JP4563983B2 - Engine rotation angle detection device - Google Patents

Description

  According to the present invention, a rotor main portion surrounding at least a part of the camshaft is protruded from the rotor main portion at an axially intermediate portion of a camshaft having a valve cam and rotatably supported by a cylinder head. The present invention relates to an engine rotation angle detection device in which a pulsar rotor integrally having a detected protrusion is fixed, and a sensor for detecting the detected protrusion is fixed to a non-rotating portion of the engine in the vicinity of the pulsar rotor.

Patent Document 1 discloses that a pulsar rotor formed in an endless ring shape is fixed to a camshaft between a pair of valve cams adjacent in the axial direction.
JP 2004-116463 A

  However, when the pulsar rotor is formed in an endless ring shape as disclosed in Patent Document 1, the pulsar rotor is provided on the camshaft when the pulsar rotor is attached to the axially intermediate attachment portion of the camshaft. It is necessary to move the pulsar rotor along the axial direction of the camshaft so that the projection such as a valve cam passes, and the inner diameter of the pulsar rotor must be set large in order to allow the projection to pass therethrough. Absent. Thus, if the inner diameter is set large, the outer diameter of the pulsar rotor increases to ensure rigidity, and the detection protrusion needs to protrude relatively large from the outer periphery of the pulsar rotor in order to improve detection accuracy. As a result, the outer diameter of the rotation locus of the detected protrusion increases. Therefore, downsizing of the cylinder head is hindered.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an engine rotation angle detection device that enables a cylinder head to be made compact even when a pulsar rotor is fixed to a camshaft.

In order to achieve the above object, according to a first aspect of the present invention, at least a part of the camshaft is surrounded by an axially intermediate portion of the camshaft having a valve cam and rotatably supported by a cylinder head. A pulsar rotor integrally including a rotor main portion and a detected protrusion protruding from the rotor main portion is fixed, and a sensor for detecting the detected protrusion is disposed in a non-rotating portion of the engine in the vicinity of the pulsar rotor. In the engine rotation angle detection device to be fixed, the pulsar rotor is configured as a single component, and the rotor main part can be fitted to the camshaft in a direction perpendicular to the axis of the camshaft. is formed in a shape, the cam shaft, and the minimum diameter portion in which the outer diameter and minimum, than the small diameter and the minimum diameter portion than the outer peripheral diameter of rotational path of the valve operating cam (24) A fitting portion that is formed in a diameter and is adjacent to the minimum diameter portion in the axial direction and is fitted with the rotor main portion, and the fitting portion is sandwiched between the minimum diameter portion to fasten the pulsar rotor A flange portion, and a fitting surface between the fitting portion and the rotor main portion is formed on a cylindrical surface so that a centrifugal force applied to the pulsar rotor is received by the fitting portion, and the rotor main portion Is formed in an arc shape so as to cover the outer periphery of the fitting portion in a range exceeding 180 degrees, and the distance between both circumferential ends of the rotor main portion is set larger than the diameter of the minimum diameter portion. characterized in that that.

According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, a fastening boss portion for fastening the rotor main portion to the camshaft is provided at both circumferential ends of the rotor main portion of the pulsar rotor. It is characterized by being able to.

  According to a third aspect of the invention, in addition to the configuration of the first or second aspect of the invention, the pulsar rotor is fixed to the camshaft between a pair of cylinders adjacent to each other in the direction along the axis of the camshaft. It is characterized by that.

  Further, in the invention according to claim 4, in addition to the configuration of the invention according to any one of claims 1 to 3, a bolt for fastening the rotor main portion to the camshaft is provided on the rotor main portion of the pulsar rotor. A fastening boss portion having an insertion hole to be inserted is provided, and the detection protrusion is protruded from the fastening boss portion.

  The cylinder head 11 of the embodiment corresponds to the “non-rotating part of the engine” in the present invention.

According to the first aspect of the present invention, when the pulsar rotor is assembled to the camshaft, there is no need to pass a projection such as a valve cam provided on the camshaft through the rotor main portion of the pulsar rotor. can be reduced form the circumferential, outer diameter of the rotor main portion can also be reduced accordingly, it slaves, it is possible to compact cylinder head without lowering the detection accuracy, also Parusarota cam Assembly to the shaft is also easy . Moreover by displacing the fitting part side from the minimum diameter portion along the axis of the camshaft the rotor main portion of Parusarota was fitted to the smallest diameter portion of the cam shaft in a direction perpendicular to the axis of the camshaft, the rotor main The fitting portion is fitted to the fitting portion so as to cover a range exceeding 180 degrees on the outer periphery of the fitting portion, and a fitting surface between the fitting portion and the rotor main portion is formed on the cylindrical surface. since Parusarota in a state of fitting the rotor main part is to be fastened to the flange portion, the engaged state of the Parusarota can receive centrifugal force exerted on Parusarota in the fitting portion, thereby, the camshaft The strength of the member for fastening the pulsar rotor can be reduced, the weight can be reduced, and the positioning can be simplified at the time of fastening to increase the productivity.

  According to the invention described in claim 3, since the camshaft is not provided on the camshaft between a pair of adjacent cylinders, the camshaft is elongated in the axial direction even if the pulsar rotor is fixed to the camshaft. In addition, according to the configuration of the first aspect, even when the pulsar rotor is disposed between a pair of adjacent cylinders, the assembling property does not deteriorate.

  Furthermore, according to the fourth aspect of the invention, since the detection protrusion is protruded from the fastening boss provided in the rotor main portion, the detection accuracy of the detection protrusion can be improved and the rigidity can be ensured.

  Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 5 show an embodiment of the present invention, FIG. 1 is a plan view of a cylinder head, taken along line 1-1 in FIG. 2, and FIG. 2 is a line 2-2 in FIG. 3 is a side view showing the intake camshaft and the pulsar rotor before being assembled to the intake camshaft, FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, and FIG. 5 is 5-5 of FIG. It is line sectional drawing.

  1 and 2, this engine is a multi-cylinder engine having multiple cylinders, for example, first to fourth cylinders C1, C2, C3, and C4 arranged in series. The cylinder head 11 is coupled to the cylinder head 11. The valve operating chamber 13 formed between the head cover 12 and the head cover 12 accommodates a valve operating device 16 having an intake side camshaft 14 and an exhaust side camshaft 15 that are rotatably supported by the cylinder head 11.

  The intake side and exhaust side camshafts 14 and 15 extend in parallel along the arrangement direction of the first to fourth cylinders C1 to C4, and are at positions corresponding to each other between the first to fourth cylinders C1 to C4. It is rotatably supported between cam holders 17 provided on the cylinder head 11 and caps 18 fastened to the cam holders 17.

  The driven sprockets 19 and 20 are fastened to one end of the intake side and exhaust side camshafts 14 and 15 by a plurality of bolts 22. Thus, the driven sprockets 19 and 20 have a part of the timing transmission mechanism 21 for transmitting the rotational power of a crankshaft (not shown) to the intake side and exhaust side camshafts 14 and 15 at a reduction ratio of 1/2. Constitute.

  The intake side camshaft 14 includes intake side valve cams 24 individually corresponding to intake valves (not shown) arranged in pairs for the first to fourth cylinders C1 to C4, respectively. A pair of each is provided, and the exhaust side camshaft 15 has an exhaust side valve cam 25 individually corresponding to an exhaust valve (not shown) disposed in each of the first to fourth cylinders C1 to C4. Are provided for each of the cylinders C1 to C4.

  A pulsar rotor 28 is attached to the intake-side camshaft 14 at an axially intermediate attachment location on the intake-side camshaft 14, in this embodiment, at a portion corresponding to between the second and third cylinders C2 and C3. A sensor 35 that detects the three detected protrusions 30, 31, and 32 is fixed to the cylinder head 11 that is a non-rotating part of the engine in the vicinity of the pulsar rotor 28.

  At the mounting position in the axial direction of the intake side camshaft 14, the minimum diameter portion 36 having a minimum outer diameter and the minimum diameter portion 36 smaller than the outer diameter of the rotation restriction air of the intake side valve cams 24. There are provided a fitting portion 37 that has a larger diameter and is adjacent to the minimum diameter portion 36 in the axial direction, and a flange portion 38 that sandwiches the fitting portion 37 between the minimum diameter portion 36.

  3 and 4, the pulsar rotor 28 includes a rotor main portion 29 formed in a shape that allows fitting to the intake side camshaft 14 in a direction perpendicular to the axis of the intake side camshaft 14. The rotor main portion 29 integrally includes three detection protrusions 30 to 32 that protrude from the rotor main portion 29, and the rotor main portion 29 covers the outer periphery of the fitting portion 37 in the range of an angle α that exceeds 180 degrees. Thus, the distance L between the circumferential ends of the rotor main portion 29 is set larger than the diameter D of the minimum diameter portion 36.

  Referring also to FIG. 5, the flange portion 38 provided on the intake side camshaft 14 includes a ring plate portion 38 a projecting radially outward from the intake side camshaft 14, and a rotor main portion in the pulsar rotor 28. A pair of mounting plate portions 38b, 38b projecting radially outward from the ring plate portion 38a at positions corresponding to both circumferential end portions 29, are integrally formed. Are provided with screw holes 39, 39, respectively.

  Fastening boss portions 33, 33 are provided at both ends in the circumferential direction of the rotor main portion 29 of the pulsar rotor 28 corresponding to the mounting plate portions 38b ... of the flange portion 38 of the intake side camshaft 14, respectively. The fastening boss portions 33 are provided with insertion holes 34 corresponding to the screw holes 39 of the mounting plate portions 38b, respectively. Bolts 40 and 40 inserted into the insertion holes 34 are respectively connected to the screw holes 39. The pulsar rotor 28 is fastened to the intake camshaft 14 by being screwed together.

  In addition, a pair of detection protrusions 30 and 31 protrude from one of the fastening boss portions 33 and 33, and one detection protrusion 32 protrudes from the other fastening boss portion 33.

  The sensor 35 detects the rotational position of the intake camshaft 14 by detecting the passage of the detected protrusions 30 to 32 of the pulsar rotor 28 and faces the outer periphery of the pulsar rotor 28 from the outside in the radial direction. Thus, the cylinder head 11 is attached.

  Next, the operation of this embodiment will be described. A rotor main portion 29 is provided at an axially intermediate portion of an intake side camshaft 14 having a plurality of intake side valve cams 24... And the pulsar rotor 28 integrally having the three detected protrusions 30 to 32 protruding from the rotor main portion 29 are fixed. The rotor main portion 29 is aligned with the axis of the intake side camshaft 14. It is formed in a shape that allows the intake side camshaft 14 to be fitted in a direction orthogonal to each other.

  Therefore, when the pulsar rotor 28 is assembled to the intake side camshaft 14, it is not necessary to allow the protrusions such as the intake side valve cams 24 ... provided on the intake side camshaft 14 to pass through the rotor main portion 29 of the pulsar rotor 28. The inner periphery of the main part 29 can be formed small, and the outer diameter of the rotor main part 29 can be reduced accordingly. Therefore, the cylinder head 11 can be made compact without degrading the detection accuracy, and the assembly work of the pulsar rotor 28 to the intake side camshaft 14 is facilitated.

In addition, the intake side camshaft 14 is formed with a minimum diameter portion 36 having a minimum outer diameter and a diameter smaller than the outer peripheral diameter of the rotation locus of the intake side valve cams 24 and larger than the minimum diameter portion 36. Between the fitting portion 37 adjacent to the smallest diameter portion 36 in the axial direction and to which the rotor main portion 29 is fitted, and the fitting portion 37 between the smallest diameter portion 36 for fastening the pulsar rotor 28. A sandwiching flange portion 38 is provided, and a fitting portion between the rotor main portion 29 and the fitting portion 37 is formed on a cylindrical surface. The rotor main portion 29 is formed in an arc shape so as to cover the outer periphery of the fitting portion 37 in a range of an angle α exceeding 180 degrees, and the distance L between the circumferential ends of the rotor main portion 29 is the minimum diameter. It is set larger than the diameter D of the portion 36.

  Therefore, the rotor main portion 29 of the pulsar rotor 28 attached to the minimum diameter portion 36 of the camshaft in the direction orthogonal to the axis of the intake side camshaft 14 is fitted from the minimum diameter portion 36 to the fitting portion along the axis of the intake side camshaft 14. The rotor main portion 29 is fitted to the fitting portion 37 so as to cover a range exceeding 180 degrees on the outer periphery of the fitting portion 37 by displacing the rotor main portion 29 to the fitting portion 37. The pulsar rotor 28 is fastened to the flange portion 38 in the fitted state.

  In this state, when the pulsar rotor 28 is fastened to the flange portion 38, the centrifugal force applied to the pulsar rotor 28 can be received by the fitting portion 37. Therefore, a member that fastens the pulsar rotor 28 to the intake camshaft 14, that is, the flange portion 38. In addition, the strength of the bolts 40 can be reduced, the weight can be reduced, and the positioning can be simplified at the time of fastening to increase the productivity.

  Further, the pulsar rotor 28 is fixed to the intake side camshaft 14 between the second and third cylinders C2 and C3 adjacent to each other in the direction along the axis of the intake side camshaft 14. Since the intake side camshaft 14 is not provided with the intake side valve cams 24 between the three cylinders C2 and C3, the intake side camshaft 14 is elongated in the axial direction even if the pulsar rotor 28 is fixed to the intake side camshaft 14. Never become. Moreover, since the rotor main portion 29 of the pulsar rotor 28 is formed in a shape that enables fitting to the intake side camshaft 14 in a direction perpendicular to the axis of the intake side camshaft 14, the adjacent second and second Even if the pulsar rotor 28 is disposed between the third cylinders C2 and C3, the assemblability does not deteriorate.

  Further, a pair of fastening boss portions 33 having insertion holes 34 through which the bolts 40 for fastening the rotor main portion 29 to the flange portion 38 of the intake side camshaft 14 are inserted in the rotor main portion 29 of the pulsar rotor 28. Since the pair of detection projections 30 and 31 protrude from one fastening boss portion 33 and one detection protrusion 32 protrudes from the other fastening boss portion 34, the detection protrusion While increasing the detection accuracy of 30 to 32, rigidity can be ensured.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

  For example, the present invention can also be applied to a sensor 35 that is fixed to the head cover 12 that is a non-rotating part of the engine in the vicinity of the pulsar rotor 28.

FIG. 3 is a plan view of the cylinder head and is a view taken along line 1-1 in FIG. 2. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a side view which shows the pulsar rotor before being assembled | attached to an intake side camshaft and this intake side camshaft. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG.

DESCRIPTION OF SYMBOLS 11 ... Cylinder head 14 ... Intake side camshaft 28 ... Pulsar rotor 29 ... Rotor main part 30, 31, 32 ... Detection protrusion 33 ... Fastening boss part 34 ... Insertion Hole 35 ... Sensor 36 ... Minimum diameter part 37 ... Fitting part 38 ... Flange part 40 ... Bolts C2, C3 ... Cylinder

Claims (4)

A rotor main portion (at least part of the camshaft (14)) is provided at an axially intermediate portion of the camshaft (14) having a valve cam (24) and rotatably supported by the cylinder head (11). 29) and the pulsar rotor (28) integrally including the detected protrusions (30, 31, 32) protruding from the rotor main portion (29) are fixed, and the detected protrusions (30 to 32) are In the engine rotation angle detection device in which the sensor (35) for detection is fixed to the non-rotation part (11) of the engine in the vicinity of the pulsar rotor (28),
The Parusarota (28) with is configured as a single part, the rotor main portion (29), enabling fitted to the cam shaft (14) in a direction perpendicular to the axis of the camshaft (14) Formed into a shape ,
The camshaft (14) has a minimum diameter portion (36) having a minimum outer diameter and a diameter smaller than the outer peripheral diameter of the rotation locus of the valve cam (24) and larger than the minimum diameter portion (36). A fitting portion (37) formed in a diameter and adjacent to the minimum diameter portion (36) in the axial direction and fitted with the rotor main portion (29), and the fitting to fasten the pulsar rotor (28) A flange portion (38) sandwiching the joint portion (37) with the minimum diameter portion (36) is provided, and the centrifugal force applied to the pulsar rotor (28) can be received by the fitting portion (37). Thus, the fitting surface between the fitting portion (37) and the rotor main portion (29) is formed in a cylindrical surface,
The rotor main portion (29) is formed in an arc shape so as to cover the outer periphery of the fitting portion (37) in a range exceeding 180 degrees, and between the circumferential ends of the rotor main portion (29). The engine rotation angle detecting device, wherein the distance (L) is set larger than the diameter (D) of the minimum diameter portion (36) . A fastening boss portion (33) for fastening the rotor main portion (29) to the camshaft (14) is provided at both circumferential ends of the rotor main portion (29) of the pulsar rotor (28). The engine rotation angle detection device according to claim 1.   The pulsar rotor (28) is fixed to the camshaft (14) between a pair of cylinders (C2, C3) adjacent to each other in a direction along the axis of the camshaft (14). Or the engine rotation angle detection device of 2.   A fastening boss having an insertion hole (34) through which a bolt (40) for fastening the rotor main portion (29) to the camshaft (14) is inserted into the rotor main portion (29) of the pulsar rotor (28). A rotation angle of the engine according to any one of claims 1 to 3, wherein a part (33) is provided, and the detected protrusion (30 to 32) protrudes from the fastening boss part (33). Detection device.

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