JP2021071175A - Oil control valve - Google Patents

Abstract

To provide an oil control valve capable of controlling an output hydraulic pressure.SOLUTION: A housing 17 has: a supply port 17a which is supplied with an oil from a variable displacement oil pump 102; an output port 17b which outputs the oil to the variable displacement oil pump 102; a discharge port 17c which discharges the oil to an oil pan 101; and a protruding part 17e provided on an inner peripheral surface of a housing hole 17d. A spool 16 has: a first groove part 16a which causes the oil to flow from the supply port 17a to the output port 17b; a second groove part 16b which causes the oil to flow from the output port 17b to the discharge port 17c; and a recessed part 16d which is provided on a slide surface 16c located between the first groove part 16a and the second groove part 16b and engages with the protruding part 17e.SELECTED DRAWING: Figure 4

Description

The present invention relates to an oil control valve that controls a variable displacement oil pump.

In the variable capacity oil pump, an inner rotor having a plurality of partitions is installed in the outer rotor, and the inside of the outer rotor is divided into a plurality of hydraulic chambers by the plurality of partitions. The amount of eccentricity of the outer rotor is adjusted by the balance between the load of the spring acting on the outer rotor and the oil pressure acting on the outer rotor. Since the outer rotor is eccentric, the capacity of each hydraulic chamber in the outer rotor changes, so that the discharge pressure of the variable capacity oil pump changes.

The oil pressure acting on the outer rotor of the variable displacement oil pump is supplied from an oil control valve (hereinafter referred to as "OCV"). The conventional OCV has a structure in which the supply port opened in the housing and the output port communicate with each other by changing the position of the spool in the housing, and oil flows from the output port to the variable displacement oil pump (for example, Patent Document). 1).

As an OCV drive method, there is a method that utilizes the magnetic attraction force of the solenoid portion and the load of the spring. The solenoid unit generates magnetic attraction by energizing the coil with a current corresponding to the target value of the oil flow rate (hereinafter referred to as "output flow rate") output from the output port, and slides the spool in the axial direction. Move. The spring applies a load to the spool in the direction opposite to the magnetic attraction. The position of the spool changes according to the balance between the magnetic attraction force and the load of the spring.

Japanese Unexamined Patent Publication No. 2006-348794

Conventionally, the output flow rate is changed by the current control received by the solenoid portion of the OCV, so that the amount of eccentricity of the outer rotor is adjusted, that is, the oil pressure acting on the outer rotor is adjusted. When controlling the output flow rate of the OCV, the oil pressure of the output port (hereinafter referred to as "output oil pressure") has a characteristic that it suddenly rises and is immediately saturated, and it is difficult to control the output oil pressure. Therefore, the conventional OCV cannot finely adjust the eccentricity of the outer rotor.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an OCV capable of controlling an output oil pressure.

The oil control valve according to the present invention generates a cylindrical housing provided with an accommodating hole, a spool coaxially accommodating in the accommodating hole and sliding in the axial direction, and a magnetic attraction force for sliding the spool. It is an oil control valve that controls the discharge pressure of a variable displacement oil pump with a solenoid part to make it and a spring that applies a load in the direction opposite to the magnetic attraction force to the spool, and the housing is supplied with oil from the outside. It has a supply port, an output port that outputs oil to a variable-capacity oil pump, a discharge port that discharges oil to the outside, and a convex portion provided on the inner peripheral surface of the accommodating hole. A first groove for flowing oil to the output port, a second groove for flowing oil from the output port to the discharge port, and a recess provided on the sliding surface between the first groove and the second groove and engaging with the convex portion. It has.

According to the present invention, the recess provided on the sliding surface of the spool serves as the pressure receiving surface for receiving the output hydraulic pressure, so that the position of the spool is balanced between the magnetic attraction force of the solenoid portion and the load of the spring and the output hydraulic pressure. Will change. Therefore, if the output oil pressure is larger than the target, the spool moves and the discharge port and the output port communicate with each other to reduce the output oil pressure. If the output oil pressure is smaller than the target, the spool moves to move the supply port and the output port. The output oil pressure increases due to the communication with. Therefore, it is possible to provide an OCV capable of controlling the output oil pressure.

It is a block diagram which shows the structural example of the engine oil system which concerns on Embodiment 1. FIG. It is a figure which shows the configuration example of a variable capacity oil pump. It is sectional drawing which shows the structural example of the whole OCV. It is sectional drawing which shows the structural example of the valve part of OCV. It is an enlarged cross-sectional view of the main part of the conventional OCV. It is a figure explaining the output principle of OCV, and shows the state of A> B + C. It is a figure explaining the output principle of OCV, and shows the state of A <B + C. It is a figure explaining the output principle of OCV, and shows the state of A = B + C. It is a graph which shows the relationship between the current to OCV and the output oil pressure.

Embodiment 1.
FIG. 1 is a block diagram showing a configuration example of an engine oil system according to a first embodiment. The oil in the oil pan 101 is sucked by the variable capacity oil pump 102 and supplied to each system 103, and then returns to the oil pan 101 again. Each system 103 operates by flood control such as a variable valve timing mechanism mounted on a vehicle. The pressure sensor 104 detects the pressure of the oil supplied from the variable displacement oil pump 102 to each system 103 (hereinafter referred to as “discharge pressure”), and transmits the detected discharge pressure to the ECU (Electronic Control Unit) 105. .. The ECU 105 calculates a target of the output oil pressure of the OCV 106 based on the discharge pressure detected by the pressure sensor 104, and energizes the OCV 106 with a current corresponding to the calculated target. The OCV 106, which has received current control by the ECU 105, supplies the output hydraulic pressure to the hydraulic chamber (hydraulic chamber 1 in FIG. 2) of the variable displacement oil pump 102. The discharge pressure of the variable displacement oil pump 102 is variably controlled according to the output oil pressure of the OCV 106.

FIG. 2 is a diagram showing a configuration example of the variable displacement oil pump 102. In the variable capacity oil pump 102, an inner rotor 2 having a plurality of partition portions 2a to 2d is installed in the outer rotor 3, and in the outer rotor 3, a plurality of hydraulic chambers 5a having different capacities depending on the plurality of partition portions 2a to 2d. It is divided into ~ 5d. The oil that has flowed into the oil suction port 7 from the oil pan 101 enters the hydraulic chamber 5d in the example of FIG. The oil pressure in the hydraulic chamber 5d rises as the capacity of the hydraulic chamber 5d decreases due to the rotation of the inner rotor 2, and then is supplied from the oil discharge port 8 to each system 103. Further, a part of the flood pressure discharged from the oil discharge port 8 is supplied to the supply port 17a (see FIG. 3) of the OCV 106.

The outer rotor 3 is rotatable about the support portion 3a, and the oil pressure of the hydraulic chamber 1 generated by the load of the spring 4 and the oil flowing into the output flow path 6 from the output port 17b (see FIG. 3) of the OCV 106. The amount of eccentricity is adjusted by the balance with. Since the outer rotor 3 is eccentric, the capacities of the hydraulic chambers 5a to 5d change, so that the discharge pressure changes.

Since the eccentricity of the outer rotor 3 changes depending on the output oil pressure of the OCV 106, the ECU 105 does not control the output flow rate from the OCV 106 to the variable capacity oil pump 102 as in the conventional case, but outputs from the OCV 106 to the variable capacity oil pump 102. It is preferable to control the oil pressure. Therefore, in the first embodiment, the OCV 106 capable of controlling the output oil pressure is proposed.

FIG. 3 is a cross-sectional view showing a configuration example of the entire OCV 106. FIG. 4 is a cross-sectional view showing a configuration example of the valve portion of the OCV 106. The OCV 106 includes a solenoid portion and a valve portion. The solenoid unit includes a core 9, a case 10, a power supply terminal 11, a coil 12, a boss 13, a bracket 14, and a plunger 15. The case 10, the boss 13, the bracket 14, and the plunger 15 are magnetic materials. The valve portion includes a spool 16, a housing 17, and a spring 18.

When the current from the ECU 105 energizes the coil 12 via the power supply terminal 11, magnetism is generated in the coil 12. The magnetism generated in the coil 12 flows in the order of the plunger 15, the boss 13, the bracket 14, and the case 10, so that a magnetic attraction force is generated from the plunger 15 to the boss 13. Due to this magnetic attraction, the plunger 15 and the spool 16 fixed to the plunger 15 are pushed toward the spring 18 side against the load of the spring 18. When the energization of the coil 12 is stopped, the plunger 15 and the spool 16 are pushed back by the load of the spring 18 in the direction opposite to the magnetic attraction force. The solenoid unit may be any as long as it generates a magnetic attraction force proportional to the current value, and is not limited to the configuration shown in FIG.

The housing 17 has a cylindrical shape and has an accommodation hole 17d extending in the axial direction. A spring 18 is installed at an axial end portion of the accommodating hole 17d opposite to the solenoid portion. Further, the housing 17 has a supply port 17a, an output port 17b, and an discharge port 17c. The supply port 17a communicates with the oil discharge port 8 of the variable displacement oil pump 102. The output port 17b communicates with the output flow path 6 of the variable displacement oil pump 102. The discharge port 17c communicates with the oil pan 101. Of the inner peripheral surface of the accommodating hole 17d, a convex portion 17e is provided on the inner peripheral surface between the output port 17b and the discharge port 17c. Therefore, the inner diameter of the convex portion 17e is smaller than the inner diameter of the accommodating hole 17d by the amount of protrusion D1 of the convex portion 17e.

The spool 16 is coaxially accommodated in the accommodating hole 17d of the housing 17, and slides in the axial direction by receiving the magnetic attraction force of the solenoid portion and the load of the spring 18. The outer peripheral surface of the spool 16 is a sliding surface that moves while being in contact with the inner peripheral surface of the accommodating hole 17d. The sliding surface is provided with a first groove portion 16a for flowing oil from the supply port 17a to the output port 17b and a second groove portion 16b for flowing oil from the output port 17b to the discharge port 17c. The first groove portion 16a and the second groove portion 16b are annular grooves. Further, a recess 16d is provided on the sliding surface 16c between the first groove portion 16a and the second groove portion 16b. The surface connecting the sliding surface 16c and the bottom surface of the recess 16d is a pressure receiving surface 16e that receives output hydraulic pressure. The outer diameter of the recess 16d is smaller than the outer diameter of the sliding surface (including the sliding surface 16c) of the spool 16 by the amount D2 of the recess 16d. The protrusion amount D1 of the convex portion 17e and the recess amount D2 of the concave portion 16d are substantially the same value, and the concave portion 16d has a shape that engages with the convex portion 17e. Therefore, the sliding of the spool 16 is not hindered, and oil leakage from between the convex portion 17e and the concave portion 16d is suppressed.

The spool 16 is preferably made of lightweight aluminum. Further, it is desirable that the sliding surface of the spool 16 is covered with an oxide film formed by alumite treatment in order to improve the slidability and wear resistance.

Next, the operation of the OCV 106 according to the first embodiment will be described.
First, the conventional OCV will be described. FIG. 5 is an enlarged cross-sectional view of a main part of the conventional OCV. In the conventional OCV, the convex portion 17e is not provided on the inner peripheral surface between the output port 17b and the discharge port 17c among the inner peripheral surfaces of the accommodating hole 17d. Further, in the conventional OCV, the recess 16d is not provided on the sliding surface 16c between the first groove portion 16a and the second groove portion 16b. The conventional OCV has the same configuration as the OCV 106 of the first embodiment except that the convex portion 17e and the concave portion 16d are not provided. In the conventional OCV, the position of the spool 16 changes depending on the balance between the magnetic attraction force proportional to the current value applied to the coil 12 and the load of the spring 18. As the spool 16 moves in the axial direction, the oil flow path from the supply port 17a to the output port 17b and the oil flow path from the output port 17b to the discharge port 17c are switched. By switching the oil flow path, the output flow rate from the output port 17b to the output flow path 6 of the variable displacement oil pump 102 changes. In the conventional OCV, when the supply port 17a, the first groove portion 16a, the output port 17b, and the hydraulic chamber 1 of the variable displacement oil pump 102 communicate with each other, oil flows, so that the output oil pressure rises sharply and becomes saturated immediately.

Subsequently, the OCV 106 according to the first embodiment will be described. 6A, 6B, and 6C are diagrams illustrating the output principle of the OCV 106. In the OCV 106 of the first embodiment, the position of the spool 16 is a magnetic attraction force (hereinafter, referred to as "magnetic attraction force A") proportional to the current value applied to the coil 12 and a load of the spring 18 (hereinafter, "" It changes depending on the balance between the spring load (referred to as "spring load B") and the output hydraulic pressure (hereinafter referred to as "output hydraulic pressure C") received by the pressure receiving surface 16e.

Here, it is assumed that the ECU 105 energizes the coil 12 with a current value corresponding to the target output oil pressure.
When the output oil pressure C of the output port 17b is smaller than the target, the magnetic attraction force A> (spring load B + output oil pressure C) is obtained as shown in FIG. 6A. Therefore, the spool 16 is pushed out to the spring 18 side by the magnetic attraction force A, the supply port 17a, the first groove portion 16a, and the output port 17b communicate with each other, and the output oil pressure C increases.

When the output oil pressure C of the output port 17b is larger than the target, the magnetic attraction force A <(spring load B + output oil pressure C) is obtained as shown in FIG. 6B. Therefore, the spool 16 is pushed back to the solenoid portion side by the spring load B and the output oil pressure C, the output port 17b, the second groove portion 16b, and the discharge port 17c communicate with each other, and the output oil pressure C decreases.

When the output oil pressure C of the output port 17b matches the target through the states shown in FIGS. 6A and 6B, the magnetic attraction force A = (spring load B + output oil pressure C) is obtained as shown in FIG. 6C. .. When the magnetic attraction force A, the spring load B, and the output oil pressure C are balanced, the output port 17b is blocked by the sliding surface 16c, and the space between the output port 17b and the hydraulic chamber 1 of the variable displacement oil pump 102 is closed. Since it becomes a space, the state where the output oil pressure C matches the target is maintained. Therefore, the ECU 105 can control the output oil pressure C by controlling the current for the solenoid unit.

FIG. 7 is a graph showing the relationship between the current to the OCV 106 and the output oil pressure C. The horizontal axis is the current value applied to the coil 12, and the vertical axis is the output oil pressure C of the OCV 106. The line E shows the hydraulic current characteristics of the OCV 106 of the first embodiment, and the line F shows the hydraulic current characteristics of the conventional OCV shown in FIG. The OCV 106 of the first embodiment can maintain the output oil pressure C in a state where the magnetic attraction force A proportional to the current value, the spring load B, and the output oil pressure C are balanced. Therefore, the current control range of the output oil pressure C is large. Therefore, the OCV 106 can finely adjust the discharge pressure of the variable displacement oil pump 102 adjusted by the output oil pressure C, and the control accuracy of the discharge pressure is improved. On the other hand, in the conventional OCV, the current control width is small because the output oil pressure C suddenly rises and saturates immediately as described above. Therefore, the conventional OCV cannot finely adjust the discharge pressure of the variable displacement oil pump 102.

As described above, the OCV 106 according to the first embodiment includes a cylindrical housing 17 provided with a housing hole 17d, a spool 16 coaxially housed in the housing hole 17d and sliding in the axial direction, and a spool. It includes a solenoid portion that generates a magnetic attraction force A that slides the 16 and a spring 18 that applies a load B in the direction opposite to the magnetic attraction force A to the spool 16. The housing 17 has a supply port 17a for supplying oil from the variable capacity oil pump 102, an output port 17b for outputting oil to the variable capacity oil pump 102, a discharge port 17c for discharging oil to the oil pan 101, and a storage hole. It has a convex portion 17e provided on the inner peripheral surface of 17d. The spool 16 is located between a first groove portion 16a for flowing oil from the supply port 17a to the output port 17b, a second groove portion 16b for flowing oil from the output port 17b to the discharge port 17c, and between the first groove portion 16a and the second groove portion 16b. It has a recess 16d provided on the sliding surface 16c and engages with the convex portion 17e. Since the recess 16d serves as the pressure receiving surface 16e that receives the output hydraulic pressure C, the position of the spool 16 changes depending on the balance between the magnetic attraction force A of the solenoid portion, the load B of the spring 18, and the output hydraulic pressure C. Therefore, when the output oil pressure C is larger than the target, the spool 16 moves and the discharge port 17c and the output port 17b communicate with each other to lower the output oil pressure C, and when the output oil pressure C is smaller than the target, the spool 16 moves. Then, the output oil pressure C is increased by communicating the supply port 17a and the output port 17b. Therefore, it is possible to provide an OCV 106 capable of controlling the output oil pressure C.

Further, the spool 16 of the first embodiment is made of alumite-treated aluminum. When the spool 16 is made of aluminum, the weight of the spool 16 can be reduced as compared with the case where the spool 16 is made of iron or the like. Further, since the spool 16 is covered with an oxide film by the alumite treatment, the slidability and wear resistance of the spool 16 are improved.

The supply port 17a and the discharge port 17c of the housing 17 may be in opposite positions. That is, in FIG. 3, the discharge port 17c is arranged at the position closest to the solenoid portion, and the supply port 17a is arranged at the position closest to the spring 18.

Within the scope of the present invention, it is possible to modify any component of the embodiment or omit any component of the embodiment.

1 hydraulic chamber, 2 inner rotor, 2a to 2d partition, 3 outer rotor, 3a support, 4 spring, 5a to 5d hydraulic chamber, 6 output flow path, 7 oil suction port, 8 oil discharge port, 9 core, 10 cases, 11 Feed terminal, 12 coil, 13 boss, 14 bracket, 15 plunger, 16 spool, 16a 1st groove, 16b 2nd groove, 16c sliding surface, 16d recess, 16e pressure receiving surface, 17 housing, 17a supply port, 17b output Port, 17c discharge port, 17d accommodation hole, 17e convex part, 18 spring, 101 oil pan, 102 variable capacity oil pump, 103 systems, 104 pressure sensor, 105 ECU, 106 OCV.

Claims (2)

A cylindrical housing provided with an accommodating hole, a spool coaxially accommodating in the accommodating hole and sliding in the axial direction, a solenoid unit for generating a magnetic attraction force for sliding the spool, and the magnetism. An oil control valve that controls the discharge pressure of a variable displacement oil pump, including a spring that applies a load in the direction opposite to the suction force to the spool.
The housing is
A supply port where oil is supplied from the outside and
An output port that outputs the oil to the variable capacity oil pump,
A discharge port for discharging the oil to the outside and
It has a convex portion provided on the inner peripheral surface of the accommodating hole.
The spool
A first groove for flowing the oil from the supply port to the output port, and
A second groove for flowing the oil from the output port to the discharge port, and
An oil control valve characterized by having a concave portion provided on a sliding surface between the first groove portion and the second groove portion and engaging with the convex portion. The oil control valve according to claim 1, wherein the spool is made of alumite-treated aluminum.

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