A clutch actuator spring force system

Abstract

This invention relates to a spring force system for a clutch actuator, solving the technical problem of excessive fluctuations in the clutch displacement output curve in existing technologies, leading to insufficient performance in vehicles. The spring force system for a clutch actuator provided by this invention analyzes the clutch engagement and disengagement process, experimentally compares the spring force ratio, parameter design, and piston displacement parameters of the balance spring and wave spring clip, clarifies the relationship between the values ​​of the balance spring and wave spring clip and the clutch displacement output curve, and proposes the ranges for the slip safety factor K and the self-aligning safety factor J, thus solving the problem of excessive fluctuations in the clutch displacement output curve.

Description

Technical Field

[0001] This invention relates to AMT clutches, and more specifically to a clutch actuator spring force system. Background Technology

[0002] With the rapid development of intelligent products, the clutch actuator, as one of the core components of intelligent products, has attracted much attention. The performance of the clutch actuator directly determines the smoothness of AMT gear shifting. Performance indicators for evaluating clutch actuators include slip resistance, cylinder output force, and clutch displacement output curve, among which the stability of the clutch displacement output curve is crucial. Most existing clutch actuators have certain shortcomings in vehicle performance, mainly due to excessive fluctuations in the clutch displacement output curve. For example, Chinese patent CN112360876A discloses an AMT clutch release bearing unit for commercial vehicles, including a closed bearing assembly, a piston assembly with a rubber ring, a cylinder block assembly with an air intake, a bearing connecting wave spring clip, and a position sensor assembly with a movable block. The spring force system included in its disclosure belongs to a traditional structure.

[0003] The main reason affecting the clutch displacement output curve is the unreasonable design of the spring force system of the clutch actuator. Therefore, a detailed analysis and design of the spring force system is needed to determine the optimal parameters of each spring component. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problem that the existing technology has excessive fluctuations in the clutch displacement output curve, resulting in certain deficiencies in vehicle performance, and to provide a spring force system for the clutch actuator.

[0005] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0006] A clutch actuator spring force system, comprising:

[0007] The system includes an outer casing, a piston, a release bearing, and a flange mounted on the transmission. The outer casing is coaxially mounted on the flange and has vent holes for connecting to an external air source. The piston is coaxially embedded within the outer casing. A balance spring is located between the inner end of the outer casing and the piston, and the balance spring is normally in a compressed state. The release bearing is coaxially embedded within the piston. The inner ring of the release bearing is used to contact the clutch release finger, and the outer ring is connected to the outer end of the piston via a wave spring.

[0008] A displacement sensor is mounted on the flange via a sensor bracket; a limiting groove parallel to the axial direction is provided on the sensor bracket, and a magnet assembly with clearance fit is provided in the limiting groove; the magnet assembly is connected to the piston; the displacement sensor determines the position of the piston by detecting the axial position of the magnet assembly in the limiting groove, thereby outputting the displacement of the release bearing and obtaining the clutch displacement output curve;

[0009] Its special feature is:

[0010] Let F1 be the axial spring force exerted by the balance spring on the piston when the clutch is engaged, and F0 be the critical spring force at which there is no relative sliding between the inner ring of the release bearing and the clutch release finger. Then the parameters of the balance spring satisfy the condition: F1>F0.

[0011] Let F4 be the axial spring force exerted by the wave spring on the piston when the clutch is disengaged, and T be the self-aligning force from the clutch disengagement finger on the inner ring of the release bearing. Then the parameters of the wave spring satisfy the condition: F4 > T.

[0012] Furthermore, F1 = K × F0, where K is the sliding safety factor, satisfying the condition: 1.8 ≤ K ≤ 5;

[0013] F4 = J × T, where J is the centering safety factor, satisfying the condition: 2 ≤ J ≤ 4.

[0014] Furthermore, 2≤K≤3; 2.5≤J≤3.5.

[0015] Furthermore, K = 2.5; J = 3.

[0016] Furthermore, the outer casing has a recessed spring-locking boss inside, and the piston has a corresponding spring mounting ring cavity; the two ends of the balance spring are respectively locked onto the outer side wall of the spring-locking boss and the inner side wall of the spring mounting ring cavity.

[0017] Furthermore, the wave spring clip includes a wave ring and six limiting claws evenly arranged on the wave ring; the crests of the wave ring form the top surface, the troughs form the bottom surface, the limiting claws are set at positions corresponding to the top surface, and the bottom surface contacts the outer ring of the release bearing; F4 is the axial spring force applied to the piston by the limiting claws.

[0018] Furthermore, the outer casing and the flange are fixedly connected by riveting; the flange, sensor bracket and displacement sensor are connected by bolts.

[0019] The advantages of this invention compared to the prior art are:

[0020] This invention provides a spring force system for a clutch actuator. By analyzing the clutch engagement and disengagement process, and experimentally comparing the spring force ratio, parameter design, and piston displacement of the balance spring and wave spring clip, the relationship between the values ​​of the balance spring and wave spring clip and the clutch displacement output curve is clarified. Furthermore, the ranges of the sliding safety factor K and the self-aligning safety factor J are proposed, thus solving the problem of excessive fluctuation in the clutch displacement output curve. Attached Figure Description

[0021] Figure 1 This is a force analysis diagram of an embodiment of the spring force system of a clutch actuator according to the present invention during the engagement process;

[0022] Figure 2 This is a force analysis diagram of the separation process in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the installation of the displacement sensor in an embodiment of the present invention, where A is a top view and B is a three-dimensional structural sectional view;

[0024] Figure 4 This is a force analysis diagram of the waveform spring clip in an embodiment of the present invention;

[0025] Figure 5 This is an experimental relationship diagram between the centering safety factor and the fluctuation amount in an embodiment of the present invention.

[0026] Icon labels:

[0027] 1-Balance spring; 2-Outer shell; 3-Piston; 4-Wave spring clip; 41-Wave ring; 42-Limiting claw; 43-Top surface; 44-Bottom surface; 5-Release bearing; 6-Clutch release finger; 7-Magnetic assembly; 8-Flange; 9-Sensor bracket; 10-Displacement sensor. Detailed Implementation

[0028] The specific technical solutions in the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0029] Figures 1-2A clutch actuator spring force system provided in this embodiment of the invention includes a housing 2, a piston 3, a release bearing 5, and a flange 8 fitted onto a transmission. The housing 2 is coaxially mounted on the flange 8 and has an air hole for communication with an external air source. The piston 3 is coaxially embedded inside the housing 2. A balance spring 1 is provided between the inner end of the housing 2 and the piston 3. The balance spring 1 is normally in a compressed state and serves as an axial guide. The housing 2 has a concave spring-locking boss inside, and the piston 3 has a corresponding spring mounting ring cavity. The two ends of the balance spring 1 are respectively locked onto the outer side wall of the spring-locking boss and the inner side wall of the spring mounting ring cavity. The release bearing 5 is coaxially embedded inside the piston 3. The inner ring of the release bearing 5 is used to contact and engage with the clutch release finger 6, and the outer ring is connected to the outer end of the piston 3 through a wave spring clip 4.

[0030] refer to Figure 3 A displacement sensor 10 is mounted on the flange 8 via a sensor bracket 9. A limiting groove parallel to the axial direction is provided on the sensor bracket 9, and a magnet assembly 7 with clearance fit is provided in the limiting groove. The magnet assembly 7 is connected to the piston 3. The displacement sensor 10 determines the position of the piston 3 by detecting the axial position of the magnet assembly 7 in the limiting groove, thereby outputting the displacement of the release bearing 5 and obtaining the clutch displacement output curve.

[0031] refer to Figure 4 The wave spring clip 4 includes a wave ring 41 and multiple limiting claws 42 evenly arranged on the wave ring 41 (the number of which depends on the actual size); the crests of the wave ring 41 form the top surface 43, and the troughs form the bottom surface 44. The limiting claws 42 are positioned corresponding to the top surface 43, and the bottom surface 44 contacts the outer ring of the release bearing 5; F4 is the axial spring force applied by the limiting claws 42 to the piston 3. The outer casing 2 and the flange 8 are fixedly connected by riveting; the flange 8, the sensor bracket 9, and the displacement sensor 10 are connected by bolts.

[0032] The spring force system provided in this embodiment is analyzed during the clutch engagement and disengagement process:

[0033] 1. Combination state

[0034] Clutch engagement state as follows Figure 1 As shown, the balance spring 1 compresses and pushes the piston 3 and the release bearing 5 into contact with the clutch release finger 6. The clutch release finger 6 drives the inner ring of the release bearing 5 to rotate together. Therefore, the clutch release finger 6 will transmit vibration to the release bearing 5, thus affecting the sensor displacement fluctuation.

[0035] If the spring force of the balance spring 1 is too small, it will cause relative sliding between the clutch release finger 6 and the inner ring of the release bearing 5, resulting in large fluctuations in the clutch displacement output curve.

[0036] In the engaged state, let F1 be the axial spring force exerted by the balance spring 1 on the piston 3, and F0 be the critical spring force at which there is no relative slippage between the inner ring of the release bearing 5 and the clutch release finger 6. The parameters of the balance spring 1 satisfy the condition: F1 = K × F0, where the slip safety factor K has a range of 2 ≤ K ≤ 3, and can be taken as 2.5. As the clutch wears, the engaged position in the figure will continue to move to the right. At this time, the new spring force F1' is always greater than F1, so only the spring force F1 when the clutch is not worn needs to be considered.

[0037] 2. Separation state

[0038] Clutch disengagement state as follows Figure 2 As shown, the external air source input gas flow and the balance spring 1 together push the piston 3 to move and overcome the clutch disengagement force Q. When stopped at a certain disengagement position, the release bearing 5 is in a state of force balance, at which time F3 + F2 = Q, where F3 is the cylinder pressure and F2 is the spring force of the balance spring 1. Since F2 is relatively small in magnitude compared to F3 and Q, it can be ignored.

[0039] At this time, the clutch disengagement finger 6 will adjust the release bearing 4 through the inner ring during rotation. In the disengaged state, the axial spring force (i.e., normal force) applied by the wave spring 4 to the piston 3 is denoted as F4. The inner ring of the release bearing 5 is subjected to the self-aligning force from the clutch disengagement finger 6 as T. The parameters of the wave spring 4 satisfy the condition: F4 = J × T, where the self-aligning safety factor J is taken as 3.

[0040] Given a fixed centering force T, the larger the centering safety factor J, the larger F4.

[0041] The experiment yielded the following curve showing the relationship between the center-adjusting safety factor J and volatility: Figure 5 As shown, as the centering safety factor J increases from 1 to 2.5, the fluctuation decreases exponentially.

[0042] After the self-aligning safety factor J is greater than 2.5, the fluctuation shows a slow downward trend and approaches stability. However, as the self-aligning safety factor J increases, the larger the F4 value, the more difficult the disassembly and assembly become.

[0043] When the safety factor is greater than 3.5, on-site assembly becomes quite difficult, and assembly efficiency is greatly reduced.

[0044] Therefore, the self-aligning safety factor J is designed in the range of 2.5-3.5, which can reduce the clutch displacement fluctuation, improve product performance to meet requirements, and not affect assembly efficiency.

[0045] The above description is merely one embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A spring force system for a clutch actuator, comprising: The outer casing (2), piston (3), release bearing (5), and flange (8) fitted onto the transmission; The outer shell (2) is coaxially mounted on the flange (8), and the outer shell (2) is provided with air holes for communicating with an external air source through the air holes; The piston (3) is coaxially embedded in the outer shell (2); A balance spring (1) is provided between the outer shell (2) and the inner end of the piston (3), and the balance spring (1) is normally in a compressed state. The release bearing (5) is coaxially embedded in the piston (3); the inner ring of the release bearing (5) is used to contact and cooperate with the clutch release finger (6), and the outer ring is connected to the outer end of the piston (3) through a wave spring clip (4); A displacement sensor (10) is mounted on the flange (8) via a sensor bracket (9); a limiting groove parallel to the axial direction is provided on the sensor bracket (9), and a magnet assembly (7) with clearance fit is provided in the limiting groove; the magnet assembly (7) is connected to the piston (3); the displacement sensor (10) determines the position of the piston (3) by detecting the axial position of the magnet assembly (7) in the limiting groove, thereby outputting the displacement of the release bearing (5) and obtaining the clutch displacement output curve; Its features are: Let F1 be the axial spring force exerted by the balance spring (1) on the piston (3) when the clutch is engaged, and F0 be the critical spring force at which there is no relative sliding between the inner ring of the release bearing (5) and the clutch release finger (6). Then the parameters of the balance spring (1) satisfy the condition: F1>F0. When the clutch is in the disengaged state, the axial spring force applied by the wave spring clip (4) to the piston (3) is F4, and the inner ring of the release bearing (5) is subjected to a self-aligning force from the clutch release finger (6) is T. Then the parameters of the wave spring clip (4) satisfy the condition: F4>T.

2. The spring force system of a clutch actuator according to claim 1, characterized in that: F1 = K × F0, where K is the sliding safety factor, satisfying the condition: 1.8 ≤ K ≤ 5; F4 = J × T, where J is the centering safety factor, satisfying the condition: 2 ≤ J ≤ 4.

3. The spring force system of a clutch actuator according to claim 2, characterized in that: 2≤K≤3； 2.5≤J≤3.5。 4. The spring force system of a clutch actuator according to claim 3, characterized in that: K = 2.5; J = 3.

5. A clutch actuator spring force system according to claim 1, characterized in that: The outer shell (2) has a recessed spring-locking boss inside, and the piston (3) has a corresponding spring mounting ring cavity; the two ends of the balance spring (1) are respectively locked onto the outer side wall of the spring-locking boss and the inner side wall of the spring mounting ring cavity.

6. A clutch actuator spring force system according to claim 1, characterized in that: The wave spring clip (4) includes a wave ring (41) and six limiting claws (42) evenly arranged on the wave ring (41); the crests of the wave ring (41) form the top surface (43), the troughs form the bottom surface (44), the limiting claws (42) are arranged at positions corresponding to the top surface (43), and the bottom surface (44) contacts the outer ring of the release bearing (5); F4 is the axial spring force applied by the limiting claw (42) to the piston (3).

7. A clutch actuator spring force system according to claim 1, characterized in that: The outer shell (2) and the flange (8) are fixedly connected by riveting; The flange (8), sensor bracket (9) and displacement sensor (10) are connected by bolts.

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