JPS6140957Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel feed pump for an internal combustion engine.

Conventional internal combustion engine fuel feed pumps
As shown in the figure, pump body 1 and pump lid 2
It supports a pump shaft 19 with a trochoid rotor 13 fixed therein, and is generally attached to the gear case lid 12 of the internal combustion engine so as to protrude outward.

In this structure, the trochoid rotor 13
A portion is exposed outside the gear case lid 12. In FIG. 1, the right side of the lid 12 is (the inside of) the gear case. The drain port 23, which is provided downward in the pump body 1 from around the oil seal 7 fitted on the pump shaft 19, is also all exposed to the outside, making the fuel feed pump that much larger. This makes the design layout extremely difficult.

This means that if fuel oil leaks from the fuel feed pump into the crankcase from inside the gear case lid 12, the lubricating oil of the engine will be diluted by the fuel oil, reducing the lubrication function and causing the engine to burn out. Conventionally, this kind of fuel feed pump was built inside the gear case lid 12 of the engine because of the risk of causing problems such as oil leakage, and conventionally, it was a technology to ensure that the fuel oil would never leak into the gear case lid 12. It has been said that this cannot be done without certain conviction.

Further, in the fuel feed pump shown in FIG. 1, the pump shaft 19 is driven by an end nut 22 attached to the end of a camshaft (not shown), and therefore, the pump shaft 19 is connected to the crankshaft of the internal combustion engine. Since the pump body 1 is rotated at only half the rotation speed, it was necessary to increase the size of the pump body 1 to increase its discharge capacity.

Furthermore, attach the pump shaft 19 to the camshaft end nut 2.
2, the pump shaft 19 had to be constructed coaxially with the valve arm lubrication pump 21 due to the location, and there was a problem in that this fuel feed pump had to be further enlarged.

Therefore, the present invention was devised to solve the above-mentioned conventional problems, and it prevents fuel oil from leaking into the gear case lid, and even if oil leaks, the leaked oil is always removed to the outside of the gear case lid. The object of the present invention is to provide a fuel feed pump that can be built into a gear case lid and has a structure in which fuel is discharged and the discharge can be visually confirmed.

That is, the present invention provides a fuel feed pump for an internal combustion engine in which a pump shaft is supported within a pump body and a pump lid, in which the pump body protrudes inside the lid of the gear case so that the pump body protrudes into the gear case of the internal combustion engine. and connects the pump shaft to a drive gear interlocking with the crankshaft, and further opens from around the seal attachment part on the drive gear side of the pump shaft to the joint between the pump body and the pump lid, and , providing a port inclined downward, and penetrating into the opening of the port into a hole provided in the pump lid while maintaining a gap, and
It is constructed by screwing the inlet of a pipe joint having an outlet on the outside of the gear case lid, and further arranging an O-ring on the joint surface between the pump body and the pump lid.

Embodiments of the present invention will be described below with reference to the drawings, in which the same parts as in the conventional example shown in FIG. 1 are designated by the same part numbers.

First, the fuel feed pump in the embodiment of the present invention shown in FIG. 2 is similar to the conventional example shown in FIG.
A pump shaft 19 with a trochoid rotor 13 fixed inside the pump body 1 and pump lid 2 is supported. , inside the gear case). The pump shaft 19 is connected to and interlocked with a drive gear 10 that meshes with a crank gear provided on a crankshaft (not shown), so that the pump shaft 19 rotates at a speed higher than that of the internal combustion engine. For example, the fuel feed pump can be rotated at twice the speed, and as a result, the dimensions of the fuel feed pump can be reduced, and the part of the pump shaft 19 that protrudes outside the gear case lid 12 is reduced, so The axial dimension will also be reduced.

In the internal combustion engine of this embodiment, the valve arm lubrication pump 21 shown in FIG. 1 is conventionally arranged at the end of the camshaft (not shown).

Also, the pump shaft 19 of this fuel feed pump
The end on the drive gear 10 side is an open type bearing 1.
5 and its inside (i.e. left side in the figure)
is supported by a single-seal type bearing 16, and three oil seals 7 are installed inside the bearing, and the lip portions of these oil seals 7 are arranged in the direction to receive fuel oil leaking from the rotor 13 side of the trochoid. are doing.

In addition, since the trochoid rotor 13 is located further inside the oil seal 7 and near the gear case lid 12 via a fuel oil sealing bush 14, the pump body 1 is completely attached to the gear case lid 12. Since the fuel feed pump is located inside the gear case lid 12, the portion of the fuel feed pump that protrudes to the outside can be significantly reduced in size.

In addition, 18 in the figure is a lock nut, and 20 is a distance piece.

That is, what protrudes to the outside is the pump lid 2.
and the inlet and outlet flanges 3 shown by dotted lines,
It will only be the size of 4.

Next, the port is attached to the pump shaft 19, a spacer 17 is fitted around the oil seal 7, and the port is inclined downward from the periphery of the spacer 17 toward the joint between the pump body 1 and the pump lid 2. 6 is bored and the port 6 is opened at the joint.

The opening of this port 6 is screwed with the inlet of a union 8, which is a pipe fitting that penetrates the hole provided in the pump lid 2 while maintaining the gap 11, and the outlet of the union 8 is connected to the outside from the gear case lid 12. A leakage oil discharge pipe 24 located at is connected.

Note that when the union 8 is screwed on, a copper packing 9 is interposed at the joint between the union 8 and the pump body 1.

Here, the reason why the port 6 is bored with a downward slope is that even if the pump shaft 19 shakes up and down due to pitching of the internal combustion engine, it is possible to easily recover fuel oil leaked around the oil seal 7. In particular, when the end of the pump shaft 19 on the drive gear 10 side is on the internal combustion engine side, this drive gear
This is because when the side goes down, it is difficult to recover the leaked fuel oil with a horizontal port 6. By tilting the port 6 downward as in the present invention, it is possible to recover the leaked fuel oil with a pitting of about 10 degrees. We have confirmed through actual machine tests that it works without any problems.

Furthermore, an O-ring 5 is interposed between the pump body 1 and the pump lid 2, but if the O-ring 5 is damaged, fuel oil will directly leak from the trochoid rotor 13 to the pump body 1 and the pump lid. 2, the leaked fuel oil will flow out from the gap 11 in the hole in the pump lid 2 that penetrates the union 8, so the state of the leakage will be determined. Damage to the O-ring 5 can be detected.

In addition, in the fuel feed pump of the present invention, the fuel oil leaking from the rotor 13 of the trochoid via the pump shaft 19 is collected by the port 6 provided at an angle from the spacer 17 provided around the three oil seals 7. and gear case lid 12 through union 8
However, in the above embodiment, the oil seal 7 portion of the pump shaft 19 is further discharged from the drive gear 10 side to the single seal bearing 16.
By providing this, leaked fuel oil is further prevented from flowing into the internal combustion engine side, and safety is ensured by performing two-step sealing against fuel oil leaking in the axial direction of the pump shaft 19.

Therefore, in the fuel feed pump of the present invention, it is possible to completely prevent fuel oil leaking from the axial direction of the pump from mixing with the lubricating oil of the internal combustion engine, thereby preventing the engine from seizing due to the leakage of the lubricating oil from the fuel oil. It is possible to prevent such troubles from occurring and improve the reliability and safety of the engine.

In addition, as a result, the fuel feed pump body can be built inside the gear case lid, and the pump shaft can be rotated at twice the rotation speed of the crankshaft by a drive gear linked to the engine crankshaft, making the fuel feed pump compact. Moreover, it has the advantage that it can be formed lightweight, and is effective in reducing the size of the fuel feed pump.

Further, even if the O-ring at the joint between the pump body and the pump lid is damaged, the fuel oil leaking therefrom can be discharged to the outside and the leakage can be visually detected.

Note that the present invention can be effectively applied to various fuel feed pumps for internal combustion engines.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view of a main part of a conventional fuel feed pump for an internal combustion engine, and FIG. 2 is a sectional side view of a main part of a fuel feed pump for an internal combustion engine according to an embodiment of the present invention. 1...Pump body, 2...Pump lid, 6...
Port, 7...Oil seal, 8...Union,
10... Drive gear, 11... Gap, 12... Gear case lid, 13... Trochoid rotor, 16
...Single seal bearing, 17...Spacer, 19...
...Pump shaft.

Claims (1)

[Scope of utility model registration request] In a fuel feed pump for an internal combustion engine in which a pump shaft is supported within a pump body and a pump lid, the pump body is provided so as to protrude inside the lid of the gear case so that the pump body projects into the gear case of the internal combustion engine, and the pump body is provided so as to protrude inside the lid of the gear case. The pump shaft is connected to a drive gear that interlocks with the crankshaft, and the pump shaft is opened from around the seal attachment part on the drive gear side of the pump shaft to the joint between the pump body and the pump lid, and is inclined downward. A boat is provided, and an inlet of a pipe fitting that penetrates a hole provided in the pump lid while maintaining a gap and has an outlet outside the gear case lid is screwed into the opening of the port,
A fuel feed pump for an internal combustion engine, further comprising an O-ring disposed on the joint surface between the pump body and the pump lid.