JP5277232B2 - Pulsar plate mounting structure - Google Patents

Description

  According to the present invention, a key groove is formed on an end surface of a rotating wall portion made of a crank arm and a counterweight of a crankshaft for an internal combustion engine, and a key portion that engages with the key groove is formed on a pulsar plate that is overlaid on the end surface. The present invention relates to an improvement in the mounting structure of the pulsar plate, which is formed by press molding and is fixed to the rotating wall portion by a fixing member.

  Such a pulsar plate mounting structure is already known, as disclosed in Patent Document 1.

Japanese Patent Laid-Open No. 10-331681

  In the conventional pulsar plate mounting structure, the key portion is composed of an L-shaped bent portion cut and raised from the pulsar plate to one end face side thereof.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a pulsar plate mounting structure with high pulsar plate positioning accuracy with respect to a crankshaft and good pulsar plate productivity.

In order to achieve the above object, the present invention provides a plurality of screw holes arranged at intervals in the circumferential direction on an end surface of a rotating wall portion comprising a crank arm and a counterweight of a crankshaft for an internal combustion engine, a key groove, The pulsar plate stacked on the end surface is provided with a plurality of bolt holes respectively corresponding to the plurality of screw holes and a key portion that engages with the key groove, and the pulsar plate is attached to the rotating wall. In the pulsar plate mounting structure, which is fixed to the portion by a bolt inserted into the bolt hole and screwed into the screw hole, the key portion is adjacent to the two in the circumferential direction of the pulsar plate. between the bolt holes, the said key groove and said key unit are engaged with each other are arranged at positions biased to one of the bolt hole side from between the circumferential center position, their length The direction of the key groove is arranged along a radial line of the pulsar plate, and both side surfaces of the key portion extending along the radial line of the key groove are densely connected to both inner side surfaces of the key groove extending along the radial line. A first feature is that the pulsar plate is provided with a long hole facing the both side surfaces of the key portion .

The end face of the rotating wall portion, that corresponds to the mounting surface 10 in the embodiment of the present invention to be described later.

In addition to the first feature of the present invention, the key portion is integrally formed with the pulsar plate so as to bend and deform a part of the pulsar plate toward the rotating wall portion. A second feature is that a tangent to the tip surface extends along a radial direction of the pulsar plate.

The present invention, in addition to the first or second feature, the pulser plate, a third feature in that both side surfaces of the key portion is bored long holes facing each.

Further, according to the present invention, in addition to any one of the first to third features, the circumferential distance between the plurality of bolt holes is not equal, and the key portion is spaced circumferentially between the plurality of bolt holes. The fourth feature is that the two bolt holes are arranged so as to avoid the gap between the two bolt holes arranged at the maximum circumferential interval.

According to the onset Ming, the keyway and the key part, will be both side surfaces extending in the radial direction of the pulser plate abuts in a wide range of one another, a predetermined circumferential position of the pulser plate relative to the crankshaft, more precisely Can be held . In addition, the key groove and the key portion are arranged so that their longitudinal directions are along the radius line of the pulsar plate, and both side surfaces of the key portion are closely fitted to both inner side surfaces of the key groove extending along the radius line. As a result, both side surfaces of the key groove and the key portion extending in the radial direction of the pulsar plate abut on each other in a wide range, and the predetermined circumferential direction position of the pulsar plate with respect to the crankshaft is more accurately maintained. be able to.

Further, the pulsar plate is provided with a long hole facing both side surfaces of the key portion, and the key portion can be easily pressed without being resisted by the pulsar plate body.

The principal part vertical side view of the crankshaft for internal combustion engines provided with the attachment structure of the pulsar plate of this invention. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1. FIG. 3 is an enlarged sectional view taken along line 3-3 in FIG. 2.

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

  1 is a longitudinal sectional side view of a main part of a crankshaft for an internal combustion engine equipped with a pulsar plate mounting structure according to the present invention, FIG. 2 is a sectional view taken along arrow 2 in FIG. 1, and FIG. FIG.

  1 and 2, the crankshaft C is for a multi-cylinder internal combustion engine, and a plurality of journals 1 supported by a plurality of main bearings of the crankcase and a plurality of connecting rods connected to the large ends. And a plurality of crank arms 3 that integrally connect the adjacent journal 1 and crank pin 2 to each other. Each crank arm 3 includes a crank arm 3 sandwiching the central axis of the journal 1. A counterweight 4 extending in the opposite direction is integrally provided. At one end of the crankshaft C, a flange 5 to which a driven member such as a crank pulley or a flywheel is bolted is formed.

  As shown in FIG. 2, the crank arm 3 is formed to be narrow along the circumferential direction, and the counterweight 4 is formed to be wide along the circumferential direction, and the crank wall 3 and the counterweight 4 form a rotating wall portion 9. Composed. A pulsar plate P formed by press-molding a magnetic metal plate is attached to the outermost rotating wall 9 on the flange 5 side. The pulsar plate P has a large number of protrusions 7 arranged on its outer periphery, and a rotation sensor (not shown) installed on the engine body is disposed opposite the outer peripheral surface.

  Thus, the rotation sensor incorporates a Hall element and a magnet in its detection part. When the pulsar plate P rotates with the crankshaft C, the magnetic fluctuation in the rotation sensor is converted into an electrical signal by the Hall element. By converting and calculating it, the rotational position, rotational speed, rotational acceleration, etc. of the crankshaft C can be known.

  Now, a structure for attaching the pulsar plate P to the rotating wall portion 9 of the crankshaft C will be described with reference to FIGS.

  As shown in FIG. 1, on the outer end surface of the outermost rotating wall portion 9, an annular positioning step portion 8 having a diameter larger than the flange 5 and concentric with the journal 1, and the crank arm 3 from the root of the annular positioning step portion 8. And the attachment surface 10 which spreads in the radial direction toward the counterweight 4 is formed. Slopes 3a for reducing the thickness of the crank arm 3 are formed on both sides of the outer surface of the crank arm 3 along the rotation direction. For this reason, the mounting surface 10 is on the counterweight 4 side on the crank arm 3 side. It is narrower than that.

  As shown in FIGS. 1 and 2, the mounting surface 10 is provided with a plurality (four in the illustrated example) of recesses 12 having the same shape (circular in the illustrated example) arranged in the circumferential direction. In that case, the four recessed parts 12 are arrange | positioned so that each circumferential direction space | interval S1, S2 of at least 1 recessed part 12 and the other recessed part 12 adjacent to the both sides of this one recessed part 12 may mutually differ. . In the case of the illustrated example, the four recesses 12 are arranged on the virtual circle 20 concentric with the journal 1 so that the circumferential intervals between the adjacent recesses 12 are all different. A screw hole 13 is formed in each central portion of the four recesses 12. Further, a key groove 14 is formed at a predetermined location on the mounting surface 10 on the counterweight 4 side. At that time, the key groove 14 is arranged so that the longitudinal direction thereof follows the radius line of the pulsar plate P.

  On the other hand, the pulsar plate P has a positioning hole 11 that fits into the annular positioning step 8 at the center thereof, and also fits into the four recesses 12 so as to surround the positioning hole 11. Four bottom cylindrical bosses 15 are formed, and bolt holes 17 corresponding to the screw holes 13 of the respective recesses 12 are provided at the bottom of each boss 15.

  Further, the pulsar plate P is integrally formed with a key portion 16 that engages with the key groove 14. The key portion 16 includes an arched belt-like portion 16a protruding from the pulsar plate P toward one end surface thereof, and a pair of connecting portions 16b that integrally connect both ends of the arched belt-like portion 16a to the pulsar plate P. Similarly to the key groove 14, the bow-like band-shaped portion 16 a is arranged so that its longitudinal direction is along the radial direction of the pulsar plate P, and is fitted between both inner side surfaces of the key groove 14. (See FIG. 3). When the bow-like band portion 16a is closely fitted in the key groove 14, all the bosses 15 of the pulsar plate P are loosely fitted in all the concave portions 12 of the mounting surface 10.

Further, as shown in FIG. 2, the key portion 16 is disposed between two bolt holes 17 adjacent to each other in the circumferential direction of the pulsar plate P (that is, between the bolt hole 17 at the right end and the bolt hole 17 at the lower end in FIG. 2). Is arranged at a position deviated from the circumferential center position toward the one bolt hole 17 side .

  When the key portion 16 is formed, first, a pair of long holes 19 (see FIG. 2) are punched into the pulsar plate P so that both side surfaces of the key portion 16 face each other, and then an arcuate belt-shaped portion 16a sandwiched between the long holes 19 is formed. Is formed in the protruding direction of the boss 15 in the form of a bow, whereby the bow-shaped strip 16a can be easily formed without being resisted by the pulsar plate body.

  Next, the operation of this embodiment will be described.

  In attaching the pulsar plate P to the attachment surface 10 of the rotating wall 9, first, the positioning hole 11 of the pulsar plate P is fitted into the annular positioning step 8 of the rotating wall 9 from the flange 5 side of the crankshaft C. . At that time, the key portion 16 of the pulsar plate P is engaged with the key groove 14 of the mounting surface 10, and each boss 15 of the pulsar plate P is fitted into the corresponding recess 12 of the mounting surface 10, while the pulsar plate P is placed on the mounting surface 10. Next, if the bolts 18 inserted into the respective bolt holes 17 are screwed into the screw holes 13 and tightened, the pulsar plate P can be accurately attached to the fixed position of the mounting surface 10. At that time, the heads 18a of the bolts 18 are accommodated in the corresponding bosses 15 and do not become protrusions from the outer end surface of the pulsar plate P. Therefore, the pulsar plate P is disposed close to the inner wall of the crankcase. to enable.

  By the way, the key portion 16 of the pulsar plate P has an arched belt-like portion 16a that protrudes from the pulsar plate P toward one end surface and engages the key groove 14, and both ends of the arched belt-like portion are connected to the pulsar plate P. Since it is comprised with a pair of connection part 16b connected integrally, it can be supported by the pulsar plate P by a double-sided type, and can be provided with high rigidity. Therefore, in cooperation with the key groove, the circumferential positioning accuracy with respect to the mounting surface 10 of the pulsar plate P, that is, the crankshaft C can be increased. In addition, since the sharpened tip portion does not exist in the both-end key portion 16, finishing processing such as chamfering is unnecessary after press working, and the productivity of the pulsar plate P can be increased.

  In particular, the key groove 14 and the bow-shaped band portion 16a that are fitted to each other are disposed along the radial direction of the pulsar plate P. Therefore, the bow-shaped band-shaped section 16a is formed on both inner side surfaces of the key groove 14 extending along the radial direction. Thus, both side surfaces along the same radial direction come into close contact with each other in a wide range, and the predetermined circumferential position of the pulsar plate P with respect to the crankshaft C can be held more accurately.

  As described above, the mounting surface 10 is wider on the counterweight 4 side than the crank arm 3 side. Therefore, when the key groove 14 is formed on the mounting surface 10 on the counterweight 4 side, the formation position is selected in a wide range. This increases the degree of freedom in design and is advantageous in positioning the pulsar plate P. In addition, when the key groove 14 is formed, it is not necessary to build up the mounting surface 10, so that the productivity is good and the collapse of the weight balance due to the build up of the crankshaft C can be prevented.

  Furthermore, the fixing portions of the pulsar plate P and the rotating wall portion 9 by the bolts 18, that is, the recesses 12 and the bosses 15 are provided at a plurality of locations aligned in the circumferential direction of the pulsar plate P, and at least one fixing portion 12, 15, Since the circumferential distances S1 and S2 between the fixing portions 12 and 15 adjacent to both sides of the one fixing portion 12 and 15 are different from each other, the pulsar for the rotating wall portion 9 is arranged. Since the mounting position of the plate P is limited to one place, it is possible to prevent erroneous assembly, and thus it is possible to prevent damage to the key portion 16 due to erroneous assembly.

  The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the invention. For example, at least two fixing portions of the pulsar plate P and the rotating wall portion 9 by the bolt 18 may be provided. In the case of only two locations, if the circumferential intervals on both sides of the two fixing portions are different, an error may occur. Assembly can be prevented.

C ... Crankshaft P ... Pulsar plate 2 ... Crank pin 3 ... Crank arm 4 ... Counter weight 9 ... Rotary wall 10 ... End face (attachment) surface)
12 ... recess 14 ... keyway 15 ... boss 16 ... key 18 ... bolt 18a ... head 19 ... long hole

Claims (4)

A plurality of screw holes (13) arranged at intervals in the circumferential direction on the end surface (10) of the rotating wall (9) comprising the crank arm (3) and the counterweight (4) of the crankshaft (C) for the internal combustion engine. ) And a key groove (14), and a pulsar plate (P) overlapped with the end face (10) has a plurality of bolt holes (17) respectively corresponding to the plurality of screw holes (13). A key portion (16) that engages with the key groove (14), and the pulsar plate (P) is inserted into the rotating wall portion (9) through the bolt hole (17) and the screw hole ( 13) In the mounting structure of the pulsar plate fixed by the bolt (18) screwed to
The key portion (16) is biased between the two bolt holes (17) adjacent to each other in the circumferential direction of the pulsar plate (P) from the circumferential center position therebetween to one bolt hole (17) side. disposed position,
The key groove (14) and the key portion (16) that are engaged with each other are arranged such that their longitudinal directions are along the radius line of the pulsar plate (P), and the key groove (14) Both side surfaces of the key portion (16) extending along the radial line are closely fitted to both inner side surfaces extending along the radial line,
Wherein the pulser plate (P), the sides faces the long hole (19) is characterized in that it is bored, the attachment structure of the pulser plate of the key portion (16). In the pulsar plate mounting structure according to claim 1 ,
The key portion (16) is formed integrally with the pulsar plate (P) so as to bend and deform a part of the pulsar plate (P) toward the rotating wall portion (9). The pulsar plate mounting structure is characterized in that the tangent to the tip surface of the pulsar plate extends along the radial direction of the pulsar plate (P). In the mounting structure of the pulsar plate according to claim 1 or 2 ,
The pulsar plate mounting structure, wherein the pulsar plate (P) is provided with long holes (19) facing both side surfaces of the key portion (16). In the attachment structure of the pulsar plate according to any one of claims 1 to 3 ,
The circumferential intervals between the plurality of bolt holes (17) are not equal, and the key portion (16) has the largest circumferential interval among the circumferential intervals between the plurality of bolt holes (17). A structure for attaching a pulsar plate, characterized in that it is arranged so as to avoid a space between two bolt holes (17) arranged side by side.

Images