WO2022185847A1

WO2022185847A1 - Relief valve

Info

Publication number: WO2022185847A1
Application number: PCT/JP2022/004649
Authority: WO
Inventors: 敦君垣
Original assignee: 株式会社山田製作所
Priority date: 2021-03-03
Filing date: 2022-02-07
Publication date: 2022-09-09
Also published as: WO2022185846A1

Abstract

A valve housing (31) of this relief valve (30) has: a first discharge port (51) which opens when discharge pressure (PO) in an oil pump (10) has risen to a first reference pressure level (P1) so as to have caused a valve body (32) to move in a direction of contracting a valve spring (33); a connection port (53) which is connected to the first discharge port via a discharge passage (55), is further connected to a spring chamber (44), and closes when the aforementioned discharge pressure has risen to a second reference pressure level (P2) so as to have caused the valve body to move in the direction of contracting the valve spring; a pressure relief port (54) which is connected from the spring chamber to an intake part (13) of the oil pump or an oil pan (21); and a second discharge port (52) which opens to introduce oil when the discharge pressure has risen to a third reference pressure level (P3) so as to have caused the valve body to move in the direction of contracting the valve spring and which discharges the introduced oil to the intake part or the oil pan. The first discharge port, the second discharge port, the connection port, and the pressure relief port are disposed in the stated order in the direction of contracting the valve spring.

Description

relief valve

The present invention relates to a relief valve that controls the discharge pressure of an oil pump.

An engine mounted on a vehicle is equipped with a rotating shaft such as a crankshaft or a camshaft, a bearing that supports this rotating shaft, and an oil pump that supplies an appropriate amount of oil to these bearings. This oil pump has a relief valve. When the discharge pressure of the oil pump becomes higher than a predetermined reference pressure, the discharge pressure can be optimized by letting the oil escape from the relief valve.

When the discharge pressure reaches the reference pressure, the relief valve opens, but this alone may be too simple to control the discharge pressure. Therefore, conventionally, a relief valve that can be opened and closed more finely has been proposed (see, for example, Patent Document 1).

According to Patent Document 1, when the discharge pressure of the oil pump rises to the reference pressure and the valve element moves in the direction in which the valve spring contracts due to the oil introduced from the introducing portion, the introduced oil is stored in the housing. By selectively opening and closing the outlet of the pump, the liquid is discharged to the suction side of the pump. As a result, the discharge pressure can be controlled in two stages.

However, the technique of Patent Literature 1 has a configuration in which two stages of discharge ports with different opening areas are opened sequentially as the discharge pressure increases. In order to further improve the fuel efficiency of the engine, it is required to finely control the discharge pressure of the oil pump in accordance with the rotational speed of the engine.

For this purpose, for example, when the discharge pressure of the oil pump rises to the reference pressure and the valve body moves in the direction in which the valve spring contracts due to the oil introduced from the introduction part, the oil introduced through the through hole formed in the valve body is discharged to the suction side of the pump by selectively opening and closing a multistage discharge portion provided in the housing.

However, since the valve body has a through hole, the structure of the valve body becomes complicated. Moreover, the stroke of the valve body for controlling the discharge pressure in two stages is large.

Japanese Patent No. 5215959

An object of the present invention is to provide a technology that enables a relief valve that controls the discharge pressure in two stages to be simple in configuration and downsized.

According to the present invention, a valve housing having an introduction portion for introducing oil from a discharge portion of an oil pump and a valve housing chamber communicating with the introduction portion; and a valve slidably housed in the valve housing chamber. and a valve spring that biases the valve body toward the introduction portion, wherein the valve housing chamber is configured such that the side opposite to the introduction portion is urged by the valve body to the valve spring. The valve housing is partitioned into a spring chamber in which the discharge pressure of the oil pump is increased to a preset first reference pressure, and the valve spring is compressed by the oil introduced from the introduction portion. a first discharge hole that opens when the valve body moves; and a discharge passage that is connected to the first discharge hole and communicates with the spring chamber so that the discharge pressure is higher than the first reference pressure. a communication hole which is closed when the valve body moves in the direction in which the valve spring contracts due to the oil introduced from the introduction portion when the pressure rises to a high second reference pressure; and from the spring chamber to the suction portion of the oil pump or the oil pan. When the discharge pressure rises to a third reference pressure higher than the second reference pressure and the oil introduced from the introduction portion causes the valve body to move in the direction in which the valve spring contracts. a second discharge hole that opens to discharge the introduced oil to the suction portion of the oil pump or the oil pan, the first discharge hole, the second discharge hole, the communication hole, and the pressure A relief hole is provided in this order in the direction in which the valve spring contracts, and a relief valve is provided in which the discharge passage is formed in the valve housing.

According to the present invention, the relief valve that controls the discharge pressure in two stages can be made simple and compact.

FIG. 2 is a side view illustrating the basic configuration of the relief valve according to Example 1 with the cover removed. Figure 2 is a cross-section along line 2-2 of Figure 1 with a cover; FIG. 3A is an action diagram of the relief valve when the discharge pressure of the oil pump rises to the first reference pressure. FIG. 3B is an action diagram of the relief valve when the discharge pressure of the oil pump rises to the second reference pressure. FIG. 3C is an action diagram of the relief valve when the discharge pressure of the oil pump rises to the third reference pressure. FIG. 2 is a diagram conceptually showing the relationship between the rotational speed of an engine and the discharge pressure of an oil pump; FIG. 4 is a cross-sectional view of a relief valve according to Example 2 (corresponding to FIG. 2); FIG. 6 is a cross-sectional view of a relief valve according to Example 3 (corresponding to FIG. 5); FIG. 7 is an exploded view with a part of the relief valve shown in FIG. 6 omitted;

A mode for carrying out the present invention will be described below based on the accompanying drawings. In addition, the form shown in the accompanying drawings is an example of the present invention, and the present invention is not limited to the form.

<Example 1>
The relief valve 30 of Example 1 will be described with reference to FIGS. 1 to 4. FIG.

FIG. 1 shows an oil pump 10 in which a relief valve 30 is integrally incorporated. The oil pump 10 has a pump body 11, a rotor chamber 12, a suction portion 13 (suction port 13), and a discharge portion 14 (discharge port 14).

The rotor chamber 12 houses an inner rotor 15 and an outer rotor 16 surrounding the inner rotor 15 . The oil pump 10 including the inner rotor 15 and the outer rotor 16 is called an internal gear pump or trochoid pump. When the inner rotor 15 is rotated directly or indirectly by the crankshaft (not shown) of the engine 20, the outer rotor 16 rotates along with it. This rotation changes the size of the gap between the inner rotor 15 and the outer rotor 16 . The change in gap size produces a pumping action consisting of intake, transport and discharge. The oil pump 10 sucks oil from an oil pan 21 (oil reservoir 21 ) of the engine 20 into a suction portion 13 by a pumping action, and supplies the oil from a discharge portion 14 to various parts of the engine 20 .

The pump body 11 is further attached with a relief valve 30 arranged downstream of the discharge portion 14 . The relief valve 30 can optimize the discharge pressure PO by releasing the oil when the discharge pressure PO of the oil becomes higher than a predetermined reference pressure.

In other words, in the oil pump 10, the power of the engine 20 is wasted when the oil discharge pressure PO becomes higher than necessary. Therefore, when the oil discharge pressure PO increases, the relief valve 30 allows the discharge portion 14 and the suction portion 13 of the oil pump 10 to communicate with each other. As a result, it is possible to suppress wasteful consumption of the power of the engine 20 due to pressurization of the oil. That is, the fuel efficiency of the engine 20 can be improved.

As shown in FIGS. 1 and 2, the relief valve 30 includes a valve housing 31 formed integrally with the pump body 11 and a valve element slidably accommodated in a valve accommodating chamber 43 of the valve housing 31 . 32 (spool 32 ) and a valve spring 33 that biases the valve element 32 toward the introduction portion 42 of the valve housing 31 .

The valve housing 31 is composed of a housing body 40 and a cover 60 (see FIG. 2) that covers the side surface 41 of the housing body 40.

The housing main body 40 is formed with an introduction portion 42 for introducing oil from the discharge portion 14 of the oil pump 10 and a valve accommodating chamber 43 communicating with the introduction portion 42 . The valve storage chamber 43 is, for example, a long through-hole having a circular cross section and extending in the vertical direction or the horizontal direction. Therefore, the valve body 32 is also a circular member having a shape and size matching the cross-sectional shape of the valve storage chamber 43 . The valve body 32 does not have a through hole on its outer peripheral surface.

The introduction part 42 is a circular hole positioned on the center line CL of the valve housing chamber 43 . The diameter of the introduction portion 42 is smaller than the diameter of the valve accommodating chamber 43 . Note that the position of the introduction portion 42 is not limited to the center line CL of the valve accommodating chamber 43 .

The valve housing chamber 43 is partitioned by the valve element 32 into a spring chamber 44 in which the valve spring 33 is housed on the side opposite to the introduction portion 42 . That is, the spring chamber 44 is located on the side opposite to the introduction portion 42 with respect to the valve spring 33 . The valve spring 33 is retained by a spring restraining member 34 attached to one end of the housing body 40 (the end opposite to the introduction portion 42). The spring restraining member 34 may be a threaded plug, a driven plug, a lid member, or other member that restrains one end of the valve spring 33, and the type and form are not limited. Since the diameter of the introducing portion 42 is smaller than the diameter of the valve accommodating chamber 43, the valve body 32 biased by the valve spring 33 is pressed against the interface 45 (valve seat 45) between the introducing portion 42 and the valve accommodating chamber 43. It is As is clear from the above description, the spring chamber 44 is a substantially closed space defined by the valve body 32 and the spring restraining member 34 within the valve housing chamber 43 .

One side surface 41 of the housing body 40 is configured as a flat flange surface parallel to the center line CL of the valve accommodating chamber 43 . Hereinafter, this side surface 41 may be referred to as "flange surface 41" as appropriate. The cover 60 has a flat cover surface 61 that can be overlaid on the side surface 41 of the housing body 40 . The cover 60 is placed on the flange surface 41 with the cover surface 61 (matching surface 61) hermetically sealed, and is detachably attached to the housing body 40 with fastening members such as bolts.

In the housing body 40 in the valve housing 31, a first discharge hole 51, a second discharge hole 52, a communication hole 53, and a pressure relief hole 54 are arranged from the introduction portion 42 side in the direction Rc in which the valve spring 33 contracts. are provided in this order. All the holes 51 to 54 are through holes that open from the valve storage chamber 43 to the flange surface 41, and are arranged in a straight line along the center line CL of the valve storage chamber 43. (see FIG. 1).

The first discharge hole 51 is located away from the introduction portion 42 in the direction Rc in which the valve spring 33 contracts, and is closed by the valve body 32 during normal times when the discharge pressure PO of the oil pump 10 is low. In the first discharge hole 51, the discharge pressure PO of the oil pump 10 rises to a preset first reference pressure P1 (see FIG. 4), and the valve spring 33 is compressed by the oil introduced from the introduction portion 42 in the direction Rc. It opens when the valve body 32 moves.

The communication hole 53 is open without being closed by the valve body 32 during normal times when the discharge pressure PO of the oil pump 10 is low. The communication hole 53 is connected only to the first discharge hole 51 by a discharge passage 55, and communicates with the spring chamber 44. The discharge pressure PO is preset to be higher than the first reference pressure P1. The second reference pressure P2 (see FIG. 4) is reached and closed when the valve body 32 further moves in the direction Rc in which the valve spring 33 contracts due to the oil introduced from the introduction portion 42 .

By constantly communicating with the spring chamber 44, the pressure relief hole 54 communicates from the spring chamber 44 to the suction portion 13 of the oil pump 10 through the bypass passage 56 (pressure relief passage 56).

The second discharge hole 52 is closed by the valve body 32 during normal times when the discharge pressure PO of the oil pump 10 is low. In the second discharge hole 52, the discharge pressure PO increases to a preset third reference pressure P3 (see FIG. 4) higher than the second reference pressure P2, and the oil introduced from the introduction portion 42 causes the valve spring 33 to move. When the valve body 32 moves further in the contracting direction Rc, it opens to discharge the introduced oil to the suction portion 13 of the oil pump 10 through the bypass passage 56 . The opening area of the second discharge hole 52 is larger than the opening area of the first discharge hole 51 .

Thus, the first reference pressure P1, the second reference pressure P2, and the third reference pressure P3 have a relationship of P1<P2<P3.

The discharge passage 55 and bypass passage 56 are formed in the valve housing 31 . The discharge passage 55 and the bypass passage 56 are separated and independent of each other. Specifically, the exhaust passage 55 is defined by a groove 55a formed in the flange surface 41 within the valve housing 31. As shown in FIG. As described above, the second discharge hole 52 is positioned between the first discharge hole 51 and the communication hole 53 along the centerline CL of the valve housing chamber 43 . Therefore, the groove 55a is formed in a U shape that bypasses the second discharge hole 52 when viewed from the side surface 41 of the housing body 40 (see FIG. 1). The opening of the groove 55 a , the opening of the first discharge hole 51 , and the opening of the communication hole 53 are closed by the cover surface 61 of the cover 60 . Similarly, the bypass passage 56 is constituted by a groove 56a formed in the flange face 41 in the valve housing 31. As shown in FIG. The opening of the groove 56a is closed by the cover surface 61 of the cover 60. As shown in FIG.

Next, the operation of the relief valve 30 having the above configuration will be described with reference to FIGS. 1 and 2. FIG.

For example, at the idling speed of the engine 20, the discharge pressure PO of the oil pump 10 is sufficiently small and is in a lower pressure state than the first reference pressure P1. Therefore, the biasing action of the valve spring 33 pushes the valve body 32 against the boundary surface 45 to the retraction limit position. The first discharge hole 51 and the second discharge hole 52 are closed by the valve body 32 . The communication hole 53 and the pressure relief hole 54 are in an open state, not closed by the valve body 32 . After that, when the discharge pressure PO increases, the valve body 32 moves in the direction Rc in which the valve spring 33 contracts.

When the discharge pressure PO increases to the first reference pressure P1, as shown in FIG. 3A, the valve body 32 moves to switch the first discharge hole 51, which has been closed until now, to the open state. The oil introduced from the introduction portion 42 enters the spring chamber 44 through the discharge passage 55 and the communication hole 53, passes through the pressure relief hole 54 and the bypass passage 56 from the spring chamber 44, and flows into the oil pump 10 (see FIG. 1). It is discharged to the intake section 13 . This discharge mitigates the increase in the discharge pressure PO. When the discharge pressure PO further increases gradually, the valve body 32 moves further in the direction Rc in which the valve spring 33 contracts.

When the discharge pressure PO increases to the second reference pressure P2, as shown in FIG. 3B, the valve body 32 moves further, thereby maintaining the open state of the first discharge hole 51 and Switch the hole 53 to the closed state. As a result, the discharge pressure PO rises rapidly, and the valve element 32 rapidly moves in the direction Rc in which the valve spring 33 contracts.

When the discharge pressure PO rises to the third reference pressure P3, as shown in FIG. 3C, the valve body 32 moves further to maintain the closed state of the communication hole 53 while maintaining the closed state of the second discharge. Switch the hole 52 to the open state. The oil introduced from the introduction portion 42 is discharged from the second discharge hole 52 through the bypass passage 56 to the intake portion 13 of the oil pump 10 (see FIG. 1). This discharge moderates or regulates the increase in the discharge pressure PO.

As is clear from the above description, (1) the distance between the first discharge hole 51, the second discharge hole 52, and the communication hole 53 in the direction Rc in which the valve spring 33 contracts; ) The length and stroke of the valve body 32 are set so as to satisfy all of the following four conditions.
The first condition is, as shown in FIG. 2, when both the first discharge hole 51 and the second discharge hole 52 are closed by the valve body 32, the communication hole 53 is open.
The second condition is that, as shown in FIG. 3A, when the first discharge hole 51 is open and the second discharge hole 52 is closed by the valve body 32, the communication hole 53 is open. It is in.
The third condition is that both the second discharge hole 52 and the communication hole 53 are closed by the valve body 32 when the first discharge hole 51 is open, as shown in FIG. 3B.
The fourth condition is that the communication hole 53 is closed by the valve body 32 when both the first discharge hole 51 and the second discharge hole 52 are open, as shown in FIG. 3C.

Next, the relationship between the rotational speed Ne of the engine 20 and the discharge pressure PO (oil pressure PO) of the oil pump 10 when the relief valve 30 having the above configuration is used will be described with reference to FIGS. 2 to 4. FIG. FIG. 4 conceptually shows changes in the discharge pressure PO with respect to the rotation speed Ne, with the rotation speed Ne of the engine 20 on the horizontal axis and the discharge pressure PO of the oil pump 10 on the vertical axis.

When the rotation speed Ne of the engine 20 is in the low speed range N1 shown in FIG. 4, the discharge pressure PO is sufficiently low and is in a lower pressure state than the first reference pressure P1. Therefore, the first discharge hole 51 is closed (see FIG. 2). As the rotation speed Ne of the engine 20 increases, the discharge pressure PO increases.

After that, when the discharge pressure PO has increased to the first reference pressure P1, the first discharge hole 51 is switched to the open state (see FIG. 3A), thereby mitigating the increase in the discharge pressure PO. That is, when the rotation speed Ne of the engine 20 is in the middle speed range N2, the increase in the discharge pressure PO is moderated.

After that, when the discharge pressure PO rises to the second reference pressure P2, the communication hole 53 is switched to the closed state (see FIG. 3B), and the discharge pressure PO rises sharply.

After that, when the discharge pressure PO has increased to the third reference pressure P3, the second discharge hole 52 is switched to the open state (see FIG. 3C), thereby mitigating or restricting the increase in the discharge pressure PO. That is, when the rotational speed Ne of the engine 20 is in the high speed region N3, the increase in the discharge pressure PO is moderated or restricted.

As described above, according to the relief valve 30 of the present invention, the discharge pressure PO can be controlled in two stages, the first reference pressure P1 and the third reference pressure P3. The discharge pressure PO of the oil pump 10 can be finely controlled according to the rotation speed Ne of the engine 20 . Since the discharge pressure PO is not increased more than necessary, the load on the oil pump 10 can be reduced. As a result, the fuel efficiency of the engine 20 can be improved.

The above description can be summarized as follows.
As shown in FIGS. 1 and 2, the relief valve 30 includes a valve housing having an introduction portion 42 for introducing oil from the discharge portion 14 of the oil pump 10 and a valve housing chamber 43 communicating with the introduction portion 42. 31 , a valve element 32 slidably accommodated in the valve accommodating chamber 43 , and a valve spring 33 that biases the valve element 32 toward the introduction portion 42 . The valve housing chamber 43 is partitioned by the valve body 32 into a spring chamber 44 in which the valve spring 33 is housed on the side opposite to the introduction portion 42 .

The valve housing 31 is
The first discharge hole 51 opens when the discharge pressure PO of the oil pump 10 rises to a preset first reference pressure P1 and the valve body 32 moves in the direction Rc in which the valve spring 33 contracts due to the oil introduced from the introduction portion 42 . When,
The discharge passage 55 is connected only to the first discharge hole 51 and communicates with the spring chamber 44, and the discharge pressure PO increases to the second reference pressure P2 higher than the first reference pressure P1. a communication hole 53 that closes when the valve body 32 moves in the direction Rc in which the valve spring 33 contracts due to the oil introduced from 42;
a pressure relief hole 54 communicating from the spring chamber 44 to the suction portion 13 of the oil pump 10;
When the discharge pressure PO increases to a third reference pressure P3, which is higher than the second reference pressure P2, and the oil introduced from the introduction portion 42 causes the valve body 32 to move in the direction Rc in which the valve spring 33 contracts, the valve spring 33 is opened. and a second discharge hole 52 for discharging to the suction portion 13 of the oil pump 10 .

The first discharge hole 51, the second discharge hole 52, the communication hole 53, and the pressure relief hole 54 are provided in this order in the direction Rc in which the valve spring 33 contracts. A discharge passage 55 is formed in the valve housing 31 .

Thus, in the valve housing 31, the first discharge hole 51, the second discharge hole 52, the communication hole 53, and the pressure relief hole 54 are provided in this order in the direction Rc in which the valve spring 33 contracts. In general, the spring chamber 44 is provided with a pressure relief hole 54 communicating with the suction portion 13 of the oil pump 10 . The present invention takes advantage of this pressure relief hole 54 .

The communication hole 53 can communicate with the pressure relief hole 54 via the spring chamber 44 . The first discharge hole 51 communicates with the communication hole 53 via a discharge passage 55 formed in the valve housing 31 . Moreover, the first discharge hole 51 and the communication hole 53 do not communicate with the second discharge hole 52 . The discharge pressure PO can be controlled step by step by simply opening and closing the first discharge hole 51, the communication hole 53, and the second discharge hole 52 sequentially by the valve body 32 as the discharge pressure PO increases. Therefore, the sliding stroke of the valve element 32 can be shortened as the discharge pressure PO increases. Accordingly, the size and weight of the relief valve 30 can be reduced, and the degree of freedom in arranging the holes 51 to 54 can be increased. Moreover, since the stroke of the valve body 32 is shortened, the durability of the valve spring 33 can be enhanced.

In addition, the first discharge hole 51 and a communication hole 53 spaced apart from the first discharge hole 51 in the direction Rc in which the valve spring 33 contracts are communicated by a discharge passage 55 . For this reason, the opening and closing timings of the valve body 32 are determined by the separate holes, ie, the first discharge hole 51 and the communication hole 53, when the discharge pressure PO rises to the first reference pressure P1 and when the discharge pressure PO rises to the second reference pressure P2. Can be done at different times. Therefore, in the relief valve 30 of the present invention, it is possible to set relief characteristics that could not be achieved with conventional relief valves. Therefore, the discharge characteristics of the oil pump 10 can be diversified.

Furthermore, all the holes 51-54 are concentrated only in the valve housing 31. The valve body 32 only needs to sequentially open and close the first discharge hole 51, the communication hole 53, and the second discharge hole 52 as the discharge pressure PO increases. Therefore, the valve body 32 does not need to be provided with holes or grooves for controlling the discharge pressure PO. Since the valve body 32 can have a simple structure, the manufacturing cost can be reduced.

As is clear from the above description, in the present invention, the relief valve 30 that controls the discharge pressure PO of the oil pump 10 in two steps can be made simple and compact.

Further, the valve housing 31 includes a housing body 40 having an introduction portion 42, a valve accommodating chamber 43, a first discharge hole 51, a second discharge hole 52, a communication hole 53, and a pressure relief hole 54; A cover 60 that covers the side surface 41 of the main body 40 to close the first discharge hole 51, the second discharge hole 52, the communication hole 53, and the pressure relief hole 54 from the outside. The discharge passage 55 is constituted by a groove 55a formed in the housing body 40. As shown in FIG. The opening of this groove 55a is closed by a cover 60. As shown in FIG.

Thus, all the holes 51 to 54 and the discharge passages 55 formed in the housing body 40 are closed by covering the side surface 41 of the housing body 40 with the cover 60. As shown in FIG. That is, the positions of all the holes 51 to 54 and the discharge passage 55 are concentrated on the side surface 41 (flange surface 41) of the housing body 40. As shown in FIG. Therefore, for example, when the housing main body 40 is made of a cast product (such as a die-cast product), it can be made by casting in the casting stage. Although the valve housing 31 has a large number of holes 51-54 and discharge passages 55, the manufacturing cost of the valve housing 31 can be suppressed.

Next, the relief valve 130 of Example 2 will be described with reference to FIG.
<Example 2>

FIG. 5 is a cross-sectional view for explaining the relief valve 130 of Example 2, and corresponds to FIG. 2 for explaining the relief valve 30 of Example 1 above. A valve housing 131 of the relief valve 130 of Example 2 includes a housing body 40 and a cover 160 . The structure of the housing body 40 is similar to that of the first embodiment. However, the side surface 41 of the housing body 40 of Example 2 does not have the discharge passage 55 . That is, the relief valve 130 of Example 2 is characterized in that the discharge passage 155 is provided in the cover 160 . The cover 160 corresponds to the cover 60 of Example 1 shown in FIG. Similar to the cover 60 of the first embodiment, the cover 160 has a flat cover surface 161 (matching surface 161) that is hermetically overlapped with the flange surface 41, and is detachably attached to the housing body 40 by fastening members such as bolts. It is

The discharge passage 155 corresponds to the discharge passage 55 of Embodiment 1 shown in FIGS. That is, the relief valve 130 of the second embodiment is characterized in that the discharge passage 155 is formed in the cover surface 161 of the cover 160 . Other basic configurations are common to the relief valve 30 . Reference numerals are used for parts common to the relief valve 30, and detailed description thereof is omitted.

More specifically, the valve housing 131 of the relief valve 130 is a housing body defining an introduction portion 42, a valve accommodating chamber 43, a first discharge hole 51, a second discharge hole 52, a communication hole 53, and a pressure relief hole 54. 40, and a cover 160 that closes the first discharge hole 51, the second discharge hole 52, the communication hole 53, and the pressure relief hole 54 from the outside by covering the side surface 41 (flange surface 41) of the housing body 40. It is configured.

The communication hole 53 is connected only to the first discharge hole 51 by the discharge passage 155 . This discharge passage 155 corresponds to the discharge passage 55 of the first embodiment. This discharge passage 155 is constituted by a groove 155 a formed in the cover 160 . This groove 155a is formed in a U shape bypassing the second discharge hole 52, like the groove 55a of the first embodiment shown in FIG. The opening of this groove 155 a is closed by the housing body 40 .

Since the discharge passage 155 is thus formed in the cover 160, it is easy to manufacture. Despite having a large number of holes 51-54 and one discharge passage 55 in the valve housing 131, the manufacturing cost of the valve housing 131 can be suppressed. Other actions and effects are the same as those of the relief valve 30 shown in FIGS.

Next, the relief valve 230 of Example 3 is demonstrated, referring FIG.6 and FIG.7.
<Example 3>

FIG. 6 is a cross-sectional view for explaining the relief valve 230 of Example 3, and corresponds to FIG. 5 for explaining the relief valve 130 of Example 2 above. FIG. 7 is an exploded view of relief valve 230 shown in FIG.

In the relief valve 230 of the third embodiment, the closing member 270 is interposed between the side surface 41 of the housing body 40 and the cover surface 261 of the cover 260, and the opening of the groove 255a of the discharge passage 255 provided in the cover 260 is closed. , is closed by a closing member 270 . The discharge passage 255 corresponds to the discharge passage 155 of the second embodiment shown in FIG. The cover 260 corresponds to the cover 160 of Example 2 shown in FIG. The flat cover surface 261 (matching surface 261) is tightly overlapped with the flange surface 41, and the cover 260 is detachably attached to the housing body 40 by fastening members such as bolts. Other basic configurations are common to the relief valves 30; 130 described above. The same reference numerals as those of the relief valves 30; 130 are used, and detailed description thereof is omitted.

More specifically, the valve housing 231 of the relief valve 230 is a housing body defining an introduction portion 42, a valve accommodating chamber 43, a first discharge hole 51, a second discharge hole 52, a communication hole 53, and a pressure relief hole 54. 40, a cover 260 that closes the first discharge hole 51, the second discharge hole 52, the communication hole 53, and the pressure relief hole 54 from the outside by covering the side surface 41 of the housing body 40 via a closing member 270; It is composed by

The communication hole 53 is connected only to the first discharge hole 51 by the discharge passage 255 . This discharge passage 255 is constituted by a groove 255 a formed in the cover 260 . The opening of this groove 255 a is closed by a closing member 270 and communicates with the first discharge hole 51 and the communication hole 53 through through

holes

271 and 272 formed in this closing member 270 .

The closing member 270 is composed of, for example, a flat plate, and is interposed between the side surface 41 (flange surface 41) of the housing body 40 and the cover surface 261 (matching surface 261) of the cover 260. The contour of this closure member 270 follows the contour of the cover surface 61 of the cover 260 . Therefore, the closing member 270 completely covers the cover surface 61 of the cover 260 and the side surface 41 of the housing body 40 . The closing member 270 is sandwiched between the housing body 40 and the cover 260 to separate the grooves 255a from the members 51 to 54, and is therefore also called a separate plate 270. As shown in FIG. The housing main body 40, the cover 260 and the closing member 270 are detachably integrated by a connecting member (not shown). As a result, the opening of the groove 255 a is closed by the closing member 270 .

The groove 255a extends linearly and slenderly in the direction in which the first discharge holes 51 and the communication holes 53 are arranged. One end 255b of the groove 255a in the longitudinal direction is located corresponding to the position of the first discharge hole 51. As shown in FIG. The other end 255 c of the groove 255 a in the longitudinal direction is positioned corresponding to the position of the communication hole 53 . One of the two through-

holes

271 and 272 formed in the closing member 270 is called a first through-hole 271 and the other is called a second through-hole 272 . The first through-hole 271 communicates the one end 255b of the groove 255a in the longitudinal direction with the first discharge hole 51 . The second through hole 272 communicates the other longitudinal end 255 c of the groove 255 a with the communication hole 53 .

As is clear from the above description, the closing member 270 is interposed between the side surface 41 of the housing body 40 and the cover surface 261 of the cover 260. As described above, the second discharge hole 52 is positioned between the first discharge hole 51 and the communication hole 53 . The closing member 270 can separate and make the first discharge hole 51 , the communication hole 53 and the groove 255 a independent from the second discharge hole 52 . The groove 255a may have a simple configuration that extends linearly and slenderly in the arrangement direction of the first discharge holes 51 and the communication holes 53 without bypassing the second discharge holes 52 . Therefore, it is easy to manufacture the cover 260 having the discharge passage 255 . Although the valve housing 231 has many holes 51-54 and the discharge passages 55, the manufacturing cost of the valve housing 231 can be suppressed.

Moreover, by using the closing member 270, it is possible to increase the degree of freedom in arranging the discharge passage 255 in the valve housing 231 and the degree of freedom in the shape of the discharge passage 255 itself. Therefore, the degree of freedom in designing the relief valve 230 can be increased. Other actions and effects are the same as those of the relief valve 30 shown in FIGS. 1 to 4 and the relief valve 130 shown in FIG.

It should be noted that the present invention is not limited to the examples and modifications as long as the actions and effects of the present invention are achieved.

The oil pump 10 is not limited to a trochoid pump, and may be, for example, a gear pump or other pumps.

Also, if it is desired to increase the amount of oil discharged from the first discharge hole 51, it is possible to increase the numbers of the first discharge holes 51, the communication holes 53, and the pressure relief holes 54 to two or more, respectively. For example, two or more first discharge holes 51, communication holes 53 and pressure relief holes 54 may be arranged in parallel along the discharge passages 55; 155; While considering the total hole area of these

holes

51, 53, and 54, rather than increasing the hole diameters of the first discharge hole 51, the communication hole 53, and the pressure relief hole 54 one by one, the small diameter holes 51, 53, and 54 are The length of the relief valves 30; 130; 230 can be shortened by providing a plurality of the

relief valves

53 and 54, respectively.

Further, as shown in FIG. 4, in order to finely control the discharge pressure PO of the oil pump 10 in accordance with the rotational speed Ne of the engine 20, the hole area (opening area) of the first discharge hole 51 is The opening area of the hole 53 and the area of the discharge passage 55 are preferably set to be equal or larger.

Also, the hole area (opening area) of the pressure relief hole 54 is preferably set larger than the hole area of the first discharge hole 51 and the hole area of the communication hole 53 . This is because when the oil is discharged from the pressure relief hole 54 , the movement of the valve body 32 changes the volume of the spring chamber 44 . Therefore, the amount of oil discharged from the pressure relief hole 54 is the sum of the amount of oil discharged from the first discharge hole 51 and the communication hole 53 and the amount of oil discharged from the spring chamber 44. . Since it is necessary to discharge both oils, the hole area of the pressure relief hole 54 is increased.

Further, the valve housing 31; Oil is relieved in the oil pan 21 of 20. 131 ; 231 and the oil pump 10 are configured separately, the second discharge holes 52 discharge the introduced oil to the oil pan 21 . Also, the pressure relief hole 54 communicates the oil with the oil pan 21 . Thus, in the present invention, the second discharge hole 52 and the pressure relief hole 54 include a structure that communicates with the suction portion 13 of the oil pump 10 or the oil pan 21 .

In addition, the valve housing 31; 131; 231 includes a structure in which the housing body 40 and the cover 60; 160; 260 are integrated.

The present invention is suitable for a relief valve provided in a flow path for engine oil or the like.

REFERENCE SIGNS LIST 10 oil pump 13 intake portion 20 engine 21

oil pan

30, 130, 230

relief valve

31, 131, 231 valve housing 32 valve element 33 valve spring 40 housing body 41 side surface (flange surface)
42 introduction part 43 valve storage chamber 44 spring chamber 51 first discharge hole 52 second discharge hole 53 communication hole 54

pressure relief hole

55, 155, 255 discharge passage 55a, 155a, 255a groove 56 bypass passage 60 cover 160 cover 260 cover 270 Closing member PO Discharge pressure of oil pump P1 First reference pressure P2 Second reference pressure P3 Third reference pressure Rc Direction in which valve spring contracts

Claims

A valve housing having an introduction portion for introducing oil from a discharge portion of an oil pump and a valve housing chamber communicating with the introduction portion, a valve body slidably housed in the valve housing chamber, and the valve body. A relief valve comprising a valve spring that biases toward the introduction portion,
The valve storage chamber is partitioned by the valve element into a spring chamber in which the valve spring is stored on the side opposite to the introduction portion,
The valve housing is
a first discharge hole that opens when the discharge pressure of the oil pump rises to a preset first reference pressure and the valve element moves in a direction in which the valve spring contracts due to the oil introduced from the introducing portion;
The oil introduced from the introduction portion is connected to the first discharge hole by a discharge passage and communicates with the spring chamber so that the discharge pressure increases to a second reference pressure higher than the first reference pressure. a communication hole that closes when the valve element moves in the direction in which the valve spring contracts due to
a pressure relief hole communicating from the spring chamber to the suction portion of the oil pump or the oil pan;
When the discharge pressure rises to a third reference pressure higher than the second reference pressure, the valve element is moved in a direction in which the valve spring contracts due to the oil introduced from the introducing portion. a second discharge hole that discharges to the suction part of the oil pump or the oil pan,
The first discharge hole, the second discharge hole, the communication hole, and the pressure relief hole are provided in this order in the direction in which the valve spring contracts,
A relief valve, wherein the discharge passage is formed in the valve housing.
The valve housing includes a housing body defining the introducing portion, the valve accommodating chamber, the first discharge hole, the second discharge hole, the communication hole, and the pressure relief hole, and a side surface of the housing body. a cover that closes the first discharge hole, the second discharge hole, the communication hole, and the pressure relief hole from the outside by covering,
The discharge passage is configured by a groove formed in the housing body,
2. The relief valve according to claim 1, wherein the opening of said groove is closed by said cover.
The valve housing includes a housing body defining the introducing portion, the valve accommodating chamber, the first discharge hole, the second discharge hole, the communication hole, and the pressure relief hole, and a side surface of the housing body. a cover that closes the first discharge hole, the second discharge hole, the communication hole, and the pressure relief hole from the outside by covering,
The discharge passage is configured by a groove formed in the cover,
2. The relief valve according to claim 1, wherein the opening of said groove is closed by said housing body.
The valve housing includes a housing body defining the introducing portion, the valve accommodating chamber, the first discharge hole, the second discharge hole, the communication hole, and the pressure relief hole, and a side surface of the housing body. a cover that closes the first discharge hole, the second discharge hole, the communication hole, and the pressure relief hole from the outside by covering via a closing member,
The discharge passage is configured by a groove formed in the cover,
2. The method according to claim 1, wherein the opening of the groove is closed by the closing member and communicates with the first discharge hole and the communication hole through a through hole formed in the closing member. relief valve.