Detection device and detection method

Abstract

The present invention includes: a displacement sensor (9) having a detection unit (9A), wherein the detection unit (9A) obtains a relative distance from a pulley (4) in the axial direction of the pulley (4) in a belt device (1) having a pulley (4) wound with a belt (5); a displacement calculation unit (110) for calculating the displacement of the pulley (4) in the axial direction based on the obtained relative distance; and an inclination calculation unit (120) for calculating the inclination of the pulley (4) relative to the axial direction based on the calculated displacement.

Description

Technical Field

[0001] The present invention relates to a detection device and a detection method, and in particular to a technology for detecting misalignment of a belt device of an engine. Background Art

[0002] Typically, such a belt device includes a drive pulley on a crankshaft and a driven pulley on an auxiliary device such as an alternator or a radiator fan. An endless belt (hereinafter referred to as a belt) is wound around the drive pulley and the driven pulley.

[0003] In such a belt device, if the pulley tilts relative to the rotating shaft due to misalignment, there is a possibility of uneven wear on the pulley or belt. For example, Patent Document 1 discloses a technology in which a three-dimensional measuring device is installed in front of a pulley located on the front side of the engine, and the misalignment of the pulley is detected using the three-dimensional measuring device.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-184151 Summary of the Invention

[0007] Technical problem to be solved by the invention

[0008] If a large three-dimensional measuring device is installed in front of the pulley as in the technique described in Patent Document 1, there is a possibility that layout restrictions will be imposed. Therefore, further simplification of the device is desired.

[0009] The technology of the present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to effectively detect the inclination of a pulley with a simple structure.

[0010] Means used to solve problems

[0011] The detection device of the present invention includes: a distance acquisition device, having a detection unit, which acquires the relative distance from the pulley in the axial direction of the pulley in a belt device having a pulley wound with a belt; a displacement calculation device, which calculates the displacement of the pulley in the axial direction based on the acquired relative distance; and an inclination calculation device, which calculates the inclination of the pulley relative to the axial direction of the pulley based on the calculated displacement.

[0012] Furthermore, the detection unit may also acquire the relative distance in the axial direction of the pulley from a circumferential center of the outer circumference of the pulley in contact with the belt. The detection unit may also be provided at a position axially away from the pulley at a central position in the longitudinal direction of the region in contact with the belt in the pulley.

[0013] Furthermore, the belt device may include a plurality of pulleys, and the detection unit may acquire a relative distance in the axial direction from a pulley having the smallest bending rigidity of the rotation shaft among the plurality of pulleys.

[0014] Furthermore, the detection device further includes a determination device for determining that a misalignment has occurred in which the pulley is installed obliquely with respect to the rotating shaft, when the inclination calculated by the calculation device exceeds a predetermined threshold value.

[0015] The detection method of the present invention includes the following steps executed by a computer: a step of obtaining a relative distance from a pulley in the axial direction of a belt device having a pulley wound with a belt; a step of calculating an axial displacement of the pulley based on the obtained relative distance; and a step of calculating an inclination of the pulley relative to the axial direction of the pulley based on the calculated displacement.

[0016] Effects of the Invention

[0017] According to the technology of the present invention, the inclination of the pulley can be effectively detected with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic front view showing the internal combustion engine of the present embodiment.

[0019] Figure 2 (A) is a schematic front view showing the configuration of the displacement sensor of this embodiment. Figure 2 (B) in FIG. 1 is a schematic side view showing the configuration of the displacement sensor of this embodiment.

[0020] Figure 3 This is a schematic functional block diagram showing the control device and related peripheral structures according to the present embodiment.

[0021] Figure 4 It is a diagram schematically showing detection values of the displacement sensor according to this embodiment.

[0022] Figure 5 It is a schematic diagram showing the inclination of the driven pulley in this embodiment.

[0023] Figure 6 This is a flowchart illustrating the flow of positional misalignment detection performed by the control device according to this embodiment.

[0024] Figure 7 This is a flowchart illustrating the flow of belt life estimation performed by the control device according to this embodiment. DETAILED DESCRIPTION

[0025] The following describes the detection device of this embodiment based on the accompanying drawings. Identical components are marked with the same reference numerals, and their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0026] [Overall structure]

[0027] Figure 1 This is a schematic front view of the internal combustion engine of this embodiment as viewed from the crankshaft direction. Figure 1 In the figure, the front direction of the paper is referred to as the front side, and the depth direction of the paper is referred to as the rear side. In addition, arrow A indicates the rotation direction of the belt.

[0028] The engine 10, which is an internal combustion engine, includes an engine main body 11 mainly composed of a cylinder block, a cylinder head, a crankcase, an oil pan, etc. A crankshaft 12 is rotatably supported on the engine main body 11 for outputting a rotational force transmitted from a piston (not shown) via a connecting rod, etc.

[0029] [With device]

[0030] Belt device 1 includes a drive pulley 2, driven pulleys 3 and 4, a tension pulley 6, a retaining portion 7 for retaining tension pulley 6, the drive pulley 2, the driven pulleys 3 and 4, and a belt 5. The belt 5 is wound around the driven pulleys 3 and 4 and the tension pulley 6. The belt 5 is, for example, a multi-V belt, and has a plurality of V-shaped grooves (not shown) formed on its inner circumference. The drive pulley 2 and the driven pulleys 3 and 4 are, for example, multi-V belt pulleys, and have a plurality of grooves formed on their outer circumferences that correspond to the grooves on the inner circumference of the belt 5. The number of driven pulleys 3 and 4 and the tension pulley 6 is not limited to the example shown in the figure, and any appropriate number may be used.

[0031] The drive pulley 2 is fixed to a front end portion of the crankshaft 12 that protrudes forward from a front end surface 11A of the engine body 11 so as to be rotatable integrally with the crankshaft 12 .

[0032] The driven pulley 3 is a pulley of the air-conditioning compressor 30 and is fixed to the front end of the rotating shaft 31, which protrudes forward from the front end surface 30A of the air-conditioning compressor 30, so as to be rotatable integrally with the rotating shaft 31. The driven pulley 3 includes an electromagnetic clutch (not shown) and is rotationally driven by the power of the engine 10 when the electromagnetic clutch is engaged.

[0033] The driven pulley 4 is a pulley of the alternator 40 and is fixed to the front end of the rotating shaft 41, which protrudes forward from the front end surface 40A of the alternator 40, so as to be rotatable integrally with the rotating shaft 41. The alternator 40 generates electricity using the power of the engine 10. The electricity generated by the alternator 40 is stored in an electrically connected battery 70.

[0034] The tension pulley 6 is a back-flat pulley around which the outer circumference of the belt 5, which has no grooves, is wound. The tension pulley 6 is fixed to the front end of the rotating shaft 8, which protrudes forward from the front end surface 7A of the retaining portion 7, so as to be rotatable integrally with the rotating shaft 8. The tension pulley 6 is arranged to reciprocate between a first position predetermined on the outer circumference of the belt 5 and a second position closer to the inner circumference of the belt 5 than the first position, while in contact with the outer circumference of the belt 5.

[0035] The holding portion 7 holds the tension pulley 6 at a predetermined position between the first position and the second position by moving the rotating shaft 8 along the guide groove 7B. By holding the tension pulley 6 at the predetermined position by the holding portion 7, the tension of the belt 5 can be appropriately adjusted.

[0036] [Detection device]

[0037] The detection device 20 includes a displacement sensor 9 and a control device 100 .

[0038] Below, refer to Figure 2 (A) in the figure describes in detail the specific configuration of the displacement sensor 9.

[0039] A belt tension in the tangential direction connecting the outer periphery of the driven pulley 4 and the outer periphery of the drive pulley 2 (hereinafter referred to as the first tension Fa) is applied to the driven pulley 4. Furthermore, a belt tension in the tangential direction connecting the outer periphery of the driven pulley 4 and the outer periphery of the driven pulley 3 (hereinafter referred to as the second tension Fb) is applied to the driven pulley 4. Specifically, the vector sum of the first tension Fa and the second tension Fb, i.e., the resultant force Fa+Fb, acts on the driven pulley 4 through the belt 5.

[0040] Therefore, when the driven pulley 4 is misaligned, the driven pulley 4 is greatly tilted due to the resultant force Fa+Fb. In the present embodiment, the displacement sensor 9 is arranged at the rear of the approximately circumferential center of the radial outer side of the driven pulley 4 (on the engine 10 side). The rear of the approximately circumferential center of the radial outer side of the driven pulley 4 is consistent with the back side (on the engine 10 side) of the approximately circumferential center of the outer peripheral side of the driven pulley 4 in contact with the belt 5, that is, the vector direction of the resultant force Fa+Fb acting on the driven pulley 4. Thus, the displacement sensor 9 can effectively detect the displacement amount of the driven pulley 4 in the axial direction (that is, in the direction of the rotation axis of the driven pulley 4) at the position where the driven pulley 4 is most tilted. The displacement amount of the driven pulley 4 is, for example, the displacement amount of the axial position of a predetermined position of the driven pulley 4 (for example, the central position of the area in contact with the belt 5).

[0041] The displacement sensor 9 (an example of the distance acquisition device of the present invention) is, for example, an optical sensor, such as Figure 2As shown in (B), the displacement sensor 9 is provided on the front end face 40A of the AC generator 40 on the back side of the driven pulley 4, and includes a detection unit 9A, which includes a light-emitting unit and a light-receiving unit. The light-emitting unit emits a laser toward the back side of the driven pulley 4 approximately parallel to the axis Y of the rotating shaft 41 of the driven pulley 4. The light-receiving unit receives the reflected light emitted by the light-emitting unit and reflected by the detection object. The displacement sensor 9 detects the axial relative distance (hereinafter also referred to as the actual relative distance D) between the driven pulley 4 and the detection unit 9A. The actual relative distance D detected by the displacement sensor 9 is sent to the electrically connected control device 100.

[0042] In this embodiment, the displacement sensor 9 is arranged at a position closer to the engine 10 than the driven pulley 4, and detects the actual relative distance D. In other words, the displacement sensor 9 is arranged behind the driven pulley 4. This improves the layout freedom compared to the conventional structure in which the misalignment detection device is arranged in front of the pulley. In addition, the displacement sensor 9 is configured to obtain Figure 1 The relative axial distance between the driven pulley 4 and the detection portion 9A is shown, where the bending stiffness of the rotating shaft 12, 31, 41, 8 of each of the plurality of pulleys 2, 3, 4, and 6 is the smallest. This effectively detects the relative axial distance between the driven pulley 4, where the rotating shaft 41 is susceptible to bending due to the tension of the belt 5, and the detection portion 9A.

[0043] [Control device]

[0044] Figure 3 1 is a schematic functional block diagram showing the control device 100 and related peripheral structures according to the present embodiment.

[0045] The control device 100 is a device for performing calculations, such as a computer, and includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), input ports and output ports, etc., which are interconnected via a bus, and executes a program.

[0046] Furthermore, through program execution, the control device 100 functions as a device including a displacement calculation unit 110, a misalignment detection unit 120, a belt life estimation unit 130, and a notification unit 140. While these functional elements are described in this embodiment as being included in an integrated piece of hardware, namely, the control device 100, any portion of these functional elements may be provided in separate hardware.

[0047] The displacement amount calculation unit 110 (an example of the displacement amount calculation device of the present invention) calculates the axial displacement amount L1 of the driven pulley 4 based on the actual relative distance D sent from the displacement sensor 9. Figure 4 and Figure 5 The calculation of the axial displacement amount L1 by the displacement amount calculation unit 110 will be described.

[0048] Figure 4 1 is a diagram schematically showing temporal changes in the actual relative distance D detected by the displacement sensor 9 .

[0049] When the driven pulley 4 is installed to be inclined at a predetermined angle (an angle greater than 0) with respect to the rotating shaft 41 , the actual relative distance D changes in a sinusoidal wave shape including a maximum value and a minimum value every time the driven pulley 4 rotates once.

[0050] With each rotation of the driven pulley 4, the displacement calculation unit 110 sequentially stores the maximum value of the actual relative distance D (the value at the inflection point where the change in the actual relative distance D changes from increasing to decreasing) in a memory (storage device) and calculates the average value of this maximum value over a predetermined period. This can reduce the influence of sensor abnormality values of the displacement sensor 9 when extreme external forces are applied.

[0051] The axial relative distance between the driven pulley 4 and the detection unit 9A when the driven pulley 4 is mounted perpendicular to the rotating shaft 41 is stored in advance in the memory of the control device 100 as a reference relative distance LK. The displacement calculation unit 110 calculates the axial displacement L1 of the driven pulley 4 by subtracting the reference relative distance LK from the average value of the maximum value of the actual relative distance D in a predetermined period (see Figure 5 The axial displacement amount L1 calculated by the displacement amount calculation unit 110 is sent to the misalignment detection unit 120 and the belt life estimation unit 130 .

[0052] The misalignment detection unit 120 (an example of the inclination calculation device and determination device of the present invention) detects the misalignment of the driven pulley 4 based on the axial displacement amount L1 sent from the displacement amount calculation unit 110 .

[0053] Specifically, the misalignment detection unit 120 calculates the radial distance L2 between the detection unit 9A and the axis Y of the rotating shaft 41 and the axial displacement L1 sent from the displacement calculation unit 110 using trigonometric functions according to formula (1): Figure 5 The inclination θ of the driven pulley 4 relative to the rotation axis is shown.

[0054] arctan(L1 / L2)=θ······(1)

[0055] When the inclination θ of the driven pulley 4 exceeds a predetermined upper limit threshold (eg, approximately 0.5 to 1.0 degrees), the misalignment detection unit 120 determines that the driven pulley 4 has misaligned.

[0056] If the axial displacement amount L1 is not transmitted from the displacement amount calculation unit 110, it is assumed that the driven pulley 4 is tilted to such an extent that the reflected light is not received by the detection unit 9A of the displacement sensor 9, or that it is offset from the rotating shaft 41. Furthermore, if the axial displacement amount L1 transmitted from the displacement amount calculation unit 110 is less than a predetermined lower limit threshold, it is assumed that an obstruction, such as a bracket (not shown) that has been detached from the engine 10, is interposed between the driven pulley 4 and the detection unit 9A. In this case, the misalignment detection unit 120 determines that it cannot detect misalignment or that an abnormality has occurred.

[0057] In this embodiment, the displacement calculation unit 110 calculates the axial displacement L1 based on the average value of the maximum value of the actual relative distance D within a predetermined period. This prevents the misalignment detection unit 120 from immediately determining that the driven pulley 4 is misaligned or abnormal when the sensor value of the displacement sensor 9 has an extremely abnormal value. The determination result of the misalignment detection unit 120 is transmitted to the notification unit 140.

[0058] The belt life estimating unit 130 estimates the life of the belt 5 based on the axial displacement amount L1 sent from the displacement amount calculating unit 110 .

[0059] Specifically, the memory of the control device 100 stores a map M1, previously determined through experiments, that represents the relationship between the axial displacement L1 and the elongation of the belt 5. As the elongation of the belt 5 increases, the tension in the belt 5 decreases, the amount of pulley 4 tilted by the belt 5 tension decreases, and thus the axial displacement L1 also decreases. Therefore, in map M1, the smaller the axial displacement L1, the greater the elongation of the belt 5. Furthermore, as the bending stiffness of the rotating shaft 41 increases, the amount of pulley 4 tilted by the belt 5 tension decreases, and thus the axial displacement L1 also decreases. Therefore, in map M1, the smaller the bending stiffness of the rotating shaft 41, the greater the elongation of the belt 5 is set at a predetermined axial displacement L1.

[0060] The memory of the control device 100 stores a map M2 obtained in advance through experiments, etc., which shows the relationship between the elongation of the belt 5 and the life of the belt 5. In the map M2, the greater the elongation of the belt 5, the shorter the life of the belt 5 is set.

[0061] First, the belt life estimating unit 130 estimates the elongation of the belt 5 by referring to the map M1 based on the axial displacement L1 sent from the displacement calculating unit 110 .

[0062] Next, the belt life estimation unit 130 estimates the life of the belt 5 by referring to the map M2 based on the elongation of the belt 5 obtained by referring to the map M1. The belt life estimation unit 130 determines that it is time to replace the belt if the life of the belt 5 is less than a predetermined lower limit.

[0063] If the axial displacement L1 is not transmitted from the displacement calculation unit 110, it is assumed that the driven pulley 4 is tilted to such an extent that the reflected light is not received by the detection unit 9A of the displacement sensor 9, or that it is deviated from the rotating shaft 41. Furthermore, if the axial displacement L1 transmitted from the displacement calculation unit 110 is less than a predetermined lower limit threshold, it is assumed that an obstruction, such as a bracket (not shown) that has been detached from the engine 10, is interposed between the driven pulley 4 and the detection unit 9A. In this case, the belt life estimation unit 130 cannot estimate the belt life or determines that an abnormality has occurred.

[0064] In this embodiment, the displacement calculation unit 110 calculates the axial displacement L1 based on the average value of the maximum actual relative distance D over a predetermined period. This prevents the belt life estimation unit 130 from overestimating or underestimating the life of the belt 5 when the sensor value of the displacement sensor 9 exhibits an extreme abnormality. The belt life estimated by the belt life estimation unit 130 and the result of the determination are transmitted to the notification unit 140.

[0065] The notification unit 140 notifies the user of the determination result transmitted from the misalignment detection unit 120 and the life of the belt 5 and the determination result transmitted from the belt life estimation unit 130 .

[0066] Specifically, when the misalignment detection unit 120 transmits a result indicating that the driven pulley 4 is misaligned or abnormal, the notification unit 140 notifies the user of the occurrence of the misalignment or abnormality. The notification unit 140 notifies the user of the occurrence of the misalignment or abnormality, for example, through the indicator light 50 or a screen (not shown). This allows for appropriate notification of the occurrence of the misalignment or abnormality in the driven pulley 4.

[0067] Furthermore, the notification unit 140 appropriately notifies the operator of any misalignment or abnormality in the driven pulley 4, thereby facilitating inspection or replacement of the driven pulley 4. This prevents the driven pulley 4 from rotating in a misaligned state and uneven wear on the driven pulley 4 or the belt 5. Furthermore, the notification unit 140 may store information regarding misalignment or abnormality in a server located in the vehicle center 200, etc., via a communication device (not shown). This allows for appropriate vehicle operation management.

[0068] Furthermore, the notification unit 140 displays the lifespan of the belt 5 and the determination result sent from the belt life estimation unit 130 via the indicator light 50 or a screen (not shown). This makes it easy to understand the lifespan of the belt 5. Furthermore, the replacement frequency of the belt 5 can be optimized to reduce costs, and failures or malfunctions of the belt device 1 can be prevented before they occur. Furthermore, the notification unit 140 can store information on the lifespan of the belt 5 and the determination result in a server located in the vehicle center 200, etc., via a communication device (not shown). This enables appropriate vehicle operation management.

[0069] Then, based on Figure 6 The flow of the positional misalignment detection control of the driven pulley 4 performed by the control device 100 of this embodiment will be described. This control is started simultaneously with, for example, the ON operation of the ignition switch.

[0070] In step S110 , the displacement amount calculation unit 110 calculates the axial displacement amount L1 of the driven pulley 4 based on the actual relative distance D sent from the displacement sensor 9 .

[0071] In step S120, the misalignment detection unit 120 determines whether an abnormality has occurred in the belt device 1 based on the axial displacement L1 transmitted from the displacement calculation unit 110. If the misalignment detection unit 120 determines that no abnormality has occurred (No), control proceeds to step 140. On the other hand, if the misalignment detection unit 120 determines that an abnormality has occurred (Yes), control proceeds to step 130.

[0072] In step S130, the notification unit 140 notifies the occurrence of an abnormality, and then the control returns.

[0073] In step S140 , the positional deviation detecting unit 120 calculates the inclination θ of the driven pulley 4 based on the axial displacement amount L1 sent from the displacement amount calculating unit 110 .

[0074] In step S150, the misalignment detection unit 120 determines whether the driven pulley 4 has misaligned based on the inclination θ of the driven pulley 4. If the misalignment detection unit 120 determines that no misalignment has occurred (No), the control returns. On the other hand, if the misalignment detection unit 120 determines that misalignment has occurred (Yes), the control proceeds to step 160.

[0075] In step S160, the notification unit 140 notifies the occurrence of the misalignment, and then the control returns.

[0076] Then, based on Figure 7 The flow of the life estimation control of the belt 5 performed by the control device 100 of the present embodiment will be described. This control is started simultaneously with, for example, the ON operation of the ignition switch.

[0077] In step S210 , the displacement amount calculation unit 110 calculates the axial displacement amount L1 of the driven pulley 4 based on the actual relative distance D sent from the displacement sensor 9 .

[0078] In step S220, the misalignment detection unit 120 determines whether an abnormality has occurred in the belt device 1 based on the axial displacement L1 transmitted from the displacement calculation unit 110. If the misalignment detection unit 120 determines that no abnormality has occurred (No), control proceeds to step 240. On the other hand, if the misalignment detection unit 120 determines that an abnormality has occurred (Yes), control proceeds to step 230.

[0079] In step S230, the notification unit 140 notifies the occurrence of an abnormality, and then the control returns.

[0080] In step S240 , the belt life estimating unit 130 estimates the life of the belt 5 based on the axial displacement amount L1 sent from the displacement amount calculating unit 110 .

[0081] In step S250, the belt life estimation unit 130 determines whether the life of the belt 5 is less than the lower life limit. If the belt life estimation unit 130 determines that the life of the belt 5 is less than the lower life limit (Yes), the control proceeds to step 260. On the other hand, if the belt life estimation unit 130 determines that the life of the belt 5 is greater than the lower life limit (No), the control proceeds to step 270.

[0082] In step S270, the notification unit 140 notifies the user of the life of the belt 5 and the result of determination that the belt does not need to be replaced.

[0083] In step S260, the notification unit 140 notifies the user of the life of the belt 5 and the result of the determination that the belt 5 needs to be replaced.

[0084] According to the embodiment described in detail above, the displacement calculation unit 110 calculates the axial displacement amount L1 based on the relative axial distance between the driven pulley 4 and the detection portion 9A of the displacement sensor 9, which is located closer to the engine 10 than the driven pulley 4. Furthermore, the misalignment detection unit 120 is configured to calculate the inclination θ of the driven pulley 4 based on the axial displacement amount L1. Thus, the misalignment detection unit 120 can reliably calculate the inclination θ of the driven pulley 4 with a simple configuration and effectively detect misalignment of the driven pulley 4 based on this inclination θ.

[0085] Furthermore, the displacement calculation unit 110 is configured to calculate the axial displacement amount L1 of the driven pulley 4 based on the relative axial distance between the driven pulley 4 and the detection portion 9A of the displacement sensor 9, and the belt life estimation unit 130 is configured to estimate the life of the belt 5 based on the axial displacement amount L1. Thus, the belt life estimation unit 130 can effectively estimate the life of the belt 5 with a simple configuration and can appropriately notify the appropriate belt replacement time.

[0086] [other]

[0087] In addition, the present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications within the scope not departing from the gist of the present invention.

[0088] For example, in the above embodiment, the displacement sensor 9 detects the relative axial distance between the driven pulley 4 and the detection portion 9A. However, the displacement sensor 9 may also detect the relative axial distance between the other pulleys 2, 3, and 6 and the detection portion 9A. In addition, multiple displacement sensors 9 may be provided to detect the relative axial distance between the multiple pulleys 2, 3, 4, and 6 and the detection portion 9A.

[0089] In addition, in the above-mentioned embodiment, the belt winding method of the belt device 1 is described as a so-called spiral method in which one belt 5 is wound around multiple pulleys 2, 3, 4, and 6. However, it is also possible to transmit power by winding separate belts around the driving pulley 2 and the driven pulley 3 and the driving pulley 2 and the driven pulley 4, respectively.

[0090] Description of Reference Numerals

[0091] 1 with device

[0092] 2 drive pulleys

[0093] 3, 4 driven pulleys

[0094] 5 belts

[0095] 6 Tension pulley

[0096] 9 Displacement sensor (distance acquisition device)

[0097] 9A Inspection Department

[0098] 10 Engine

[0099] 11 Engine body

[0100] 12 Crankshaft

[0101] 20 Detection device

[0102] 30 Air conditioning compressor

[0103] 40 AC generator

[0104] 41 Rotation axis

[0105] 50 indicator lights

[0106] 100 Control Device

[0107] 110 Displacement calculation unit (displacement calculation device)

[0108] 120 Misalignment Detection Unit (Inclination Calculation Device, Determination Device)

[0109] 130 Belt life estimation unit

[0110] 140 Notification Department.

Claims

1. An internal combustion engine, characterized in that It includes an engine main body, a belt device, and a detection device. The belt device has a plurality of pulleys around which the belt is wound. The detection device comprises: a distance acquisition device having a detection portion that acquires a relative distance in an axial direction from a driven pulley having the smallest bending rigidity of a rotating shaft among the plurality of pulleys, the distance acquisition device being provided at a position closer to the engine main body than the driven pulley; a displacement calculation device for calculating the displacement of the driven pulley in the axial direction based on the acquired relative distance; and The inclination calculation device calculates an inclination of the driven pulley with respect to the axial direction of the driven pulley based on the calculated displacement amount.

2. The internal combustion engine according to claim 1, characterized in that The detection unit acquires the relative distance in the axial direction of the driven pulley from a circumferential center portion on the outer circumference side of the driven pulley in contact with the belt.

3. The internal combustion engine according to claim 1 or 2, characterized in that The detection portion is provided at a center position in the longitudinal direction of a region of the driven pulley in contact with the belt and at a position away from the driven pulley in the axial direction of the driven pulley.

4. The internal combustion engine according to claim 1 or 2, characterized in that The detection device further includes a determination device for determining that a misalignment has occurred in which the driven pulley is installed obliquely with respect to the rotating shaft, when the inclination calculated by the calculation device exceeds a predetermined threshold value.

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