JPH029074Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is an improvement of an internal combustion engine with a lift pump that integrates an internal combustion engine and a lift pump. By fixing the flywheel to the crankshaft of the engine using the above-mentioned pump, the flywheel mounting nut is omitted, and the number of parts and assembly steps of the engine can be reduced, and the engine can be made smaller and lighter. This relates to an internal combustion engine.

Conventionally, when driving a water pump by directly connecting it to the output shaft of an internal combustion engine such as a horizontal diesel engine,
As shown in FIG. 1, a flywheel 2 is fixed to the end of a crankshaft, and an internal combustion engine 1 has an output shaft 3 projecting further to the side from the flywheel 2, and a pump shaft 4 projects horizontally. and the water pump 5,
A water pump set is assembled by installing it on one common platform 6 and connecting the output shaft 3 of the internal combustion engine 1 and the pump shaft 4 of the water pump 5 with each other using an elastic joint 7, and then transporting it to the work site. etc., and use it.

However, in the conventional water pump set as described above, the distance between the internal combustion engine 1 and the water pump 5 is wide, which increases the volume and weight of the entire set, causing inconvenience in transportation, and the installation area of the common platform 6 is large. However, there was an inconvenience in that the installation location was restricted.

For this reason, as shown in FIG. 2, the horizontal internal combustion engine 1
The casing 14 of the water pump 13 is attached to the main body 12 of 1.
is integrally fixed by a stay 15 etc., and the impeller 16 of the pump 13 is attached to the protruding end of the crankshaft 17, thereby integrating the pump 13 and the internal combustion engine 11. However, in this type of internal combustion engine with a water pump, the center hole 18a of the flywheel 18 is pre-inserted on the outer periphery of the protruding end of the crankshaft 17 with a key or the like. Crankshaft 17
After fixing the flywheel 18 by screwing the flywheel fixing nut 19 onto the crankshaft 17, another impeller fixing nut 2 is screwed onto the end of the crankshaft 17.
Since the impeller 16 is fixed by screwing the impeller 16, it is necessary to make the end of the crankshaft 17 protrude long from the engine body 12, which not only hinders the overall compactness of the engine but also prevents the flywheel from being fixed. The crankshaft 1 requires multiple nuts such as the locking nut 19 and the impeller fixing nut 20.
7, the number of parts, and the number of assembly steps increase, and there is a problem in that the manufacturing cost of the engine increases.

The present invention aims to improve such a conventional internal combustion engine with a lift pump, and the impeller boss part or pump shaft of the lift pump is also used as a locking nut for fixing the flywheel to the crankshaft. By eliminating this, it is intended to reduce the number of parts and assembly man-hours of the internal combustion engine with a lift pump, and to make the engine more compact.

That is, the present invention is characterized in that, in an internal combustion engine with a water pump, in which a water pump is directly connected to the flywheel mounting side end of the crankshaft, the flywheel housing, in which the flywheel is housed, has a water pump installed at the open end of the flywheel housing. , a plate-shaped partition wall having a sealing member fitted into the shaft hole in the center thereof, and the casing of the water pump are fixed to each other, and the said partition wall projects into the flywheel housing through the shaft hole in the partition wall. A female threaded portion is formed on the impeller boss portion of the lift pump or the engine side end of the pump shaft, and the female threaded portion is screwed into a male threaded portion formed on the shaft end of the crankshaft, thereby fixing the flywheel to the crankshaft. It is at the point.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 is a cross-sectional view of an internal combustion engine with a water pump according to the present invention. In the figure, 21 is a cylinder block, and 22 is a mounting hole 23 provided on the side of the cylinder block 21, which is fixed with a bolt 24. The flywheel housing 25 is a main bearing fitted into a shaft through hole 22a formed in the boss portion of the flywheel housing 22.
A journal portion 27a of the crankshaft 27 is inserted into the center hole 26 and is rotatably supported, and there is an oil retainer portion 28 formed in the flywheel housing 22 between the outer peripheral surface of the journal portion 27a and An oil seal 29 is interposed therebetween. In addition, a tapered portion 27b and a male threaded portion 27c are formed in a portion where the crankshaft 27 protrudes into the flywheel housing 22, continuing from the journal portion 27a.
A flywheel 31, which is prevented from rotating by interposing a key 30, is fitted into the tapered portion 27b.

On the other hand, at the open end of the flywheel housing 22, a plate-shaped partition wall 34 in which a seal member 33 is fitted into a shaft hole 32 in the center, and a spiral pump chamber 35a are formed inside. A water pump 36 consisting of a combination of a pump casing 35 and a pump casing 35 is fixed thereto. In addition, the pump casing 3
5 has a water inlet 37 outwardly along the central axis of the pump chamber 35a, and a water outlet 38 along the tangential direction, and
An impeller 39 having a large number of blades 39a is rotatably housed within the impeller 5a.

The impeller 39 has a female threaded portion 42 near the opening of a cavity 41 bored inward from the engine side end surface 40a of the boss portion 40,
By screwing the female threaded portion 42 onto the male threaded portion 27c formed at the distal end of the crankshaft 27,
The flywheel 31 and the crankshaft 27 are connected by pressing the center hole 31a of the flywheel 31 against the tapered portion 27c of the crankshaft 27. Note that a notch 43 is provided on the outer periphery of the conical head of the impeller 39 to engage a tool such as a spanner, and the inner flywheel 31 is provided on the outer periphery of the flywheel housing 22.
A tool insertion hole 44 is provided for temporarily fixing the tool.

In the figure, reference numeral 45 denotes a sleeve fitted around the outer periphery of the boss portion 40 of the impeller 39, and the sleeve 45 is connected to the sealing member 33 attached to the partition wall 34.
It has the role of ensuring liquid tightness of the pump chamber 35a by making smooth contact with the pump chamber 35a.

The internal combustion engine with a water pump of the present invention has the above-mentioned configuration. Next, the work procedure for assembling this engine will be explained. First, the flywheel housing 2 is attached to the cylinder block 21.
2 and the flywheel housing 22.
When the flywheel 31 is fixed to the crankshaft 27 of an assembled internal combustion engine by rotatably supporting the crankshaft 27 by the bearing 25 fitted in the shaft through hole 22a, the taper of the crankshaft 27 is fixed. The key 30 is attached to the portion 27b, the center hole 31a of the flywheel 31 is inserted therein, and then a tool is inserted through the tool insertion hole 44 of the flywheel housing 22 to prevent the flywheel 31 from rotating. Then, the boss portion 40 of the impeller 39 is inserted into the shaft through hole 32 at the center of the partition wall 34 so that the outer circumference of the sleeve 45 is in contact with the inner circumferential surface of the seal member 33 attached to the partition wall 34, and the boss portion 40 of the impeller 39 The female threaded portion 42 formed in the portion 40 is inserted into the crankshaft 2.
The impeller 39 is screwed into the male threaded portion 27c provided at the end of the impeller 39, and rotated by fitting a tool such as a spanner into the notch 43 formed in the conical head of the impeller 39.
The flywheel 31 is fixed to the crankshaft 27 by tightening.

Thereafter, the pump casing 35 may be attached to the outer surface of the partition wall 34, and its outer peripheral portion may be fixed together with the partition wall 34 to the opening edge of the flywheel housing 22 using bolts or the like.

FIG. 4 is a sectional view showing another embodiment of the internal combustion engine with a water pump according to the present invention. In the embodiment shown in FIG. 27 End male thread part 2
7c, the impeller 39 and the crankshaft 27 are connected via the pump shaft 46, and in the figure, parts with the same reference numerals as in FIG. 3 are the same members, respectively. The same parts are shown.

That is, in this embodiment, the boss portion 4 of the impeller 39
The pump shaft 46 is
A male threaded portion 47 formed at one end is screwed into the pump shaft 46, and a female threaded portion 49 which is threaded into the male threaded portion 27c formed at the distal end of the crankshaft 27 is recessed inward from the end surface 48 on the other end side of the pump shaft 46. The outer periphery of the portion where the female threaded portion 49 is provided is formed into a prismatic shape into which a tool such as a spanner can be fitted.
This is also used as a locking nut.

In addition, when assembling an internal combustion engine with a water pump having the above configuration, the flywheel 31 is attached to the crankshaft 2.
7 to prevent rotation by inserting it into the tapered part 27b,
The female threaded part 49 of the pump shaft 46 is screwed onto the male threaded part 27c at the end of the crankshaft 27, and the flywheel 3
1 is fixed to the crankshaft 27, the shaft through hole 32 in the center of the partition wall 34 is inserted into the outer periphery of the pump shaft 46 via the seal member 33, and the impeller 39 is fixed to the threaded portion 47 on the other end side of the pump shaft 46. After that, the pump casing 35 is attached to the partition wall 34.
At the same time, it may be fixed to the opening edge of the flywheel housing 22.

As described above, the internal combustion engine with a water pump of the present invention includes a plate-shaped partition wall in which a sealing member is fitted into the shaft hole in the center at the open end of the flywheel housing that houses the flywheel; At the same time as fixing the casing of the water pump, a female threaded portion is formed on the engine side end of the impeller boss portion or the pump shaft of the water pump that protrudes into the flywheel housing through the shaft through hole of the partition wall, and Since the flywheel is fixed to the crankshaft by screwing the female threaded part to the male threaded part formed at the end of the crankshaft, there is no need for a special fixing nut to fix the flywheel to the crankshaft. In addition to reducing the number of parts and assembly man-hours, existing crankshafts can be used (combined), and impeller materials can be easily changed (separately for pumping water), especially if the impeller boss or pump shaft is Since it also serves as a nut for fixing the flywheel, it is possible to reduce the amount of external thread machining required for the crankshaft.Also, since the centering is set using the flywheel housing spigot, the centering accuracy is high and assembly work efficiency is improved. Furthermore, the axial length of the crankshaft can be shortened to achieve the excellent effect of making the internal combustion engine equipped with a water pump more compact.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional lift pump set driven by an internal combustion engine, Fig. 2 is a partial cross-sectional schematic diagram of a conventional internal combustion engine with a lift pump, and Fig. 3 is an internal combustion engine with a lift pump of the present invention. FIG. 4 is a sectional view showing another embodiment of the internal combustion engine with a water pump according to the present invention. 27...Crankshaft, 27c...Male thread part, 3
1... Flywheel, 36... Water pump, 4
0... Impeller boss part, 42, 49... Female thread part, 46... Pump shaft.

Claims (1)

[Scope of utility model registration request] In an internal combustion engine with a lift pump in which a lift pump is directly connected to the end of the crankshaft on the flywheel mounting side, a sealing member is installed in the shaft hole in the center of the open end of the flywheel housing that houses the flywheel. The impeller boss portion of the pump shaft or the engine side of the pump shaft is fixed to the fitted plate-shaped partition wall and the casing of the pump shaft and protrudes into the flywheel housing through the shaft through hole of the partition wall. An internal combustion engine with a water pump, characterized in that a flywheel is fixed to the crankshaft by forming a female thread at the end thereof and screwing the female thread into a male thread formed at the end of the crankshaft. .