JP4845595B2 - Pump drive system in engine - Google Patents

Description

  The present invention relates to an improvement in a pump drive device in an engine in which a pump shaft of a pump attached to an engine body is driven by a valve cam shaft supported by the engine body.

Conventionally, in an engine, a pump shaft of a pump attached to an engine main body is driven by a valve cam shaft supported by the engine main body in Patent Document 1, and a valve cam shaft, A device in which a pulsar rotor for generating a pulse is fixed to a pulsar coil attached to an engine body is already known as disclosed in Patent Document 2, respectively.
No. 56-27367 JP-A-6-117289

  In the conventional engine, the pump driving device and the mounting structure of the pulsar rotor are individually provided independently of each other, so that the number of parts is large and it is difficult to reduce the cost.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a pump drive device for an engine that has a small number of parts and is inexpensive by driving a pump using a pulsar rotor mounting structure. Objective.

In order to achieve the above object, according to the present invention, there is provided a pump drive device for an engine, wherein a pump shaft of a pump attached to the engine body is driven by a valve cam shaft supported by the engine body. The pump chamber is formed between a pump housing fixed to the engine body with a pump bolt and a pump cover coupled to the pump housing. The pump housing is coaxial with the camshaft. And a bearing hole for rotatably fitting an intermediate portion of the pump shaft, and a ring-shaped pulsar rotor is fitted to a boss portion protruding from one end surface of the cam shaft so as not to be relatively rotatable. , the Parusarota is fixed to the boss portion by Parusarota bolt screwed into the cam shaft through the Parusarota, this The end face of the head of Parusarota bolt, the wrench with matable square holes are provided, at one end of said pump shaft, square shaft portion for relative rotation directly fitted to the rectangular holes is integrally In the inner rotor in the pump chamber, a shaft hole for fitting the other end of the pump shaft is formed, and in the notch-shaped key groove formed in the inner rotor so as to open to the shaft hole, A pin-shaped key provided at the other end of the pump shaft is engaged, and the pump shaft and the inner rotor are connected to each other through the key and the key groove so as not to be relatively rotatable. The cam of the pulsar rotor bolt threaded shank screwed into the shaft, the load of the pump upon rotation of the cam shaft and feature to be formed to act as a tightening direction of the torque to the Parusarota bolt.

Incidentally, the engine body corresponds to the cylinder head 11 in an embodiment of the present invention which will be described later, also the pump that corresponds to the oil pump 21.

According to the onset bright, Parusarota bolt to secure the Parusarota the end of the cam shaft is supposed to serve as a joint member for connecting the camshaft to the pump shaft, a dedicated joint for connecting the oil pump to the camshaft Since no member is required, the oil pump can be driven with a simple structure having a small number of parts, and the cost of the drive device can be reduced.

In particular, the fitting part on the bolt side for the pulsar rotor is composed of a square hole for wrench fitting provided on the head of the bolt, so that a special connecting part for connecting to the pump shaft is formed on the bolt. Therefore, the structure of the drive device can be further simplified, and the fitting of the square hole of the pulsar rotor bolt and the square shaft portion of the pump shaft enables transmission of a large torque, The durability of these fitting portions can be improved . Furthermore during the driving of the pump by the cam shaft, always the torque tightening direction acts on Parusarota bolt, thus it is possible to prevent the loosening of Parusarota bolt.

  Embodiments of the present invention will be described below based on preferred embodiments of the present invention shown in the drawings.

  1 is a side view of an outboard motor equipped with the pump drive device of the present invention, FIG. 2 is an enlarged sectional view of two parts (pump drive device portion) of FIG. 1, and FIG. 3 is a sectional view taken along line 3-3 of FIG. 4 is an exploded perspective view of the main part of FIG. 2, FIG. 5 is a sectional view taken along line 5-5 in FIG. 2, and FIG. 6 is a sectional view taken along line 6-6 in FIG.

  First, in FIG. 1, a vertical swivel shaft 4 attached to an outboard motor O via an upper arm 2 and a lower arm 3 is disposed immediately before the casing 1, and the swivel shaft 4 is rotatably supported. The swivel case 5 is connected to a stern bracket 6 clamped to the transom Bt of the hull via a tilt shaft 7 in the horizontal direction. Therefore, the casing 1 can be steered left and right around the swivel shaft 4 and can be tilted up and down around the tilt shaft 7. A water-cooled four-stroke engine E covered with a detachable engine hood 8 is mounted on the upper portion of the casing 1.

  The engine E is mounted with the vertically placed crankshaft 10 close to the swivel shaft 5 and the cylinder head 11 facing rearward. In the casing 1, a vertical output shaft 12 driven by a crankshaft 10 and a horizontally disposed propeller shaft 14 driven from the output shaft 12 via a forward / reverse switching gear device 13 are disposed. A propeller 15 is attached to the rear end of the shaft 14 protruding from the casing 1. Further, an oil tank 9 for storing oil for lubricating the engine E is disposed in the casing 1.

  The cylinder head 11 of the engine E is supported by a camshaft 20 for valve drive, which is driven from the crankshaft 10 through a timing transmission device 19 with a reduction ratio of 1/2, in a posture parallel to the crankshaft 10. An oil pump 21 driven by the cam shaft 20 is attached to the lower part of the cylinder head 11. The oil pump 21 sucks up the oil in the oil tank 9 and supplies it to the lubrication part of the engine E.

  The oil pump 21 and its driving device will be described with reference to FIGS.

  2 to 4, a pulsar rotor 22 having a plurality of protrusions 22a, 22a... Formed at predetermined positions on the outer peripheral surface is fixed to the lower end of the camshaft 20 by bolts 23 as follows. The pulsar rotor 22 is provided with a mounting hole 22b at its center and a positioning recess 22c concentric with the mounting hole 22b on its upper surface, and a key 22d is integrally projected from the inner peripheral surface of the positioning recess 22c. On the other hand, a boss 20a concentric with the lower end surface of the camshaft 20 is integrally projected. The boss 20a is provided with a screw hole 20b at the center thereof and a key groove 20c at the outer peripheral surface thereof. The head 23a of the bolt 23 is provided with a wrench-fitting square hole, preferably a hexagonal hole 23c, which opens at the center of the lower end surface thereof.

  In fixing the pulsar rotor 22 to the cam shaft 20, the positioning recess 22c of the pulsar rotor 22 is fitted to the boss 20a portion of the cam shaft 20, and the key 22d is fitted to the key groove 20c, and the bolt 23 inserted through the mounting hole 22b is inserted. The screw shaft portion 23b is screwed into the screw hole 20b and tightened. The screwing operation of the bolt 23 is performed by a wrench fitted into the hexagon hole 23c of the head portion 23a.

  A pulsar coil 25 (see FIG. 3) facing the outer peripheral surface of the pulsar rotor 22 is fixed to the cylinder head 11 with bolts 26. The pulsar coil 25 generates a pulse signal every time each projection 22a on the outer periphery of the pulsar rotor 22 passes immediately before (that is, at a predetermined crank position or piston position). The pulsar signal is used for various controls of the engine E. It is used for operation of equipment such as an ignition device and a fuel injection device.

  2, 5, and 6, an oil pump 21 that is driven from the cam shaft 20 through the bolt 23 is attached to the lower portion of the cylinder head 11. The oil pump 21 has a pump housing 28 fixed to the lower end surface of the cylinder head 11 by a plurality of bolts 27, 27. The pump housing 28 is provided with a positioning cylindrical portion 28a, a bearing hole 28b arranged coaxially with the positioning cylindrical portion 28a, and a circular pump chamber 28c eccentric from the bearing hole 28b by a certain distance. The positioning cylindrical portion 28 a is fitted into a positioning hole 11 a that is open on the lower surface of the cylinder head 11 and is coaxial with the cam shaft 20. Therefore, in the fitted state, the bearing holes 28b are also arranged coaxially with the cam shaft 20. The positioning hole 11a has a shoulder portion 11b with which a flange 20d formed on the outer periphery of the lower end portion of the cam shaft 20 abuts. The positioning cylindrical portion 28a cooperates with the shoulder portion 11b, and the flange 20d, that is, the cam. It also serves to regulate the axial movement of the shaft 20.

  An outer rotor 30 is rotatably fitted in the pump chamber 28c, and an inner rotor 31 that meshes with the outer rotor 30 on one side is disposed inside the outer rotor 30. The inner rotor 31 is fitted into the shaft hole 31a of the inner rotor 31 and is fitted to the inner rotor 31. The pump shaft 32 to be driven is rotatably supported in the bearing hole 28b.

  One end of the pump shaft 32 is integrally formed with a hexagonal shaft portion 32a that fits into the hexagonal hole 23c of the head portion 23a of the bolt 23, and the other end is opened to the shaft hole 31a of the inner rotor 31. A pin-like key 33 (see FIG. 4) is provided to engage with the notch-like key groove 31b. Thus, the pump shaft 32 is connected to the camshaft 20 via the bolt 23 and also connected to the inner rotor 31 via the key 33.

  A pump cover 34 for closing the pump chamber 28c is joined to the lower surface of the pump housing 28 by a plurality of bolts 35, 35. The screw shaft portion 23b of the bolt 23 that is screwed to the cam shaft 20 is formed so that the load of the oil pump 21 acts as a torque in the tightening direction on the bolt 23 when the cam shaft 20 rotates. Thus, the oil pump 21 is configured as a trochoid type.

  As shown in FIGS. 5 and 6, the pump housing 28 is provided with a suction port 36 and a discharge port 37. A suction pipe 38 (FIG. 1) is immersed in the stored oil in the oil tank 9 in the suction port 36. The discharge port 37 is connected to a lubricating oil passage (not shown) connected to the lubricating portion of the engine E. Therefore, the oil pump 21 can suck up the oil in the oil tank 9 through the suction port 36 by the cooperation of the inner rotor 31 and the outer rotor 30 and supply the oil to the lubricating portion of the engine E through the discharge port 37. In FIG. 5, reference numeral 39 denotes a relief valve.

  Next, the operation of this embodiment will be described.

  During operation of the engine E, the rotation of the camshaft 20 for valve actuation is transmitted to the pulsar rotor 22 fixed to the lower end portion of the camshaft 20 with the bolt 23 and the hexagonal hole 23c of the head 23a of the bolt 23. Are also transmitted to the pump shaft 32 fitted with the hexagonal shaft portion 32a to rotationally drive them. Thus, according to the rotation of the pulsar rotor 22, the pulsar coil 25 generates a pulse signal for operating various control devices at a predetermined crank position or piston position as described above, and the pump shaft 32 is rotated. For example, as described above, the oil in the oil tank 9 is sucked up by the cooperation of the inner rotor 31 and the outer rotor 30 and supplied to the lubricating portion of the engine E.

  Thus, the bolt 23 that fixes the pulsar rotor 22 to the end of the camshaft 20 serves as a joint member and connects the camshaft 20 to the pump shaft 32 of the oil pump 21, so that the oil pump 21 is connected to the camshaft 20. Therefore, the oil pump 21 can be driven with a simple structure with a small number of parts, and the cost of the driving device can be reduced. In particular, the connection structure of the bolt 23 and the pump shaft 32 is obtained by fitting a wrench-fitting hexagonal hole 23 c provided in the head 23 a of the bolt 23 and a hexagonal shaft portion 32 a formed at one end of the pump shaft 32. Since it is configured, it is not necessary to specially form a fitting portion for connection with the pump shaft 32 in the bolt 23, and therefore, it can contribute to further simplification of the structure of the drive device. The screw bolt 23 hexagonal hole 23c and the hexagonal shaft portion 32a of the pump shaft 32 can secure a wide fitting surface, enable transmission of large torque, and improve the durability of the fitting portion. .

  Further, the screw shaft portion 23b of the bolt 23 screwed to the cam shaft 20 is formed so that the load of the oil pump 21 acts as a torque in the tightening direction on the bolt 23 when the cam shaft 20 rotates. While the oil pump 21 is being driven, a torque in the tightening direction always acts on the bolt 23, and the bolt 23 can be prevented from loosening.

  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, the pump drive device of the present invention can also be applied to drive a water pump.

The side view of an outboard motor provided with the pump drive device of the present invention. The expanded sectional view of 2 parts (pump drive device part) of FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. The disassembled perspective view of the principal part of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG.

E .... Engine 11 ... Engine body (cylinder head)
20 ... Camshaft 21 ... Pump (oil pump)
22... Pulsar rotor 23... Pulsar rotor bolt 23 a... Head 23 b... Screw shaft portion 23 c.
27 ... Bolt for pump
28 ... Pump housing
28b ... Bearing hole
28c ... Pump room
31 ... Inner rotor
31a ... ・ Shaft hole
31b ··· Notched keyway 32 ··· Pump shaft 32a ··· Square shaft (hexagonal shaft)
33 ... Key
34 ... Pump cover

Claims (1)

In the pump drive apparatus for an engine, the pump shaft (32) of the pump (21) attached to the engine body (11) is driven by the valve shaft cam shaft (20) supported by the engine body (11). ,
The pump chamber (28c) of the pump (21) has a pump housing (28) fixed to the engine body (11) with pump bolts (27), and a pump cover (34) coupled to the pump housing (28). ), And the pump housing (28) is formed coaxially with the camshaft (20) so as to rotatably fit the intermediate portion of the pump shaft (32). A hole (28b) is provided,
A ring-shaped pulsar rotor (22) is fitted in a boss portion (20a) projecting from one end surface of the cam shaft (20) so as not to be relatively rotatable, and penetrates the pulsar rotor (22) to the cam shaft ( 20) the pulsar rotor (22) is fixed to the boss portion (20a) by a pulsar rotor bolt (23) screwed to the boss portion (20a);
The end face of the head (23a) of the pulsar rotor bolt (23) is provided with a square hole (23c) into which a wrench can be fitted, and at one end of the pump shaft (32), the square hole ( 23c) is integrally formed with a square shaft portion (32a) that is directly fitted so as not to be relatively rotatable.
A shaft hole (31a) for fitting the other end of the pump shaft (32) is formed in the inner rotor (31) in the pump chamber (28c), and the shaft hole (31a) is opened to the shaft rotor (31a). A pin-like key (33) provided at the other end of the pump shaft (32) is engaged with a notch-like key groove (31b) formed in the inner rotor (31), and these keys (33) And the pump shaft (32) and the inner rotor (31) are connected to each other through a keyway (31b) so as not to be relatively rotatable.
When the screw shaft portion (23b) of the pulsar rotor bolt (23) screwed into the cam shaft (20) is rotated, the load of the pump (21) is applied when the cam shaft (20) rotates. ), characterized in that it is formed so as to act as a tightening direction of the torque, the pump drive equipment in the engine.

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