JPS6220649Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field] The present invention provides a relief valve for an oil pump that is formed integrally with an oil seal retainer of the engine, which can reduce the size of engines for automatic use and improve the reliability of the relief valve. Regarding structure.

[Prior art]

For example, in automobile engines, in recent years gears,
Oil pumps that are directly driven by a crankshaft are often used because they eliminate drive members such as chains and are designed to be easier to install, more compact, lighter, reduce costs, and reduce noise. An example of such an oil pump is a crescent-type oil pump that includes a drive gear that is externally fitted onto a crankshaft and a driven gear that is internally connected to the drive gear. This type of crescent type pump is known, for example, from Utility Model Application No. 121187/1987 (Utility Model Application No. 121187)
25605), and as shown in Fig. 4, it is integrally attached to an oil seal retainer b attached to the front end surface of a cylinder block a, and a predetermined discharge pressure of an oil pump P is applied to this oil seal retainer b. A relief valve R is also formed to set the value below the value.

Furthermore, in a system in which the oil pump and the relief valve are not integrated, there is also one in which two relief holes are provided concentrically in the valve hole of the relief valve, as disclosed in, for example, Japanese Utility Model Application No. 124438/1983.

[Problem that the invention attempts to solve]

However, in the latter case where the relief valve is installed separately, the installation space increases,
There are problems in that the increased number of parts increases costs and complicates assembly.

In order to solve this problem, when the oil pump and the relief valve are integrated as in the former case, the relief valve R has its valve hole integrated with the outer wall of the oil seal retainer which also serves as the outer wall of the cylinder block a. Therefore, there is a problem in that the relief hole d, which is the oil release port of the oil pump P, can only be formed with one hole that opens on the mounting surface side because it is necessary to prevent it from penetrating outward.

On the other hand, in engines with a displacement of about 1000 c.c., especially at low temperatures when the oil viscosity increases, the relief hole requires an opening area of about 50 mm ² , so that the valve body c gets caught on the periphery of the relief hole d. In order to slide smoothly without causing any problems, it is necessary to increase the inner diameter of the valve hole itself. Accordingly, the spring, valve body c, and oil seal retainer b become larger, leading to an increase in cost. Furthermore, when there is only one relief hole, as shown in FIG. 5, the oil flowing out from the relief hole d creates an imbalance in the pressing force on the valve body c, and by tilting the valve body c, The lower end rubs against the inner surface of the valve hole, causing wear and galling between the inner surface and the so-called stuck.

In order to solve some of these problems, it has been attempted to improve the stay resistance by casting a cast iron sleeve around the valve hole, but this method is time-consuming to manufacture and increases costs. I'm inviting you.

[Purpose of invention]

The present invention solves the various problems mentioned above, makes the relief valve smaller and lighter, effectively prevents stagnation, improves durability and reliability, and contributes to the downsizing of the engine. The object of the present invention is to provide a relief valve structure for an oil pump that is formed integrally with a seal retainer.

[Means for solving problems]

In order to achieve the above object, the present invention includes a housing portion 7 of an oil pump 5 having a drive gear 40 externally fitted onto a crankshaft 27 on an oil seal retainer 4 attached to a front end surface of a cylinder block 3; The outer box part 8 of the relief valve 6 which communicates with the discharge side of the pump 5 is formed integrally with the outer box part 8 of the relief valve 6, and the outer box part 8 of the relief valve 6 has a protrusion that rises inward from the main body part 37 of the oil seal retainer 4. A portion 9 is provided, and two relief holes 10 and 11 are provided concentrically penetrating the protrusion 9.

[Effect]

As the crankshaft 27 rotates, the drive gear 4
0, the oil pump 5 is driven, and oil is pumped up by the drive. Oil is discharged from the discharge side of the oil pump 5 and lubricates the engine, while excess oil is discharged from the relief holes 10 and 11 of the relief valve 6 and is reduced.

The relief valve 6 has two relief holes 1.
0 and 11 are provided concentrically, and therefore, when the relief valve 6 is pressed down, a uniform pressing force is generated on the valve body, and in order to prevent the valve body from tilting, galling and sticking can be suppressed. In addition, the opening area of each relief hole 10, 11 can be reduced to half that of a conventional one having a single relief hole, and as a result, the relief valve 6 can be made smaller.

Further, since the oil pump 5 is formed as a so-called crescent-type pump having a drive gear 40 externally fitted onto the crankshaft 27, the number of driving members is reduced, so that the oil pump 5 operates quietly.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, the relief valve structure (hereinafter referred to as structure) of the oil pump, which is formed integrally with the oil seal retainer of the engine, has an oil seal retainer 4 attached to the front end surface of the cylinder block 3 of the engine, and a housing part of the oil pump 5. 7 and the outer box part 8 of the relief valve 6 are integrally formed, and a projection part 9 is formed on the outer box part 8 of the relief valve 6 so as to float above the oil seal retainer 4. Relief holes 10 and 11 are bored.

The cylinder block 3 is provided with a crankcase 15 that spreads out like a skirt at the lower part of a body 14 in which a cylinder 13 is provided, and one side wall of the crankcase 15 has a rectangular shape extending laterally for mounting an alternator, for example. Shape extension 17
is formed, and a flange portion 20 for attaching the oil pan 19 is provided at the lower part. Further, the cylinder block 3 is provided with a mounting seat 22 on the front edge of the crankcase 15, which comes into contact with the oil seal retainer 4. Note that the mounting seat 22 is formed with a fuel filler port 23 and a plurality of bolt holes, and also has a cylinder block 3.
An inner wall 25 forming a recess 24 is vertically provided at a position slightly inward from the mounting seat 22, and the tip of the crankshaft 27 is mounted on the inner wall 25 in cooperation with a main bearing cap 26. A pivoting half-shaped bearing portion 29 is formed on the lower surface thereof.

The oil seal retainer 4 includes a peripheral wall 33 that includes a mounting seat 32 that is flush with the mounting seat 22 and has an extension 39 having the same shape as the extension 17.
An oil pump 5 is attached to a main body 37 having a front wall 35 connecting the front edges thereof and forming a recess 34 inside.
The housing portion 7 of the relief valve 6 and the outer box portion 8 of the relief valve 6 are integrally formed. oil pump 5
A drive gear 40 that is externally inserted and fitted into a notch provided in the crankshaft 27, and a driven gear 41 that is eccentric to the drive gear 40 and inscribed in the gear 40 are housed in the housing 7, and the pump The oil from a suction pipe 45, which is a so-called crescent-type pump shielded by a cover 42 and equipped with a strainer 44 at the lower end, is transferred to a conduit section 4 installed on the discharge side of the housing 7.
6, the oil can be discharged from a delivery port 47 that can communicate with the oil supply port 23. The relief valve 6 is branched into a conduit portion 46 .

The relief valve 6 has the outer box part 8 in which a slightly larger diameter valve hole 51 is downwardly bored in a small diameter part 50 that communicates with the conduit part 46.
By providing a blind hole portion 53 communicating below between the main body portion 37 of the oil seal retainer 4 and the lower portion where the outer box portion 8 is provided with On the other hand, two relief holes 10 and 11 are formed in the upper end of the protrusion 9 at right angles to the mounting seat 32 and are through holes reaching the blind hole 53. In this example, the two relief holes 10, 1
1 are formed to have the same diameter. A valve body 12 is inserted into the valve hole 51 so as to be movable up and down so as to normally close the relief holes 10 and 11.
is a spring 56 supported by a retaining ring at the lower end of the valve hole 51;
When oil pressure becomes excessive due to overcoming pressure and being pushed down, the oil is released through the relief holes 10 and
It can be released from 1. Further, in this embodiment, a projecting piece 57 of the pump cover 42 is disposed close to the relief hole 10, and the ejected oil is guided by the guide groove 58 and flows downward, and the oil seal 42 is connected to the cylinder block 3 and the oil seal retainer 4. extension 17,
39, by alternately arranging ribs 60 vertically in parallel, an oil separator 61 consisting of a vertically meandering ventilation passage is formed. may leak into the

However, in the structure of this embodiment, the mounting seat 22,
Align 32 and secure with bolts. crankshaft 27
As the drive gear 40 and driven gear 41 rotate, the oil is pumped up through the suction pipe 45 and passed through the oil pump 5, conduit section 46, outlet port 47, and oil filler port 23 to lubricate the engine. do. Further, the excess oil causes an increase in discharge pressure, pushes down the valve body 12 against the spring 56, and is discharged from the two relief holes 10 and 11.
The oil from one relief hole 11 is transferred to the blind hole portion 53.
The oil from the other relief hole 10 collides with the protruding piece 57 and returns to the oil pan 19 without being scattered in the form of mist. Also, the relief valve 6 has 2
Since two relief holes 10 and 11 are provided, the opening area is reduced to one half, and as a result, catching and interference between the periphery of the relief holes 10 and 11 and the valve body 12 is significantly reduced, and the valve hole 5 can reduce the inner diameter of
This helps reduce the size of the relief valve 6. In addition, since the two relief holes 10 and 11 are provided concentrically, when the relief holes 10 and 11 are pressed down, a uniform pressing force is generated on the upper surface of the valve body 12, and in order to prevent it from tilting, there is no galling with the inner surface of the valve hole 51. Stakes can be suppressed. Further, the protrusion 9 floats inward from the main body 37 of the oil seal retainer 4, and therefore directs the oil flowing out from the relief hole 11 on the side facing the main body 37 to the main body 37.
By guiding with the front wall 35 of 7 and flowing downward,
Reduces oil diffusion and suppresses oil mist generation. Furthermore, since the oil pump 5 adopts a so-called crescent type in which the drive gear 40 is directly inserted onto the crankshaft 27, its operation is quiet.

In the structure of the present invention, the relief hole may be formed not only at right angles to the mounting seat, but also at an angle.
In addition to the two relief holes, a desired number of relief holes can be added, and the shape of the relief holes can be modified into various shapes, such as a non-circular shape.

[Effect of idea]

As mentioned above, the structure of the present invention is such that the housing part of the oil pump and the outer box part of the relief valve communicating with the discharge side of the pump are integrally formed in the oil seal retainer attached to the front end surface of the cylinder block. The space between the oil seal retainer and the cylinder block, which is usually left idle, is effectively utilized to make the engine smaller, lighter, and lower in cost. Furthermore, since the oil pump has a drive gear that is externally fitted onto the crankshaft, the number of driving members can be reduced, the labor of installation can be reduced, and engine noise can be reduced. Furthermore, since a protrusion that rises inward from the main body of the oil seal retainer is provided on the outer box of the relief valve, it is possible to drill two relief holes concentrically penetrating the protrusion. By providing a relief hole, the opening area can be reduced compared to a conventional structure with a single relief hole, making it possible to make the relief valve smaller and lighter. Stakes caused by getting caught or interfering with the body,
This can be prevented without casting a cast iron sleeve, and the reliability and longevity of the relief valve can be improved with a simple structure.

As described above, the structure of the present application has many advantages such as organically integrating and combining the above-mentioned configurations, which can increase the reliability of the engine, reduce noise, and further reduce the cost of the engine. This effect can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an oil pump section showing an embodiment of the present invention, Fig. 2 is a sectional view of a relief valve section, Fig. 3 is an exploded perspective view thereof, and Figs. 4 and 5 illustrate a conventional structure. FIG. 3... Cylinder block, 4... Oil seal retainer, 5... Oil pump, 6... Relief valve, 7... Housing section, 8... Outer box section, 9...
Projection, 10, 11... Relief hole, 12... Valve body, 27... Crankshaft, 37... Main body, 40
... Drive gear, 41 ... Driven gear, 51
...Valve hole.

Claims (1)

[Scope of utility model registration request] an oil pump housing portion having a drive gear externally fitted onto a crankshaft in an oil seal retainer attached to a front end surface of a cylinder block;
The outer box portion of the relief valve that communicates with the discharge side of the pump is provided with a protrusion that floats inward from the main body of the oil seal retainer, and the protrusion is provided with two relief holes penetrating concentrically. An oil pump relief valve structure that is integrally formed with the engine's oil seal retainer.