JP2015025551A - Valve structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve structure capable of suppressing a hunting phenomenon that may occur when a valve is operated in an oil circuit including an oil pump such as an engine for a vehicle with an extremely simple configuration.SOLUTION: A valve structure includes: a valve element 5; a valve housing A1 having an outflow hole 2A, a back pressure releasing hole 3, and a hunting preventing hole 4 in a valve element passage 11 having an inflow channel 12A on one end side; and an elastic member 6 for energizing the valve element 5 toward the inflow channel 12A of the valve element passage 11. The hunting preventing hole 4 is positioned between the outflow hole 2A and the back pressure releasing hole 3. The valve element 5 closes the outflow hole 2A and opens the hunting preventing hole 4 in a low engine speed range, and opens the outflow hole 2A and closes the hunting preventing hole 4 in a middle engine speed range and a high engine speed range.

Description

  The present invention relates to a valve structure that can suppress a hunting phenomenon that occurs when a valve operates in an oil circuit including an oil pump such as a vehicle engine with a very simple configuration.

  An oil pump that supplies lubricating oil to an automobile engine is equipped with a relief valve device for performing pressure control and an oil passage switching valve device that performs oil passage switching control for a variable displacement type oil pump. . First, the relief valve structure keeps the oil pressure below a certain level by letting the oil escape to another route so as not to adversely affect the equipment when the supply oil becomes high pressure in the oil pump. .

  In this relief valve structure, hunting may occur immediately after the relief is started. In particular, the relief valve of the oil pump often performs a hunting operation in a region immediately after the engine speed changes from a medium speed range to a high speed range. When hunting occurs, the hydraulic pressure increases and decreases violently and the valve body vibrates particularly in the axial direction.

  FIG. 11 is a graph showing this situation. According to this, it vibrates violently from the middle period to the latter period of the middle rotation speed range. Then, due to hunting, the components arranged in the oil circuit vibrate vigorously, which causes a problem that a large abnormal noise is generated. Also, in the oil passage switching valve device, hunting occurs when the oil passage switching valve is operated and the oil passage is switched. As a result, there is a similar problem in that a part or component on the downstream side of the oil passage switching valve vibrates violently and a large noise is generated.

JP 2001-263026 A

  As a means for preventing hunting, the relief valve or the oil passage switching valve has a spring constant such as a coil spring, or the weight of the relief valve or the oil passage switching valve is changed. Alternatively, the resonance point of the oil passage switching valve may be shifted. In such a means, for various oil pumps, relief valve devices or oil path switching valve devices having different characteristics, appropriate components such as a relief valve or an oil path switching valve and a spring mounted on them are used. Must be prepared. Therefore, there is a drawback that parts cannot be used in common, production of a large variety of products is in small quantities, and costs increase.

  In addition, as disclosed in Patent Document 1, there is a mechanism that includes a damper mechanism in the mechanism itself around the relief valve. In this patent document 1, a valve member that opens and closes a back pressure chamber side of a relief valve or an oil passage switching valve and a suction side of an oil pump by a temperature sensitive member is disposed, and this valve member is opened at a low temperature, A means for eliminating the damping action of the valve body of the relief valve device or the oil passage switching valve device is disclosed. When the valve member closes the passage, the back pressure chamber communicates with the suction side of the oil pump through the orifice to obtain a damping effect.

  Thus, it seems that there is a damping effect when the temperature is high, and the relief valve device or the oil path switching valve device will not cause hunting, but since the damping effect is eliminated when the oil is low temperature, the relief valve device or The oil path switching valve device may cause hunting.

  Further, in Patent Document 1, since a temperature sensitive member is required, the cost is high, and if the temperature sensitive member fails and the valve member remains open, the damping effect cannot be obtained. It is. Accordingly, an object of the present invention (technical problem to be solved) is to suppress hunting of the valve body in the relief valve device or the oil passage switching valve device with an extremely simple structure.

  In the first aspect of the present invention, the valve body, a valve housing having an outflow hole, a back pressure relief hole, and a hunting prevention hole in the valve body passage having an inflow channel formed on one end side, and the valve body An elastic member that urges the valve body passage toward the inflow channel, the anti-hunting hole is located between the outflow hole and the back pressure relief hole, and the valve body is in a low engine speed range. By closing the outflow hole and opening the hunting prevention hole, the valve body opens the outflow hole and closes the hunting prevention hole in the middle rotation speed range and the high rotation speed range. Solved the problem.

  In the invention of claim 2, the valve body, a valve housing having an outflow hole, a back pressure relief hole, and a hunting prevention hole in the valve body passage having an inflow channel formed on one end side, the valve body is An elastic member that urges the valve body passage toward the inflow channel, the anti-hunting hole is located between the outflow hole and the back pressure relief hole, and the effective axial length of the valve body is: The minimum distance from the position of the inflow opening of the inflow channel to the anti-hunting hole and the minimum distance from the outflow hole to the anti-hunting hole, and the minimum distance from the outflow hole to the anti-hunting hole The above problem was solved by using a valve structure formed longer than the above.

  According to the invention of claim 3, the valve body, a valve housing having an outflow hole, a back pressure relief hole, and a hunting prevention hole in the valve body passage having an inflow channel formed on one end side, and the valve body An elastic member that urges the valve body passage toward the inflow channel, the anti-hunting hole is located between the outflow hole and the back pressure relief hole, and the valve body is an inflow opening of the inflow channel. The inflow passage and the outflow hole are closed while being in contact with the periphery of the valve, the anti-hunting hole is in an open state, and the valve body is separated from the inflow passage, so that the outflow hole is opened. The above problem has been solved by adopting a valve structure in which the hunting prevention hole is closed and the back pressure relief hole is always open.

  According to a fourth aspect of the present invention, in any one of the first, second, and third aspects, the anti-hunting hole is configured by a plurality of holes arranged along the axial direction of the valve body passage. The above problem has been solved by adopting the valve structure as follows. The invention of claim 5 is the valve structure according to any one of claims 1, 2, or 3, wherein the anti-hunting hole is an elongated hole along the valve body passage. .

  A sixth aspect of the present invention is the valve structure according to any one of the first, second, and third aspects, wherein the anti-hunting hole and the back pressure relief hole are integrally formed in an elongated hole shape. The above problem has been solved. According to a seventh aspect of the invention, in the description of the first, second, third, fourth, fifth or sixth aspect, the outflow hole and the anti-hunting hole communicate with each other outside the valve housing. The above problem has been solved by adopting the valve structure as follows.

  According to an eighth aspect of the present invention, in any one of the first, second, third, fourth, fifth, sixth, and seventh aspects, the valve body is a relief valve, and the inflow channel relieves the valve body. The above problem has been solved by adopting a valve structure for performing a relief operation in which the relief flow path is moved and the outflow hole is a relief outflow hole.

  The invention of claim 9 is the valve body according to any one of claims 1, 2, 3, 4, 5, 6 or 7, wherein the valve body includes a first large diameter portion, a second large diameter portion, and the first large diameter portion. The inflow passage is a switching passage for switching and moving the oil passage switching valve, and the outflow hole is a switching discharge A switching inflow located between the first switching outflow hole and the second switching outflow hole, and between the first switching outflow hole and the second switching outflow hole. By forming a valve structure in which a hole is formed, the first switching outflow hole is opened and closed at the first large diameter portion, and the second switching outflow hole is opened and closed at the second large diameter portion. Solved the problem.

  In the first aspect of the present invention, the valve element closes the outflow hole and the hunting prevention hole opens in the low engine speed range, and the valve element opens the outflow hole in the medium engine speed range and the high engine speed range. By closing the hunting prevention hole, the resistance force of oil or air in the valve body passage on the rear side of the valve body is increased in the middle rotational speed range and the high rotational speed range, thereby enabling the valve by hunting. The resonance of the body can be suppressed.

  The valve body moves to the rear side of the valve body passage, opens the outflow hole and closes the anti-hunting hole, so that the discharge or inflow of oil or air in the valve body passage on the rear side of the valve body is a back pressure relief hole. Only by making it difficult for oil or air on the rear side of the valve body to enter and exit, resistance pressure increases, and resonance of the valve body can be suppressed.

  In the invention of claim 2, the axial effective length of the valve body is shorter than the minimum distance from the position of the opening of the inflow passage to the hunting prevention hole and the maximum distance between the outflow hole and the hunting prevention hole. Since it is formed and longer than the minimum distance between the outflow hole and the hunting prevention hole, the following operation is performed.

  First, when the valve body is moved to the rear side of the valve body passage by hydraulic pressure, the outflow hole is opened. When the outflow hole is opened, the hunting prevention hole can be closed. By closing the hunting prevention hole, only the back pressure relief hole is opened, and it becomes difficult for air and oil behind the valve body in the valve body passage to escape from the valve body passage. Suppresses resonance. The invention of claim 3 has the same effects as the inventions of claims 1 and 2.

  In the invention of claim 4, the hunting prevention hole is constituted by a plurality of holes arranged along the axial direction of the valve body passage, so that oil accumulated in the valve body passage on the rear side of the valve body or The resistance force of the air is changed stepwise, whereby the resonance of the valve body due to hunting according to each situation can be suppressed.

  In the invention of claim 5, the anti-hunting hole is an elongated hole along the valve body passage, so that the opening area of the anti-hunting hole gradually decreases with the movement of the valve body to the rear side. The amount of oil or air discharged can be gradually reduced.

  As a result, the resistance due to oil or air to the valve body when the valve body moves rearward gradually increases without suddenly increasing, and the impact on the valve body in the anti-hunting operation is reduced. The resonance of the valve body due to hunting can be suppressed.

  In the invention of claim 6, since the hunting prevention hole and the back pressure relief hole are integrally formed in the shape of a long and narrow hole, the hunting prevention hole and the back pressure relief hole are integrally formed to communicate with each other. The configuration can be made simpler than when the prevention hole and the back pressure relief hole are formed separately.

  And the said hunting prevention hole becomes a long and narrow hole along a valve body passage similarly to Claim 5, and the opening area of a hunting prevention hole becomes small gradually with the movement to the back side of a valve body, and it is by oil or air The resistance is gradually increased. Therefore, the resonance of the valve body due to hunting can be prevented while reducing the impact on the valve body in preventing hunting.

  According to the seventh aspect of the present invention, the outflow hole and the hunting prevention hole communicate with each other outside the valve housing, so that the oil discharged from the outflow hole passes through the back pressure relief hole and the hunting prevention hole. In some cases, a predetermined amount of oil or air can be secured in the valve body passage on the rear side of the valve body. As a result, resonance due to hunting of the valve body can be more strongly suppressed.

  In the eighth aspect of the present invention, the valve structure in the present invention is a relief valve structure, thereby preventing hunting during the relief operation. In the ninth aspect of the present invention, the valve structure in the present invention is an oil path switching valve structure, so that occurrence of hunting during the oil path switching operation can be prevented.

(A) is a plan view of a pump body provided with a relief valve structure according to the present invention, (B) is an enlarged cross-sectional view taken along line X1-X1 in (A), and (C) is an enlarged view of part (I) in (B). (D) is the (I) part enlarged view of the state which moved the valve body of (B) to the back side. (A) is an enlarged vertical side view of the present invention showing the state of the valve body in the low engine speed region of the relief valve structure of the present invention, and (B) is the state of the valve body in the medium engine speed region (previous term). FIG. 4C is an enlarged vertical side view of the present invention showing a state in which the relief discharge hole starts to open and the anti-hunting hole starts to close by the valve body in the middle rotation speed range (mid-term) of the engine. (A) is an enlarged longitudinal side view of the relief valve structure of the present invention in a state where the relief discharge hole is half-opened by the valve body and the hunting prevention hole is fully closed by the valve body in the middle rotation speed range (late stage) of the present invention, and (B) is the engine Fig. 4C is an enlarged vertical side view of the state in which the relief discharge hole is fully opened and the anti-hunting hole is fully closed by the valve body in the high engine speed range (first half), and (C) is the valve body in the high engine speed range (late stage) Furthermore, it is an expanded vertical side view of the state which moved to the back side of the valve body channel | path. (A) is an enlarged longitudinal sectional side view of the relief valve structure according to the second embodiment of the present invention in a state where the relief discharge hole is fully closed and the two anti-hunting holes are fully opened by the valve body in the low engine speed range of the engine. B) is an enlarged longitudinal side view of the engine with the relief discharge hole half-opened and one of the hunting prevention holes fully closed by the valve body in the middle rotation speed range (late stage), and (C) is the high rotation speed range of the engine ( It is an enlarged vertical side view in which the relief discharge hole is fully opened by the valve body and the two hunting prevention holes are fully closed in the previous period). (A) is an enlarged longitudinal side view of the relief valve structure according to the third embodiment of the present invention in a state where the relief discharge hole is fully closed and the hunting prevention hole is fully opened by the valve body in the low engine speed range of the engine, (B) (A) is an X2-X2 arrow view, and (C) is an enlarged longitudinal side view of a state where the relief discharge hole is half-opened by the valve body and a part of the anti-hunting hole is closed at the middle engine speed range (late stage). FIG. (A) is an enlarged longitudinal side view of the relief valve structure according to the fourth embodiment of the present invention in a state where the relief discharge hole is fully closed and the hunting prevention hole is fully opened by the valve body in the low engine speed range of the engine, (B) (C) is an enlarged longitudinal side view with the relief discharge hole half-opened by the valve body and part of the anti-hunting hole closed in the middle engine speed range (late stage). FIG. (A) is sectional drawing of the state which the oil flows out from a 1st switching hole by the structure which used the oil path switching valve structure in this invention for the variable displacement oil pump, (B) is the oil path switching valve structure in this invention. FIG. (A) is sectional drawing of the state which a valve body moves in the oil path switching valve structure in this invention, and an oil flows out from a 2nd switching hole, (B) is oil from an outflow hole in the oil path switching valve structure in this invention. It is sectional drawing of the state from which was discharged | emitted. (A) is sectional drawing of embodiment which made the hunting prevention hole of the oil-path switching valve structure in this invention the long hole, (B) is X4-X4 arrow line view of (A), (C) is the oil in this invention Sectional drawing of embodiment which formed the hunting prevention hole and back pressure relief hole of a path switching valve structure continuously, (D) is a X5-X5 arrow line view of (C). It is a graph which shows the characteristic of this invention. It is a graph which shows the characteristic of a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. There are two types of valve structures in the present invention, one is a relief valve structure, and the other is an oil passage switching valve structure. First, in the valve structure of the present invention, a relief valve structure will be described, and then an oil passage switching valve structure will be described. The relief valve structure is mainly composed of a valve housing A1 and a valve body 5 (see FIGS. 1A and 1B).

  Further, the relief valve structure and the oil passage switching valve structure both have an inflow passage 12A and an outflow hole 2A, which are a common concept. According to the respective roles in the relief valve structure and the oil passage switching valve structure, they have further individual names. Specifically, the inflow passage 12A is referred to as a relief passage 12 in the relief valve structure, and is referred to as a switching passage 18 in the oil passage switching valve structure. The outflow hole 2A is called a relief discharge hole 2 in the relief valve structure, and is called a switching discharge hole 19 in the oil passage switching valve structure.

  First, the first embodiment of the relief valve structure will be described. Although the relief valve structure may be incorporated on the engine block side, it is often incorporated into a part of the pump body A (see FIG. 1A). The relief valve structure will be described as an embodiment incorporated in the pump body A. In addition, the relief in this invention means discharging | emitting a part of the oil out of a circuit, when the pressure of the oil in the oil circuit in which the relief valve structure of this invention was integrated exceeds a preset value.

  The valve housing A1 is formed in a part of the pump body A [see FIG. 1 (A)]. A valve body passage 11 and a relief flow path 12 are provided inside the valve housing A1, and the valve body passage 11 and the relief flow path 12 are formed continuously in the axial direction. Specifically, the valve body passage 11 has a structure in which one axial end of the valve body passage 11 communicates with the relief flow path 12 (see FIGS. 1B and 1D). Here, in the valve body passage 11, the side communicating with the relief flow path 12 in the axial direction is the front side of the valve body passage 11, and the opposite side of the relief flow path 12 in the axial direction is the rear side of the valve body passage 11. And And the relief flow path 12 becomes a relief inflow path into which oil flows in to relieve the valve body 5 described later.

  The valve housing A1 is formed to bulge and form a substantially halved cylinder at a predetermined position in the pump body A. A valve body 5 is disposed in the valve body passage 11, and the valve body 5 reciprocates between the front side and the rear side along the axial direction of the valve body passage 11.

  The relief flow path 12 communicates with a discharge branch flow path 15 a from an oil pump discharge port 15 provided in the pump body A. When the oil discharged to the discharge port 15 exceeds a predetermined value and becomes a high pressure, the valve body 5 is caused by the force due to the pressure applied to the valve body 5 mounted in the valve housing A1 from the discharge branch flow path 15a. Is moved from the front side to the rear side in the valve body passage 11, and oil is fed into the valve body passage 11 through the relief flow path 12 to perform a relief operation.

  The relief flow path 12 communicates with the valve body passage 11. Specifically, the relief opening 12a of the relief flow channel 12 and the valve body passage 11 communicate with each other. The relief opening 12a is formed as a conical slope, and is formed so that the diameter gradually increases toward the valve body passage 11 (see FIG. 1D). The relief opening 12a is a portion where a chamfered portion 53 of the valve body 5 described later comes into contact, and the valve body 5 when stationary in this state is set to the initial position state of the valve body 5 [FIG. (See (C)).

  In the valve housing A1 and the valve body passage 11, a relief discharge hole 2, a back pressure relief hole 3, and a hunting prevention hole 4 are formed, and the relief discharge hole extends from the front to the rear in the axial direction of the valve body passage 11. 2, an anti-hunting hole 4 and a back pressure relief hole 3 are formed in this order (see FIGS. 1B and 1C).

  The relief discharge hole 2, the back pressure relief hole 3, and the hunting prevention hole 4 are portions that communicate the inside (the valve body passage 11) of the valve housing A1 with the outside. The relief discharge hole 2, the back pressure relief hole 3, and the hunting prevention hole 4 are configured to communicate with each other outside the valve housing A1.

  The back pressure relief hole 3 and the hunting prevention hole 4 are formed at different positions along the axial direction of the valve body passage 11, and the hunting prevention hole 4 is closer to the relief flow path 12 than the back pressure relief hole 3. That is, it is located on the front side in the axial direction of the valve body passage 11. The hunting prevention hole 4 is located between the back pressure relief hole 3 and the relief discharge hole 2.

  The hunting prevention hole 4 is opened and closed by the valve body 5 and is in a closed state or an open state. Further, the back pressure relief hole 3 is always open. The back pressure relief hole 3 and the hunting prevention hole 4 are equivalent in size, and specifically, are circular through holes having the same diameter.

  Further, the back pressure relief hole 3 and the hunting prevention hole 4 may be set to have different sizes. Specifically, the back pressure relief hole 3 is formed smaller than the hunting prevention hole 4 or the back pressure relief hole 3 is formed larger than the hunting prevention hole 4.

  The back pressure relief hole 3 is also referred to as a breathing hole. In the axial reciprocation of the valve body passage 11 of the valve body 5, the valve body 5 moves the valve body passage 11 to the opposite side of the relief flow path 12 by the oil pressure. When trying to move, the oil in the valve body passage 11 serves to smoothly move the valve body 5 by discharging resistance pressure due to air from the valve body passage 11 to the outside of the valve housing A1.

  The back pressure relief hole 3 is not closed by the valve body 5 and is always open. The hunting prevention hole 4 also serves as the aforementioned breathing hole, but is opened and closed by the reciprocating movement of the valve body 5.

  The relief discharge hole 2 is a through-hole, and usually has a larger area than the back pressure relief hole 3 and the anti-hunting hole 4 and may be circular, rectangular, or trapezoidal. Further, as shown in FIG. 1 (A), two through holes are arranged substantially symmetrically at an appropriate interval in the direction orthogonal to the axial direction of the valve housing A1, that is, in the width direction. See FIG. 1A].

  Inside the pump body A, a rotor chamber 13 constituting the pump is formed. An inner rotor 81 provided with external teeth in the rotor chamber 13 and an outer rotor 82 provided with internal teeth are eccentrically housed while meshing with each other.

  The inner rotor 81 and the outer rotor 82 are disclosed by an imaginary line (two-dot chain line) in FIG. Specifically, the inner rotor 81 is of a trochoid type. Then, the oil is sucked from the suction port 14 formed in the rotor chamber 13, and the oil is discharged from the discharge port 15 and circulated to the equipment.

  Next, the valve body 5 is composed of a cylindrical outer peripheral side portion 51 and a pressure receiving top portion 52, the cylindrical outer peripheral side portion 51 is formed in a cylindrical shape, and the disk-shaped pressure receiving portion is formed on the front side of the cylindrical outer peripheral side portion 51. A top 52 is formed. A chamfered portion 53 having a conical side surface is formed between the cylindrical outer peripheral side portion 51 and the pressure receiving top portion 52.

  In the present invention, the total length of the valve body 5 refers to the length from the axially rear end of the cylindrical outer peripheral side 51 to the pressure receiving top 52, but the relief discharge hole 2 and the hunting prevention hole 4 are closed on the outer peripheral side of the cylinder. Part 51. The axial length dimension of only the cylindrical outer peripheral portion 51 is referred to as an effective length Ls.

  When the valve body 5 is in the initial position state, the chamfered portion 53 abuts on the relief opening 12a of the valve body passage 11 to block the oil flow between the relief flow path 12 and the valve body passage 11; The relief channel 12 is closed (see FIGS. 1C and 2A).

  The chamfered portion 53 is in surface contact with the relief opening 12a of the relief flow path 12 and closes the relief opening 12a of the relief flow path 12. The cylindrical outer peripheral side portion 51 has a cylindrical shape having the same diameter at any position along the axial direction. The pressure receiving top portion 52 is a portion that receives the pressure of the oil flowing into the relief flow path 12, and the valve body 5 moves in the valve body passage 11 by the pressure.

  The valve body 5 housed in the valve body passage 11 of the valve housing A1 is disposed with the pressure receiving top portion 52 facing the relief flow path 12 (see FIGS. 1B and 1C). An elastic member 6 is attached to the valve body passage 11, and the valve body 5 is always elastically biased toward the front side of the valve body passage 11, that is, the relief flow path 12 side by the elastic member 6. The

  Specifically, a coil spring is used as the elastic member 6 (see FIG. 1B). The elastic member 6 is fixed by a support member 16 mounted at a position on the rear side in the axial direction of the valve body passage 11, that is, on the side opposite to the relief flow path 12.

The position of the valve body 5 when the relief pressure is not applied in the valve housing A1 is referred to as an initial position of the valve body 5. At this initial position, the chamfered portion 53 of the valve body 5 contacts the relief opening 12a in the valve body passage 11, and the relief flow path 12 is closed.

である。 In the present invention, the hunting prevention hole 4 is located between the relief discharge hole 2 and the back pressure relief hole 3. The effective length Ls in the axial direction of the valve body 5 is shorter than the minimum distance La from the position of the inflow opening 12a of the inflow channel 12A to the hunting prevention hole 4.
That is,

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である。 The effective length Ls in the axial direction of the valve body 5 is shorter than the maximum distance Lb between the relief discharge hole 2 and the anti-hunting hole 4.
That is,

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である。 The effective length Ls in the axial direction of the valve body 5 is formed longer than the minimum distance Lc between the relief discharge hole 2 and the anti-hunting hole 4.
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It is.

  With the above configuration, in the initial position of the valve body 5 in the valve housing A1, that is, in a state where the valve body 5 is disposed at a position close to the relief flow path 12 of the valve body passage 11, the following occurs. The relief flow path 12 is closed, and the relief discharge hole 2 is closed by the cylindrical outer peripheral side portion 51 of the valve body 5 (see FIG. 1B). Further, the back pressure relief hole 3 and the hunting prevention hole 4 are in an open state.

  Next, the relief operation in the low engine speed range, medium engine speed range, and high engine speed range of the present invention will be described. Here, the elastic member 6 in the present invention is a coil spring, and elastically biases the valve body 5 at the initial position from the rear side of the valve body passage 11 toward the relief opening 12a on the front side. .

  And the force by the pressure at the time of relief which the valve body 5 receives shall not shrink a coil spring unless it exceeds the predetermined elastic force which the elastic member 6 made into a coil spring has. That is, as long as the force due to the oil pressure does not exceed a predetermined value, the valve body 5 is brought into a stationary state by the elastic member 6.

  In the case of a low engine speed range (including an idling state) from the start of the engine, as shown in FIGS. 2A and 4, the discharge pressure is low even if the pump is operated. Therefore, since the elastic force by the elastic member 6 exceeds the force due to the pressure received by the pressure receiving top 52 of the valve body 5, the valve body 5 is maintained in the initial position in the valve body passage 11 [FIG. (See (A)). Therefore, relief (oil discharge) is not performed. At the initial position of the valve body 5, the relief discharge hole 2 is closed and the hunting prevention hole 4 is open.

  The rotational speed increases within the range of the low rotational speed range of the engine, and the pressure received by the pressure receiving top 52 of the valve body 5 also increases. However, the elastic force of the elastic member 6 exceeds the force due to this pressure. Is set as follows. Therefore, in the low rotation speed range, the valve body 5 is maintained in an immobile state at the initial position.

  Therefore, the relief flow path 12 remains closed in the low rotational speed range (see FIG. 4), and in the low rotational speed range, the hydraulic pressure by the pump is approximately proportional to the rotational speed as shown in the graph of FIG. To rise.

  Next, when the engine is in the middle rotation speed range, first, in the first half of the period, the hydraulic force received by the pressure receiving top 52 of the valve body 5 from the relief flow path 12 exceeds the elastic force of the elastic member 6. It starts to move toward the rear side in the axial direction of the passage 11 (the side opposite to the relief flow path 12) (see FIG. 2B).

  In the valve body 5 that moves the valve body passage 11 rearward, the valve body passage 11 on the rear side of the valve body 5 is filled with oil or air. This oil or air works as a resistance force Pt that resists the movement of the valve body 5. The back pressure relief holes 3 serve to discharge these to the outside of the valve housing A1 and make the movement of the valve body 5 smooth.

Similarly, the anti-hunting hole 4 plays the same role as the back pressure relief hole 3 as long as it is open. That is, when both the back pressure relief hole 3 and the hunting prevention hole 4 are open, the oil or air that fills the rear side of the valve body 5 is valved from both the back pressure relief hole 3 and the hunting prevention hole 4. It is discharged outside the housing A1. When the hunting prevention hole 4 is closed, the oil or air filled in the rear side of the valve body 5 from only the back pressure relief hole 3 is discharged to the outside of the valve housing A1.

  In the middle period of the medium speed range, the hydraulic pressure continues to rise, the valve body 5 continues to move, and the front end of the cylindrical outer peripheral side 51 passes through the relief discharge hole 2 and starts to open the relief discharge hole 2. At this time, the rear end of the cylindrical outer peripheral portion 51 starts to close the hunting prevention hole 4 (see FIG. 2C).

  Then, in the latter period of the middle rotation speed range, the valve body 5 moves, the relief discharge hole 2 is fully opened, and the hunting prevention hole 4 is fully closed (see FIG. 3A). That is, when the valve body 5 becomes slightly higher in hydraulic pressure than when the relief discharge hole 2 starts to open, the relief discharge hole 2 is fully opened and the hunting prevention hole 4 is fully closed.

  As described above, when the anti-hunting hole 4 is closed by the valve body 5, the oil or air in the valve body passage 11 on the rear side of the valve body 5 is discharged only from the back pressure relief hole 3. It becomes. Thereby, the resistance force Pt with respect to the movement to the valve body 5 by the oil in the valve body channel | path 11 or air will increase, and the movement to the back side of the valve body 5 is suppressed.

  Then, hunting occurs when the relief operation of the valve body 5 starts to be performed. At this time, the hunting prevention hole 4 is closed by the valve body 5, and oil or air on the rear side of the valve body 5 is discharged only from the back pressure relief hole 3. As a result, the amount of oil or air discharged is reduced, the resistance force Pt due to oil or air is increased, and the resonance of the valve body 5 due to hunting is suppressed.

  Next, when the engine is in a high speed range, the valve body 5 tends to move to the rear side of the valve body passage 11 as the hydraulic pressure continues to increase in the previous period. At this time, the anti-hunting hole 4 is closed, and the resistance force Pt due to the oil or air filled in the valve body passage 11 on the rear side of the valve body 5 further increases, and the resonance of the valve body 5 due to the hunting phenomenon. Is suppressed more strongly [see FIGS. 3B and 3C]. In this way, resonance due to hunting of the valve body 5 that occurs from the end of the medium engine speed range to the beginning of the high engine speed range is suppressed.

As described above, the relief discharge hole 2, the back pressure relief hole 3, and the hunting prevention hole 4 are configured to communicate with each other outside the valve housing A1. by this,
Oil discharged from the relief discharge hole 2 can flow from the back pressure relief hole 3 and the hunting prevention hole 4 and be sent to the valve body passage 11 on the rear side of the valve body 5. A predetermined amount of oil or air can always be ensured in the valve body passage 11 on the rear side of the valve body 5, and resonance due to hunting of the valve body 5 can be suppressed more strongly. it can.

  Next, a second embodiment of the relief valve structure will be described. In the second embodiment, a plurality of anti-hunting holes 4 are provided. The number of the hunting prevention holes 4 is set as appropriate, and as a specific example, a case where two are formed will be described. The two anti-hunting holes 4 are a first anti-hunting hole 41 and a second anti-hunting hole 42, and are arranged in a line along the axial direction of the valve housing A1.

The second hunting prevention hole 42 is formed at a position closer to the back pressure relief hole 3 than the first hunting prevention hole 41. The first hunting prevention hole 41 is formed at a position closer to the relief discharge hole 2 than the second hunting prevention hole 42. In this embodiment, when the valve body 5 moves rearward in the valve body passage 11, the first hunting prevention hole 41 is first closed by the valve body 5 (see FIG. 4B).

  And if the valve body 5 moves to the back side further, the 2nd hunting prevention hole 42 will close. In this way, the resistance force Pt of the oil or air in the valve body passage 11 on the rear side of the valve body 5 increases stepwise. As a result, the valve body 5 receives an appropriate resistance force Pt of appropriate oil or air in accordance with an increase in hydraulic pressure, and can suppress hunting.

  Furthermore, the opening area of each of the first hunting prevention hole 41 and the second hunting prevention hole 42 can be appropriately changed. By doing so, the magnitude of the resistance force Pt can be changed as appropriate, and ideal hunting can be suppressed.

  Next, a third embodiment of the relief valve structure will be described. In the third embodiment, the anti-hunting hole 4 is formed as an elongated hole along the valve body passage 11 (see FIG. 5). Specifically, the elongated anti-hunting hole 4 preferably has a slit shape (see FIG. 5B).

  With such a configuration, oil or air on the rear side of the valve body 5 in the valve body passage 11 is discharged from the anti-hunting hole 4 formed as an elongated hole by the movement of the valve body 5 to the rear side. The amount is limited so that the valve body 5 gradually decreases by starting to close from the front side to the rear side of the anti-hunting hole 4.

  As a result, the resistance force Pt due to oil or air to the valve body 5 when the valve body 5 moves rearward is gradually increased without suddenly increasing, and the valve body 5 in the anti-hunting operation is increased. Resonance of the valve body 5 due to hunting can be suppressed while reducing the impact.

  In the third embodiment, when the valve element 5 moves to the rear side of the valve element passage 11 in the latter half of the middle rotation speed range and the relief discharge hole 2 is in a half-open state, A part is closed (see FIG. 5C). In the high rotational speed range, the valve body 5 further moves to the rear side of the valve body passage 11 to fully close the anti-hunting hole 4 formed as an elongated hole, and resistance to the rearward movement of the valve body 5 The force Pt is further increased.

  Next, a fourth embodiment of the relief valve structure will be described. In the fourth embodiment, the anti-hunting hole 4 and the back pressure relief hole 3 are communicated to form a single elongated hole, and the longitudinal direction thereof is along the longitudinal direction of the valve body passage 11. (See FIG. 6). The portion near the rear end of the elongated hole formed integrally along the longitudinal direction of the valve body passage 11 is the back pressure relief hole 3, and the other portion (region) is the anti-hunting hole 4. 6 (A), (B)]. That is, most part (region) of the elongated hole formed by integrally forming the back pressure relief hole 3 and the anti-hunting hole 4 is within the range of the anti-hunting hole 4, and a part of the elongated hole is the back pressure relief hole 3. Part.

  With such a configuration, the opening area of the hunting prevention hole 4 is gradually reduced as the valve body 5 moves rearward, and the amount of oil or air discharged from the hunting prevention hole 4 can be gradually reduced.

  As a result, the resistance of the valve body due to oil or air to the valve body when it moves rearward gradually increases without gradually increasing, and the impact on the valve body in the anti-hunting operation is reduced. Meanwhile, resonance of the valve body due to hunting can be suppressed. In the fourth embodiment, when the valve body 5 moves to the rear side of the valve body passage 11 in the latter half of the middle rotation speed range and the relief discharge hole 2 is in a half-open state, the elongated hole-like hunting prevention hole 4 A part is closed (see FIG. 6C).

  Next, the structure which made the valve structure of this invention the oil-path switching valve structure is demonstrated. The oil passage switching valve structure is a valve that serves to switch the oil passage by the valve body 5. FIG. 7A shows an oil path switching valve structure applied to control the oil discharge amount of the variable capacity oil pump 9. The valve body 5 in the oil passage switching valve structure is used as an oil passage switching valve.

  The valve housing A1 is provided with a valve body passage 11 and a switching passage 18 corresponding to the relief passage 12 as in the case of the relief valve structure. That is, in the oil passage switching valve structure, the inflow passage 12A is referred to as a switching passage 18. The valve body passage 11 and the switching flow path 18 are formed continuously in the axial direction, and one end of the valve body passage 11 in the axial direction communicates with the switching flow path 18.

  In the valve housing A1, as in the relief valve structure, the valve valve body passage 11 has a side communicating with the switching passage 18 in the axial direction as a front side of the valve passage 11, and the switching passage 18 in the axial direction. The opposite side is the rear side of the valve body passage 11. A valve body 5 is disposed in the valve body passage 11, and the valve body 5 reciprocates between the front side and the rear side along the axial direction of the valve body passage 11.

  The valve housing A1 has a switching discharge hole 19, a back pressure relief hole 3, and a hunting prevention hole 4, and the arrangement thereof is substantially the same as in the case of the relief valve structure. A first switching outflow hole 71 and a second switching outflow hole 72 are provided between the switching discharge hole 19 and the hunting prevention hole 4. A switching inflow hole 73 is formed between the first switching outflow hole 71 and the second switching outflow hole 72. And the oil which flowed out from the switching inflow hole 73 is controlled so that it may flow out from either the 1st switching outflow hole 71 or the 2nd switching outflow hole 72 by the switching operation | movement of the valve body 5 mentioned later. .

  The valve body 5 serving as an oil passage switching valve includes a first large diameter portion 54, a second large diameter portion 55, and a small diameter shaft portion 56. The first large diameter from the front side of the valve body 5 toward the rear side. The portion 54, the small-diameter shaft portion 56, and the second large-diameter portion 55 are integrally formed in a state of being arranged on the same axis line in this order. The front end surface of the first large diameter portion 54 is a pressure receiving surface 54a. The valve body 5 is disposed with respect to the valve body passage 11 of the valve housing A1 so that the pressure receiving surface 54a of the first large diameter portion 54 faces the switching opening 18a of the switching flow path 18 [FIGS. )reference〕.

  Further, the protruding portion 57 may be formed in the axial direction from the rear end portion of the second large diameter portion 55. The projecting portion 57 is loosely inserted into the front end portion of the elastic member 6 which is a coil spring mounted in the valve body passage 11 and serves to support the elastic member 6 so as to expand and contract in a stable state in the axial direction. .

  Also in the oil passage switching valve structure, as in the relief valve structure, the axial effective length Ls of the valve body 5 is the minimum distance La from the position of the switching opening 18a of the switching flow path 18 to the anti-hunting hole 4. It is formed shorter (see FIG. 7B).

  The effective length Ls in the axial direction of the valve body 5 is formed shorter than the maximum distance Lb between the switching discharge hole 19 and the anti-hunting hole 4. Further, the effective length Ls in the axial direction of the valve body 5 is formed longer than the minimum distance Lc between the switching discharge hole 19 and the anti-hunting hole 4 (see FIG. 7B).

である。 The effective length Ls of the valve body 5 in the oil passage switching valve structure is the length from the front end on the front side in the axial direction of the first large diameter portion 54 to the end on the rear side in the axial direction of the second large diameter portion 55. The total axial length Lt of the first large diameter portion 54 is formed to be shorter than the maximum distance Ld of the first switching outflow hole 71 from the position of the switching opening 18a of the switching channel 18. That is, in the initial position where the valve body 5 is in a stationary state, the first switching outflow hole 71 is in an open state (see FIG. 7B).
That is,

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及び

である。 The effective length Ls of the valve body 5 is formed longer than the maximum distance Le of the second switching outflow hole 72 from the position of the switching opening 18 a of the switching flow path 18. Further, the axial length Lu from the front end of the valve body 5 to the front end of the second large diameter portion 55 is the minimum distance Lf of the second switching outflow hole 72 from the position of the switching opening 18a of the switching channel 18. It is formed shorter.
That is,

as well as

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  That is, in the initial position where the valve body 5 is in a stationary state, the second switching outflow hole 72 is closed by the second large diameter portion 55 (see FIG. 7B). In the switching inflow hole 73, only the small-diameter shaft portion 56 always passes and the first large-diameter portion 54 and the second large-diameter portion 55 do not pass within the range in which the valve body 5 reciprocates. The switching inflow hole 73 is always open.

  In the oil passage switching valve structure, as in the case of the relief valve structure, there is a configuration in which a plurality of anti-hunting holes 4 are provided. Moreover, the said hunting prevention hole 4 also has the structure formed as an elongate hole along the valve body channel | path 11 [refer FIG. 9 (A), (B)]. Further, there is a configuration in which the hunting prevention hole 4 and the back pressure relief hole 3 communicate with each other and are integrally formed as one elongated hole, and the longitudinal direction thereof is along the longitudinal direction of the valve body passage 11. (See FIGS. 9C and 9D).

  The variable displacement oil pump 9 to which the oil passage switching valve structure is applied includes a pump housing 91, an inner rotor 92, and an outer rotor 93 that rotates with a predetermined amount of eccentricity with respect to the rotation center of the inner rotor 92. , And an outer ring 94 for rotatably holding the outer rotor 93.

  The inner rotor 92, the outer rotor 93, and the outer ring 94 are accommodated in the rotor chamber 91a of the pump housing 91. Then, the outer ring 94 is moved in the rotor chamber 91 a while swinging in the rotor chamber 91 a while maintaining the rotation center of the outer rotor 93 at an equal interval from the rotation center of the inner rotor 92. This changes the amount of oil discharged.

  The outer ring 94 has an operation protrusion 94a on the outer peripheral side, and the operation protrusion 94a is disposed in the operation chamber 91b of the pump housing 91 so that oil hits one of both sides of the operation protrusion 94a in the swing direction. In addition, the oil passage switching valve structure is used. The operation chamber 91b includes a first operation oil passage 95 and a second operation oil passage 96, and the first switching outflow hole 71 of the oil passage switching valve structure communicates with the first operation oil passage 95; The second switching outflow hole 72 communicates with the second operation oil passage 96.

  Next, the oil path switching operation in the oil path switching valve structure will be described. In the initial state, the first switching outflow hole 71 communicates with the switching inflow hole 73 of the valve housing A1, the oil flows out of the first switching outflow hole 71, and the oil is supplied to the first operation oil passage 95 of the variable capacity oil pump 9. send.

  In order to increase the discharge amount of the variable capacity oil pump 9, the pressure of the oil flowing out from the first switching outflow hole 71 is increased and the outer ring 94 is rotated. Then, by rotating the outer ring 94, the rotational center position of the outer rotor 93 can be moved to increase the discharge amount (see FIG. 8A).

  In order to reduce the discharge amount of the variable capacity oil pump 9, oil pressure is applied to the valve body 5 from the switching flow path 18, the valve body 5 is moved, and the first large diameter portion 54 performs the first switching. The outflow hole 71 is closed, the second switching outflow hole 72 is opened at the second large diameter portion 55, and oil is sent from the second switching outflow hole 72 to the second operation oil passage 96 of the variable capacity oil pump 9. As a result, the outer ring 94 swings in the opposite direction to reduce the discharge amount.

  The valve body 5 continues to move in response to the oil pressure from the switching flow path 18, and the first large-diameter portion 54 passes through the switching discharge hole 19 and opens the switching discharge hole 19. Can be discharged from the valve body passage 11. Further, in the process in which the valve body 5 moves rearward in the valve body passage 11, oil on the rear side of the valve body 5 is discharged from the back pressure relief hole 3, and the occurrence of hunting can be prevented by the hunting prevention hole 4.

  When the valve body 5 continues to move backward due to the oil pressure from the switching flow path 18, the second large diameter portion 55 of the valve body 5 narrows the opening area of the hunting prevention hole 4 and finally prevents hunting. The hole 4 is fully closed [see FIG. 8B]. As a result, as with the valve body 5 in the relief valve structure described above, the resistance due to oil or air to the valve body 5 when the valve body 5 in the oil path switching valve structure moves rearwardly increases rapidly. However, the resonance of the valve body due to hunting can be suppressed while gradually increasing and reducing the impact on the valve body 5 in the anti-hunting operation.

A1 ... valve housing, 5 ... valve body, 11 ... valve body passage, 12A ... inflow passage,
12 ... Relief flow path, 18 ... Switching flow path, 2A ... Outflow hole, 2 ... Relief discharge hole,
19 ... switching discharge hole, 3 ... back pressure relief hole, 4 ... hunting prevention hole, 5 ... valve body,
6 ... elastic member, 71 ... first switching outflow hole, 72 ... second switching outflow hole, 73 ... switching inflow hole.

According to a second aspect of the present invention, there is provided a valve body, a valve housing having an outflow hole, a back pressure relief hole, and a hunting prevention hole in a valve body passage having an inflow passage formed on one end side, and the valve body is the valve. An elastic member that urges the body passage toward the inflow channel, the anti-hunting hole is located between the outflow hole and the back pressure relief hole, and the effective axial length of the valve body is Than the minimum distance from the position of the inflow opening of the inflow channel to the anti-hunting hole and the maximum distance from the outflow hole to the anti-hunting hole, and the minimum distance from the outflow hole to the anti-hunting hole The above problem is solved by forming a valve structure in which the hunting prevention hole is opened and closed by reciprocating the valve body in the valve body passage by pressure.

Claims (9)

  A valve housing having an outflow hole, a back pressure relief hole, and a hunting prevention hole in the valve body passage having an inflow channel formed on one end side; and the valve body through the inflow flow of the valve body passage. The hunting prevention hole is located between the outflow hole and the back pressure relief hole, and the valve body closes the outflow hole and closes the outflow hole in a low engine speed range. The valve structure is characterized in that the hunting prevention hole is opened, and the valve element opens the outflow hole and closes the hunting prevention hole in the middle rotation speed range and the high rotation speed range.   A valve housing having an outflow hole, a back pressure relief hole, and a hunting prevention hole in the valve body passage having an inflow channel formed on one end side; and the valve body through the inflow flow of the valve body passage. The hunting prevention hole is located between the outflow hole and the back pressure relief hole, and the axial effective length of the valve body is the inflow opening of the inflow channel. Is formed shorter than the minimum distance from the position to the anti-hunting hole and the maximum distance from the outflow hole to the anti-hunting hole, and longer than the minimum distance from the outflow hole to the anti-hunting hole. A valve structure characterized by that.   A valve housing having an outflow hole, a back pressure relief hole, and a hunting prevention hole in the valve body passage having an inflow channel formed on one end side; and the valve body through the inflow flow of the valve body passage. The hunting prevention hole is located between the outflow hole and the back pressure relief hole, and the valve body is in contact with the periphery of the inflow opening of the inflow channel. The inflow channel and the outflow hole are closed, the hunting prevention hole is opened, and the valve body is separated from the inflow channel, so that the outflow hole is opened and the hunting prevention hole is closed. The valve structure is characterized in that the back pressure relief hole is always open.   4. The valve according to claim 1, wherein the anti-hunting hole is composed of a plurality of holes arranged along an axial direction of the valve body passage. Construction.   4. The valve structure according to claim 1, wherein the anti-hunting hole is an elongated hole along the valve body passage.   4. The valve structure according to claim 1, wherein the hunting prevention hole and the back pressure relief hole are integrally formed in an elongated hole shape.   The valve according to any one of claims 1, 2, 3, 4, 5, and 6, wherein the outflow hole and the anti-hunting hole are in communication with each other outside the valve housing. Construction.   8. The method according to claim 1, wherein the inflow channel is a relief channel for moving the valve body by relief, and the outflow hole is a relief outflow hole. A valve structure characterized by performing a relief operation.   8. The valve body according to claim 1, wherein the valve body includes a first large diameter portion, a second large diameter portion, the first large diameter portion, and the first large diameter portion. A small-diameter shaft portion located between two large-diameter portions, the inflow passage is a switching passage for switching the oil passage switching valve, the outflow hole is a switching discharge hole, and the switching discharge hole A first switching outflow hole and a second switching outflow hole, and a switching inflow hole positioned between the first switching outflow hole and the second switching outflow hole are formed between the first and second switching outflow holes, The valve structure is characterized in that one switching outflow hole is opened and closed at the first large diameter portion, and the second switching outflow hole is opened and closed at the second large diameter portion.

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