JP4447939B2 - Variable check valve - Google Patents

Description

  The present invention relates to a variable check valve that can vary a valve opening pressure.

2. Description of the Related Art Conventionally, an engine lubricating oil pump has been known as one that supplies lubricating oil to an engine. Such a lubricating oil pump for an engine is disclosed in Patent Document 1. In this engine lubricating oil pump, the oil discharge amount is adjusted according to the engine negative pressure by a check valve.
Japanese Patent Laid-Open No. 2000-320313 (FIG. 5)

  A conventionally known check valve is shown in FIG. The check valve 60 forms a discharge passage 62 that communicates with the engine (intake manifold). The check valve 60 communicates with a main body 64 attached to the body 63, the discharge passage 62, and an oil pump (not shown). It is comprised from the pipe 66 which formed the introduction channel | path 65 inside. A valve seat 67 as a step portion is formed in the middle of the discharge passage 62. A ball-shaped valve body 68 and a spring 69 that urges the valve body 68 toward the valve seat 67 are provided in the discharge passage 62. When the operation is stopped, the valve body 68 is seated on the valve seat 67 by the spring 69 and the discharge passage 62 is closed by the valve body 68, and when negative pressure on the engine side acts on the discharge passage 62, the negative pressure is applied to the spring 69. Accordingly, the valve body 68 is separated from the valve seat 67 to open the discharge passage 62, and oil from the oil pump is discharged to the engine side via the introduction passage 65 and the discharge passage 62.

  In the conventional check valve shown in FIG. 3, a valve body 68 and a spring 69 are provided in a discharge passage 62 through which oil flows, and the valve opening pressure acting on the valve body 68 is constant. Therefore, if you try to minimize the amount of oil discharged by the engine side negative pressure (intake manifold negative pressure for 2-cycle reciprocating engines, negative pressure in the rotor intake process for rotary engines), the valve opening pressure will be the maximum negative pressure. It is necessary to set it to correspondence. As a result, when the valve opening pressure is set to correspond to the maximum negative pressure, the discharge load increases and the oil discharge amount decreases from the time when the negative pressure is low to the time when the negative pressure is positive. The oil discharge amount characteristic in this case is a dotted line (1) in FIG. The oil discharge amount characteristic is considered to be the solid line (2) in FIG. 4 where the engine speed and the oil discharge amount are directly proportional, but the oil discharge amount characteristic (dotted line (1)) of the conventional check valve is It is in a state far from its ideal form. On the other hand, even if the valve opening pressure is set so as to correspond to a low negative pressure, there is a problem in that the oil is discharged more than necessary at the maximum negative pressure, and white smoke is generated due to excessive consumption of oil.

  The conventional rotary engine lubrication oil pump is combined with a check valve that adjusts the oil amount and an air amount adjusting means that is introduced into the engine together with the oil to eliminate the conventional problems. Has been proposed. This flow control valve is shown in FIG. The flow rate adjusting valve 70 includes a check valve 72 and an air amount adjusting means 74. The check valve 72 includes a first body 76 and a second body 78, a first oil introduction passage 80 is formed inside the first body 76, and a second oil introduction passage 82 is formed inside the second body 78. To do. A ball-shaped valve body 84 is provided in the second oil introduction passage 82, and the valve body 84 is attached so that the connection position between the first oil introduction passage 80 and the second oil introduction passage 82 is closed by the valve body 84 when the operation is stopped. And a spring 86 to be energized.

  The air amount adjusting means 74 is formed in the connector bolt 88 fixed to the body 87, the air introduction passage 90 formed inside the connector bolt 88, for introducing air from the outside, and the air introduction passage 90. A pipe 94 forming an air communication passage 92, an umbrella valve 96 for opening and closing the air introduction passage 90 in the middle of the air introduction passage 90, and a second oil introduction passage 82 of the check valve 72. The third oil introduction passage 98 formed outside the pipe 92 inside the connector bolt 88 and on the one hand the third oil introduction passage 98 and the air communication passage 90 in the pipe 92 and the engine ( The injection nozzle 100 communicates with the intake manifold side.

  In the flow rate adjusting valve shown in FIG. 5, when the engine negative pressure reaches the injection nozzle 100, the negative pressure reaches the second oil introduction passage 82 from the third oil introduction passage 98, and resists the valve body 84 against the spring 84. Move. By the movement of the valve body 84, the first oil introduction passage 80 and the second oil introduction passage 82 are brought into communication, and oil is introduced into the injection nozzle 100 from an oil pump (not shown). On the other hand, when the engine negative pressure reaches the injection nozzle 100, the negative pressure reaches the air communication passage 92 and operates the umbrella valve 96 to open the air introduction passage 90, whereby air is introduced into the injection nozzle 100. . In the injection nozzle 100, oil and air are mixed, the amount of oil is adjusted, and oil and air are discharged to the engine side. Thus, in the flow rate adjusting valve, by mixing air with oil, the oil discharge amount can be made substantially proportional to the engine speed, and the oil discharge amount characteristic of the solid line (2) in FIG. 4 can be obtained.

  In the flow rate adjusting valve shown in FIG. 5, the oil discharge amount characteristic can be brought into a state close to the solid line (2) in FIG. 4 in which the engine speed and the oil discharge amount are directly proportional. However, the solid line (2) in FIG. 4 is considered to be an ideal form, but this solid line (2) is an oil discharge amount characteristic that is assumed to be ideal for convenience. The curve (3) shown is the ideal oil discharge amount characteristic. Therefore, also in the flow rate adjusting valve shown in FIG. 5, the oil discharge amount characteristic is different from the actual ideal characteristic (curve (3) in FIG. 4).

  In the flow rate adjusting valve shown in FIG. 5, air and oil are guided to the injection nozzle 100 by the negative pressure from the engine. However, since the negative pressure exerts a greater influence on the air than the negative pressure exerts on the oil, the oil is mixed with the air injected from the injection nozzle 100, and the oil is ejected vigorously on the engine side (inside the intake manifold). To be scattered in the engine. For this reason, there has been a problem that oil cannot be injected to an appropriate position on the engine side (inside the intake manifold).

  The present invention has been made in view of the above points, and provides a variable check valve capable of adjusting the oil discharge amount characteristic to an actual ideal characteristic and discharging oil to an appropriate position on the engine side. It is for the purpose.

To achieve the above object, the present invention provides a body, an oil passage formed in the body and communicating with the engine, a piston movably provided in the body, and opening and closing the oil passage. And a first spring provided between the valve body and the piston for biasing the valve body and the piston in a direction away from each other, opposite to a position of the piston in contact with the first spring a diaphragm for fixing the ends of the side, and the negative pressure introducing chamber communicating with the engine be one that is divided into the piston side by said body and its diaphragm, there is provided in the negative pressure introducing in entering the A second spring is provided to bias the piston and the diaphragm in a direction away from the first spring side. In the present invention, a plurality of the oil passages are formed in the body, the valve body and the first spring are provided for each oil passage, and one main piston for fixing the piston to the diaphragm and each of the oils Each of the passages includes a plurality of sub-pistons that come into contact with the first spring and a connecting member that fixes the plurality of sub-pistons and the main piston. The present invention, said the oil passage oil guide passage is obtained by the consist and the oil discharge passage, a space for accommodating them contact to those in a in a front Kiben member and said first spring.

  In the present invention, two engine negative pressure operating spaces and two types of springs are used, and one of the two effective areas is formed using a diaphragm, thereby increasing the ratio of the two effective areas. Can be set. As a result, it is possible to obtain an ideal oil discharge characteristic of the pump by including not only the engine negative pressure but also many other elements in the element of the calculation formula of the valve opening pressure S. As a result, it becomes possible to supply an appropriate amount of oil according to the operating state, and the economy can be improved. In the present invention, since oil is not injected together with air as in the conventional example, the oil can be discharged to an appropriate position in the intake manifold (engine), so that lubricity in various engines can be improved.

Next, the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view of a variable check valve according to the present invention. The variable check valve 10 has a body 12, and a piston 14 is movably provided on the body 12. A chamber 16 is formed inside the body 12 by the piston 14 and the body 12. One of the body 12 is connected to an oil pump (not shown) and the other is connected to the chamber 16. An oil introduction passage 18 is connected to the engine (not shown) and the other is connected to the chamber 16. A discharge passage 20 is formed. Accordingly, in the variable check valve, oil is discharged from the oil introduction passage 18 through the chamber 16 to the engine side from the oil discharge passage 20. In the variable check valve, the oil introduction passage 18 through which oil passes, the chamber 16 and the oil discharge passage 20 are combined to form an oil passage.

  Inside the chamber 16, for example, a ball-shaped valve body 22 and a first spring 24 for urging them in opposite directions are provided between the valve body 22 and the piston 14. The position of the opening of the oil introduction passage 18 on the chamber 16 side is a valve seat 26, and the valve body 22 is urged by the first spring 24 in the direction of seating on the valve seat 26.

  A cover 30 is attached to the body 12 with the diaphragm 28 sandwiched therebetween. In a state where the cover 30 is fixed to the body 12, the body 12 and the diaphragm 28 form a negative pressure introduction chamber 32, and the cover 30 and the diaphragm 28 form an air chamber 34. The body 12 is formed with a negative pressure introduction passage 36 that communicates one side with the engine (not shown) and communicates the other side with the negative pressure introduction chamber 32. The opposite side of the piston 14 from the position in contact with the first spring 24 passes through the negative pressure introduction chamber 32 and is fixed to the diaphragm 28. A second spring 38 is provided in the negative pressure introducing chamber 32 between the diaphragm 28 and the body 12 to urge them in opposite directions. By this second spring 38, the diaphragm 28 and the piston 14 are always urged in the direction of moving to the air chamber 34 side (the side opposite to the chamber 16). A communication hole 40 for connecting the air chamber 34 and the atmosphere is formed in the cover 30, and atmospheric pressure always reaches the air chamber 34.

Here, the effective area of the diaphragm 28 is A, and the pressure receiving area of the oil introduction passage 18 is B. The spring constant of the first spring 24 is k1, the initial set load of the first spring 24 is F1, the spring constant of the second spring 38 is k2, and the initial set load of the second spring 38 is F2. . The initial set load F2 of the second spring 38 is an initial set load in consideration of vibration acceleration so that there is no displacement due to vibration. Further, let R be the sliding resistance of the piston 14. Since the oil discharge passage 20 communicating with the chamber 16 and the negative pressure introduction passage 36 communicating with the negative pressure introduction chamber 32 are both in communication with the engine, if the pressure applied to the chamber 16 is P, the pressure applied to the negative pressure introduction chamber 32 is also P. If the valve opening pressure at which the valve body 22 opens under the above premise is S,
The valve opening pressure S = ((− PA−F2−R) × k1 ÷ k2 + F1 + PB) ÷ B.

  In order to reflect the pressure fluctuation sensitively in the valve opening pressure S, it is preferable to increase the difference between the effective area A of the diaphragm 28 and the pressure receiving area B of the oil introduction passage 18. Therefore, the diaphragm 28 is used so that the effective area A can be set large.

  In the present invention, the valve opening pressure S changes based on the above calculation formula, and includes not only the engine-side negative pressure P (intake manifold negative pressure) but also many other elements. As a result, conventionally, the valve opening pressure is greatly influenced directly by the engine-side negative pressure, whereas the valve-opening pressure of the present invention includes many other elements, so that the influence of the engine-side negative pressure is reduced. Can do. Furthermore, the valve opening pressure S is changed by changing the position of the piston 14 in accordance with the pressure P, and the ideal oil discharge amount ((3) in FIG. 4) of the pump can be discharged to the intake manifold. . Specifically, in the present invention, the valve is opened by two springs, a first spring 24 interposed between the piston 14 and the valve body 22, and a second spring 38 that controls the movement of the piston 14 and the diaphragm 28. Since the pressure is controlled, it is possible to obtain oil discharge characteristics ((3) in FIG. 4) more in accordance with engine characteristics.

  As described above, according to the present invention, the oil discharge characteristic according to the engine characteristic can be obtained, so that an appropriate amount of oil according to the operation state can be supplied, and the economic efficiency can be improved. In the present invention, since oil is not injected together with air as in the conventional example, it is possible to prevent the oil from scattering into the intake manifold (engine) and discharge the oil to an appropriate position. Lubricity is improved.

  The variable check valve 10 shown in FIG. 1 has one oil passage, but FIG. 2 shows an example in which a plurality of oil passages are provided. 2, the same reference numerals as those in FIG. 1 denote the same members. The difference between the variable check valve 42 shown in FIG. 2 and the variable check valve 10 shown in FIG. 1 will be described. First, two oil passages (the oil introduction passage 18, the chamber 16, and the oil discharge passage 20) are formed in the body 44, and one communication space 46 that communicates with the two chambers 16 is formed in the body 44. Next, the piston 48 has one end fixed to the diaphragm 28 and the other end reaching the communication space 46, and a connecting member 52 that is accommodated in the communication space 46 and fixed to the main piston 50. The sub piston 54 is inserted into each chamber 16 and once fixed to the connecting member 52. Furthermore, the valve body 22 is provided in each of the two chambers 16, and a first spring 56 is provided between the valve body 22 and the sub-piston 54 to urge them in opposite directions.

  The valve opening pressure S of the variable check valve 42 shown in FIG. 2 is compared with the valve opening pressure S of the variable check valve 10 shown in FIG. 1, the spring constants and initial set loads of the two first springs 56, and the piston 48. The numerical value of the sliding resistance is slightly different and basically does not change. Therefore, the same effect as the variable check valve 10 shown in FIG. 1 can be obtained. Furthermore, since the variable check valve 42 shown in FIG. 2 has two oil discharge passages 20, there is an advantage that oil can be discharged to two places of the intake manifold. In addition, although the variable check valve 42 in FIG. 2 has two oil passages formed therein, it is also possible to form three or more oil passages in the variable check valve.

It is sectional drawing of the variable check valve which concerns on this invention. It is sectional drawing of the variable check valve | bulb which showed the application example of this invention. It is sectional drawing which shows the conventional check valve. It is a figure which shows the oil discharge amount characteristic of the past and this invention. It is sectional drawing which shows the conventional flow regulating valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Variable check valve 12 Body 14 Piston 16 Chamber 18 Oil introduction passage 20 Oil discharge passage 22 Valve body 24 First spring 28 Diaphragm 32 Negative pressure introduction chamber 36 Negative pressure introduction passage 38 Second spring 42 Variable check valve 44 Body 48 Piston 50 Main piston 52 Connecting member 54 Sub piston 56 First spring

Claims (3)

A body, an oil passage formed in the body and communicating with the engine, a piston movably provided in the body, a valve body for opening and closing the oil passage, the valve body, and the A first spring provided between the piston and biasing the valve body and the piston away from each other; a diaphragm for fixing an end of the piston opposite to a position in contact with the first spring; and the diaphragm the body and by the negative pressure introducing chamber communicating with the engine be one that is divided into the piston side, said diaphragm and said first spring side to the piston be those provided in the negative pressure introducing the entry and And a second spring biased in a direction away from the variable check valve. A plurality of oil passages are formed in the body, the valve body and the first spring are provided for each oil passage, and one main piston for fixing the piston to the diaphragm is provided for each oil passage. The variable check valve according to claim 1 , comprising a plurality of sub-pistons that are in contact with the first spring, and a connecting member that fixes the plurality of sub-pistons and the main piston. Wherein the oil passage is an oil introduction passage, the oil and the discharge passage, according to claim 1 or 2, characterized in that comprising a space for accommodating them contact to those in a in a front Kiben member and said first spring Variable check valve.

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