Motive force transmitting device and position detection apparatus

Abstract

To provide a motive force transmitting device which can detect a relative positional relation between gear teeth of a pair of gear parts in a manner that does not depend on gear shapes.SOLUTION: A motive force transmitting device 1 comprises: a driven member 20 including a first gear portion 22 in which a plurality of first gear teeth 231 and a plurality of first projecting portions 241 are formed; and a sleeve 30 including a second gear portion 31 in which a plurality of second gear teeth 311 and a plurality of second projecting portions 321 are formed. The motive force transmitting device 1 comprises a position detection apparatus 60 for detecting a relative positional relation between the first gear teeth 231 and the second gear teeth 311 on the basis of a physical quantity indicating a relative positional relation between the plurality of first projecting portions 241 and the plurality of second projecting portions 321. The motive force transmitting device 1 includes a driving apparatus 50 for switching, on the basis of the relative positional relation between the gear teeth 231, 311, between a released state in which the driven member 20 and the sleeve 30 are separated from one another and a connected state in which the driven member 20 and the sleeve 30 rotate integrally.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power transmission device and a position detection device applied to the power transmission device. [Background technology]

[0002] Conventionally, a power transmission device is known in which a position detection device detects the relative positional relationship between the gear teeth of a pair of gear portions, and switches the pair of gear portions between a connected state and a released state based on the information detected by the position detection device (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-144021 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the inventors' investigations, the position detector of Patent Document 1 detects magnetic flux changes near the gear teeth of each of a pair of gears using a magnetic detection element, and the output of the magnetic detection element depends on the gear shape of the pair of gears. In order to properly detect the relative positional relationship between the gear teeth of each of the pair of gears using the position detector, the position detector needs to be customized according to the gear shape, which makes the position detector less versatile. This problem can also occur when using a position detector other than a magnetic type.

[0005] An object of the present disclosure is to provide a power transmission device that can detect the relative positional relationship between the gear teeth of a pair of gear portions in a manner that is independent of the gear shapes. [Means for solving the problem]

[0006] The invention described in claim 1 is A power transmission device, a first rotating member (20, 20A) including a first gear portion (22, 22A) in which, in addition to a plurality of first gear teeth (231, 231A), a plurality of first protrusions (241, 241A) separate from the plurality of first gear teeth are formed as elements for specifying the positions of the plurality of first gear teeth, and the first rotating member (20, 20A) rotates around a predetermined axis (CL); a second rotating member (30, 40, 40A) including a second gear portion (31, 42A) in which, in addition to a plurality of second gear teeth (311, 421A) capable of meshing with the plurality of first gear teeth, a plurality of second protrusions (321, 431A) separate from the plurality of second gear teeth are formed as elements for specifying the positions of the plurality of second gear teeth, the second rotating member (30, 40, 40A) rotating integrally with the first rotating member about the axis with the plurality of second gear teeth meshed with the plurality of first gear teeth; a position detection device (60) that detects the relative positional relationship between the first gear teeth and the second gear teeth based on a physical quantity that indicates the relative positional relationship between the plurality of first protrusions and the plurality of second protrusions; The drive device (50) switches between a released state in which the first rotating member and the second rotating member are separated and a connected state in which the first gear teeth and the second gear teeth are engaged and the first rotating member and the second rotating member rotate integrally, based on the relative positional relationship between the first gear teeth and the second gear teeth.

[0007] The invention described in claim 12 is A position detection device applied to a power transmission device (1), a first target portion (24, 24A) provided to rotate integrally with a first rotating member (20, 20A) including a plurality of first gear teeth (231, 231A), and having a plurality of first protrusions (241, 241A) separate from the plurality of first gear teeth formed as elements for identifying the positions of the plurality of first gear teeth; a second target portion (32, 43A) provided to rotate integrally with a second rotating member (30, 40, 40A) including a plurality of second gear teeth (311, 421A) that can mesh with the plurality of first gear teeth, and having a plurality of second protrusions (321, 431A) separate from the plurality of second gear teeth formed as elements for identifying the positions of the plurality of second gear teeth; a sensor (70) that detects the relative positional relationship between the first gear teeth and the second gear teeth; The power transmission device includes a drive device (50) that switches between a released state in which the first rotating member and the second rotating member are separated from each other and a connected state in which the first gear teeth and the second gear teeth are engaged with each other and the first rotating member and the second rotating member rotate integrally, based on the relative positional relationship between the first gear teeth and the second gear teeth; The sensor detects the relative positional relationship between the first gear teeth and the second gear teeth based on a physical quantity indicating the relative positional relationship between the plurality of first protrusions and the plurality of second protrusions.

[0008] As described above, if the configuration is such that the relative positional relationship between the first gear tooth and the second gear tooth is indirectly detected based on a physical quantity indicating the positional relationship between the first convex portion and the second convex portion, the relative positional relationship between the gear teeth of each of a pair of gear portions can be detected in a manner that is independent of the gear shape.

[0009] Furthermore, since the shapes of the first gear teeth and the second gear teeth do not affect the detection of the relative positional relationship between the first gear teeth and the second gear teeth, freedom in designing the first gear teeth and the second gear teeth can be ensured.

[0010] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of a power transmission device according to a first embodiment. [Figure 2] FIG. 4 is a schematic front view of a first gear portion. [Figure 3] FIG. 4 is a schematic front view of a second gear portion. [Figure 4] FIG. 10 is a schematic front view of a third gear portion. [Figure 5] 10 is a schematic diagram showing a state in which a plurality of first gear teeth and a plurality of second gear teeth cannot be meshed with each other. FIG. [Figure 6]FIG. 10 is an explanatory view for explaining a state in which a plurality of first gear teeth and a plurality of second gear teeth cannot be meshed with each other. [Figure 7] FIG. 10 is a schematic diagram showing a state in which a plurality of first gear teeth and a plurality of second gear teeth can be meshed with each other. [Figure 8] FIG. 10 is an explanatory diagram for explaining a state in which a plurality of first gear teeth and a plurality of second gear teeth can be meshed with each other. [Figure 9] 10A and 10B are explanatory diagrams for explaining switching between a released state and an engaged state of a dog clutch. [Figure 10] FIG. 2 is a schematic diagram illustrating the configuration of a position detection device. [Figure 11] FIG. 2 is a schematic front view of the magnetic sensor. [Figure 12] 2 is a schematic diagram showing the positional relationship between a magnetic sensor and a dog clutch included in a position detection device. FIG. [Figure 13] 2 is a schematic perspective view showing the positional relationship between a magnetic sensor and a dog clutch included in a position detection device. FIG. [Figure 14] 10 is an explanatory diagram illustrating a change in magnetic flux near the magnetic detection element when a plurality of first protrusions and a plurality of second protrusions are overlapped in the axial direction. FIG. [Figure 15] 10 is an explanatory diagram illustrating a change in magnetic flux near the magnetic detection element when the first protrusions and the second protrusions do not overlap in the axial direction. FIG. [Figure 16] 10 is an explanatory diagram for explaining a change in magnetic flux near the magnetic detection element when the relative positional relationship between the plurality of first protrusions and the plurality of second protrusions changes. FIG. [Figure 17] 10 is an explanatory diagram for explaining a change in magnetic flux near a magnetic detection element when the arrangement of the magnetic sensor is shifted in the axial direction. FIG. [Figure 18] 10 is an explanatory diagram for explaining the change over time in the output of the magnetic sensor when the driven member and the sleeve are rotated at different rotational speeds. FIG. [Figure 19] FIG. 10 is an explanatory diagram for explaining the meshing timing at which the first gear teeth and the second gear teeth can mesh with each other. [Figure 20]10 is a flowchart showing the flow of a drive control process executed by a control device of a moving machine. [Figure 21] 10 is a flowchart showing the flow of a meshing timing specification process executed by a signal processing circuit of the position detection device. [Figure 22] 10A and 10B are diagrams illustrating a change in magnetic flux near the magnetic detection element when the dog clutch is switched from a released state to a connected state. [Figure 23] 10 is an explanatory diagram for explaining the influence on the output of the magnetic sensor due to differences in the materials of the first protrusions and the second protrusions when the first protrusions and the second protrusions are overlapped in the axial direction. [Figure 24] FIG. 10 is an explanatory diagram for explaining the influence on the output of the magnetic sensor due to differences in the materials of the first protrusions and the second protrusions when the first protrusions and the second protrusions do not overlap in the axial direction. [Figure 25] FIG. 10 is a schematic front view of a first gear portion according to a first modified example of the first embodiment. [Figure 26] FIG. 10 is a schematic front view of a second gear portion according to a first modified example of the first embodiment. [Figure 27] FIG. 10 is an explanatory diagram illustrating a change in magnetic flux near the magnetic detection element in a state in which a plurality of first protrusions and a plurality of second protrusions overlap in the axial direction according to a second modified example of the first embodiment. [Figure 28] FIG. 10 is an explanatory diagram illustrating a change in magnetic flux near the magnetic detection element in a state in which the plurality of first protrusions and the plurality of second protrusions do not overlap in the axial direction according to a second modified example of the first embodiment. [Figure 29] FIG. 10 is a schematic front view of a magnetic sensor according to a third modified example of the first embodiment. [Figure 30] 10 is an explanatory diagram illustrating a change in magnetic flux near the magnetic detection element of the third modified example in a state in which a plurality of first protrusions and a plurality of second protrusions overlap in the axial direction. FIG. [Figure 31] FIG. 10 is a schematic front view of a magnetic sensor according to a fourth modified example of the first embodiment. [Figure 32]10 is an explanatory diagram illustrating a change in magnetic flux near the magnetic detection element of the fifth modified example in a state in which a plurality of first protrusions and a plurality of second protrusions overlap in the axial direction. FIG. [Figure 33] FIG. 10 is a schematic front view of a magnetic sensor according to a fifth modified example of the first embodiment. [Figure 34] FIG. 10 is a schematic front view of a magnetic sensor according to a sixth modified example of the first embodiment. [Figure 35] FIG. 6 is an explanatory diagram for explaining a power transmission device according to a second embodiment. [Figure 36] 10 is an explanatory diagram for explaining a change in magnetic flux near the magnetic detection element when the relative positional relationship between the plurality of first protrusions and the plurality of second protrusions changes. FIG. [Figure 37] FIG. 10 is a schematic configuration diagram of a power transmission device according to a third embodiment. [Figure 38] FIG. 4 is a schematic front view of a first gear portion. [Figure 39] FIG. 4 is a schematic front view of a second gear portion. [Figure 40] 10 is a schematic diagram showing a state in which a plurality of first gear teeth and a plurality of second gear teeth cannot be meshed with each other. FIG. [Figure 41] FIG. 10 is an explanatory view for explaining a state in which a plurality of first gear teeth and a plurality of second gear teeth cannot be meshed with each other. [Figure 42] FIG. 10 is a schematic diagram showing a state in which a plurality of first gear teeth and a plurality of second gear teeth can be meshed with each other. [Figure 43] FIG. 10 is an explanatory diagram for explaining a state in which a plurality of first gear teeth and a plurality of second gear teeth can be meshed with each other. [Figure 44] 10A and 10B are explanatory views for explaining switching between a released state and an engaged state of a dog clutch in a third embodiment. [Figure 45] 10 is an explanatory diagram for explaining a change in magnetic flux near the magnetic detection element when the relative positional relationship between the plurality of first protrusions and the plurality of second protrusions changes. FIG. [Figure 46] FIG. 2 is an explanatory diagram for explaining a first example of a magnetic sensor. [Figure 47]FIG. 10 is an explanatory diagram for explaining a second example of a magnetic sensor. [Figure 48] FIG. 10 is an explanatory diagram for explaining a third example of the magnetic sensor. [Figure 49] FIG. 10 is an explanatory diagram for explaining a fourth example of a magnetic sensor. [Figure 50] FIG. 10 is an explanatory diagram for explaining a fifth example of a magnetic sensor. [Figure 51] FIG. 10 is an explanatory diagram for explaining a sixth example of the magnetic sensor. [Figure 52] FIG. 10 is an explanatory diagram for explaining a seventh example of the magnetic sensor. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments will be given the same reference numerals, and their description may be omitted. Furthermore, in the embodiments, when only some of the components are described, the components described in the preceding embodiments can be applied to the remaining components. The following embodiments can be partially combined with each other, even if not specifically stated, as long as there is no particular problem with the combination.

[0013] (First embodiment) This embodiment will be described with reference to Figs. 1 to 24. In this embodiment, an example will be described in which a power transmission device 1 of the present disclosure is applied to a vehicle. The power transmission device 1 connects and disconnects the transmission of power output from a traveling drive source 51 such as an internal combustion engine or a motor to the axles of the vehicle. As shown in Fig. 1, the power transmission device 1 includes a dog clutch 10, a drive device 50, and a position detection device 60.

[0014] The dog clutch 10 includes a driven member 20, a sleeve 30, and a driving member 40. The driven member 20, the sleeve 30, and the driving member 40 are configured to be rotatable about the same axis CL.

[0015] The driven member 20 is a rotating member that receives power output from the traveling drive source 51 via the sleeve 30 and the driving member 40 and rotates about the axis CL. The rotation of the driven member 20 is transmitted to the axle of the vehicle. Although not shown, the driven member 20 can be rotated by a driving element other than the traveling drive source 51. In this embodiment, the driven member 20 corresponds to the "first rotating member."

[0016] The driven member 20 includes a first shaft member 21 formed in a cylindrical shape and a first gear portion 22 provided on one side in the axial direction Dax of the first shaft member 21. The first shaft member 21 and the first gear portion 22 are connected to rotate integrally.

[0017] The first gear portion 22 is formed with a plurality of first gear teeth 231. The first gear portion 22 is formed with a plurality of first protrusions 241, separate from the plurality of first gear teeth 231, as elements for specifying the positions of the plurality of first gear teeth 231. For convenience, in FIG. 1, reference numerals are assigned to representative ones of the plurality of first gear teeth 231 and the plurality of first protrusions 241, and reference numerals for other ones are omitted. This is the same in other drawings besides FIG. 1.

[0018] The multiple first gear teeth 231 are formed on a first tip portion 23 of the first gear portion 22 on one side in the axial direction Dax. The multiple first gear teeth 231 protrude from the first tip portion 23 in a direction away from the axis CL (i.e., outward in the radial direction Dor). The multiple first gear teeth 231 are provided at predetermined intervals all around the entire circumference in the circumferential direction Dr centered on the axis CL. The multiple first gear teeth 231 are each configured with the same shape. The interval between adjacent first gear teeth 231 in the circumferential direction Dr is large enough to allow the first gear teeth 231 to mesh with second gear teeth 311, which will be described later. The multiple first gear teeth 231 have a shape suitable for meshing with the second gear teeth 311, which will be described later.

[0019] The multiple first protrusions 241 are formed on a brim-shaped first flange portion 24 provided adjacent to the first tip portion 23 of the first gear portion 22. The multiple first protrusions 241 protrude from the first flange portion 24 in a direction away from the axis CL (i.e., outward in the radial direction Dor). The multiple first protrusions 241 are provided at predetermined intervals around the entire circumference in the circumferential direction Dr centered on the axis CL. Each of the multiple first protrusions 241 is configured to have the same shape.

[0020] The first flange portion 24 is provided so as to rotate integrally with the driven member 20. In this embodiment, the first flange portion 24 constitutes a "first target portion" having a plurality of first protrusions 241 separate from the plurality of first gear teeth 231. The first flange portion 24 can be considered as one of the components of the position detection device 60.

[0021] The first gear portion 22 is provided with first convex portions 241 in a number that is a divisor of the plurality of first gear teeth 231. As shown in Fig. 2, the first gear portion 22 of this embodiment is provided with the same number of first convex portions 241 as the plurality of first gear teeth 231. Note that Fig. 2 shows, as an example, the first gear portion 22 in which 12 first gear teeth 231 and first convex portions 241 are provided, but the numbers of first gear teeth 231 and first convex portions 241 are not limited to those shown in Fig. 2 and can be set to any numbers.

[0022] Each of the multiple first protrusions 241 protrudes in the same direction as the first gear tooth 231. That is, each of the multiple first protrusions 241 is formed so as to overlap with the first gear tooth 231 in the radial direction Dor when the first gear portion 22 is viewed from the axial direction Dax.

[0023] The multiple first protrusions 241 have a different shape from the multiple first gear teeth 231. Specifically, the first protrusions 241 have a smaller amount of protrusion in the radial direction Dor than the multiple first gear teeth 231. Note that the first protrusions 241 may have an amount of protrusion in the radial direction Dor that is equal to or greater than that of the multiple first gear teeth 231.

[0024] The entire first gear portion 22 is made of a magnetic material (for example, a material containing iron). Note that, as long as at least the plurality of first protrusions 241 of the first gear portion 22 are made of a magnetic material, other elements may be made of a different material.

[0025] The sleeve 30 and the driving member 40 are rotating members that transmit the power output from the traveling drive source 51 to the driven member 20. The sleeve 30 and the driving member 40 are connected to each other so that they rotate together about the axis CL by the power output from the traveling drive source 51. In this embodiment, the sleeve 30 and the driving member 40 correspond to the "second rotating member."

[0026] The sleeve 30 is a member for connecting the driven member 20 and the driving member 40. The inner diameter of the sleeve 30 is larger than the outer diameter of the first tip portion 23 of the driven member 20 and the outer diameter of the third gear portion 42 of the driving member 40 so that the sleeve 30 can cover the first tip portion 23 of the driven member 20 and the third gear portion 42 of the driving member 40.

[0027] The sleeve 30 includes a cylindrical second gear portion 31. The entire sleeve 30 of this embodiment constitutes the second gear portion 31. As shown in FIG. 3 , the second gear portion 31 is formed with a plurality of second gear teeth 311 that can mesh with the plurality of first gear teeth 231. The second gear portion 31 is formed with a plurality of second protrusions 321 that are separate from the plurality of second gear teeth 311 and serve as elements for specifying the positions of the plurality of second gear teeth 311. Note that in FIG. 3 , for convenience, reference numerals are assigned to representative ones of the plurality of second gear teeth 311 and the plurality of second protrusions 321, and reference numerals for other ones are omitted. This is the same in other drawings besides FIG. 3 .

[0028] The sleeve 30 rotates integrally with the driven member 20 about the axis CL with the plurality of second gear teeth 311 meshing with the plurality of first gear teeth 231. The plurality of second gear teeth 311 are formed inside the second gear portion 31. The second gear portion 31 is provided with the same number of second gear teeth 311 as the plurality of first gear teeth 231. The plurality of second gear teeth 311 protrude from the second gear portion 31 in a direction approaching the axis CL (i.e., inward in the radial direction Dor). The plurality of second gear teeth 311 are provided at predetermined intervals around the entire circumference in the circumferential direction Dr centered on the axis CL. Each of the plurality of second gear teeth 311 is configured to have the same shape. The interval between adjacent second gear teeth 311 in the circumferential direction Dr is large enough to allow the first gear teeth 231 and the second gear teeth 311 to mesh with each other. The plurality of second gear teeth 311 have a shape suitable for meshing with the first gear teeth 231.

[0029] The multiple second protrusions 321 are formed on a brim-shaped second flange portion 32 provided on the outer side of the second gear portion 31. The second flange portion 32 is provided on the other end of the second gear portion 31 in the axial direction Dax.

[0030] The second flange portion 32 is provided so as to rotate integrally with the sleeve 30. In this embodiment, the second flange portion 32 constitutes a "second target portion" having a plurality of second protrusions 321 separate from the plurality of second gear teeth 311. The second flange portion 32 can be considered as one of the components of the position detection device 60.

[0031] The second protrusions 321 protrude from the second flange 32 in a direction away from the axis CL (i.e., outward in the radial direction Dor). The second protrusions 321 are provided at predetermined intervals around the entire circumference in the circumferential direction Dr centered on the axis CL. The second protrusions 321 are each configured to have the same shape.

[0032] Further, the second gear portion 31 is provided with second convex portions 321 in a number that is a divisor of the plurality of second gear teeth 311. The second gear portion 31 of this embodiment is provided with the same number of second convex portions 321 as the plurality of second gear teeth 311. Note that, while Fig. 3 shows, as an example, the second gear portion 31 provided with 12 second gear teeth 311 and second convex portions 321, the numbers of second gear teeth 311 and second convex portions 321 are not limited to those shown in Fig. 3.

[0033] Each of the multiple second protrusions 321 protrudes in a direction away from the axis CL so as to correspond to a recess between adjacent second gear teeth 311. That is, each of the multiple second protrusions 321 is formed so as to overlap a recess between adjacent second gear teeth 311 in the radial direction Dor when the second gear portion 31 is viewed from the axial direction Dax.

[0034] The plurality of second protrusions 321 have a different shape from the plurality of second gear teeth 311. The plurality of second protrusions 321 are configured to have the same shape as the plurality of first protrusions 241. Specifically, the plurality of first protrusions 241 and the plurality of second protrusions 321 are fan-shaped protrusions whose length in the circumferential direction Dr is greater than their dimension in the radial direction Dor. Note that the plurality of first protrusions 241 and the plurality of second protrusions 321 may have a length in the circumferential direction Dr that is equal to or smaller than their dimension in the radial direction Dor. Furthermore, the plurality of first protrusions 241 and the plurality of second protrusions 321 may be rectangular protrusions.

[0035] The first flange portion 24 including the multiple first protrusions 241 and the second flange portion 32 including the multiple second protrusions 321 are of similar size. That is, a circle passing through the portions of the multiple first protrusions 241 that are farthest from the axis CL is defined as a first imaginary circle IR1, and a circle passing through the portions of the multiple second protrusions 321 that are farthest from the axis CL is defined as a second imaginary circle IR2. In this case, the first imaginary circle IR1 and the second imaginary circle IR2 are of the same size.

[0036] The entire second gear portion 31 is made of a magnetic material (for example, a material containing iron). Specifically, the second gear portion 31 is made of the same magnetic material (i.e., the same material) as the first gear portion 22. Note that, as long as at least the plurality of second protrusions 321 of the second gear portion 31 are made of a magnetic material, other elements may be made of different materials.

[0037] The sleeve 30 is connected to the actuator 522 via a shift fork 521. Specifically, the sleeve 30 has an engagement groove 33 formed in a portion of the second gear portion 31 that is located on one side of the second flange portion 32 in the axial direction Dax, for engaging with one end of a shift fork 521 (described later).

[0038] This allows the sleeve 30 to be displaced in the axial direction Dax. The sleeve 30 of this embodiment is displaceable in the radial direction Dor within a range from a position where it overlaps with both the driven member 20 and the driving member 40 to a position where it overlaps with the driving member 40 but does not overlap with the driven member 20.

[0039] The driving member 40 is disposed so as to face the driven member 20 with a predetermined gap therebetween in the axial direction Dax. A portion of the driving member 40 is disposed inside the sleeve 30. The driving member 40 includes a third shaft member 41 formed in a cylindrical shape and a third gear portion 42. The third shaft member 41 and the third gear portion 42 are connected to each other so as to rotate integrally about the axis CL.

[0040] One side of the third shaft member 41 in the axial direction Dax is connected to the traveling drive source 51. The third shaft member 41 rotates together with the third gear portion 42 about the axis CL by the power of the traveling drive source 51. The third gear portion 42 is provided on the other side of the third shaft member 41 in the axial direction Dax. In the drive member 40, the outer diameter of the third gear portion 42 is smaller than the inner diameter of the sleeve 30 so that the third gear portion 42 can be inserted inside the sleeve 30. In addition, in the drive member 40, the dimension of the third gear portion 42 in the axial direction Dax is larger than the dimension of the sleeve 30 in the axial direction Dax.

[0041] As shown in Fig. 4, the third gear portion 42 is formed with a plurality of third gear teeth 421 that mesh with a plurality of second gear teeth 311. For convenience, in Fig. 4, reference numerals are assigned to representative ones of the plurality of third gear teeth 421, and reference numerals to other ones are omitted. This is the same in other drawings besides Fig. 4.

[0042] Similar to the multiple first gear teeth 231, the multiple third gear teeth 421 protrude in a direction away from the axis CL (i.e., outward in the radial direction Dor). The multiple third gear teeth 421 are provided at predetermined intervals around the entire circumference in the circumferential direction Dr centered on the axis CL. The multiple third gear teeth 421 are each configured with the same shape. The interval between adjacent third gear teeth 421 in the circumferential direction Dr is large enough to allow the third gear teeth 421 to mesh with the second gear teeth 311. The multiple third gear teeth 421 have a shape suitable for meshing with the second gear teeth 311.

[0043] The third gear portion 42 is provided with a brim-shaped third flange portion 43 at one end in the axial direction Dax. The third flange portion 43 functions as a stopper when the sleeve 30 is displaced to one side in the axial direction Dax. The third flange portion 43 may be provided on the third shaft member 41.

[0044] As shown in Fig. 5, the dog clutch 10 configured in this manner cannot mesh the first gear teeth 231 with the second gear teeth 311 at the timing when the multiple first gear teeth 231 and the multiple second gear teeth 311 overlap in the axial direction Dax. In other words, the timing when the first gear teeth 231 and the second gear teeth 311 overlap in the axial direction Dax is an incompatible timing when it is not possible to mesh the first gear teeth 231 with the second gear teeth 311. At this incompatible timing, as shown in Fig. 6, an edge portion EG1 on one side of the first gear tooth 231 in the circumferential direction Dr and an edge portion EG2 on one side of the third gear tooth 421 in the circumferential direction Dr do not match in the axial direction Dax.

[0045] On the other hand, as shown in Fig. 7, the first gear teeth 231 and the second gear teeth 311 can be meshed with each other at a timing when the plurality of first gear teeth 231 and the plurality of second gear teeth 311 do not overlap with each other in the axial direction Dax. That is, the timing when the first gear teeth 231 and the second gear teeth 311 do not overlap with each other in the axial direction Dax is the meshing timing at which the first gear teeth 231 and the second gear teeth 311 can be meshed with each other. At this meshing timing, as shown in Fig. 8, an edge portion EG1 on one side of the first gear teeth 231 in the circumferential direction Dr and an edge portion EG2 on one side of the third gear teeth 421 in the circumferential direction Dr are substantially aligned in the axial direction Dax.

[0046] As shown in Figure 9, when the dog clutch 10 displaces the sleeve 30 to approach the driven member 20 at the timing of engagement, the first gear teeth 231 and the second gear teeth 311 mesh with each other, causing the driven member 20 and the sleeve 30 to rotate together.

[0047] The first convex portion 241 and the second convex portion 321 are configured not to interfere with each other. Furthermore, the first convex portion 241 and the second convex portion 321 are configured not to interfere with the first gear tooth 231 and the second gear tooth 311. Specifically, in a connected state in which the driven member 20 and the sleeve 30 rotate integrally, the first convex portion 241 is spaced apart from both the second gear tooth 311 and the second convex portion 321, and the second convex portion 321 is spaced apart from both the first gear tooth 231 and the first convex portion 241.

[0048] Here, in the engaged state of the dog clutch 10, the first flange portion 24 and the second flange portion 32 may or may not be in contact with each other. Furthermore, the first flange portion 24 and the second flange portion 32 may function as stoppers that limit displacement of the sleeve 30 to the other side in the axial direction Dax.

[0049] Next, the driving device 50 will be described with reference to Fig. 1. The driving device 50 is a device that switches between a released state in which the driven member 20 and the sleeve 30 are separated, and a connected state in which the first gear teeth 231 and the second gear teeth 311 mesh with each other, causing the driven member 20 and the sleeve 30 to rotate together. As shown in Fig. 1, the driving device 50 includes a traveling drive source 51, a linear motion device 52, and a control device 53.

[0050] The traveling drive source 51 is configured by an internal combustion engine mounted on the vehicle, a motor for traveling the vehicle, etc. The traveling drive source 51 is connected to the drive member 40. The traveling drive source 51 outputs rotational power for rotating the sleeve 30 and the drive member 40.

[0051] The linear motion device 52 is a device for displacing the sleeve 30 along the axial direction Dax. The linear motion device 52 includes a shift fork 521 and a linear motion actuator 522.

[0052] The shift fork 521 is a member that connects the sleeve 30 and the actuator 522. One end of the shift fork 521 in the axial direction Dax is connected to the actuator 522, and the other end of the shift fork 521 in the axial direction Dax is connected to the sleeve 30.

[0053] The actuator 522 is configured by an electric motor, an electromagnetic solenoid, etc. The actuator 522 displaces the shift fork 521 together with the sleeve 30 in the axial direction Dax, thereby connecting and disconnecting the dog clutch 10.

[0054] The control device 53 constitutes an electronic control unit of the power transmission device 1. The control device 53 is composed of a computer including a processor P and memory M such as ROM and RAM, and its peripheral circuits. The memory M includes volatile memory and non-volatile memory. The memory M is composed of a non-transitory tangible storage medium.

[0055] A host ECU for controlling the entire vehicle is connected to the control device 53 so as to be able to communicate bidirectionally. Also, various sensors such as a position detection device 60 are connected to the input side of the control device 53.

[0056] The position detection device 60 is a device that detects the relative positional relationship between the first gear teeth 231 and the second gear teeth 311 based on a physical quantity that indicates the relative positional relationship between the plurality of first convex portions 241 and the plurality of second convex portions 321. Details of the position detection device 60 will be described later.

[0057] The output side of the control device 53 is connected to the travel drive source 51 and the actuator 522. The control device 53 executes a computer program stored in the memory M, and also executes various control processes in accordance with the computer program.

[0058] The control device 53 switches the dog clutch 10 between a released state and an engaged state based on the output of the position detection device 60. That is, the control device 53 switches between the released state and the engaged state based on the relative positional relationship between the first gear tooth 231 and the second gear tooth 311.

[0059] Next, details of the position detection device 60 will be described with reference to Fig. 10 to Fig. 19. As shown in Fig. 10, the position detection device 60 includes a magnetic sensor 70 and a signal processing circuit 80. The position detection device 60 can be interpreted as including, as components, a first flange portion 24 as a "first target portion" and a second flange portion 32 as a "second target portion."

[0060] The magnetic sensor 70 is a "sensor" that detects a "physical quantity" that indicates the relative positional relationship between the first convex portion 241 and the second convex portion 321. The magnetic sensor 70 of this embodiment detects a change in magnetic flux that changes depending on the relative positional relationship between the first convex portion 241 and the second convex portion 321.

[0061] The magnetic sensor 70 is a self-exciting sensor that generates a magnetic field by itself to form a magnetic circuit. The magnetic sensor 70 of this embodiment has a magnetic circuit unit 71, a magnetic detection element 72, and a case (not shown) that houses the magnetic circuit unit 71 and the magnetic detection element 72.

[0062] The magnetic circuit unit 71 is a member that forms a magnetic circuit. The overall shape of the magnetic circuit unit 71 is U-shaped. As shown in Figures 10 and 11, the magnetic circuit unit 71 has a first magnet 711, a second magnet 712, a first yoke 713, a second yoke 714, and a third yoke 715.

[0063] The first magnet 711 and the second magnet 712 are magnetic field generating units that generate a magnetic field. The first magnet 711 and the second magnet 712 are made of permanent magnets. The first magnet 711 and the second magnet 712 are substantially the same in size, shape, and material. The first magnet 711 and the second magnet 712 are arranged in parallel at a predetermined interval so that a first magnetic pole line ML1 connecting the centers of the magnetic poles of the first magnet 711 with a straight line and a second magnetic pole line ML2 connecting the centers of the magnetic poles of the second magnet 712 with a straight line are substantially parallel.

[0064] Specifically, the first magnet 711 has a first magnetic pole surface 711a that constitutes the N pole and a second magnetic pole surface 711b that constitutes the S pole. The first magnetic pole surface 711a and the second magnetic pole surface 711b face each other with the main body of the first magnet 711 in between.

[0065] The second magnet 712 has a third magnetic pole face 712a that forms an N pole and a fourth magnetic pole face 712b that forms an S pole. The third magnetic pole face 712a and the fourth magnetic pole face 712b face each other with the main body of the second magnet 712 in between.

[0066] The first yoke 713 is connected to the first magnetic pole surface 711a of the first magnet 711. The first yoke 713 extends along the first magnetic pole line ML1. Specifically, the first yoke 713 has a first contact surface 713a that contacts the first magnet 711, a first inner surface 713b that faces the second yoke 714, a first outer surface 713c on the opposite side of the first inner surface 713b, and a first tip surface 713d on the opposite side of the first contact surface 713a. The first yoke 713 has a tapered shape that narrows from the first contact surface 713a side toward the first tip surface 713d side. In this embodiment, the first inner surface 713b extends linearly along the first magnetic pole line ML1. The first outer surface 713c is curved so as to gradually approach the first inner surface 713b from the first contact surface 713a side toward the first tip surface 713d side. This increases the magnetic flux density at first tip surface 713d. Note that first yoke 713 may be spaced apart from first magnet 711 as long as magnetic flux can pass between first yoke 713 and first magnet 711.

[0067] The second yoke 714 is connected to the third magnetic pole surface 712a of the second magnet 712. The second yoke 714 extends along the second magnetic pole line ML2. Specifically, the second yoke 714 has a second contact surface 714a that contacts the second magnet 712, a second inner surface 714b that faces the first yoke 713, a second outer surface 714c on the opposite side of the second inner surface 714b, and a second tip surface 714d on the opposite side of the second contact surface 714a. The second yoke 714 has a tapered shape that narrows from the second contact surface 714a side toward the second tip surface 714d side. In this embodiment, the second inner surface 714b extends linearly along the second magnetic pole line ML2. The second outer surface 714c is curved so as to gradually approach the second inner surface 714b from the second contact surface 714a side toward the second tip surface 714d side. This increases the magnetic flux density at second tip surface 714d. Note that second yoke 714 may be spaced apart from second magnet 712 as long as magnetic flux can pass between second yoke 714 and second magnet 712.

[0068] The third yoke 715 is connected to both the second magnetic pole surface 711b of the first magnet 711 and the fourth magnetic pole surface 712b of the second magnet 712. The third yoke 715 is configured in a U-shape. Note that the third yoke 715 is provided to connect the first magnet 711 and the second magnet 712, but the third yoke 715 may be omitted from the magnetic circuit unit 71.

[0069] The magnetic detection element 72 is an element that detects, as a "physical quantity," a change in magnetic flux that changes depending on the relative positional relationship between the first convex portion 241 and the second convex portion 321. The magnetic detection element 72 is disposed between the first yoke 713 and the second yoke 714. The magnetic detection element 72 detects a change in magnetic flux between the first yoke 713 and the second yoke 714. Although not shown, the magnetic detection element 72 includes a detection circuit that detects the magnetic flux direction Md, and an output circuit that outputs, as a sensor signal, a voltage corresponding to the magnetic flux direction Md detected by the detection unit.

[0070] Here, the direction in which first yoke 713 and second yoke 714 are arranged is defined as the x-axis, the direction in which first yoke 713 and second yoke 714 extend is defined as the y-axis, and the direction perpendicular to each of the x-axis and y-axis is defined as the z-axis. The detection circuit of this embodiment includes a first Hall element that detects magnetic flux density Mz in the direction of the z-axis and a second Hall element that detects magnetic flux density My in the direction of the y-axis.

[0071] The output circuit of the magnetic detection element 72 determines the magnetic flux angle θor with respect to the radial direction Dor based on the magnetic flux density Mz in the z-axis direction and the magnetic flux density My in the y-axis direction, and outputs the magnetic flux angle θor as a physical quantity. The magnetic flux angle θor can be determined, for example, using the following formula F1.

[0072] θor=arctan(Mz / My) …(F1) 12 and 13, the magnetic sensor 70 configured in this manner is disposed so as to face the first gear portion 22 and the second gear portion 31 with a predetermined gap therebetween in the radial direction Dor. Specifically, the magnetic sensor 70 is disposed outside the gear portions 22 and 31 in the radial direction Dor so that the tip end surfaces 713d and 714d face the protrusions 241 and 321 and the flange portions 24 and 32, respectively.

[0073] The length Lax of the magnetic sensor 70 in the axial direction Dax is greater than the distance Lg in the axial direction Dax between the first flange portion 24 and the second flange portion 32 in the "released state." Note that the length Lax may be equal to or less than the distance Lg, as long as the magnetic sensor 70 can detect changes in magnetic flux. Furthermore, the gaps between the magnetic sensor 70 and the first convex portion 241 and the second convex portion 321 are set appropriately depending on the magnitude of the output of the magnetic sensor 70, etc.

[0074] Here, when at least one of the driven member 20 and the sleeve 30 rotates, the position in the circumferential direction Dr of at least one of the plurality of first protrusions 241 and the plurality of second protrusions 321 changes. At this time, when the relative positional relationship between the plurality of first protrusions 241 and the plurality of second protrusions 321 changes, the direction Md of the magnetic flux near the magnetic detection element 72 changes, for example, as shown in FIGS. 14 to 16.

[0075] Specifically, when the driven member 20 and the sleeve 30 rotate at the same speed with the multiple first protrusions 241 and the multiple second protrusions 321 overlapping in the axial direction Dax, the direction Md of the magnetic flux near the magnetic detection element 72 does not change.

[0076] For example, as shown in the first and third illustrations from the left in Fig. 14, when the first protrusion 241 and the second protrusion 321 overlap in the axial direction Dax at a position close to the magnetic sensor 70, the direction of the magnetic flux Md near the magnetic detection element 72 is aligned with the radial direction Dor. In this case, the magnetic flux angle θor is approximately zero. The magnetic sensor 70 outputs a voltage indicating that the magnetic flux angle θor is approximately zero.

[0077] 14, even when the first protrusion 241 and the second protrusion 321 overlap in the axial direction Dax at a position away from the magnetic sensor 70, the magnetic flux direction Md near the magnetic detection element 72 is oriented along the radial direction Dor. In this case, the magnetic flux angle θor is approximately zero. The magnetic sensor 70 outputs a voltage indicating that the magnetic flux angle θor is approximately zero.

[0078] On the other hand, when the multiple first convex portions 241 and the multiple second convex portions 321 do not overlap in the axial direction Dax, the relative positional relationship between the first convex portions 241 and the second convex portions 321 with respect to the magnetic sensor 70 changes, thereby changing the direction Md of the magnetic flux near the magnetic detection element 72.

[0079] For example, as shown in the first and third diagrams from the left in Fig. 15, when the multiple first protrusions 241 and the multiple second protrusions 321 are each spaced at equal distances from the magnetic sensor 70, the direction of the magnetic flux Md near the magnetic detection element 72 is oriented along the radial direction Dor. In this case, the magnetic flux angle θor is approximately zero. The magnetic sensor 70 outputs a voltage indicating that the magnetic flux angle θor is approximately zero.

[0080] As shown in the second image from the left in FIG. 15 , when the multiple first convex portions 241 are close to the magnetic sensor 70 and the multiple second convex portions 321 are located farther away from the magnetic sensor 70, the magnetic flux direction Md near the magnetic detection element 72 is tilted toward the first convex portions 241. In this case, the magnetic flux angle θor indicates that the magnetic flux direction Md is tilted toward the first convex portions 241. The magnetic sensor 70 outputs a voltage corresponding to the magnetic flux angle θor. Note that the greater the degree of overlap between the first convex portions 241 and the second convex portions 321, the smaller the tilt of the magnetic flux direction Md toward the first convex portions 241, and the smaller the amplitude of the voltage output by the magnetic sensor 70.

[0081] As shown in the fourth image from the left in FIG. 15 , when the second protrusions 321 are close to the magnetic sensor 70 and the first protrusions 241 are far from the magnetic sensor 70, the magnetic flux direction Md near the magnetic detection element 72 is tilted toward the second protrusions 321. In this case, the magnetic flux angle θor indicates that the magnetic flux direction Md is tilted toward the second protrusions 321. The magnetic sensor 70 outputs a voltage corresponding to the magnetic flux angle θor. Note that the greater the degree of overlap between the first protrusions 241 and the second protrusions 321, the smaller the tilt of the magnetic flux direction Md toward the second protrusions 321, and the smaller the amplitude of the voltage output by the magnetic sensor 70.

[0082] Furthermore, when the relative positional relationship between the plurality of first protrusions 241 and the plurality of second protrusions 321 with respect to the magnetic sensor 70 changes, the direction Md of the magnetic flux near the magnetic detection element 72 also changes.

[0083] For example, as shown in the first left-hand portion of Fig. 16, when the multiple first protrusions 241 and the multiple second protrusions 321 overlap in the axial direction Dax at a position close to the magnetic sensor 70, the direction of the magnetic flux Md near the magnetic detection element 72 is aligned with the radial direction Dor. In this case, the magnetic flux angle θor is approximately zero. The magnetic sensor 70 outputs a voltage indicating that the magnetic flux angle θor is approximately zero.

[0084] 16, when the multiple first convex portions 241 are close to the magnetic sensor 70 and the multiple second convex portions 321 are far from the magnetic sensor 70, the direction Md of the magnetic flux near the magnetic detection element 72 is tilted toward the first convex portions 241. In this case, the magnetic flux angle θor indicates that the direction Md of the magnetic flux is tilted toward the first convex portions 241. The magnetic sensor 70 outputs a voltage corresponding to the magnetic flux angle θor.

[0085] 16, when the multiple first protrusions 241 and the multiple second protrusions 321 overlap in the axial direction Dax at a position away from the magnetic sensor 70, the direction of the magnetic flux Md near the magnetic detection element 72 is aligned with the radial direction Dor. In this case, the magnetic flux angle θor is approximately zero. The magnetic sensor 70 outputs a voltage indicating that the magnetic flux angle θor is approximately zero.

[0086] 16, when the second protrusions 321 are close to the magnetic sensor 70 and the first protrusions 241 are far from the magnetic sensor 70, the direction of the magnetic flux Md near the magnetic detection element 72 is tilted toward the second protrusions 321. In this case, the magnetic flux angle θor indicates that the direction of the magnetic flux Md is tilted toward the second protrusions 321. The magnetic sensor 70 outputs a voltage corresponding to the magnetic flux angle θor.

[0087] As shown in these figures, there is a certain correlation between the relative positional relationship of the first convex portions 241 and the second convex portions 321 with respect to the magnetic sensor 70 and the direction Md of the magnetic flux near the magnetic detection element 72. Therefore, by detecting the magnetic flux angle θor using the magnetic sensor 70, the relative positional relationship between the multiple first convex portions 241 and the multiple second convex portions 321 can be determined.

[0088] Here, if the position of the magnetic sensor 70 is shifted in the axial direction Dax, the detection value of the magnetic flux angle θor by the magnetic sensor 70 changes, for example, as shown in Fig. 17. In this case, however, the detection value of the magnetic flux angle θor by the magnetic sensor 70 is simply offset by a predetermined angle Δθ, and there is a certain correlation between the relative positional relationship between the first convex portions 241 and the second convex portions 321 and the direction of the magnetic flux Md near the magnetic detection element 72. Therefore, the relative positional relationship between the multiple first convex portions 241 and the multiple second convex portions 321 can be determined based on the magnetic flux angle θor detected by the magnetic sensor 70.

[0089] The signal processing circuit 80 is a circuit for identifying the meshing timing at which the first gear teeth 231 and the second gear teeth 311 can mesh with each other, based on the physical quantity detected by the magnetic sensor 70. The signal processing circuit 80 is incorporated into the position detection device 60 as an assembly integrated with the magnetic sensor 70.

[0090] The signal processing circuit 80 of this embodiment identifies the meshing timing based on the change over time in the output of the magnetic sensor 70 when the driven member 20 and the sleeve 30 are rotated at different speeds.

[0091] A method for identifying the meshing timing will be described below with reference to Figures 18 and 19. Figure 18 shows the change in output of the magnetic sensor 70 over time when the driven member 20 and the sleeve 30 are rotated at different speeds.

[0092] As shown in Figure 18, when the driven member 20 and the sleeve 30 are rotated at different speeds, the relative position between the first convex portion 241 and the second convex portion 321 changes over time, causing the output waveform of the magnetic sensor 70 to have a "beat" waveform.

[0093] The timing KNa at which the amplitude change in the output waveform of the magnetic sensor 70 is greatest corresponds to the incompatible timing at which the first convex portion 241 and the second convex portion 321 do not overlap in the axial direction Dax, making it impossible for the first gear tooth 231 and the second gear tooth 311 to mesh with each other.

[0094] On the other hand, the timing KTa at which the change in amplitude is smallest corresponds to the meshing timing at which the first convex portion 241 and the second convex portion 321 overlap in the axial direction Dax, and the first gear tooth 231 and the second gear tooth 311 can mesh with each other.

[0095] Based on these output characteristics, the signal processing circuit 80 identifies the meshing timing. The signal processing circuit 80 identifies the meshing timing from the output waveform of the magnetic sensor 70 shown in Fig. 19, for example, and turns on a meshing flag indicating the meshing timing, and notifies the control device 53 of the driving machine 50 of the information. The process of identifying the meshing timing in the signal processing circuit 80 will be described in detail later.

[0096] The driving machine 50 of this embodiment switches the dog clutch 10 from a released state to a connected state at the engagement timing identified by the signal processing circuit 80. The drive control process executed by the control device 53 of the driving machine 50 will be described below with reference to Fig. 20. The control routine shown in Fig. 20 is executed periodically or irregularly, for example, when the ignition switch of the vehicle is turned on and the driven member 20, sleeve 30, and driving member 40 are rotated.

[0097] 20, in step S100, the control device 53 determines whether or not there is a request to connect the dog clutch 10. For example, the control device 53 determines whether or not a request signal requesting connection of the dog clutch 10 has been received from a higher-level ECU (not shown). This request signal is a signal requesting switching of the dog clutch 10 from the "released state" to the "connected state."

[0098] When there is a request to connect the dog clutch 10, in step S110, the control device 53 receives information indicating whether the dog clutch 10 can be connected from the position detection device 60. Specifically, the control device 53 receives information indicating the timing of engagement from the signal processing circuit 80.

[0099] Here, the process of specifying the meshing timing executed by the signal processing circuit 80 will be described with reference to Fig. 21. The control routine shown in Fig. 21 is executed periodically or irregularly when the ignition switch of the vehicle is turned on and the driven member 20 and the sleeve 30 are rotated.

[0100] 21, in step S200, the signal processing circuit 80 determines whether the change in amplitude of the output of the magnetic sensor 70 is equal to or less than a predetermined value. For example, the signal processing circuit 80 obtains the envelope Xa of the output waveform of the magnetic sensor 70 shown in FIG. 19, and determines whether the change in amplitude of the envelope Xa is equal to or less than a predetermined value.

[0101] If the change in amplitude of the output of the magnetic sensor 70 is equal to or smaller than the predetermined value, the signal processing circuit 80 determines in step S210 that the section in which the change in amplitude of the output of the magnetic sensor 70 is equal to or smaller than the predetermined value as the meshing timing and turns on the meshing flag indicating the meshing timing. Then, in step S220, the signal processing circuit 80 notifies the control device 53 of the driving device 50 of information indicating the meshing timing.

[0102] Returning to Figure 20, when information indicating whether the dog clutch 10 can be connected is received from the position detection device 60, the control device 53 determines in step S120 whether the information received from the position detection device 60 indicates the timing for engagement.

[0103] As a result, if the information received from the position detection device 60 indicates the timing of engagement, the control device 53 executes, in step S130, the connection process for the dog clutch 10. For example, the control device 53 controls the actuator 522 of the linear motion device 52 so as to displace the sleeve 30 to the other side in the axial direction Dax.

[0104] When the meshing between the first gear teeth 231 and the second gear teeth 311 is completed and the dog clutch 10 switches from the released state to the connected state, the first convex portion 241 and the second convex portion 321 overlap in the axial direction Dax, as shown in FIG. 22 . At this time, the second convex portion 321 approaches the first convex portion 241 in the axial direction Dax, causing the magnetic flux direction Md near the magnetic detection element 72 to tilt significantly toward the first convex portion 241. In this case, the magnetic flux angle θor becomes a negative value. The magnetic sensor 70 outputs a voltage corresponding to the magnetic flux angle θor.

[0105] In this way, the output of the magnetic sensor 70 changes significantly between when the dog clutch 10 is in the engaged state and when it is in the released state. Taking this into consideration, the control device 53 determines whether or not the meshing between the first gear teeth 231 and the second gear teeth 311 has been completed based on the output of the magnetic sensor 70 during the connection process of the dog clutch 10. If such a determination is included in the connection process of the dog clutch 10, it is possible for the driving device 50 to know whether or not the connection of the dog clutch 10 has been completed normally.

[0106] The power transmission device 1 described above is configured to determine the meshing timing based on the relative positional relationship between the first gear teeth 231 and the second gear teeth 311. This makes it possible to reduce damage and hitting noise caused by the gear teeth 231, 311 colliding with each other when switching the dog clutch 10 from the released state to the engaged state.

[0107] In particular, the position detection device 60 is configured to indirectly detect the relative positional relationship between the first gear tooth 231 and the second gear tooth 311 based on a physical quantity indicating the positional relationship between the first convex portion 241, which is different from the first gear tooth 231, and the second convex portion 321, which is different from the second gear tooth 311. This allows the relative positional relationship between the first gear tooth 231 and the second gear tooth 311 to be detected in a manner independent of the gear shapes. Furthermore, the respective shapes of the plurality of first gear teeth 231 and the plurality of second gear teeth 311 do not affect the detection of the relative positional relationship between the first gear tooth 231 and the second gear tooth 311, ensuring freedom in designing the plurality of first gear teeth 231 and the plurality of second gear teeth 311.

[0108] Furthermore, the power transmission device 1 and the position detection device 60 of this embodiment have the following features.

[0109] (1) When the sleeve 30 is displaced in the axial direction Dax along the axis CL so as to approach the driven member 20, the first gear teeth 231 and the second gear teeth 311 mesh with each other and rotate together. At this time, the driven member 20 and the sleeve 30 are in a state in which the first convex portion 241 is separated from both the second gear teeth 311 and the second convex portion 321, and the second convex portion 321 is separated from both the first gear teeth 231 and the first convex portion 241.

[0110] In this way, if the first convex portion 241 and the second convex portion 321 are structured so as not to affect the meshing of the first gear teeth 231 and the second gear teeth 311, it is possible to ensure freedom in designing the first convex portion 241 and the second convex portion 321. This has the advantage that it becomes easier to form the first convex portion 241 and the second convex portion 321 in a shape suitable for detecting the relative positional relationship between the first convex portion 241 and the second convex portion 321.

[0111] (2) The position detection device 60 includes a magnetic detection element 72 that detects, as a "physical quantity," a change in magnetic flux that changes depending on the relative positional relationship between the first convex portion 241 and the second convex portion 321. As a result, the magnetic detection element 72 detects changes in magnetic flux near each of the convex portions 241, 321, and the output of the magnetic detection element 72 does not depend on the gear shape of each of the gear portions 22, 31, so there is no need to customize the position detection device 60 according to the gear shape.

[0112] Specifically, the direction of the magnetic flux passing through the magnetic detection element 72 changes in the axial direction Dax as the relative positional relationship between the protrusions 241 and 321 changes. Therefore, based on the direction of the magnetic flux passing through the magnetic detection element 72, it can be determined whether or not the engagement of the dog clutch 10 has been completed.

[0113] Here, if the position of each of the protrusions 241, 321 is displaced in the axial direction Dax due to assembly or part play, the amplitude of the output of the magnetic sensor 70 changes so as to be offset. The position detection device 60 of this embodiment identifies the meshing timing based on the magnitude of the change in amplitude of the output of the magnetic sensor 70. Therefore, even if the position of each of the protrusions 241, 321 is displaced in the axial direction Dax due to assembly or part play, the meshing timing can be appropriately identified.

[0114] Furthermore, the magnetic detection element 72 detects magnetic flux density on two axes that are perpendicular to each other, and outputs the direction Md of the magnetic flux passing through the magnetic detection element 72. As a result, even if, for example, the distance between each of the protrusions 241, 321 and the magnetic circuit unit 71 increases and the strength of the magnetic flux passing through the magnetic detection element 72 decreases, it is possible to appropriately detect changes in the magnetic flux that change depending on the relative positional relationship with each of the protrusions 241, 321.

[0115] Furthermore, the position detection device 60 detects the relative positional relationship between two targets such as the convex portions 241 and 321 using a single magnetic sensor 70, and therefore can be placed in a small space, providing excellent mountability.

[0116] Here, the position detection device 60 may be configured to use multiple sensors to detect the relative positional relationship between the convex portions 241 and 321. However, using a single sensor as in this embodiment requires less calculation of the output value and is superior in responsiveness, so it is preferable that the position detection device 60 be configured as in this embodiment.

[0117] (3) If the first protrusions 241 and the second protrusions 321 are made of different materials, this disrupts the balance of magnetic flux between the first protrusions 241 and the second protrusions 321. When the protrusions 241, 321 are made of different materials, the center of the amplitude change in the output of the magnetic sensor 70 is likely to deviate from the target value, as shown in Figures 23 and 24, for example. This deviation may be undesirable because it affects various processes, such as the detection of the relative positions of the protrusions 241, 321 and the determination of meshing timing.

[0118] In contrast, in this embodiment, the multiple first convex portions 241 and the multiple second convex portions 321 are made of the same material. This reduces the effect of differences in constituent materials on the detection of the relative positions of the first convex portions 241 and the second convex portions 321. For example, when determining the meshing timing when the amplitude of a signal corresponding to the relative positional relationship between the convex portions 241 and 321 falls within a certain standard line, the threshold value can be set to 0±A [V] if the materials are the same. On the other hand, if the materials are different, the threshold value becomes B±A [V] due to a center value shift, and B must be set, which makes determining the meshing timing complicated.

[0119] In particular, when the position detector 60 includes the magnetic detection element 72 as in this embodiment, it becomes easier to balance the magnetic flux between the first convex portion 241 and the second convex portion 321, and it becomes easier to set the output of the magnetic detection element 72 to a target value. This has the advantage that it becomes easier to appropriately perform various processes such as determining the meshing timing and controlling the driving device 50.

[0120] (4) The plurality of first protrusions 241 are each configured to have the same shape. The plurality of second protrusions 321 are each configured to have the same shape. The first protrusions 241 and the second protrusions 321 are each configured to have the same shape.

[0121] This can reduce the effect of differences in convex shape on the detection of the relative position between the first convex portion 241 and the second convex portion 321. In particular, when the position detection device 60 includes the magnetic detection element 72, as in this embodiment, it becomes easier to balance the magnetic flux between the convex portions 241, 321. Note that when the magnetic flux near each gear tooth 231, 311 is to be detected, it is necessary to create a magnetic circuit that is not symmetrical in cross section in the axial direction Dax, for example, in order to balance the magnetic flux taking into account the differences in shape of each gear tooth 231, 311. This increases the number of development steps and limits the manufacturing methods, resulting in increased costs.

[0122] Here, "the same shape" and "the same size" in this specification do not necessarily mean that they are the same in the strict sense, and for example, differences within the range of allowable manufacturing errors can be interpreted as being the same.

[0123] (5) A first imaginary circle IR1 passing through the portion of the plurality of first protrusions 241 that is farthest from the axis CL and a second imaginary circle IR2 passing through the portion of the plurality of second protrusions 321 that is farthest from the axis CL are the same size. In this way, if the portion including the plurality of first protrusions 241 and the portion including the plurality of second protrusions 321 are of similar size, it is possible to suppress the influence of differences in size of the portions including each protrusion 241, 321 on detection of the relative positions of each protrusion 241, 321.

[0124] (6) The first gear teeth 231 and the second gear teeth 311 have the same number of teeth. The first gear portion 22 is provided with evenly spaced first protrusions 241, the number of which is a divisor of the number of teeth of the first gear teeth 231. The second gear portion 31 is provided with evenly spaced second protrusions 321, the number of which is a divisor of the number of teeth of the second gear teeth 311. This increases the correlation between the relative positional relationship between the gear teeth 231, 311 and the relative positional relationship between the protrusions 241, 321. This makes it possible to stabilize detection of the relative positional relationship between the first gear teeth 231 and the second gear teeth 311, based on a physical quantity indicating the positional relationship between the first protrusions 241 and the second protrusions 321. Furthermore, if the number of each protrusion 241, 321 is a multiple of the number of the first gear tooth 231 and the second gear tooth 311 that is two or more, the correlation between the relative positional relationship of each gear tooth 231, 311 and the relative positional relationship of each protrusion 241, 321 becomes low, making it difficult to determine the meshing timing.

[0125] (7) The first gear portion 22 has a plurality of first gear teeth 231 protruding in a direction away from the axis CL and a plurality of first protrusions 241 protruding in a direction away from the axis CL, which are provided all around the circumference in the circumferential direction Dr about the axis CL. The second gear portion 31 has a cylindrical shape centered on the axis CL, and a plurality of second gear teeth 311 protruding in a direction approaching the axis CL are provided all around the circumference in the circumferential direction Dr on the inside of the second gear portion 31. Furthermore, the second gear portion 31 has a plurality of second protrusions 321 protruding in a direction away from the axis CL, which are provided all around the circumference in the circumferential direction Dr on the outside of the second gear portion 31.

[0126] In this way, if the protrusions 241, 321 protrude in a direction away from the axis CL, a structure can be obtained in which the protrusions 241, 321 do not interfere with each other when the gear teeth 231, 311 mesh with each other.

[0127] Furthermore, in this type of dog clutch 10, the second gear teeth 311 are formed inside the cylindrical second gear portion 31 and are not exposed to the outside, making it difficult to detect magnetic flux near each gear tooth 231, 311.

[0128] In contrast, in the power transmission device 1 of this embodiment, the magnetic flux near each of the protrusions 241, 321 provided separately from each of the gear teeth 231, 311 is the detection target of the position detection device 60, and the magnetic flux near each of the protrusions 241, 321 can be detected by the position detection device 60. Therefore, the power transmission device 1 of this embodiment is suitable for a dog clutch 10 of the type in which the first gear teeth 231 protruding in a direction away from the axis CL and the second gear teeth 311 protruding in a direction toward the axis CL are engaged with each other.

[0129] (8) The power transmission device 1 includes a signal processing circuit 80 that identifies the meshing timing at which the first gear teeth 231 and the second gear teeth 311 can mesh with each other based on the "physical quantity" detected by the position detection device 60. The driving device 50 switches the dog clutch 10 from a released state to a connected state at the meshing timing identified by the signal processing circuit 80. In this way, by identifying the meshing timing using the signal processing circuit 80, it is possible to simplify the configuration of the control device 53 on the driving device 50 side and reduce the processing load.

[0130] (9) The position detecting device 60 includes, in addition to the magnetic sensor 70, which is a sensor for detecting a "physical quantity," a signal processing circuit 80 that identifies the meshing timing based on the "physical quantity" detected by the magnetic sensor 70. In this way, if the position detecting device 60 is configured to include the signal processing circuit 80 for identifying the meshing timing, the configuration of the power transmission device 1 can be simplified compared to when the signal processing circuit 80 is provided independently. Furthermore, if the signal processing circuit 80 is configured to be included in the position detecting device 60, high-frequency sampling is not required on the driving device 50 side, and the processing load on the driving device 50 side can be reduced.

[0131] (Modification of the first embodiment) The power transmission device 1 and the position detection device 60 of the first embodiment are not limited to those described above. The power transmission device 1 and the position detection device 60 of the first embodiment can be modified, for example, as follows.

[0132] (First Modification) In the first embodiment, the number of protrusions 241, 321 provided on each gear portion 22, 31 is the same as the number of teeth on each gear tooth 231, 311. However, the number of protrusions 241, 321 may be different from that shown in the first embodiment. For example, as shown in FIGS. 25 and 26 , each gear portion 22, 31 may be provided with half the number of protrusions 241, 321 on each gear tooth 231, 311. This also makes it possible to appropriately detect the relative positional relationship between the first gear tooth 231 and the second gear tooth 311 based on a physical quantity indicating the positional relationship between the first protrusions 241 and the second protrusions 321. This configuration is particularly suitable when the number of teeth on each gear tooth 231, 311 is large.

[0133] (Second Modification) The magnetic sensor 70 of the first embodiment has been described as an example in which the detection circuit includes a first Hall element that detects magnetic flux density Mz in the z-axis direction and a second Hall element that detects magnetic flux density My in the y-axis direction, but is not limited to this. The detection circuit of the magnetic sensor 70 may include a first Hall element that detects magnetic flux density Mx in the x-axis direction and a second Hall element that detects magnetic flux density My in the y-axis direction, and may output the magnetic flux angle θor with respect to the radial direction Dor based on the detection values ​​of each element as a "physical quantity."

[0134] When using a magnetic sensor 70 configured in this manner, if the driven member 20 and the sleeve 30 rotate at the same speed with the multiple first convex portions 241 and the multiple second convex portions 321 overlapping in the axial direction Dax, the direction Md of the magnetic flux near the magnetic detection element 72 changes.

[0135] 27, when the first protrusion 241 and the second protrusion 321 overlap in the axial direction Dax at a position close to the magnetic sensor 70, the direction Md of the magnetic flux near the magnetic detection element 72 is aligned with the radial direction Dor. In this case, the magnetic flux angle θor is approximately zero.

[0136] Furthermore, as shown in the second and fourth from the left in Figure 27, when the first convex portion 241 and the second convex portion 321 overlap in the axial direction Dax at a position away from the magnetic sensor 70, the direction Md of the magnetic flux near the magnetic detection element 72 is inclined with respect to the radial direction Dor.

[0137] On the other hand, when the multiple first protrusions 241 and the multiple second protrusions 321 do not overlap in the axial direction Dax, the relative positional relationship between the first protrusions 241 and the second protrusions 321 and the magnetic sensor 70 changes, but the direction of the magnetic flux Md near the magnetic detection element 72 does not change. For example, as shown in FIG. 28 , the direction of the magnetic flux Md near the magnetic detection element 72 is oriented along the radial direction Dor. In this case, the magnetic flux angle θor is approximately zero. The magnetic sensor 70 outputs a voltage indicating that the magnetic flux angle θor is approximately zero.

[0138] As shown in these figures, there is a certain correlation between the relative positional relationship of the first convex portions 241 and the second convex portions 321 with respect to the magnetic sensor 70 of the second modified example, and the direction Md of the magnetic flux near the magnetic detection element 72. Therefore, by detecting the magnetic flux angle θor using the magnetic sensor 70 of the second modified example, it is possible to grasp the relative positional relationship between the multiple first convex portions 241 and the multiple second convex portions 321.

[0139] (Third Modification) The magnetic sensor 70 may be configured, for example, as shown in FIG. 29, in which the first yoke 713 is connected to the second pole face 711b of the first magnet 711, and the second yoke 714 is connected to the fourth pole face 712b of the second magnet 712.

[0140] 30, for example, there is a certain correlation between the relative positional relationship of the first convex portions 241 and the second convex portions 321 with respect to the magnetic sensor 70 and the direction Md of the magnetic flux near the magnetic detection element 72. Therefore, by detecting the magnetic flux angle θor using the magnetic sensor 70 of the third modified example, it is possible to grasp the relative positional relationship between the multiple first convex portions 241 and the multiple second convex portions 321.

[0141] (Fourth Modification) The magnetic sensor 70 may be configured, for example, as shown in FIG. 31, in which the first yoke 713 is connected to the first magnetic pole face 711a of the first magnet 711, and the second yoke 714 is connected to the fourth magnetic pole face 712b of the second magnet 712.

[0142] 32, there is a certain correlation between the relative positional relationship of the first convex portions 241 and the second convex portions 321 with respect to the magnetic sensor 70 and the direction Md of the magnetic flux near the magnetic detection element 72. Therefore, by using the magnetic sensor 70 of the fourth modification to detect the magnetic flux angle θr with respect to the circumferential direction Dr, it is possible to grasp the relative positional relationship between the multiple first convex portions 241 and the multiple second convex portions 321.

[0143] (Fifth Modification) The magnetic sensor 70 may have a configuration in which a single magnet 716 is arranged on a third yoke 715 instead of the first magnet 711 and the second magnet 712, as shown in FIG.

[0144] (Sixth Modification) The magnetic sensor 70 may be configured, for example, as shown in FIG. 34, in which the first yoke 713 is connected to the second pole surface 711b of the first magnet 711, and the second yoke 714 is connected to the third pole surface 712a of the second magnet 712.

[0145] (Second embodiment) Next, a second embodiment will be described with reference to Figures 35 and 36. In this embodiment, differences from the first embodiment will be mainly described.

[0146] 35, the magnetic sensor 70 is disposed outside the gear portions 22 and 31 in the radial direction Dor so that the first tip surface 713d faces the first convex portion 241 and the first flange portion 24, and the second tip surface 714d faces the second convex portion 321 and the second flange portion 32. The detection circuit of the magnetic sensor 70 includes a first Hall element that detects the magnetic flux density Mx in the x-axis direction and a second Hall element that detects the magnetic flux density My in the y-axis direction, and outputs the magnetic flux angle θor with respect to the radial direction Dor based on the detection values ​​of each element as a "physical quantity."

[0147] When using a magnetic sensor 70 configured in this manner, if the relative positional relationship between the multiple first convex portions 241 and the multiple second convex portions 321 changes, the direction Md of the magnetic flux near the magnetic detection element 72 changes, for example, as shown in Figure 36.

[0148] For example, when the first protrusion 241 and the second protrusion 321 overlap in the axial direction Dax at a position close to the magnetic sensor 70, the direction of the magnetic flux Md near the magnetic detection element 72 is aligned with the radial direction Dor. In this case, the magnetic flux angle θor is approximately zero. The magnetic sensor 70 outputs a voltage indicating that the magnetic flux angle θor is approximately zero.

[0149] On the other hand, when the first protrusions 241 and the second protrusions 321 do not overlap in the axial direction Dax, the magnetic flux direction Md near the magnetic detection element 72 is tilted with respect to the radial direction Dor. The magnetic sensor 70 outputs a voltage according to the magnetic flux angle θor.

[0150] As shown in these figures, there is a certain correlation between the relative positional relationship of the first convex portions 241 and the second convex portions 321 with respect to the magnetic sensor 70 of this embodiment and the direction Md of the magnetic flux near the magnetic detection element 72. Therefore, by detecting the magnetic flux angle θor using the magnetic sensor 70 of this embodiment, it is possible to grasp the relative positional relationship between the multiple first convex portions 241 and the multiple second convex portions 321.

[0151] The rest of the configuration is the same as in the first embodiment. The power transmission device 1 and the position detection device 60 of this embodiment can obtain the same effects as in the first embodiment that are achieved by the configuration common to or equivalent to the first embodiment.

[0152] (Third embodiment) Next, a third embodiment will be described with reference to Figures 37 to 45. In this embodiment, differences from the first embodiment will be mainly described.

[0153] As shown in FIG. 37, the dog clutch 10 of the third embodiment does not have the sleeve 30 described in the first embodiment, and has a configuration in which a driven member 20A and a driving member 40A are directly connected to each other.

[0154] The driven member 20A is a rotating member that receives power output from the travel drive source 51 via the driving member 40A and rotates about the axis CL. In this embodiment, the driven member 20 corresponds to the "first rotating member."

[0155] The driven member 20 includes a first shaft member 21A formed in a cylindrical shape and a first gear portion 22A provided on one side in the axial direction Dax of the first shaft member 21. The first shaft member 21A and the first gear portion 22A are connected to rotate integrally.

[0156] The first gear portion 22A has a plurality of first gear teeth 231A formed thereon. The first gear portion 22A has a plurality of first protrusions 241A formed thereon, separate from the plurality of first gear teeth 231A, as elements for specifying the positions of the plurality of first gear teeth 231A. For convenience, in FIG. 37, reference numerals are assigned to representative ones of the plurality of first gear teeth 231A and the plurality of first protrusions 241A, and reference numerals for other ones are omitted. This also applies to drawings other than FIG. 37.

[0157] The multiple first gear teeth 231A are formed on a first tip portion 23A of the first gear portion 22A on one side in the axial direction Dax. The multiple first gear teeth 231A protrude from the other side in the axial direction Dax to one side at the first tip portion 23A so as to approach the second gear portion 42A. The multiple first gear teeth 231A are provided at predetermined intervals around the entire circumference in the circumferential direction Dr centered on the axis CL. The multiple first gear teeth 231A are each configured with the same shape. The interval between adjacent first gear teeth 231A in the circumferential direction Dr is large enough to allow the first gear teeth 231A to mesh with second gear teeth 421A, which will be described later. The multiple first gear teeth 231A have a shape suitable for meshing with the second gear teeth 421A, which will be described later.

[0158] The multiple first protrusions 241A are formed on a brim-shaped first flange portion 24A provided adjacent to the first tip portion 23A of the first gear portion 22A. The multiple first protrusions 241A protrude from the first flange portion 24A in a direction away from the axis CL. The multiple first protrusions 241A are provided at predetermined intervals around the entire circumference in the circumferential direction Dr centered on the axis CL. Each of the multiple first protrusions 241A is configured to have the same shape.

[0159] The first flange portion 24A is provided to rotate integrally with the driven member 20A. In this embodiment, the first flange portion 24A constitutes a "first target portion" having a plurality of first protrusions 241A separate from the plurality of first gear teeth 231A. The first flange portion 24A can be considered as one of the components of the position detection device 60.

[0160] The first gear portion 22A is provided with first protrusions 241A in a number that is a divisor of the plurality of first gear teeth 231A. As shown in FIG. 38, the first gear portion 22A of this embodiment is provided with the same number of first protrusions 241A as the plurality of first gear teeth 231A. Note that FIG. 38 shows, as an example, the first gear portion 22A provided with 12 first gear teeth 231A and first protrusions 241A, but the numbers of the first gear teeth 231A and first protrusions 241A are not limited to those shown in FIG. 38 and can be set to any numbers. Also, in FIG. 38, the first gear teeth 231A are hatched with a dot pattern so that the positions where the first gear teeth 231A are provided can be identified.

[0161] The entire first gear portion 22A is made of a magnetic material (for example, a material containing iron). Note that, as long as at least the plurality of first protrusions 241A of the first gear portion 22A are made of a magnetic material, other elements may be made of a different material.

[0162] The driving member 40A is a rotating member that transmits the power output from the traveling drive source 51 to the driven member 20A. The driving members 40A are connected to each other so as to rotate together about the axis CL by the power output from the traveling drive source 51. In this embodiment, the driving member 40A corresponds to the "second rotating member."

[0163] The driving member 40A is disposed so as to face the driven member 20A in the axial direction Dax. The driving member 40A includes a cylindrical second shaft member 41A and a second gear portion 42A. The second shaft member 41A and the second gear portion 42A are connected to each other so as to rotate integrally about an axis CL.

[0164] One side of the second shaft member 41A in the axial direction Dax is connected to the traveling drive source 51. The second shaft member 41A rotates around the axis CL together with the second gear portion 42A by the power of the traveling drive source 51. The second gear portion 42A is provided on the other side of the second shaft member 41A in the axial direction Dax.

[0165] The second gear portion 42A is formed with a plurality of second gear teeth 421A that can mesh with the plurality of first gear teeth 231A. The second gear portion 42A is formed with a plurality of second protrusions 431A that are separate from the plurality of second gear teeth 421A and serve as elements for specifying the positions of the plurality of second gear teeth 421A. Note that in FIG. 39, for convenience, reference numerals are assigned to representative ones of the plurality of second gear teeth 421A and the plurality of second protrusions 431A, and reference numerals for other ones are omitted. This is the same in other drawings as well. In FIG. 39, the second gear teeth 421A are hatched with a dot pattern to indicate the positions of the second gear teeth 421A.

[0166] The multiple second gear teeth 421A are formed at the end of the second gear portion 42A on the other side in the axial direction Dax. The multiple second gear teeth 421A protrude from one side to the other side in the axial direction Dax so as to approach the first gear portion 22A. The multiple second gear teeth 421A are provided at predetermined intervals all around the circumference in the circumferential direction Dr centered on the axis CL. The multiple second gear teeth 421A are each configured with the same shape. The interval between the second gear teeth 421A adjacent to each other in the circumferential direction Dr is large enough to allow the first gear teeth 231A to mesh with the second gear teeth 421A. The multiple second gear teeth 421A have a shape suitable for meshing with the first gear teeth 231A.

[0167] The multiple second protrusions 431A are formed on a brim-shaped second flange portion 43A provided adjacent to the end of the second gear portion 42A. The multiple second protrusions 431A protrude from the second flange portion 43A in a direction away from the axis CL. The multiple second protrusions 431A are provided at predetermined intervals around the entire circumference in the circumferential direction Dr centered on the axis CL. Each of the multiple second protrusions 431A is configured to have the same shape.

[0168] The second flange portion 43A is provided so as to rotate integrally with the driving member 40A. In this embodiment, the second flange portion 43A constitutes a "second target portion" having a plurality of second protrusions 431A separate from the plurality of second gear teeth 421A. The second flange portion 43A can be considered as one of the components of the position detection device 60.

[0169] As shown in Fig. 39, the second gear portion 42A is provided with second convex portions 431A in a number that is a divisor of the plurality of second gear teeth 421A. The second gear portion 42A of the present embodiment is provided with the same number of second convex portions 431A as the plurality of second gear teeth 421A. Note that Fig. 39 shows, as an example, the second gear portion 42A provided with 12 second gear teeth 421A and second convex portions 431A, but the numbers of second gear teeth 421A and second convex portions 431A are not limited to those shown in Fig. 39.

[0170] Each of the second protrusions 431A protrudes in a direction away from the axis CL so as to correspond to a recess between adjacent second gear teeth 421A. Each of the second protrusions 431A is formed so as to overlap a recess between adjacent second gear teeth 421A in the radial direction Dor when the second gear portion 42A is viewed from the axial direction Dax.

[0171] The second protrusions 431A have a different shape from the second gear teeth 421A. As in the first embodiment, the second protrusions 431A are configured to have the same shape as the first protrusions 241A.

[0172] The entire second gear portion 42A is made of a magnetic material (for example, a material containing iron). Specifically, the second gear portion 42A is made of the same magnetic material (i.e., the same material) as the first gear portion 22A. Note that, as long as at least the plurality of second protrusions 431A of the second gear portion 42A are made of a magnetic material, other elements of the second gear portion 42A may be made of a different material.

[0173] The second gear portion 42A of the driving member 40A is connected to a linear motion device 52A that displaces the second gear portion 42A along the axial direction Dax, thereby enabling the driving member 40A to be displaced in the axial direction Dax.

[0174] 40 and 41, the dog clutch 10A configured in this manner cannot mesh the first gear teeth 231A with the second gear teeth 421A at the timing when the multiple first gear teeth 231A and the multiple second gear teeth 421A overlap in the axial direction Dax. In other words, the timing when the first gear teeth 231A and the second gear teeth 421A overlap in the axial direction Dax is an incompatible timing when it is not possible to mesh the first gear teeth 231A with the second gear teeth 421A.

[0175] 42 and 43, the first gear teeth 231A and the second gear teeth 421A can be meshed with each other at a timing when the plurality of first gear teeth 231A and the plurality of second gear teeth 421A do not overlap with each other in the axial direction Dax. That is, the timing when the first gear teeth 231A and the second gear teeth 421A do not overlap with each other in the axial direction Dax is the meshing timing at which the first gear teeth 231A and the second gear teeth 421A can be meshed with each other.

[0176] As shown in Figure 44, when the dog clutch 10A displaces the second gear portion 42A so that it approaches the driven member 20A at the timing of engagement, the first gear teeth 231A and the second gear teeth 421A mesh with each other, causing the driven member 20A and the driving member 40A to rotate together.

[0177] In a connected state in which the driven member 20A and the driving member 40A rotate together, the first convex portion 241A is spaced apart from both the second gear tooth 421A and the second convex portion 431A, and the second convex portion 431A is spaced apart from both the first gear tooth 231A and the first convex portion 241A.

[0178] In the position detection device 60 of this embodiment, the magnetic sensor 70 is disposed so as to face the first gear portion 22A and the second gear portion 42A with a predetermined gap therebetween in the radial direction Dor, as in the first embodiment. Specifically, the magnetic sensor 70 is disposed outside the gear portions 22A and 42A in the radial direction Dor so that the tip end surfaces 713d and 714d face the protrusions 241A and 431A and the flange portions 24A and 43A, respectively.

[0179] 45, for example, there is a certain correlation between the relative positional relationship of the first convex portion 241A and the second convex portion 431A with respect to the magnetic sensor 70 and the direction Md of the magnetic flux near the magnetic detection element 72. Therefore, by detecting the magnetic flux angle θor using the magnetic sensor 70 of this embodiment, it is possible to grasp the relative positional relationship between the multiple first convex portions 241 and the multiple second convex portions 321.

[0180] The rest of the configuration is the same as in the first embodiment. The power transmission device 1 and the position detection device 60 of this embodiment can obtain the same effects as in the first embodiment that are achieved by the configuration common to or equivalent to the first embodiment.

[0181] Furthermore, the power transmission device 1 and the position detection device 60 of this embodiment have the following features.

[0182] (1) The first gear portion 22A has a plurality of first gear teeth 231A protruding toward the second gear portion 42A along the axial direction Dax and a plurality of first protruding portions 241A protruding in a direction away from the axis CL, all around the circumference in the circumferential direction Dr about the axis CL. The second gear portion 42A has a plurality of second gear teeth 421A protruding toward the first gear portion 22A along the axial direction Dax and a plurality of second protruding portions 431A protruding in a direction away from the axis CL, all around the circumference in the circumferential direction Dr. In this type of dog clutch 10A, by having the protruding portions 241A, 431A protruding in a direction away from the axis CL, a structure can be obtained in which the first protruding portions 241A and the second protruding portions 431A do not affect the meshing of the first gear teeth 231A and the second gear teeth 421A.

[0183] (Modification of the third embodiment) The power transmission device 1 and the position detection device 60 of the third embodiment are not limited to those described above. For example, as long as the number of protruding portions 241A, 431A provided for each gear portion 22A, 42A is a divisor of the number of teeth of each gear tooth 231A, 421A, the number of teeth of each gear tooth 231A, 421A and the number of protruding portions 241A, 431A may be different.

[0184] The magnetic sensor 70 may be configured such that the detection circuit includes a first Hall element that detects magnetic flux density Mx in the x-axis direction and a second Hall element that detects magnetic flux density My in the y-axis direction. The magnetic sensor 70 may also be configured as shown in, for example, Figures 29, 31, 33, and 34.

[0185] (Other embodiments) The magnetic sensor 70 can be modified in various ways, for example, as shown in the following first to seventh examples.

[0186] (Example 1) As shown in FIG. 46, the first yoke 713 and the second yoke 714 of the magnetic sensor 70 may have substantially constant sizes on the contact surfaces 713a and 714a sides and the tip surfaces 713d and 714d sides.

[0187] (Example 2) As shown in FIG. 47, the magnetic sensor 70 may be configured such that a magnet 716 is arranged in a third yoke 715, and the first yoke 713 and the second yoke 714 have approximately constant sizes on the contact surface 713a, 714a side and the tip surface 713d, 714d side.

[0188] (Example 3) As shown in FIG. 48, the first yoke 713 and the second yoke 714 may be inclined such that the inner surfaces 713b and 714b approach the outer surfaces 713c and 714c toward the tip surfaces 713d and 714d.

[0189] (Example 4) As shown in FIG. 49, the magnetic sensor 70 may be configured such that a magnet 716 is disposed in a third yoke 715, and the inner surfaces 713b, 714b of the first yoke 713 and the second yoke 714 may be inclined so as to approach the outer surfaces 713c, 714c, respectively, as shown in FIG. 48.

[0190] (Example 5) The magnetic sensor 70 does not require that the first yoke 713 and the second yoke 714 are in direct contact with the magnetic detection element 72; for example, as shown in FIG. 50, the first yoke 713 and the second yoke 714 may be configured to be spaced apart from the magnetic detection element 72.

[0191] (Example 6) As shown in FIG. 51, the magnetic sensor 70 may be disposed such that a part of the magnetic detection element 72 is out of contact with the first yoke 713 and the second yoke 714.

[0192] (Example 7) As shown in FIG. 52, the magnetic sensor 70 may be configured such that the portions of the first yoke 713 and the second yoke 714 that come into contact with the magnetic detection element 72 protrude closer to each other.

[0193] Furthermore, the present disclosure is not limited to the above-described embodiment, and various modifications are possible, for example, as follows.

[0194] As in the first embodiment described above, it is desirable that when the gear teeth 231, 311 mesh with each other, the first convex portion 241 is spaced apart from the second gear tooth 311 and the second convex portion 321, and the second convex portion 321 is spaced apart from the first gear tooth 231 and the first convex portion 241, but this is not limitative. Each gear portion 22, 31 may be configured such that when the gear teeth 231, 311 mesh with each other, the first convex portion 241 comes into contact with one of the second gear tooth 311 and the second convex portion 321, or the second convex portion 321 comes into contact with one of the first gear tooth 231 and the first convex portion 241. This also applies to embodiments other than the first embodiment.

[0195] In the first embodiment described above, the gear teeth 231, 311 and the protruding portions 241, 321 are specifically illustrated using drawings, but are not limited to those described above. The gear teeth 231, 311 and the protruding portions 241, 321 may have different shapes, sizes, arrangements, numbers, positions, materials, etc. This also applies to embodiments other than the first embodiment. For example, each of the multiple first protruding portions 241 may protrude in a direction away from the axis CL to correspond to a recess between adjacent first gear teeth 231. Furthermore, each of the multiple second protruding portions 321 may protrude in a direction away from the axis CL to correspond to a second gear tooth 311.

[0196] In the dog clutch 10 of the first embodiment described above, the driving member 40 and the sleeve 30 are always engaged and operate as a unit, but this is not limiting, and for example, the driven member 20 and the sleeve 30 may always be engaged and operate as a unit. In this case, one of the sleeve 30 and the driving member 40 constitutes the "first rotating member" and the other constitutes the "second rotating member."

[0197] In the above embodiment, the position detection device 60 includes the magnetic detection element 72, but the position detection device 60 is not limited to this. The position detection device 60 may include, for example, a mechanical sensor, an optical sensor, or the like.

[0198] As in the above-described embodiment, the position detection device 60 is preferably configured to include the signal processing circuit 80, but is not limited to this. For example, the signal processing circuit 80 may be provided in the movable device 50.

[0199] In the above embodiment, an example has been described in which the power transmission device 1 of the present disclosure is applied to a vehicle, but the power transmission device 1 and position detection device 60 of the present disclosure can also be applied to devices other than vehicles.

[0200] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0201] In the above-described embodiments, when numerical values ​​such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers unless they are expressly stated as being essential or are clearly limited to a specific number in principle.

[0202] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., the shapes, positional relationships, etc. are not limited to those unless otherwise specified or when they are limited in principle to specific shapes, positional relationships, etc.

[0203] The controller and method of the present disclosure may be implemented on a special-purpose computer by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. The controller and method of the present disclosure may be implemented on a special-purpose computer by configuring a processor with one or more dedicated hardware logic circuits. The controller and method of the present disclosure may be implemented on one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. The computer program may also be stored on a computer-readable non-transitory tangible storage medium as instructions executed by a computer. (Aspects of the present disclosure)

[0204] According to a first aspect of the present disclosure, The power transmission device is a first rotating member (20, 20A) including a first gear portion (22, 22A) in which, in addition to a plurality of first gear teeth (231, 231A), a plurality of first protrusions (241, 241A) separate from the plurality of first gear teeth are formed as elements for specifying the positions of the plurality of first gear teeth, and the first rotating member (20, 20A) rotates around a predetermined axis (CL); a second rotating member (30, 40A) including a second gear portion (31, 42A) in which, in addition to a plurality of second gear teeth (311, 421A) capable of meshing with the plurality of first gear teeth, a plurality of second protrusions (321, 431A) separate from the plurality of second gear teeth are formed as elements for identifying the positions of the plurality of second gear teeth, the second rotating member (30, 40A) rotating integrally with the first rotating member around the axis center with the plurality of second gear teeth meshed with the plurality of first gear teeth; a position detection device (60) that detects the relative positional relationship between the first gear teeth and the second gear teeth based on a physical quantity that indicates the relative positional relationship between the plurality of first convex portions and the plurality of second convex portions; and a driving device (50) that switches between a released state in which the first rotating member and the second rotating member are separated and a connected state in which the first gear teeth and the second gear teeth are meshed together and the first rotating member and the second rotating member rotate together, based on the relative positional relationship between the first gear teeth and the second gear teeth.

[0205] According to a second aspect of the present disclosure, The power transmission device described in the first aspect, wherein, when the first rotating member and the second rotating member are displaced in the axial direction along the axis so that one moves closer to the other, the first convex portion is separated from both the second gear tooth and the second convex portion, and the second convex portion is separated from both the first gear tooth and the first convex portion, and the first gear tooth and the second gear tooth mesh with each other and rotate together.

[0206] According to a third aspect of the present disclosure, The power transmission device according to the first or second aspect, wherein the position detection device includes a magnetic detection element (72) that detects, as the physical quantity, a change in magnetic flux that changes depending on the relative positional relationship between the first convex portion and the second convex portion.

[0207] According to a fourth aspect of the present disclosure, The power transmission device according to any one of the first to third aspects, wherein the plurality of first protrusions and the plurality of second protrusions are made of the same material.

[0208] According to a fifth aspect of the present disclosure, The plurality of first protrusions are each configured to have the same shape, The plurality of second protrusions are each configured to have the same shape, The power transmission device according to any one of the first to fourth aspects, wherein the first convex portion and the second convex portion are configured to have the same shape.

[0209] According to a sixth aspect of the present disclosure, A power transmission device according to any one of the first to fifth aspects, wherein when a circle passing through the portions of the plurality of first convex portions that are farthest from the axis center is defined as a first imaginary circle (IR1) and a circle passing through the portions of the plurality of second convex portions that are farthest from the axis center is defined as a second imaginary circle (IR2), the first imaginary circle and the second imaginary circle have the same size.

[0210] According to a seventh aspect of the present disclosure, the first gear teeth and the second gear teeth have the same number of teeth, The first gear portion is provided with the first convex portions at equal intervals, the number of which is a divisor of the number of teeth of the first gear, A power transmission device according to any one of the first to sixth aspects, wherein the second gear portion has the second protrusions provided at equal intervals in a number that is a divisor of the number of teeth of the second gear.

[0211] According to an eighth aspect of the present disclosure, the first gear portion (22) has a plurality of first gear teeth (231) protruding in a direction away from the axis and a plurality of first protrusions (241) protruding in a direction away from the axis, and the first gear portion (22) is provided over the entire circumferential direction around the axis; The power transmission device according to any one of the first to seventh aspects, wherein the second gear portion (31) has a cylindrical shape centered on the axis, and a plurality of second gear teeth (311) protruding in a direction approaching the axis are provided around the entire circumference in the circumferential direction on the inside of the second gear portion, and a plurality of second protrusions (321) protruding in a direction away from the axis are provided around the entire circumference in the circumferential direction on the outside of the second gear portion.

[0212] According to a ninth aspect of the present disclosure, the first gear portion (22A) has a plurality of first gear teeth (231A) protruding toward the second gear portion (42A) along the axial direction and a plurality of first convex portions (241A) protruding in a direction away from the axis, and the first gear portion (22A) is provided over the entire circumferential direction around the axis; The power transmission device according to any one of the first to seventh aspects, wherein the second gear portion (42A) has a plurality of second gear teeth (421A) protruding toward the first gear portion along the axial direction and a plurality of second protrusions (431A) protruding in a direction away from the axis center, provided around the entire circumference in the circumferential direction.

[0213] According to a tenth aspect of the present disclosure, a signal processing circuit (80) that identifies a timing at which the first gear teeth and the second gear teeth can be meshed together based on the physical quantity detected by the position detection device; The power transmission device according to any one of the first to ninth aspects, wherein the drive device switches from the released state to the connected state at the meshing timing specified by the signal processing circuit.

[0214] According to an eleventh aspect of the present disclosure, the position detection device includes, in addition to a sensor (70) that detects the physical quantity, a signal processing circuit (80) that identifies an engagement timing at which the first gear teeth and the second gear teeth can be engaged with each other based on the physical quantity detected by the sensor; The power transmission device according to any one of the first to tenth aspects, wherein the drive device switches from the released state to the connected state at the meshing timing identified by the signal processing circuit.

[0215] According to a twelfth aspect of the present disclosure, The position detection device applied to the power transmission device (1) is a first target portion (24, 24A) provided to rotate integrally with a first rotating member (20, 20A) including a plurality of first gear teeth (231, 231A), and having a plurality of first protrusions (241, 241A) separate from the plurality of first gear teeth formed as elements for identifying the positions of the plurality of first gear teeth; a second target portion (32, 43A) provided to rotate integrally with a second rotating member (30, 40A) including a plurality of second gear teeth (311, 421A) that can mesh with the plurality of first gear teeth, and having a plurality of second protrusions (321, 431A) separate from the plurality of second gear teeth formed as elements for identifying the positions of the plurality of second gear teeth; a sensor (70) that detects the relative positional relationship between the first gear teeth and the second gear teeth; the power transmission device includes a driving device (50) that switches between a released state in which the first rotating member and the second rotating member are separated and a connected state in which the first gear teeth and the second gear teeth are meshed with each other and the first rotating member and the second rotating member rotate integrally, based on a relative positional relationship between the first gear teeth and the second gear teeth; The sensor detects the relative positional relationship between the first gear teeth and the second gear teeth based on a physical quantity indicating the relative positional relationship between the plurality of first convex portions and the plurality of second convex portions. [Explanation of symbols]

[0216] 1 Power transmission device 20 driven member (first rotating member) 231 1st gear tooth 241 First convex part 30 Sleeve (second rotating member) 311 2nd gear tooth 321 Second convex part 40 driving member (second rotating member) 50 Drive equipment 60 Position detection equipment

Claims

1. A power transmission device, a first rotating member (20, 20A) including a first gear portion (22, 22A) in which, in addition to a plurality of first gear teeth (231, 231A), a plurality of first protrusions (241, 241A) separate from the plurality of first gear teeth are formed as elements for specifying the positions of the plurality of first gear teeth, and the first rotating member (20, 20A) rotates around a predetermined axis (CL); a second rotating member (30, 40A) including a second gear portion (31, 42A) in which, in addition to a plurality of second gear teeth (311, 421A) capable of meshing with the plurality of first gear teeth, a plurality of second protrusions (321, 431A) separate from the plurality of second gear teeth are formed as elements for specifying the positions of the plurality of second gear teeth, and which rotates integrally with the first rotating member around the axis center with the plurality of second gear teeth meshed with the plurality of first gear teeth; a position detection device (60) that detects a relative positional relationship between the first gear tooth and the second gear tooth based on a physical quantity that indicates a relative positional relationship between the plurality of first convex portions and the plurality of second convex portions; and a driving device (50) that switches between a released state in which the first rotating member and the second rotating member are separated and a connected state in which the first gear teeth and the second gear teeth mesh and the first rotating member and the second rotating member rotate integrally, based on the relative positional relationship between the first gear teeth and the second gear teeth.

2. 2. The power transmission device according to claim 1, wherein, when the first rotating member and the second rotating member are displaced in the axial direction along the axis so that one moves closer to the other, the first convex portion is separated from both the second gear tooth and the second convex portion, and the second convex portion is separated from both the first gear tooth and the first convex portion, with the first gear tooth and the second gear tooth meshing and rotating together.

3. 3. The power transmission device according to claim 1, wherein the position detection device includes a magnetic detection element (72) that detects a change in magnetic flux that changes depending on the relative positional relationship between the first convex portion and the second convex portion as the physical quantity.

4. The power transmission device according to claim 1 , wherein the first protrusions and the second protrusions are made of the same material.

5. The plurality of first protrusions are each configured to have the same shape, The plurality of second protrusions are each configured to have the same shape, The power transmission device according to claim 1 or 2, wherein the first convex portion and the second convex portion are configured to have the same shape.

6. 3. The power transmission device according to claim 1, wherein when a circle passing through the portions of the plurality of first convex portions that are farthest from the axis center is defined as a first imaginary circle (IR1) and a circle passing through the portions of the plurality of second convex portions that are farthest from the axis center is defined as a second imaginary circle (IR2), the first imaginary circle and the second imaginary circle have the same size.

7. the first gear teeth and the second gear teeth have the same number of teeth, The first gear portion is provided with the first convex portions at equal intervals, the number of which is a divisor of the number of teeth of the first gear, 3. The power transmission device according to claim 1, wherein the second gear portion is provided with the second protrusions at equal intervals, the number of the second protrusions being a divisor of the number of the second gear teeth.

8. The first gear portion (22) has a plurality of first gear teeth (231) protruding in a direction away from the axis and a plurality of first protrusions (241) protruding in a direction away from the axis, and the first gear portion (22) is provided over the entire circumferential direction around the axis, 3. The power transmission device according to claim 1 or 2, wherein the second gear portion (31) has a cylindrical shape centered on the axis, and a plurality of second gear teeth (311) protruding in a direction toward the axis are provided around the entire circumference inside the second gear portion in the circumferential direction, and a plurality of second protrusions (321) protruding in a direction away from the axis are provided around the entire circumference outside the second gear portion in the circumferential direction.

9. the first gear portion (22A) has a plurality of first gear teeth (231A) protruding toward the second gear portion (42A) along the axial direction and a plurality of first convex portions (241A) protruding in a direction away from the axis center, and the first gear portion (22A) is provided over the entire circumferential direction around the axis center, 3. The power transmission device according to claim 2, wherein the second gear portion (42A) has a plurality of second gear teeth (421A) protruding toward the first gear portion along the axial direction and a plurality of second protrusions (431A) protruding in a direction away from the axis center, provided around the entire circumferential circumference.

10. a signal processing circuit (80) that identifies an engagement timing at which the first gear teeth and the second gear teeth can be engaged based on the physical quantity detected by the position detection device; The power transmission device according to claim 1 or 2, wherein the driving device switches from the disengaged state to the connected state at the meshing timing specified by the signal processing circuit.

11. the position detection device includes, in addition to a sensor (70) that detects the physical quantity, a signal processing circuit (80) that identifies an engagement timing at which the first gear teeth and the second gear teeth can be engaged with each other based on the physical quantity detected by the sensor; The power transmission device according to claim 1 or 2, wherein the driving device switches from the disengaged state to the connected state at the meshing timing specified by the signal processing circuit.

12. A position detection device applied to a power transmission device (1), a first target portion (24, 24A) provided to rotate integrally with a first rotating member (20, 20A) including a plurality of first gear teeth (231, 231A), and having a plurality of first protrusions (241, 241A) separate from the plurality of first gear teeth formed as elements for identifying the positions of the plurality of first gear teeth; a second target portion (32, 43A) provided to rotate integrally with a second rotating member (30, 40A) including a plurality of second gear teeth (311, 421A) that can mesh with the plurality of first gear teeth, and having a plurality of second protrusions (321, 431A) separate from the plurality of second gear teeth formed as elements for identifying the positions of the plurality of second gear teeth; a sensor (70) that detects a relative positional relationship between the first gear teeth and the second gear teeth; The power transmission device includes a driving device (50) that switches between a release state in which the first rotating member and the second rotating member are separated from each other and a connection state in which the first gear teeth and the second gear teeth are meshed with each other and the first rotating member and the second rotating member rotate integrally, based on a relative positional relationship between the first gear teeth and the second gear teeth, The sensor is a position detection device that detects the relative positional relationship between the first gear teeth and the second gear teeth based on a physical quantity that indicates the relative positional relationship between the multiple first convex portions and the multiple second convex portions.

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