Crankshaft angle detection device

Abstract

Crankshaft angle detection device, which includes: an alternating current generator rotor (20) which is held by one end of a crankshaft (10) and is designed to rotate integrally with the crankshaft (10); a pulse generator ring (30) made of a metal plate, having an outer diameter (D2) larger than an outer diameter (D1) of the AC generator rotor (20), wherein the pulse generator ring (30) has an annular plate region (31) and a detected region (32) having a plurality of convex regions (32) formed on an outer circumference of the annular plate region (31), which form a predetermined void between themselves and an outer circumferential surface (22) of the AC generator rotor (20), being curved in the direction of the outer circumferential surface (22) of the AC generator rotor (20) in an axial direction of the crankshaft (10), and is configured to rotate integrally with the AC generator rotor (20), wherein the annular plate region (31) is attached to a side surface (21) of the AC generator rotor (20); and a magnetic sensor (40) which is formed on an outer circumference of the pulse generator ring (30) and is designed to detect the detected area (32).

Description

[0001] The present invention relates to a detection device for a crankshaft angle.

[0002] Traditionally, as disclosed for example in JP 5 942 035 B2, a crankshaft angle detection device is known for detecting a rotation angle (crank angle) of a crankshaft by using an electromagnetic sensor to detect convex areas which act as a detected area integral with an outer circumferential surface of an AC generator rotor.

[0003] Since, according to the conventional crankshaft angle detection device described above, the detected area is composed of convex regions that are integral with the outer circumferential surface of the AC generator rotor, it was difficult to improve the detection accuracy of a crankshaft angle. This is because increasing the number of convex regions is difficult when the convex regions are integral with the outer circumferential surface of the AC generator rotor.

[0004] JP 2003-172 168 A discloses a crankshaft angle detection device for a crankshaft of an internal combustion engine with a pulse generator ring. DE 10 2014 206 173 A1 discloses an alternating current generator coupled to an internal combustion engine with a sensor wheel and a method for determining a rotational speed.

[0005] One objective of the present invention is to provide a crankshaft angle detection device designed to detect a crankshaft angle with high accuracy.

[0006] To achieve the above-described objective, the present invention provides a crankshaft angle detection device comprising an AC generator rotor held at one end of a crankshaft and designed to rotate integrally with the crankshaft;a pulse generator ring made of a metal, having an outer diameter larger than the outer diameter of the AC generator rotor, the pulse generator ring comprising an annular plate region and a sensing region having a plurality of convex regions formed on an outer circumference of the annular plate region, which form a predetermined void between themselves and an outer circumferential surface of the AC generator rotor, being curved in the direction of the outer circumferential surface of the AC generator rotor in an axial direction of the crankshaft, and which is configured to rotate integrally with the AC generator rotor, the annular plate region being attached to a side surface of the AC generator rotor; and a magnetic sensor arranged on an outer circumference of the pulse generator ring and configured to sensing the sensing region.

[0007] Since, according to the crankshaft angle detection device, the detected area is formed from convex areas on the outer circumference of the pulse generator ring made from a metal plate, which rotates integrally with the AC generator rotor by being attached to the AC generator rotor, the detection accuracy of a crankshaft angle can be improved.

[0008] Since the pulse generator ring is made from a metal plate or separately from the AC generator rotor, convex areas that act as the detected area can be easily formed, for example by pressing.

[0009] Accordingly, the number of convex areas that act as the detected area can simply be increased, thus improving the detection accuracy of a crankshaft angle.

[0010] Furthermore, the outer diameter of the pulse generator ring is larger than the outer diameter of the AC generator rotor. Consequently, the number of convex areas that serve as the detection area can be more easily increased, thus further improving the detection accuracy of a crankshaft angle.

[0011] Furthermore, the convex areas, which serve as the detection area, are curved towards the axial direction of the crankshaft. Accordingly, a curved surface faces the magnetic sensor and is thus detected, thereby further improving the detection accuracy.

[0012] Since the annular plate area remains attached to a side surface of the AC generator rotor, and the convex areas, which function as the captured area, are curved towards an outer circumferential surface of the AC generator rotor, the curved portions of the convex areas can overlap the outer circumferential surface of the AC generator rotor in the axial direction of the crankshaft. Accordingly, the length of the device can be shortened by this amount in the axial direction.

[0013] In the crankshaft angle detection device, a convex area can be arranged circularly on the side surface of the AC generator rotor concentrically to the crankshaft, and an inner circumferential surface of the annular plate area can be in close contact with an outer circumferential surface of the circularly arranged convex area.

[0014] Since the pulse generator ring can be attached to the AC generator rotor with high accuracy in this design, the detection accuracy can be improved.

[0015] In the crankshaft angle detection device, a starter gear can be arranged on the crankshaft adjacent to the AC generator rotor, and the pulse generator ring can be located between the AC generator rotor and the starter gear.

[0016] In this design, the starter gear and the pulse generator ring, each with a relatively large diameter, are located close to the AC generator rotor, which also has a relatively large diameter. Consequently, space within a crankcase can be used effectively.

[0017] In the crankshaft angle detection device, the outer diameter of the pulse generator ring can be larger than the outer diameter of the starter gear.

[0018] In this design, the detected area is enlarged in diameter and even protrudes radially outwards from the start gear, so that a detection error in the magnetic sensor can be suppressed.

[0019] In the crankshaft angle detection device, a one-way clutch designed to transmit power from the starter gear to the crankshaft can be arranged adjacent to the side surface of the AC generator rotor, and the pulse generator ring can be located overlapping in the axial direction on an outer circumference of the one-way clutch.

[0020] With this design, the length of the device can be shortened in the axial direction. Fig. Figure 1 is a side view showing a main component of an embodiment of a crankshaft angle detection device of the present invention. Fig. 2 is a section view along line 2-2 of Fig. 1. Fig. 3A is a left-hand view of an AC generator rotor 20, and Fig. 3B is a section view along line bb of Fig. 3A. Fig. 4A is a right-hand view of the AC generator rotor 20, Fig. 4B is an enlarged section view along line bb of Fig. 4A, and Fig. 4C is an enlarged sectional view at line cc of Fig. 4A. Fig. 5A is a right-hand view of a pulse generator ring 30, Fig. 5B is a section view along line bb of Fig. 5A, Fig. 5C is a perspective view in the direction of c, with part of it omitted, and Fig. 5D is an explanatory view of a comparative example, corresponding to the perspective view in the direction of c. Fig. Figure 6 is an exemplary view of a positioning area in the circumferential direction of the pulse generator ring 30 with respect to the AC generator rotor 20.

[0021] The following is a description of embodiments of a crankshaft angle detection device of the present invention. In all drawings, the same reference numeral is used for the same or similar component.

[0022] As in Fig. 1 and Fig. Figure 2 shows a crankshaft angle detection device 1 of the present invention comprising a crankshaft 10, an alternating current generator rotor (ACG rotor) 20, a pulse generator ring made from a metal plate and a magnetic sensor 40.

[0023] The AC generator rotor 20 is held by one end of the crankshaft 10 and is rotated integrally with the crankshaft 10.

[0024] The pulse generator ring 30 has an annular plate area 31 (see Fig. 5A), and a detected area, formed from a plurality of convex areas 32, is formed on an outer circumference of the annular plate area 31. The annular plate area 31 is attached to the AC generator rotor 20, so that the pulse generator ring 30 rotates integrally with the AC generator rotor 20.

[0025] The magnetic sensor 40 is formed on an outer circumference of the pulse generator ring 30 in order to detect the detected area.

[0026] Since, according to the crankshaft angle detection device 1, the detected area is formed from convex areas 32 which are formed on the outer circumference of the pulse generator ring 30 made from a metal plate, which is rotated integrally with the AC generator rotor 20 by being attached to the AC generator rotor 20, the detection accuracy of a crankshaft angle can be improved.

[0027] As also in Fig. As shown in Figure 5, since the pulse generator ring 30 is made from a metal plate separate from the AC generator rotor 20, convex areas 32, which act as the detected areas, can be easily formed, for example by pressing.

[0028] Accordingly, the number of convex areas 32, which act as the detected area, can simply be increased, thus improving the detection accuracy of a crankshaft angle.

[0029] As in Fig. As shown in Figure 1, the outer diameter D2 of the pulse generator ring 30 is larger than the outer diameter D1 of the AC generator rotor 20.

[0030] In this configuration, the number of convex areas 32 that function as the detected area can be increased more easily, so that the detection accuracy of a crankshaft angle can be further improved.

[0031] As in Fig. 1 and Fig. As shown in Figure 2, the convex areas 32, which act as the detected area, are bent in the direction of the axial direction of the crankshaft 10.

[0032] In this configuration, a curved surface 32s faces the magnetic sensor 40 and is detected as the detected area, so that the detection accuracy can be further improved.

[0033] For example, it is like in Fig. In 5D representation, it is possible to capture the leading end surfaces 32c of the convex areas 32, even without them being bent in the direction of the axial direction of the crankshaft 10.

[0034] However, if, as in the present embodiment, the convex areas 32 are bent in the direction of the axial direction of the crankshaft 10, each bent surface 32s (see Fig. 5C), which has a larger area than any non-bent leading end face 32c, are detected by the magnetic sensor 40 as the detected area is facing it.

[0035] As in Fig. As shown in Figure 2, the annular plate area 31 is attached to a side surface 21 of the AC generator rotor 20, and the convex areas 32, which act as the captured area, are bent towards an outer circumferential side 22 of the AC generator rotor 20.

[0036] In this embodiment, the curved sections 32b of the captured sections 32 can overlap the outer circumferential surface 22 of the AC generator rotor 20 in the axial direction of the crankshaft 10. Accordingly, the length of the device can be shortened by this amount in the axial direction.

[0037] As in Fig. 3B and Fig. As shown in Figure 4A, convex areas 23 are arranged concentrically to the crankshaft 10 on the side surface 21 of the AC generator rotor 20. Fig. 2 and Fig. Figure 6 shows an inner circumferential surface 31s (see Fig. 5A and Fig. 5B) of the annular plate area 31 in close contact with the outer circumferential surfaces 23s of the circularly arranged convex areas 23.

[0038] Since the pulse generator ring 30 can be attached to the AC generator rotor 20 with high accuracy in this design, the detection accuracy can be improved.

[0039] As in Fig. As shown in 4A to 4C, a section area 23h is formed on one of the circularly arranged convex areas 23.

[0040] However, as in Fig. 5A and Fig. As shown in Figure 5B, a convex area (protrusion) 33, which protrudes inwards in the radial direction, is arranged on a part of the inner circumferential surface 31a of the annular plate area 31.

[0041] As in Fig. As shown in Figure 6, the inner circumferential surface 31s of the annular plate area 31 of the pulse generator ring 30 is in close contact with the outer circumferential surfaces 23s of the circularly arranged convex areas 23 of the AC generator rotor 20, with the convex area 33 being fitted into the cutout area 23h. Accordingly, the pulse generator ring 30 is positioned both circumferentially and relative to the AC generator rotor 20.

[0042] As in Fig. As shown in Figure 2, the pulse generator ring 30 is attached to the AC generator rotor 20 by fastening screws 30b. Fig. 4A to 6 are screw holes 20h for the screws 30b on the AC generator rotor 20 and through openings 30h are provided for this purpose on the pulse generator ring 30.

[0043] As in Fig. Figure 2 shows a starter gear 50 located on the crankshaft 10 next to the AC generator rotor 20. The pulse generator ring 30 is located between the AC generator rotor 20 and the starter gear 50.

[0044] In this configuration, the starter gear 50 and the pulse generator ring 30, each with a relatively large diameter, are located close to the AC generator rotor 20, which also has a relatively large diameter. Accordingly, space within a crankshaft housing 60 can be used effectively.

[0045] Furthermore, the outer diameter D2 of the pulse generator ring 30 is larger than the outer diameter D3 (see Fig. 2) of the starting tooth edge 50.

[0046] In this configuration, the convex areas 32, which function as the detected area, are enlarged in diameter and project radially outwards from the start gear 50. Accordingly, a detection error in the magnetic sensor 40 can be suppressed.

[0047] As in Fig. As shown in Figure 2, the crankshaft 10 can be rotatably held by the crankcase 60. The AC generator rotor 20 is attached to one end of the crankshaft 10 by fastening a screw 20b.

[0048] A stator 70 is arranged on the inside of the AC generator rotor 20. The AC generator rotor 20 and the stator 70 form an AC generator (ACG).

[0049] The stator 70 is attached to the crankcase 60 by a screw 70b, which also serves as an AC generator housing.

[0050] Magnets 24, which are arranged on the AC generator rotor 20, and coils, which are arranged on the stator 70, are in Fig. 2 shown.

[0051] As in Fig. As shown in Figure 2, the magnetic sensor 40 is attached to the inside of the crankcase 60.

[0052] The starter gear 50 is attached to the crankshaft 10 in such a way that it can only rotate in one direction via a one-way clutch 51 to transmit power from the starter gear 50 to the crankshaft 10. The starter gear 50 is driven to rotate by a starter motor (not shown) at the time of engine start.

[0053] The one-way coupling 51 is located adjacent to the side surface 21 of the AC generator rotor 20. The pulse generator ring 30 is located overlapping axially on an outer circumference of the one-way coupling 51.

[0054] With this design, the length of the device can be shortened in the axial direction.

[0055] As in Fig. As shown in Figure 2, a balance shaft 80 with a counterweight 81 is provided. The balance shaft 80 is rotatably mounted on the crankcase 60. The balance shaft 80 is driven to rotate by a driven gear 82 being driven by a drive gear 83 located in the crankshaft 10.

[0056] The present invention, which is not limited to the embodiment described above, can be appropriately modified within the scope of the present invention.

[0057] For example, in the embodiment discussed above, there are a plurality of convex areas 23 (6 pieces in Fig.4) arranged in a circular pattern on the side surface 21 of the AC generator rotor 20, in an interrupted manner concentric to the crankshaft 10. Here, the convex areas 23 can be formed in a continuous ring shape. 10 Crankshaft 20 AC generator rotor 21 side surface 22 External perimeter area 23 Circularly arranged convex area 30 Pulse generator ring 31 Ring-shaped plate area 32 Convex area (detected area) 40 Magnetic sensor 50 Starting gear

Claims

[1] Crankshaft angle detection device comprising: an alternating current generator rotor (20) which is held by one end of a crankshaft (10) and is designed to rotate integrally with the crankshaft (10); a pulse generator ring (30) made of a metal plate, having an outer diameter (D2) larger than an outer diameter (D1) of the AC generator rotor (20), wherein the pulse generator ring (30) has an annular plate region (31) and a detected region (32) having a plurality of convex regions (32) formed on an outer circumference of the annular plate region (31), which form a predetermined void between themselves and an outer circumferential surface (22) of the AC generator rotor (20), being curved in the direction of the outer circumferential surface (22) of the AC generator rotor (20) in an axial direction of the crankshaft (10), and is configured to rotate integrally with the AC generator rotor (20), wherein the annular plate region (31) is attached to a side surface (21) of the AC generator rotor (20); and a magnetic sensor (40) which is formed on an outer circumference of the pulse generator ring (30) and is designed to detect the detected area (32). [2] Crankshaft angle detection device according to claim 1, wherein a convex area (23) is arranged circularly on the side surface (21) of the AC generator rotor (20) concentrically to the crankshaft (10), and an inner circumferential surface (31s) of the ring-shaped plate area (31) is in close contact with an outer circumferential surface of the circularly arranged convex area (23). [3] Crankshaft angle detection device according to claim 1 or 2, wherein a starter gear (50) is arranged on the crankshaft (10) as being located next to the AC generator rotor (20), and the pulse generator ring (30) is located between the AC generator rotor (20) and the starter gear (50). [4] Crankshaft angle detection device according to claim 3, wherein the outer diameter (D2) of the pulse generator ring (30) is larger than the outer diameter (D3) of the starter gear (50). [5] Crankshaft angle detection device according to claim 3 or 4, wherein a one-way coupling (51) designed to transmit power from the starter gear (50) to the crankshaft (10) is arranged adjacent to the side surface (21) of the AC generator rotor (20), and The pulse generator ring (30) is located as overlapping in the axial direction on an outer circumference of the one-way coupling (51).

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