Clutch diagnostic device

Abstract

To detect a situation in which a push-in load of a release bearing is increased.SOLUTION: A clutch diagnostic device includes: a fork side cylinder having a push rod contacting a force point section of a release fork; and a pedal side cylinder connected to the fork side cylinder through a connection pipe. The clutch diagnostic device further includes: an accumulator connected to the connection pipe through a branch pipe; and a vibration sensor mounted in the release fork or the clutch pedal. A control system constituting the clutch diagnostic device issues a warning signal when a vibration level is below a vibration threshold in a process in which the release bearing moves from a fastening position to a release position.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a clutch diagnosis device.

Background Art

[0002] A starting clutch operated by a clutch pedal is provided between the engine and the transmission (see Patent Documents 1-3). The starting clutch has a release bearing facing a diaphragm spring. By pushing the release bearing against the diaphragm spring, the biasing force of the diaphragm spring is released and the starting clutch is switched to the released state. On the other hand, by releasing the pushing of the release bearing against the diaphragm spring, the starting clutch is switched to the engaged state by the biasing force of the diaphragm spring.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, as the wear of the clutch disc progresses with the aging of the starting clutch, the pushing load of the release bearing increases. In addition, since an increase in the pushing load of the release bearing is a factor that increases the load on the operating mechanism of the starting clutch, it is required to detect at an early stage the situation where the pushing load of the release bearing is increasing.

Means for Solving the Problems

[0005] According to the present disclosure, a clutch diagnosis device has a release bearing that is disposed opposite to a diaphragm spring of a starting clutch and moves between a fastening position for fastening the starting clutch and a release position for releasing the starting clutch. The clutch diagnosis device has a release fork that includes a fulcrum portion supported by a housing of a transmission and an action point portion that contacts the release bearing. The clutch diagnosis device has a fork-side cylinder that is attached to the housing and includes a push rod that contacts a force point portion of the release fork. The clutch diagnosis device has a pedal-side cylinder that is connected to the fork-side cylinder via a connection pipe and includes a push rod that is connected to a clutch pedal. The clutch diagnosis device has an accumulator that is connected to the connection pipe via a branch pipe and to which clutch fluid is supplied from the connection pipe. The clutch diagnosis device has a vibration sensor that is attached to the release fork or the clutch pedal, detects vibration, and transmits a vibration signal. The clutch diagnosis device includes a processor and a memory that are communicably connected to each other, and has a control system that calculates a vibration level from the vibration signal. The control system issues a warning signal when the vibration level falls below a vibration threshold value in a process in which the release bearing moves from the fastening position to the release position.

Advantages of the Invention

[0006] According to the present disclosure, the control system issues a warning signal when the vibration level falls below a vibration threshold value in a process in which the release bearing moves from the fastening position to the release position. Thereby, it is possible to detect a situation in which the pushing load of the release bearing is increasing.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or substantially the same configurations and elements are denoted by the same reference numerals, and repeated descriptions are omitted.

[0009] <Vehicle> FIG. 1 is a diagram showing an example of a vehicle 11 equipped with a clutch diagnosis device 10 which is an embodiment of the present disclosure. As shown in FIG. 1, the vehicle 11 has a power unit 14 composed of an engine 12 and a transmission (gearbox) 13. The rear wheel output shaft 15 of the power unit 14 is connected to the rear wheels 18 via a propeller shaft 16 and a rear differential mechanism 17. Further, the power unit 14 is provided with a front differential mechanism 19, and the front differential mechanism 19 is connected to the front wheels 20. Note that the illustrated power unit 14 is a power unit for all-wheel drive, but it is not limited thereto, and it may be a power unit for front-wheel drive or rear-wheel drive.

[0010] <Starting Clutch> FIG. 2 is a diagram showing the power unit 14 and the clutch diagnostic device 10. As shown in FIG. 2, a starting clutch 21 that can be switched between a engaged state and a released state is disposed between the engine 12 and the transmission 13. As will be described later, by depressing the clutch pedal 44 to release the starting clutch 21, the crankshaft 22 of the engine 12 and the transmission input shaft 23 of the transmission 13 can be disengaged from each other. On the other hand, by releasing the depression of the clutch pedal 44 to engage the starting clutch 21, the crankshaft 22 and the transmission input shaft 23 can be connected to each other.

[0011] The starting clutch 21 has a flywheel 24 connected to the crankshaft 22 and a clutch cover 25 attached to the flywheel 24. The starting clutch 21 also has an annular pressure plate 26 housed in the clutch cover 25 and a disc-shaped diaphragm spring 27 housed in the clutch cover 25. Further, the starting clutch 21, which is a friction clutch, has a clutch disc 28 connected to the transmission input shaft 23. The clutch disc 28 is disposed between the flywheel 24 and the pressure plate 26.

[0012] The housing 30 of the transmission 13 has a partition wall 33 that partitions a gear chamber 31 and a clutch chamber 32. A release sleeve 34 and a support pin 35 protruding toward the clutch chamber 32 side are attached to the partition wall 33 of the housing 30. The transmission input shaft 23 is disposed inside the release sleeve 34, and a release bearing 36 is movably supported outside the release sleeve 34. The release bearing 36 is disposed to face the central portion of the diaphragm spring 27.

[0013] Next, the operating mechanism 40 of the starting clutch 21 will be described. As shown in FIG. 2, the operating mechanism 40 of the starting clutch 21 is composed of a release fork 41, an operating cylinder 42, a master cylinder 43, and a clutch pedal 44. A release fork 41 is swingably attached to the housing 30. The release fork 41 has a fulcrum portion 41a supported by a support pin 35, an acting point portion 41b that contacts the release bearing 36, and a force point portion 41c that protrudes outside the housing 30. Further, an operating cylinder (fork-side cylinder) 42 having a push rod 42a that contacts the force point portion 41c of the release fork 41 is attached to the housing 30.

[0014] A master cylinder (pedal-side cylinder) 43 is connected to the operating cylinder 42 via a clutch pipe (connection pipe) 45, and a clutch pedal 44 is connected to the push rod 43a of the master cylinder 43. Further, an accumulator 47 is connected to the clutch pipe 45 via a branch pipe 46. The accumulator 47, which is a pressure accumulator, includes a cylinder 48 connected to the branch pipe 46, a piston 49 housed in the cylinder 48, and a spring 50 housed in the cylinder 48 that biases the piston 49. Note that the operating cylinder 42, the master cylinder 43, the clutch pipe 45, and the branch pipe 46 are filled with clutch fluid, which is a working fluid. Further, the operating cylinder 42 is also called a release cylinder.

[0015] <Operation of the starting clutch> Figure 3 shows the released state of the starting clutch 21. As shown in Figure 3, when the clutch pedal 44 is depressed by the driver (arrow A1), the push rod 43a of the master cylinder 43 is pushed in, so that the clutch fluid is pumped from the master cylinder 43 toward the operating cylinder 42 (arrow A2). As a result, the push rod 42a is pushed out from the operating cylinder 42 (arrow A3), the release fork 41 swings about the support pin 35 as a fulcrum, and the release bearing 36 is pushed into the diaphragm spring 27 toward the release position (arrow A4).

[0016] In this way, while pushing in the diaphragm spring 27 and moving the release bearing 36 to the release position, the outer peripheral portion of the diaphragm spring 27 is displaced in a direction away from the pressure plate 26. As a result, the pushing-in of the pressure plate 26 by the diaphragm spring 27 can be released, so that the pressure plate 26 can be pulled away from the clutch disc 28 (arrow A5), and the starting clutch 21 can be released to disconnect the crankshaft 22 and the transmission input shaft 23 from each other.

[0017] As described above, when switching the starting clutch 21 to the released state, since the clutch fluid is pumped from the master cylinder 43 to the operating cylinder 42, the clutch fluid pressure (hereinafter referred to as the clutch pressure) in the clutch pipe 45 increases. Here, the biasing force of the spring 50 provided in the accumulator 47 is set to a magnitude that does not move the piston 49 until the clutch pressure exceeds a predetermined reference pressure Px. The reference pressure Px is the peak value that the clutch pressure reaches under the condition that the pushing load of the release bearing 36 reaches the upper limit value of the normal range. Note that the peak value of the clutch pressure gradually increases as the clutch disc 28 wears, but when the wear amount of the clutch disc 28 is within the normal use range, that is, when the starting clutch 21 is normal, the clutch pressure does not exceed the reference pressure Px.

[0018] That is, when the starting clutch 21 is operating normally, i.e., when the pushing load of the release bearing 36 is within the normal range, the clutch pressure transitions below the reference pressure Px. Therefore, the piston 49 of the accumulator 47 does not move and closes the connection port 48a of the cylinder 48. On the other hand, when there is a possibility that the starting clutch 21 has a problem, i.e., when the pushing load of the release bearing 36 exceeds the normal range, the clutch pressure exceeds the reference pressure Px. Therefore, the piston 49 of the accumulator 47 moves to open the connection port 48a of the cylinder 48. For example, as shown in FIG. 3, in a situation where the starting clutch 21 is operating normally, since the clutch pressure stops at a predetermined pressure Pr1 lower than the reference pressure Px, the piston 49 of the accumulator 47 does not start to move and the piston 49 stops at a position closing the connection port 48a of the cylinder 48.

[0019] FIG. 4 is a diagram showing the engaged state of the starting clutch 21. As shown in FIG. 4, when the depression of the clutch pedal 44 by the driver is released (arrow B1), the pressure feeding of the clutch fluid from the master cylinder 43 to the operating cylinder 42 is released. As a result, the release bearing 36 is pushed back to the engaged position by the diaphragm spring 27 (arrow B2). Therefore, the push rod 42a of the operating cylinder 42 is pushed back via the release fork 41 (arrow B3), and the clutch fluid is returned from the operating cylinder 42 toward the master cylinder 43 (arrow B4).

[0020] In this way, when the release bearing 36 is pushed back to the engaged position, the restraint of the diaphragm spring 27 by the release bearing 36 is released. Therefore, the outer peripheral portion of the diaphragm spring 27 is displaced in a direction approaching the pressure plate 26. As a result, the pressure plate 26 is pushed in by the diaphragm spring 27. Therefore, the pressure plate 26 can be pressed against the clutch disc 28 (arrow B5), and the starting clutch 21 can be engaged to connect the crankshaft 22 and the transmission input shaft 23 to each other.

[0021] <Control system> As shown in FIG. 2, the clutch diagnosis device 10 has a control system 52 composed of an electronic control unit 51 in order to detect deterioration exceeding the normal range due to the aging of the starting clutch 21. As sensors connected to the electronic control unit 51, there are a vibration sensor 53 that detects the vibration of the release fork 41, a pedal switch 54 that detects the depression of the clutch pedal 44, and a rotation sensor 55 that detects the engine speed, which is the rotational speed of the engine 12. Further, connected to the electronic control unit 51 are a power switch 56 for performing a start-up operation and a stop operation of the control system 52, and a warning lamp 58 provided on the meter panel 57.

[0022] FIG. 5 is a diagram showing an example of the basic structure of the electronic control unit 51. As shown in FIG. 5, the electronic control unit 51 has a microcontroller 62 in which a processor 60, a main memory (memory) 61, etc. are incorporated. A predetermined program is stored in the main memory 61, and the program is executed by the processor 60. The processor 60 and the main memory 61 are connected to be communicable with each other. Note that a plurality of processors 60 may be incorporated in the microcontroller 62, or a plurality of main memories 61 may be incorporated in the microcontroller 62.

[0023] The electronic control unit 51 also includes an input circuit 63, a drive circuit 64, a communication circuit 65, an external memory 66, and a power supply circuit 67. The input circuit 63 converts signals input from various sensors into signals that can be input to the microcontroller 62. The drive circuit 64 generates drive signals for devices such as the aforementioned meter panel 57 based on the signals output from the microcontroller 62. The communication circuit 65 converts the signals output from the microcontroller 62 into communication signals directed to other electronic control units and the like. Also, the communication circuit 65 converts the communication signals received from other electronic control units and the like into signals that can be input to the microcontroller 62. Furthermore, the power supply circuit 67 supplies a stable power supply voltage to the microcontroller 62, the input circuit 63, the drive circuit 64, the communication circuit 65, the external memory 66, and the like. Programs and various data are stored in the external memory 66 composed of a non-volatile memory and the like.

[0024] <Clutch Diagnosis Control> The clutch diagnosis device 10 has an accumulator 47 to which clutch fluid is supplied from the clutch pipe 45 in order to detect deterioration beyond the normal range due to the aging of the starting clutch 21, that is, a situation where the pushing load of the release bearing 36 increases beyond a predetermined normal range. Also, the control system 52 of the clutch diagnosis device 10 executes clutch diagnosis control, which will be described later, in order to detect a situation where the pushing load of the release bearing 36 exceeds the normal range. Note that factors causing the pushing load of the release bearing 36 to exceed the normal range include, for example, excessive wear of the clutch disc 28 and excessive increase in the rotational resistance and sliding resistance of the release bearing 36.

[0025] Figure 6 is a flowchart showing an example of the execution procedure of the clutch diagnosis control. Each step of the clutch diagnosis control shown in Figure 6 is a step executed by the processor 60 that constitutes the control system 52. Also, the clutch diagnosis control is a control that is executed by the control system 52 at a predetermined cycle after the control system 52 is activated by the ON operation of the power switch 56 by the driver.

[0026] As shown in FIG. 6, the control system 52 proceeds to step S10 and reads the accumulator operation count (count value) CA stored in the main memory 61. As will be described later, the accumulator operation count CA is the number of times it is determined that the accumulator 47 is operating when the clutch pedal 44 is depressed. Subsequently, the control system 52 proceeds to step S11 and determines whether the engine speed Ne exceeds a predetermined speed threshold N1. Further, when the control system 52 determines in step S11 that the engine speed Ne exceeds the speed threshold N1, it proceeds to step S12 and determines whether the clutch pedal 44 is depressed.

[0027] As described above, the pedal switch 54 is connected to the control system 52, and the control system 52 determines the depression of the clutch pedal 44 based on the ON signal from the pedal switch 54. That is, as shown in FIG. 3, when the clutch pedal 44 is depressed beyond the detection position Po2, the rod 54a of the pedal switch 54 is pushed in by the clutch pedal 44, and an ON signal is output from the pedal switch 54. That is, when the position of the clutch pedal 44 is between the release position Po1 and the detection position Po2, the pedal switch 54 is in an OFF state where it does not output an ON signal. Also, when the position of the clutch pedal 44 is between the detection position Po2 and the depressed position Po3, the pedal switch 54 is in an ON state where it outputs an ON signal.

[0028] As shown in FIG. 6, when the control system 52 determines in step S12 that the clutch pedal 44 is depressed, that is, when it determines that an ON signal is being output from the pedal switch 54, it proceeds to step S13 and calculates the vibration level Lx of the release fork 41 based on the vibration signal transmitted from the vibration sensor 53. Further, the control system 52 proceeds to step S14 and calculates the engine speed Ne based on the rotation signal transmitted from the rotation sensor 55. That is, the control system 52 calculates the vibration level Lx and the engine speed Ne during the process of depressing the clutch pedal 44, that is, during the process in which the release bearing 36 moves from the engaged position to the released position.

[0029] The control system 52 performs frequency analysis on the vibration signal transmitted from the vibration sensor 53 and calculates the vibration level Lx in a predetermined frequency band. For example, as the frequency band of the vibration level Lx, a frequency band including 500 [Hz] can be used. In the present embodiment, the control system 52 calculates the vibration level Lx [dB] in a frequency band (1 / 1 octave band) having a center frequency of 500 [Hz]. Further, although the vibration level Lx varies during the process in which the release bearing 36 moves from the engaged position to the released position, in steps S13 and S14, the control system 52 calculates the peak value of the vibration level Lx and also calculates the engine speed Ne when the peak value is obtained.

[0030] When the control system 52 calculates the vibration level Lx in step S13 and calculates the engine speed Ne in step S14, it proceeds to step S15 and determines whether or not the accumulator 47 is operating based on the vibration level Lx and the engine speed Ne. Here, FIG. 7 is a diagram showing an example of the vibration threshold value X1 used for determining the operation of the accumulator. The alternate long and short dash line Xa shown in FIG. 7 is a line showing the vibration level Lx of the release fork 41 for each engine speed Ne when the accumulator is not operating. The broken line Xb shown in FIG. 7 is a line showing the vibration level Lx of the release fork 41 for each engine speed Ne when the accumulator is operating.

[0031] As shown in FIG. 7, in a region where the engine speed Ne exceeds the speed threshold value N1, a vibration threshold value X1 is set based on the engine speed Ne. That is, the vibration threshold value X1 is set to be disposed between the dashed-dotted line Xa and the dashed line Xb. And as indicated by the symbol Ya, when the vibration level Lx of the release fork 41 is equal to or higher than the vibration threshold value X1 set based on the engine speed Ne, the control system 52 determines that the accumulator 47 is not operating. On the other hand, as indicated by the symbol Yb, when the vibration level Lx of the release fork 41 is lower than the vibration threshold value X1 set based on the engine speed Ne, the control system 52 determines that the accumulator 47 is operating.

[0032] Here, FIG. 8 is a diagram showing the released state of the starting clutch 21, and FIG. 8 shows the starting clutch 21 in which the pushing load of the release bearing 36 exceeds the normal range. In FIG. 8, the same arrows as those shown in FIG. 3 are denoted by the same reference numerals and their description is omitted. As shown in FIG. 8, when the pushing load of the release bearing 36 exceeds the predetermined normal range, the clutch pressure in the clutch pipe 45 rises to a predetermined pressure Pr2 higher than the aforementioned reference pressure Px. And when the clutch pressure rises to the predetermined pressure Pr2 exceeding the reference pressure Px, the clutch fluid flows into the cylinder 48 while pushing the piston 49 (arrow A10). Thus, the situation where the clutch fluid pushes the piston 49 is the situation where the accumulator 47 is operating. As shown in FIG. 3, the situation where the clutch fluid does not push the piston 49 is the situation where the accumulator 47 is not operating.

[0033] As shown in FIG. 8, when the piston 49 of the accumulator 47 is pushed in, the operation of the accumulator 47 suppresses fluctuations in the clutch pressure, thereby reducing the vibration of the operating mechanism 40 including the release fork 41 and the clutch pedal 44. That is, when the start clutch 21 is released by stepping on the clutch pedal 44, various vibrations are transmitted from the start clutch 21 to the operating mechanism 40, but the vibrations transmitted to the operating mechanism 40 are reduced when the accumulator is operating. That is, since the situation where the vibration level Lx of the release fork 41 is below the vibration threshold value X1 means that the vibration transmitted to the operating mechanism 40 is reduced, the control system 52 can determine that the accumulator 47 is operating.

[0034] As shown in FIG. 6, when the control system 52 determines in step S15 that the accumulator 47 is operating, it proceeds to step S16, increments the accumulator operation count CA, and proceeds to step S17 to determine whether the accumulator operation count CA has reached a predetermined warning threshold (specified value) C1. Then, when the control system 52 determines in step S17 that the accumulator operation count CA has reached the warning threshold C1 (for example, 10), it proceeds to step S18, issues a warning signal to turn on the warning lamp 58, and proceeds to step S19 to reset the accumulator operation count CA to zero.

[0035] In this way, the situation where the accumulator operation count CA reaches the warning threshold C1 means that the pushing load on the release bearing 36 continuously increases beyond the normal range. Therefore, in order to protect the start clutch 21 and the operating mechanism 40, the control system 52 lights the warning lamp 58 related to the start clutch 21 to prompt the driver to take the vehicle to a maintenance factory. As a result, the inspection and maintenance of the start clutch 21 can be carried out early, and the start clutch 21 and the operating mechanism 40 can be appropriately protected. Note that the accumulator operation count CA incremented in step S16 and the accumulator operation count CA reset in step S19 are stored in the main memory 61.

[0036] In the foregoing description, "10" is exemplified as the warning threshold C1, but it is not limited thereto. For example, "1" may be set as the warning threshold C1. In this way, when "1" is set as the warning threshold C1, if the control system 52 determines in step S15 that the accumulator 47 is operating, it proceeds to step S18, emits a warning signal, and turns on the warning lamp 58. That is, the control system 52 emits a warning signal when the vibration level Lx of the release fork 41 is lower than the vibration threshold X1 during the process of the release bearing 36 moving from the fastening position to the release position.

[0037] <Number of times reset control> The clutch diagnostic device 10 executes a number of times reset control to prevent misdiagnosis regarding the starting clutch 21. FIG. 9 is a flowchart showing an example of the execution procedure of the number of times reset control. Each step of the number of times reset control shown in FIG. 9 is a step executed by the processor 60 constituting the control system 52. Further, the number of times reset control is a control that is executed by the control system 52 at a predetermined cycle after the control system 52 is activated by the ON operation of the power switch 56 by the driver. That is, the number of times reset control is executed simultaneously with the foregoing clutch diagnostic control.

[0038] As shown in FIG. 9, the control system 52 proceeds to step S20 and reads the accumulator operation count CA and the clutch operation count CB stored in the main memory 61. Note that the clutch operation count CB is the number of times the clutch pedal 44 is depressed. Further, when the control system 52 reads the accumulator operation count CA and the clutch operation count CB in step S20, it proceeds to step S21 and determines whether the accumulator operation count CA exceeds a predetermined number of times C2 (for example, 3). Note that the predetermined number of times C2 is set to a value smaller than the foregoing warning threshold C1.

[0039] When the control system 52 determines in step S21 that the accumulator operation count CA exceeds a predetermined count C2, it proceeds to step S22 and determines whether the clutch pedal 44 is depressed based on the ON signal of the pedal switch 54. When the control system 52 determines in step S22 that the clutch pedal 44 is depressed, it proceeds to step S23, increments the clutch operation count CB, and then proceeds to step S24 to determine whether the clutch operation count CB exceeds a predetermined count C3 (for example, 100).

[0040] When the control system 52 determines in step S24 that the clutch operation count CB exceeds the predetermined count C3, it proceeds to step S25 and resets the accumulator operation count CA and the clutch operation count CB to zero. On the other hand, when the control system 52 determines in step S24 that the clutch operation count CB is less than or equal to the predetermined count C3, it exits the routine while maintaining the accumulator operation count CA and the clutch operation count CB. Note that when the control system 52 determines in step S21 that the accumulator operation count CA is less than or equal to the predetermined count C2, it proceeds to step S26, resets the clutch operation count CB to zero, and exits the routine.

[0041] That is, when the accumulator operation count CA reaches the predetermined count C2 (for example, 3) and then the clutch operation count CB exceeds the predetermined count C3 (for example, 100) without the accumulator operation count CA being reset, the control system 52 resets the accumulator operation count CA to zero. That is, when the accumulator operation count CA reaches the predetermined count C2 and then the clutch operation count CB exceeds the predetermined count C3 without the warning lamp 58 being lit by the clutch diagnosis control, the control system 52 resets the accumulator operation count CA to zero. In this way, when the clutch pedal 44 is depressed multiple times without operating the accumulator 47, the accumulator operation count CA is reset, so that the starting clutch 21 can be appropriately diagnosed without issuing an unnecessary warning signal.

[0042] <Other Embodiments> It goes without saying that the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof. In the above description, the vibration sensor 53 is attached to the release fork 41, but it is not limited thereto. For example, as shown by reference sign α in FIG. 1, even when the vibration sensor 53 is attached to the clutch pedal 44, the vibration level of the clutch pedal 44 constituting the operation mechanism 40 can be detected, and the situation where the pushing load of the release bearing 36 is increasing can be detected.

[0043] In the above description, the vibration level Lx is calculated as the vibration level in the frequency band (1 / 1 octave band) having a center frequency of 500 [Hz], but it is not limited thereto. For example, the vibration level Lx may be calculated as the vibration level in the frequency band (1 / 3 octave band) having a center frequency of 500 [Hz]. Needless to say, a center frequency other than 500 [Hz] may also be adopted.

[0044] The illustrated accumulator 47 is an accumulator that biases the piston 49 by the spring 50, but it is not limited thereto, and it may be an accumulator that biases the piston by gas pressure such as nitrogen gas. Further, it may be a bladder-type accumulator provided with a diaphragm that partitions the gas chamber. In the above description, the control system 52 is configured by one electronic control unit 51, but it is not limited thereto, and the control system 52 may be configured by a plurality of electronic control units.

[0045] In the example shown in FIG. 7, the vibration threshold value X1 is increased in accordance with the increase in the engine speed Ne, but this is not the only case, and the vibration threshold value X1 may be a fixed value. Further, when the vibration threshold value X1 is set to a fixed value, it is desirable to also set the engine speed range to which the fixed vibration threshold value X1 is applied. Further, in the above description, the warning lamp 58 is lit based on the warning signal issued from the control system 52, but this is not the only case, and the warning lamp 58 may be blinked. Further, based on the warning signal issued from the control system 52, a warning sound may be generated from a buzzer, and the warning content may be displayed on a display.

Explanation of Signs

[0046] 10…Clutch diagnostic device, 12…Engine, 13…Transmission (transmission), 21…Launch clutch, 27…Diaphragm spring, 30…Housing, 36…Release bearing, 41…Release fork, 41a…Fulcrum part, 41b…Acting point part, 41c…Force point part, 42…Operating cylinder (fork side cylinder), 42a…Push rod, 43…Master cylinder (pedal side cylinder), 43a…Push rod, 44…Clutch pedal, 45…Clutch pipe (connection pipe), 46…Branch pipe, 47…Accumulator, 52…Control system, 53…Vibration sensor, 60…Processor, 61…Main memory (memory), Lx…Vibration level, X1…Vibration threshold value, Ne…Engine speed (engine rotation speed), N1…Speed threshold value, CA…Accumulator operation count (count value), C1…Warning threshold value (specified value)

Claims

1. A clutch diagnostic device for diagnosing a starting clutch disposed between an engine and a transmission, a release bearing disposed opposite to a diaphragm spring of the starting clutch and moving between a fastening position for fastening the starting clutch and a release position for releasing the starting clutch; a release fork including a fulcrum portion supported by a housing of the transmission and an action point portion contacting the release bearing; a fork-side cylinder attached to the housing and including a push rod contacting a force point portion of the release fork; a pedal-side cylinder connected to the fork-side cylinder via a connection pipe and including a push rod connected to a clutch pedal; an accumulator connected to the connection pipe via a branch pipe and supplied with clutch fluid from the connection pipe; a vibration sensor attached to the release fork or the clutch pedal, detecting vibration and transmitting a vibration signal; a control system including a processor and a memory communicably connected to each other, and calculating a vibration level from the vibration signal; having when the vibration level falls below a vibration threshold during a process in which the release bearing moves from the fastening position to the release position, the control system issues a warning signal. Clutch diagnostic device.

2. The clutch diagnostic device according to claim 1, wherein the vibration threshold is set based on a rotational speed of the engine. Clutch diagnostic device.

3. The clutch diagnostic device according to claim 1, when the vibration level falls below the vibration threshold during a process in which the release bearing moves from the fastening position to the release position and under a state where the rotational speed of the engine exceeds a speed threshold, the control system issues a warning signal. Clutch diagnostic device.

4. In the clutch diagnostic device according to claim 1, the control system determines whether or not the release bearing is in the process of moving from the fastening position to the release position based on an output signal from a pedal switch that detects depression of the clutch pedal. Clutch diagnostic device.

5. In the clutch diagnostic device according to claim 1, when the vibration level falls below a vibration threshold value during the process in which the release bearing moves from the fastening position to the release position, the control system increments a count value. when the count value reaches a specified value, the control system issues a warning signal. Clutch diagnostic device.

Images