worm gear 3 to drive the camshaft 4 to rotate. At the same time, the angle sensor 7 real-time feeds back the rotation angle signal of the camshaft 4 collected to the shift controller TCU as the basis for controlling the gear shifting process to achieve closed-loop control of the gear shifting process. The cam 5 fastened on the camshaft 4 rotates synchronously with the camshaft 4. According to the outer contour motion curve on the cam 5, the cam 5 regularly pushes the release bearing 6 to move linearly along the axial direction, thereby controlling the disengagement or engagement of the clutch. In addition, the execution method of the present invention can also compensate for the wear of the clutch friction plate 17 or the cam 5 to achieve reliable engagement or complete disengagement of the clutch.

[0079] 1. Clutch disengagement execution process;

[0080] (1) When the cam 5 has no wear;

[0081] As Figure 5 and Figure 6 shown, under the control of the control component, the cam drive component drives the cam execution component to move, so that the acting point of the cam 5 and the bearing shoulder 601 of the release bearing 6 gradually moves to the end point B of the cam 5. When the acting point of the cam 5 and the bearing shoulder 601 of the release bearing 6 moves to reach the end point B, since the end point B is the acting point farthest from the cam rotation center, the end point B of the cam 5 reaches the maximum lift of the cam operation. Therefore, the release bearing 6 is pressed by the cam 5 towards the direction close to the clutch friction plate 17 to the maximum displacement. At this time, the release fingers of the diaphragm spring 15 are also pressed into the maximum displacement. The movement of the diaphragm spring 15 is transmitted to the clutch pressure plate 16 through the lever, so that the clutch pressure plate 16 moves away from the clutch friction plate 17 to the maximum displacement, causing the clutch friction plate 17 to be completely separated from the clutch pressure plate 16, and the clutch is completely disengaged and does not transmit torque;

[0082] (2) When the cam 5 has wear;

[0083] As Figure 5 and Figure 7As shown, as the cam 5 gradually wears out with the increase in the number of working cycles, the maximum lift of the working section I of the cam 5 will decrease. This will cause the release bearing 6 not to be pushed to the position corresponding to the complete release of the clutch when the clutch performs the release action. Therefore, under the control of the control component, the cam drive component drives the cam execution component to move, so that the acting point of the cam 5 and the bearing shoulder 601 of the release bearing 6 gradually moves to the cam wear compensation section III of the cam 5 until the cam 5 reaches the maximum lift of cam operation again, causing the release bearing 6 to be pressed by the cam 5 towards the clutch friction plate 17 to the maximum displacement, achieving compensation for the wear amount of the cam 5. At this time, the release fingers of the diaphragm spring 15 are also pressed to the maximum displacement. The movement of the diaphragm spring 15 is transmitted to the clutch pressure plate 16 through a lever, causing the clutch pressure plate 16 to move away from the clutch friction plate 17 to the maximum displacement, so that the clutch friction plate 17 is completely separated from the clutch pressure plate 16, and the clutch is completely separated without transmitting torque.

[0084] 2. Clutch release execution process;

[0085] (1) When the clutch friction plate 17 has no wear;

[0086] As Figure 5 and Figure 8 shown, under the control of the control component, the cam drive component drives the cam execution component to move, so that the acting point of the cam 5 and the bearing shoulder 601 of the release bearing 6 gradually moves to the end point A of the cam 5. Under the combined action of the elastic force of the diaphragm spring 15 and the cooperation of the cam 5, the release bearing 6 moves linearly away from the clutch friction plate 17. When the acting point of the cam 5 and the bearing shoulder 601 of the release bearing 6 moves to the end point A, at this time, the release fingers of the diaphragm spring 15 are not under the pressure of the release bearing 6, and the elastic force of the diaphragm spring 15 presses the clutch pressure plate 16 and the clutch friction plate 17 tightly together, and the clutch is reliably engaged to transmit torque;

[0087] (2) When the clutch friction plate 17 has wear;

[0088] As Figure 5 and Figure 9As shown, after the clutch friction plate 17 is worn, the clutch friction plate 17 becomes thinner, the distance between the clutch pressure plate 16 and the flywheel disc 18 becomes shorter, and the separation finger of the diaphragm spring 15 bulges outward. At this time, the end point A of the cam 5 still applies pressure to the diaphragm spring 15 through the release bearing 6, so that the outer edge of the diaphragm spring 15 tilts outward and reduces the pressing force on the flywheel disc 18, resulting in insufficient pressing force between the flywheel disc 18 and the clutch friction plate 17 and unable to reliably combine and transmit torque. Therefore, under the control of the control component, the cam drive component drives the cam actuator component to move, so that the action point of the cam 5 and the bearing shoulder 601 of the release bearing 6 gradually moves to the friction plate wear compensation section II of the cam 5, until the minimum lift of the cam 5 is reached, that is, the cam 5 no longer applies pressure to the separation finger of the diaphragm spring 15 through the release bearing 6, and the wear amount of the clutch friction plate 17 is compensated. At this time, the elastic force of the diaphragm spring 15 presses the clutch pressure plate 16 and the clutch friction plate 17 together, and the clutch is reliably combined to transmit torque.

Claims

1. A cam-type automatic clutch actuator for an electronically controlled mechanical clutch, characterized in that: It consists of a cam drive assembly, a cam actuator assembly and a control assembly; The cam drive assembly consists of a shift drive motor (1), a worm (2), a worm gear (3) and a camshaft (4). The output end of the shift drive motor (1) is coaxially connected to the worm (2). The worm gear (3) is in meshing transmission with the worm (2), and the camshaft (4) is coaxially connected to the worm gear (3) to transmit power; The cam actuator assembly consists of a cam (5), a release bearing (6) and a release bearing sleeve (14). The cam (5) is fixedly connected to the camshaft (4); the release bearing (6) is sleeved on the release bearing sleeve (14) and consists of a bearing shoulder (601) and a thrust bearing; the working point on the working curve of the outer contour of the cam (5) is in contact with the bearing shoulder (601) and drives the release bearing (6) to perform a reciprocating linear motion along its axis, thereby pressing into or releasing the diaphragm spring release fingers to control the separation or engagement of the clutch; The control assembly consists of a shift controller TCU and vehicle state sensors. The vehicle state sensors are respectively connected to the signal receiving end of the shift controller TCU. The signal output end of the shift controller TCU is connected to the shift drive motor (1). Based on the received vehicle state signals, after making a shift judgment, the shift controller TCU sends a shift control signal to the shift drive motor (1), and drives the cam (5) to rotate in sequence through the shift drive motor (1) to control the separation or engagement of the clutch; The working curve of the cam (5) is divided into three sections, namely: a working section (I), a friction plate wear compensation section (II) and a cam wear compensation section (III); The working section (I) is: a curve section starting from endpoint A, gradually moving away from the cam rotation center, and finally reaching endpoint B which is the farthest from the cam rotation center; The friction plate wear compensation section (II) is: a curve section starting from endpoint A, gradually approaching the cam rotation center, and finally reaching endpoint C which is the closest to the cam rotation center; The cam wear compensation section (III) is: a curve section starting from the endpoint B, with an unchanged curvature radius in the middle section, and finally reaching point D; The endpoint A is: the contact point between the cam (5) and the bearing shoulder (601) when the clutch is fully engaged without wear; The endpoint B is: the contact point between the cam (5) and the bearing shoulder (601) when the clutch is fully disengaged without wear; The endpoint C is: the contact point between the cam (5) and the bearing shoulder (601) when the clutch is fully engaged under the condition that the clutch friction plate (17) reaches the maximum wear amount within the designed service life; The vehicle state sensors include an angle sensor (22) for detecting the rotation angle of the camshaft (4), the worm (2), the worm gear (3) or the output shaft of the shift drive motor (1), as well as an accelerator pedal depth sensor, a vehicle speed sensor and a brake pedal depth sensor.

2. The cam-type automatic clutch actuator according to claim 1, characterized in that: The working curve of the cam (5) is symmetrically arranged on both sides of the cam (5); or the working curve of the cam (5) is arranged on one side of the cam (5), and the working curve of the cam (5) is greater than 180 degrees.

3. The cam-type automatic clutch actuator according to claim 1 or 2, characterized in that: The bearing shoulder (601) is a convex shoulder, that is, there are two symmetrically arranged protrusions on both sides of the bearing shoulder (601), and the outer contour surface of the cam (5) acts on the upper surface of the protrusions; lifting lugs are provided on both sides of the shoulder of the release bearing (6), and an annular groove is opened on the corresponding camshaft (4). A helical spring (13) is installed between the lifting lug and the annular groove on the same side. One end of the helical spring (13) hooks the lifting lug of the release bearing (6), and the other end hooks the annular groove on the camshaft (4). When the release bearing (6) is pressed and moves away from the camshaft (4), the helical spring (13) elongates; when the release bearing (6) is ejected and moves closer to the camshaft (4), the helical spring (13) shortens. During this process, the helical springs (13) on both sides keep the circumferential position of the release bearing (6) unchanged, restricting the rotation of the release bearing (6), so that the outer contour surface of the cam (5) can always act on the protruding position of the bearing shoulder (601).

4. The cam-type automatic clutch actuator according to claim 1 or 2, characterized in that: The bearing shoulder (601) is a flat shoulder, that is, a circular smooth table surface is provided around the bearing shoulder (601), and the cam (5) acts on the smooth table surface along the circumferential direction of the bearing shoulder (601).

5. The cam-type automatic clutch actuator according to claim 1, characterized in that: The camshaft (4) is connected to the worm gear (3) and the cam (5) respectively by means of D-shaped shaft hole fitting connection to achieve circumferential positioning between the connecting parts and transmit torque; The worm gear (3) is axially positioned on the camshaft (4) through the shoulder and snap ring (12) on the camshaft (4); The cam (5) is welded to the camshaft (4).

6. The cam-type automatic clutch actuator according to claim 1, characterized in that: The shift driving motor (1) is fixedly installed on the motor support (9); Both ends of the camshaft (4) are rotatably installed on the camshaft support (8) through lubricating bronze bushes; Both the motor support (9) and the camshaft support (8) are fixedly installed on the transmission housing.

7. The cam-type automatic clutch actuator according to claim 6, characterized in that: The angle sensor (22) in the vehicle state sensor is installed at the end of the camshaft (4). The angle sensor (22) is fixed on the camshaft support (8). The end of the camshaft (4) is processed into a flat shape and inserted into the flat groove on the angle sensor (22) to drive the rotor of the angle sensor (22) to rotate, thereby detecting the rotation angle of the camshaft (4).

8. The execution method of the cam-type automatic clutch actuator according to claim 1, characterized in that: The execution method is specifically as follows: After the shift controller TCU makes a shift decision based on the received vehicle state signal as the basis for judging the shift, it sends an instruction signal to control the engagement or disengagement of the clutch to the shift drive motor (1). The shift drive motor (1) drives the worm (2), the worm gear (3), the camshaft (4) and the cam to move in sequence. According to the outer contour working curve on the cam (5), the cam (5) regularly pushes the release bearing (6) to move linearly along the axial direction, and then presses into or releases the diaphragm spring release fingers, thereby controlling the disengagement or engagement of the clutch; The execution method further includes a compensation method for the wear of the cam (5) or the clutch friction plate (17); After the cam (5) wears, under the control of the control component, the cam drive component drives the cam execution component to move, so that the action point of the cam (5) and the bearing shoulder (601) of the release bearing (6) in the clutch disengagement state gradually moves to the cam wear compensation section (III) of the cam (5) until the cam (5) reaches the lift required for complete clutch disengagement, and the release bearing (6) is pressed by the cam (5) towards the direction close to the clutch friction plate (17) to the maximum displacement, realizing the compensation for the wear amount of the cam (5); After the clutch friction plate (17) wears, under the control of the control component, the cam drive component drives the cam execution component to move, so that the action point of the cam (5) and the bearing shoulder (601) of the release bearing (6) gradually moves to the friction plate wear compensation section (II) of the cam (5). As the clutch friction plate (17) gradually wears, the action point of the cam (5) and the bearing shoulder (601) moves along the friction plate wear compensation section (II) until it reaches the minimum lift point of the cam (5) working, realizing the compensation for the wear amount of the clutch friction plate (17).

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