JP2024066101A - Ball check valve and valve timing adjustment device using the same - Google Patents

Abstract

[Problem] To provide a ball check valve that prevents a ball valve element from hitting a valve seat on one side due to radially outward movement caused by centrifugal force, and a valve timing adjustment device using the same. [Solution] A sleeve 72 of a check valve unit (ball check valve) 701 is arranged parallel to a rotation axis O of a rotor at a position offset from the rotation axis O. A ball valve element 76 is accommodated in the sleeve 72 and is slidable in the axial direction of the sleeve 72. A bush 71 provided at one end of the axial direction of the sleeve 72 has an inlet 712 through which a fluid can flow in, and a valve seat 713 formed in an annular shape around the inlet and on which the ball valve element 76 can be seated. A valve spring 77 biases the ball valve element 76 toward the valve seat 713. A central axis Ps of the valve seat 713 is offset radially outward from a central axis Pc of the sleeve 72 by an eccentricity amount δ corresponding to a one-sided clearance between an inner diameter of a large diameter portion 733 of the sleeve 72 and an outer diameter of the ball valve element 76. [Selected Figure] Fig. 3

Description

The present invention relates to a ball check valve and a valve timing adjustment device using the same.

Conventionally, a ball check valve is known that is installed in the middle of a flow path at a position offset from the axis of rotation of a rotor, and blocks the flow path by seating a ball valve body on a valve seat, thereby preventing backflow of fluid.

For example, Patent Document 1 discloses a valve timing adjustment device equipped with a check valve unit consisting of a ball check valve in the inflow path of hydraulic oil that rotates a vane rotor relative to the housing. The check valve unit closes when a ball valve body housed in a cylindrical sleeve slides in the axial direction of the sleeve and seats on a valve seat provided at one end of the sleeve in the axial direction. The check valve unit is provided in a position offset from the rotation axis of the valve timing adjustment device in the inflow path of hydraulic oil that flows from the oil pump through a supply hole in the camshaft into the hydraulic chamber of the housing.

JP 2021-85401 A

In the check valve unit of Patent Document 1, the central axis of the sleeve and the central axis of the valve seat are formed coaxially. However, during rotation of the valve timing adjustment device, the ball valve body moves radially outward relative to the central axis of the sleeve due to centrifugal force. Because the center of the ball valve body and the central axis of the valve seat are misaligned, the ball valve body makes uneven contact with the valve seat when the valve is closed, increasing the local load on the seat surface. Furthermore, the uneven contact causes leakage and reduces sealing performance. This problem is common to all ball check valves that are generally installed at a position offset from the rotation axis of the rotor.

The object of the present invention is to provide a ball check valve that prevents the ball valve body from hitting the valve seat on one side due to radial outward movement caused by centrifugal force, and a valve timing adjustment device using the same.

The ball check valve of the present invention comprises a cylindrical sleeve (72), a ball valve body (76), a valve seat member (71), and a valve biasing member (77). The sleeve is disposed parallel to the rotation axis (O) of the rotating body (20, 30) at a position offset from the rotation axis. The ball valve body is accommodated in the sleeve and is slidable in the axial direction of the sleeve. The valve seat member provided at one end of the axial direction of the sleeve has an inlet (712) through which a fluid can flow, and a valve seat (713) formed in an annular shape around the inlet and on which the ball valve body can be seated. The valve biasing member biases the ball valve body toward the valve seat.

In the first aspect of the present invention, the central axis (Ps) of the valve seat is offset radially outward from the central axis (Pc) of the sleeve by an eccentricity (δ) that corresponds to the one-sided clearance between the inner diameter of the sleeve and the outer diameter of the ball valve body at the portion where the ball valve body is housed.

In the first embodiment, when the center of the ball valve body is displaced radially outward from the central axis of the sleeve by the amount of one-sided clearance while the rotor is rotating, the center of the ball valve body is positioned on the central axis of the valve seat. Therefore, it is possible to prevent the ball valve body from contacting the valve seat on one side.

In a second aspect of the present invention, the central axis (Ps) of the valve seat coincides with the central axis (Pc) of the sleeve. The inner wall of the sleeve is provided with a restricting portion (78, 79) that restricts the movement of the ball valve body due to centrifugal force while the rotor is rotating and keeps the center of the ball valve body on the central axis of the sleeve. The restricting portion may be formed as a separate member from the sleeve, or may be formed integrally with the sleeve.

In the second embodiment, the sliding clearance between the ball valve body and the sleeve is only on the radially inner side, and while the rotor is rotating, the center of the ball valve body is maintained on the central axis of the sleeve, i.e., on the central axis of the valve seat. Therefore, it is possible to prevent the ball valve body from hitting the valve seat on one side.

The valve timing adjustment device of the present invention adjusts the opening and closing timing of the intake valve (4) or exhaust valve (5) driven to open and close by changing the rotational phase between the drive shaft (2) and driven shaft (3) of the engine (1). The valve timing adjustment device includes a housing (20), a vane rotor (30), and a check valve unit (70).

The housing has a cylindrical portion (221) and a number of partition walls (23) protruding radially inward from the cylindrical portion, and rotates with either the drive shaft or the driven shaft. The vane rotor has a boss portion (31) provided coaxially with the cylindrical portion of the housing, and a number of vane portions (32) protruding radially from the boss portion, and is accommodated in the housing so that the vane portions can rotate between the partition walls of the housing. The vane rotor rotates with the other of the drive shaft or the driven shaft, and rotates relative to the housing due to the hydraulic pressure of the hydraulic oil supplied to a number of hydraulic chambers (201, 202) formed between the partition walls and the vane portions.

The check valve unit opens and closes parallel to the rotation axis (O) of the housing and vane rotor at a position offset from the axis, preventing backflow of hydraulic oil from the hydraulic chamber to the hydraulic oil supply source (8). The check valve unit is composed of a ball check valve of the first or second aspect, and the center of the ball valve body is located on the central axis of the valve seat while the housing and vane rotor are rotating.

The valve timing adjustment device of the present invention can prevent uneven contact of the ball valve body with the valve seat in a check valve unit installed in the hydraulic oil supply path. By reducing the local load on the seat surface, it is possible to suppress durability stress. In addition, by preventing leakage due to uneven contact, it is possible to improve the operating efficiency of the vane rotor.

1 is an axial cross-sectional view of a valve timing adjusting device to which a ball check valve according to each embodiment is applied as a check valve unit. Cross-sectional view taken along line II-II in FIG. FIG. 3 is an axial cross-sectional view of the ball check valve according to the first embodiment when the valve is open (an enlarged view of part III in FIG. 2 ). FIG. 2 is an axial cross-sectional view of the ball check valve according to the first embodiment when the valve is closed. 4 is a radial cross-sectional view of the ball check valve according to the first embodiment taken along line VV in FIG. 3 . FIG. 4 is a radial cross-sectional view of a ball check valve of a comparative example. 4A to 4C are diagrams showing examples of the configuration of position marks for assembling a check valve unit. 13A and 13B are diagrams showing another example of the configuration of position marks for assembling the check valve unit. 5A and 5B are diagrams showing an example of the configuration of a positioning portion for assembling a check valve unit. FIG. 11 is a radial cross-sectional view of a ball check valve according to a second embodiment. FIG. 11 is an axial cross-sectional view of the ball check valve according to the third embodiment when the valve is open (an enlarged view of a portion XI in FIG. 2 ). FIG. 11 is an axial cross-sectional view of the ball check valve according to the third embodiment when the valve is closed. FIG. 13 is a radial cross-sectional view of the ball check valve according to the third embodiment taken along line XIII-XIII in FIG. 11 . FIG. 13 is a radial cross-sectional view of a ball check valve according to a fourth embodiment.

A ball check valve according to multiple embodiments of the present invention and a valve timing adjustment device in which the ball check valve is applied as a check valve unit will be described with reference to the drawings. Components that are substantially the same in multiple embodiments are given the same reference numerals and descriptions will be omitted. The first to fourth embodiments will be collectively referred to as "the present embodiment."

The basic configuration of the valve timing adjustment device is similar to that described in Patent Document 1 (JP 2021-85401 A). In this specification, the names and symbols of components common to the valve timing adjustment device are, with some exceptions, the symbols in Patent Document 1. For components unique to this embodiment, symbols not used in Patent Document 1 are added.

As a name different from that of Patent Document 1, the "check valve portion 70" in Patent Document 1 is referred to as the "check valve unit 70" in this specification. The check valve unit 70 is extracted from the valve timing adjustment device and is also treated as an independent functional part called a "ball check valve." Note that the reference numerals of the check valve units in the first to fourth embodiments are given the number of the embodiment as the third digit following "70." Also, in contrast to the "valve body 76" in Patent Document 1, this specification refers to it as the "ball valve body 76" to emphasize the ball.

The hole in the vane rotor into which the check valve unit 70 is inserted during the assembly process of the valve timing adjustment device is given the name "check valve unit insertion hole 37", which is not used in Patent Document 1. Furthermore, in contrast to the "valve seat portion 71" in Patent Document 1, the "means for solving the problem" section describes it as "valve seat member", and in the embodiment, "bush 71" is used. The bush 71, which is a lid-shaped component of the check valve unit 70, has an end face exposed on the opening side when the check valve unit 70 is inserted into the check valve unit insertion hole 37.

[Basic configuration of valve timing adjustment device]
1 and 2, a basic configuration of a valve timing controller 10 will be described. The valve timing controller 10 is mounted on, for example, a vehicle, and adjusts the opening and closing timing of an intake valve 4 or an exhaust valve 5 driven to open and close by the camshaft 3, by changing the rotational phase between a crankshaft 2, which is the "drive shaft," of an engine 1, and a camshaft 3, which is the "driven shaft." The valve timing controller 10 of this embodiment adjusts the opening and closing timing of the intake valve 4.

The valve timing adjustment device 10 includes a housing 20, a vane rotor 30, a hydraulic oil control unit 11, a check valve unit 70, etc. The housing 20 rotates together with the crankshaft 2, which is the "drive shaft," via a chain 6. The vane rotor 30 is fixed to the end of the camshaft 3, which is the "driven shaft," and rotates together with the camshaft 3. The housing 20 and the vane rotor 30 rotate around a common rotation axis O.

The housing 20 has a cylindrical portion 221, a bottom plate portion 222, multiple partition wall portions 23, a gear plate portion 223, etc. The cylindrical portion 221 is formed in a cylindrical shape. The bottom plate portion 222 is formed integrally with the cylindrical portion 221 and forms the bottom of the cylindrical portion 221 on the side opposite the camshaft (the left side in FIG. 1). The multiple partition wall portions 23 protrude radially inward from the cylindrical portion. A housing opening 24 is formed in the center of the bottom plate portion 222.

The gear plate portion 223 is provided to close one end of the tubular portion 221 on the camshaft side (the right side in FIG. 1), and the gear portion 21 is formed on the outer periphery. A chain 6 is wound around the gear portion 21 and the crankshaft 2, and the housing 20 rotates in conjunction with the crankshaft 2 via the chain 6.

The vane rotor 30 has a boss portion 31 and multiple (e.g., four) vane portions 32 that protrude radially from the boss portion 31. The boss portion 31 is provided coaxially with the cylindrical portion 221 of the housing 20 and is fixed to the end of the camshaft 3 by a bolt 12. A rotor hole portion 300 passes through the center of the boss portion 31. The vane rotor 30 is accommodated in the housing 20 so that the vane portions 32 can rotate between the partition portions 23.

A number of hydraulic chambers 201, 202 are formed between the partition wall 23 and the vane portion 32. The vane rotor 30 rotates relative to the housing 20 due to the hydraulic pressure of the hydraulic oil supplied from the oil pump 8 to the number of hydraulic chambers 201, 202. A lock pin 33 and a lock spring 34 that restrict the relative rotation are provided in the accommodation hole 321 formed in the upper vane portion 32 in Figures 1 and 2.

In FIG. 2, the hydraulic chamber formed in the clockwise direction of each vane portion 32 is the retarded angle chamber 201, and the hydraulic chamber formed in the counterclockwise direction of each vane portion 32 is the advanced angle chamber 202. The boss portion 31 is formed with a retarded angle oil passage hole 301 that connects the rotor hole portion 300 and the retarded angle chamber 201, and an advanced angle oil passage hole 302 that connects the rotor hole portion 300 and the advanced angle chamber 202. When hydraulic oil is supplied to the retarded angle chamber 201 through the retarded angle oil passage hole 301, the vane rotor 30 rotates relative to the housing 20 in the retarded angle direction of the intake valve 4. When hydraulic oil is supplied to the advanced angle chamber 202 through the advanced angle oil passage hole 302, the vane rotor 30 rotates relative to the housing 20 in the advanced angle direction of the intake valve 4.

The oil pump 8, which serves as a "hydraulic oil supply source," pumps up hydraulic oil stored in the oil pan 7 and pumps it to the oil supply passage 101. The pumped hydraulic oil is supplied to the hydraulic chambers 201 and 202 in the valve timing adjustment device 10 via a supply hole 15 formed in the camshaft 3.

The hydraulic oil control unit 11 is composed of a spool valve having a control sleeve 40, a control spool 50, and a control spring 14, and is arranged to fit into the rotor hole 300 of the vane rotor 30. The rod of the linear solenoid 9 abuts against the end face of the protrusion 522 of the control spool 50 on the side opposite the camshaft. When the linear solenoid 9 is energized by a control signal from an ECU (not shown), the axial position of the control spool 50 relative to the control sleeve 40 changes.

By changing the state of communication between the recess of the control spool 50 and the port of the control sleeve 40, the flow path of the hydraulic oil and the flow rate supplied to the hydraulic chambers 201 and 202 are controlled. The detailed configuration of the hydraulic oil control unit 11 and an example of the operation of the valve timing adjustment device 10 according to the operating state of the engine 1 are described in Patent Document 1, so a description thereof will be omitted.

The check valve unit 70 is inserted into the check valve unit insertion hole 37 formed in the end face of the vane rotor 30 on the camshaft side. Because the hydraulic oil control unit 11 is provided in the rotor hole 300 in the center of the boss portion 31, the position where the check valve unit 70 is provided is necessarily "offset from the rotation axis O of the housing 20 and the vane rotor 30."

The check valve unit 70 is composed of a ball check valve including a cylindrical sleeve 72, a ball valve body 76, a bush 71 as a "valve seat member", and a valve spring 77 as a "valve biasing member". The bush 71, the sleeve 72 and the ball valve body 76 are made of, for example, metal. The sleeve 72 is arranged parallel to the rotation axis O at a position offset from the rotation axis O of the housing 20 and the vane rotor 30. The sleeve 72 is formed with a plurality of outlet ports 75 that communicate between the inside and the outside. The ball valve body 76 is housed in the sleeve 20 and is slidable in the axial direction of the sleeve 20.

The bush 71 is provided at one axial end of the sleeve 72, and has a bush body 711, an inlet 712, a valve seat 713, etc. The inlet 712 allows hydraulic oil to flow in as a "fluid". The valve seat 713 is formed in an annular shape around the inlet 712, and a ball valve body 76 can be seated on it. The valve spring 77 biases the ball valve body 76 toward the valve seat 713. The detailed configuration of the check valve unit 70 will be described later in the explanation of the first embodiment. Note that in the "III, XI parts" indicated as enlarged portions in FIG. 1, illustrations of configurations specific to each embodiment are omitted.

When the ball valve body 76 seats on the valve seat 713, the ball check valve closes and hydraulic oil pumped from the oil pump 8 is blocked from flowing into the inlet 712. When the ball valve body 76 separates from the valve seat 713, the ball check valve opens and hydraulic oil flowing in from the inlet 712 flows out from the outlet 75 and is supplied to the hydraulic chambers 201 and 202 via the rotor hole 300.

As the ball valve body 76 slides parallel to the rotation axis O, the check valve unit 70 opens and closes parallel to the rotation axis O, preventing backflow of hydraulic oil from the hydraulic chambers 201, 202 to the oil pump 8. In other words, the check valve unit 70 allows hydraulic oil to flow from the oil pump 8 to the hydraulic chambers 201, 202, and blocks the flow of hydraulic oil from the hydraulic chambers 201, 202 to the oil pump 8.

In the check valve unit of Patent Document 1 (JP 2021-85401 A, WO 2021/106892 A1), the central axis of the sleeve 72 and the central axis of the valve seat 713 are formed coaxially. However, during rotation of the valve timing adjustment device 10, the ball valve body 76 moves radially outward relative to the central axis of the sleeve 72 due to centrifugal force. Since the center of the ball valve body 76 and the central axis of the valve seat 713 are misaligned, the ball valve body 76 comes into contact with the valve seat 713 on one side when the valve is closed, increasing the local load on the seat surface. In addition, the one-sided contact causes leakage and reduces sealing performance. This leads to a decrease in the operating efficiency of the vane rotor 30.

In this embodiment, in a ball check valve applied as the check valve unit 70 of the valve timing adjustment device 10, the ball valve body 76 is prevented from hitting the valve seat 713 on one side due to the ball valve body 76 moving radially outward due to centrifugal force. To achieve this, a configuration is realized in which the center of the ball valve body 76 is located on the central axis of the valve seat 713 when centrifugal force is acting on the ball valve body 76.

Specific solutions to this problem can be broadly divided into a first group including the first and second embodiments, and a second group including the third and fourth embodiments. In the first group, the valve seat 713 is eccentric with respect to the sleeve 72. In the second group, the valve seat 713 and the sleeve 72 are coaxial, but the radially outward movement of the ball valve body 76 is restricted. Next, the detailed configuration of the check valve units 701 to 704 of each embodiment will be described in order.

(First and second embodiments)
The check valve unit 701 of the first embodiment will be described with reference to Figures 3 to 5. Axial cross sections of the check valve unit 701 of the first embodiment are shown in Figures 3 and 4, and a radial cross section is shown in Figure 5. In the figures, the central axis of the valve seat 713 is represented as the "valve seat central axis Ps," and the central axis of the sleeve 72 is represented as the "sleeve central axis Pc." The "s" in Ps comes from seat, and the "c" in Pc comes from cylinder.

In the check valve unit 701 applied to the valve timing adjustment device 10, the "rotating body" that rotates around the rotation axis O is mainly the housing 20 and the vane rotor 30. However, since it would be redundant to state "during the rotation of the housing 20 and the vane rotor 30" and "in the radially outward direction of the housing 20 and the vane rotor 30" each time, the following general descriptions will be used, such as "during the rotation of the rotating body" and "in the radially outward direction of the rotating body."

As shown in Figures 3 and 4, the sleeve 72 is integrally formed with a bottom portion 74, a small diameter portion 731, a connecting portion 732, and a large diameter portion 733. The bottom portion 74 forms a cylindrical bottom at the axial end opposite the bush 71, and supports one end of the valve spring 77 opposite the ball valve body 76. In order from the bottom portion 74 toward the bush 71, the small diameter portion 731, the connecting portion 732, and the large diameter portion 733 are formed in a stepped cylindrical shape. The inner wall of the small diameter portion 731 guides the outer periphery of the valve spring 77. The connecting portion 732 tapers in diameter from the small diameter portion 731 toward the large diameter portion 733.

The end of the large diameter portion 733 is press-fitted into the inner peripheral wall of the fitting portion 714 of the bush 71. The multiple outlet ports 75 connect the inside and outside of the large diameter portion 733. As disclosed in Figures 4 and 5 of Patent Document 1, for example, four substantially circular outlet ports 75 are formed at equal intervals in the circumferential direction of the large diameter portion 733.

The ball valve body 76 is housed inside the large diameter portion 733 and can slide in the axial direction of the sleeve 72. The large diameter portion 733 corresponds to the "portion in which the ball valve body 76 is housed." Half the difference between the inner diameter of the large diameter portion 733 of the sleeve 72 and the outer diameter of the ball valve body 76 is the "one-sided clearance." When the center of the ball valve body 76 is on the sleeve central axis Pc, the gap between the outer surface of the ball valve body 76 and the inner wall of the large diameter portion 733 corresponds to the one-sided clearance. Due to the centrifugal force during rotation of the rotor, the ball valve body 76 moves by the one-sided clearance from a state in which the center is on the sleeve central axis Pc until it abuts on the inner wall of the large diameter portion 733 in the radially outward direction of the rotor.

The valve spring 77, which serves as a "valve biasing member," is provided between the ball valve body 76 and the bottom 74 of the sleeve 72. The valve spring 77 biases the ball valve body 76 toward the valve seat 713. When the valve timing adjustment device 10 stops rotating and hydraulic oil is not supplied, the check valve unit 70 is in a closed state.

The bush 71, which serves as a "valve seat member," has a bush body 711, an inlet 712, a valve seat 713, and a fitting portion 714. The bush body 711 is formed in a generally disk shape. The inlet 712 is formed in a circular shape near the center of the bush body 711. "Near the center" means that it is not exactly in the center but is slightly eccentric, and will be described in detail later. The valve seat 713 is formed in a ring shape around the inlet 712 on the side opposite the ball valve body 76.

The fitting portion 714 is formed in a cylindrical shape extending from the outer edge of the bush body 711 toward the large diameter portion 733 of the sleeve 72. The outer peripheral wall of the large diameter portion 733 of the sleeve 72 is press-fitted into the inner peripheral wall of the fitting portion 714. Therefore, the bush body 711 is arranged coaxially with the sleeve 72. In addition, the outer peripheral wall of the fitting portion 714 is press-fitted into the inner peripheral wall of the check valve unit insertion hole 37. This fixes the check valve unit 701 to the vane rotor 30.

As a configuration unique to the check valve unit 701 of the first embodiment, the inlet 712 and the valve seat 713 of the bush 71 are eccentric with respect to the center of the bush body 711, i.e., with respect to the sleeve 72. In detail, the valve seat central axis Ps is shifted radially outward from the sleeve central axis Pc by an eccentricity amount δ that corresponds to the one-sided clearance between the inner diameter of the large diameter portion 733 of the sleeve 72 and the outer diameter of the ball valve body 76. The inner diameter of the large diameter portion 733 corresponds to the "inner diameter of the sleeve 72 at the portion where the ball valve body 76 is housed."

During rotation of the rotor, the center of the ball valve body 76 shifts radially outward from the sleeve central axis Pc by the amount of one-sided clearance, and when it comes into contact with the inner wall of the large diameter portion 733, the center of the ball valve body 76 is positioned on the valve seat central axis Ps.

When hydraulic oil is pumped from the oil pump 8, as shown in FIG. 3, the ball valve body 76 separates from the valve seat 713 (opens) due to the pressure of the hydraulic oil and moves toward the connection part 732 against the biasing force of the valve spring 77. At this time, the center of the ball valve body 76, which is subjected to centrifugal force, moves on the valve seat central axis Ps. Note that FIG. 3 shows the open valve state when it is assumed that the force due to the hydraulic pressure of the hydraulic oil and the biasing force of the valve spring 77 are balanced when the center of the ball valve body 76 is on a plane including the centers of the outlets 75. In reality, the position of the ball valve body 76 on the valve seat central axis Ps changes depending on the relationship between the force due to the hydraulic pressure of the hydraulic oil and the biasing force of the valve spring 77.

When the supply of hydraulic oil from the oil pump 8 is stopped, as shown in FIG. 4, the ball valve body 76 is seated (closed) on the valve seat 713 by the biasing force of the valve spring 77. At this time, the center of the ball valve body 76 is held on the valve seat central axis Ps, so the ball valve body 76 contacts the entire circumference of the valve seat 713 evenly. Therefore, it is possible to prevent the ball valve body 76 from hitting the valve seat 713 on one side.

Figure 5 shows a "radial cross section of the sleeve 72 including the center of the ball valve body 76," which corresponds to the cross section along line V-V in Figure 3, that is, a radial cross section of the large diameter portion 733 of the sleeve 72. The radial cross sections of each of the following embodiments are also shown in the same manner as Figure 5. The large diameter portion 733 of the sleeve 72 is formed with an outlet port 75 through which the fluid that has flowed in from the inlet port 712 flows out. Specifically, as shown in Figures 4 and 5 of Patent Document 1, four approximately circular outlet ports 75 are formed radially at 90° intervals.

Here, the straight line connecting the rotation axis O and the center of the ball valve body 76 is defined as the centrifugal force action line Y. In the check valve unit 701 of the first embodiment, the four outlets 75 are arranged at a 45° angle to the centrifugal force action line Y. In other words, the outlets 75 are not arranged on the centrifugal force action line Y, particularly on the centrifugal force action line Y on the side farther from the rotation axis O than the sleeve center axis Pc.

Figure 6 shows a check valve unit 709 of a comparative example, which is contrasted with the check valve unit 701 of the first embodiment. In the comparative example, the four outlets 75 are arranged on the centrifugal force action line Y and on a straight line X perpendicular to the centrifugal force action line Y. Therefore, the outlet 75 (75out) on the side farther from the rotation axis O with respect to the sleeve center axis Pc may be blocked by the ball valve body 76 moved radially outward by the centrifugal force, which may impede the flow of hydraulic oil.

On the other hand, in the check valve unit 701 of the first embodiment, all four outlets 75 are formed in areas excluding the range with which the ball valve body 76 comes into contact or is in close proximity while the rotor is rotating. The ball valve body 76 is moved radially outward by centrifugal force and comes into contact with the inner wall portion of the large diameter portion 733 of the sleeve 72. This prevents the flow of hydraulic oil supplied to the hydraulic chambers 201 and 202 from being obstructed, and ensures the required flow rate.

Next, referring to Figures 7 to 9, an example of a configuration that improves assembly in the assembly work of inserting the check valve unit 701 into the check valve unit insertion hole 37 of the vane rotor 30 will be described. The check valve unit 701 is inserted into the check valve unit insertion hole 37 formed in the end face of the vane rotor 30 so that the bush 71 is on the open side. At this time, the check valve unit 701 needs to be inserted in the correct orientation with respect to the rotation axis O of the vane rotor 30 because there is a direction in which the bush 71 is eccentric.

In the example shown in Figures 7 and 8, the bush 71 has a circular outer shape and is assumed to be capable of being inserted into the circular check valve unit insertion hole 37 in any rotational direction. For this reason, a position mark is provided to indicate the assembly position of the check valve unit.

In the example shown in FIG. 7, a reference line 81 is formed as a position mark spanning the bush 71 and the outer edge of the check valve unit insertion hole 37. The reference line 81 may be engraved into the surface by groove processing or the like, or paint or a chemical substance may be applied to the surface. In the production line, a machine may detect the reference line 81 by an optical sensor or the like and assemble the unit so as to align the position. Alternatively, a worker may visually confirm the reference line 81 and assemble the unit so as to align the position. This prevents incorrect assembly of the check valve unit 701 and enables efficient assembly work in the correct orientation.

In the example shown in FIG. 8, a dent 82 is provided as a position mark at a circumferential position on the eccentric side of the end face of the bush 71. By orienting the check valve unit 701 so that the dent 82 is located on the side farther from the rotation axis O on a radius passing through the rotation axis O of the vane rotor 30, the position mark may be omitted on the outer edge side of the check valve unit insertion hole 37. As with the reference line 81, the machine may detect the dent 82 with a sensor, or the worker may visually check the dent 82 and assemble it to align the position.

In the example shown in FIG. 9, the bush 71 and the check valve unit insertion hole 37 are provided with a positioning portion 83 that prevents assembly at any position other than a specific one. For example, a protrusion 837 is provided at a specific position on the outer periphery of the bush 71, and a recess 833 that receives the protrusion 837 is provided on the vane rotor 30. This makes it possible to reliably prevent incorrect assembly of the check valve unit 701. The positioning portion 83 may be configured by combining protrusions and recesses of any shape. Also, multiple sets of protrusions and recesses may be engaged with each other.

Furthermore, the position mark and the positioning portion may be used together. The position mark can be used to determine the approximate assembly position, and the check valve unit 701 can be inserted up to the mouth of the check valve unit insertion hole 37, and the positioning portion can be used to guide the check valve unit to the correct position during insertion, allowing efficient and accurate assembly work.

Second Embodiment
A check valve unit 702 according to a second embodiment, which is an improved variant of the first embodiment, will be described with reference to Fig. 10. In the first embodiment shown in Fig. 5, the radius Rw of the inner wall Wout of the large diameter portion 733 of the sleeve 72 is larger by the one-side clearance than the radius Rb of the ball valve body 76 (Rw>Rb). The ball valve body 76 contacts the inner wall Wout of the sleeve 72 at one point, so that a load is concentrated at the contact point.

In contrast, in the second embodiment, the sleeve 72 is formed so that the radius Rw of the inner wall Wout of the large diameter portion 733 on the side farther from the rotation axis O is equal to the radius Rb of the ball valve body 76 (Rw = Rb). The ball valve body 76 contacts the inner wall Wout of the large diameter portion 733 of the sleeve 72 along a line with a length equivalent to a portion of the diameter circumference. Therefore, the load can be distributed within the range of the contact line.

(Third and fourth embodiments)
Next, check valve units 703, 704 of the third and fourth embodiments will be described with reference to Figures 11 to 14. In the third and fourth embodiments, unlike the first and second embodiments, the valve seat central axis Ps coincides with the sleeve central axis Pc. Also, a "regulating portion" is provided on the inner wall of the sleeve 72 at the portion where the ball valve body 76 is housed, that is, on the inner wall of the large diameter portion 733. During rotation of the rotor, the "regulating portion" regulates the movement of the ball valve body 76 due to centrifugal force, and holds the center of the ball valve body 76 on the sleeve central axis Pc. The specific configuration of the "regulating portion" is different between the third and fourth embodiments.

Axial cross sections of the check valve unit 703 of the third embodiment are shown in Figures 11 and 12, and its radial cross section is shown in Figure 13. A spacer 78 having a thickness equivalent to the one-sided clearance is interposed as a "regulating portion" on the inner wall of the sleeve 72 on the side farther from the rotation axis O. While the rotor is rotating, the ball valve body 76 comes into contact with the wall surface of the spacer 78 due to centrifugal force. At this time, the center of the ball valve body 76 is located on the sleeve central axis Pc, and the entire circumference of the ball valve body 76 evenly abuts against the valve seat 713 when the valve is closed.

The spacer 78 as a "regulating portion" does not necessarily have to be a separate member from the sleeve 72, but may be formed integrally with the sleeve 72.

A radial cross section of the check valve unit 704 of the fourth embodiment is shown in Figure 14. The "regulating portion" is composed of a pair of inclined walls 79. The pair of inclined walls 79 are formed symmetrically with respect to a straight line (centrifugal force action line) Y connecting the rotation axis O and the center of the ball valve body 76, and the spacing between them becomes narrower toward the radial outside.

During rotation of the rotor, centrifugal force causes the ball valve body 76 to contact the inclined wall 79 at two points symmetrical with respect to the centrifugal force line of action Y. The inclined wall 79 restricts the movement of the ball valve body 76 due to centrifugal force and keeps the center of the ball valve body 76 on the sleeve central axis Pc. This reduces the contact load between the ball valve body 76 and the inner wall compared to the third embodiment, and stabilizes the position of the ball valve body 76.

Compared to the first and second embodiments, the third and fourth embodiments make it easier to machine the bush 71 because the valve seat 713 of the bush 71 only needs to be formed coaxially with the outer diameter. Also, because the internal structure of the sleeve 72 has a directional property, the check valve units 703 and 704 need to be inserted in the correct orientation when inserted into the check valve unit insertion hole 37 of the vane rotor 30. The position marks or positioning parts used in the assembly work can be similarly applied to the configuration examples shown in Figures 7 to 9.

Other embodiments
(a) The cylindrical shape of the sleeve 72 in the check valve unit 70 is not limited to a stepped shape consisting of the small diameter portion 731, the connection portion 732, and the large diameter portion 733, and may be formed, for example, into a shape of a single diameter. In that case, the inner periphery of the valve spring 77 may be guided, for example, by a guide pillar portion protruding from the center of the bottom portion 74.

(b) The number, shape, position, etc. of the outlets 75 in the check valve unit 70 are not limited to those shown in the above embodiment, and one or more outlets 75 may be formed so as to ensure the required flow rate in a smooth flow direction. For example, the outlets 75 may be formed in a range outside the sliding range of the ball valve body 76 on the bottom 74 side of the sleeve 72. If the ball valve body 76 does not block the outlets 75 due to centrifugal force during rotation, there is no need to give special consideration to the circumferential position of the outlets 75 in the first embodiment.

(c) The configuration of the hydraulic oil control unit 11 of the valve timing adjustment device 10 and the flow paths to the retard chamber 201 and advance chamber 202 are not limited to the configuration shown in the above embodiment, and may be any configuration that provides similar functions.

(d) In a valve timing adjustment device having a configuration different from that shown in FIG. 1, the housing 20 may rotate together with the camshaft 3 (driven shaft) and the vane rotor 30 may rotate together with the crankshaft 2 (drive shaft). In addition, the valve timing adjustment device of another embodiment may adjust the opening and closing timing of the exhaust valve 5 instead of the intake valve 4.

(e) The ball check valve of the present invention is applicable not only to valve timing adjustment devices but also to any device equipped with a rotating body. The fluid to be prevented from backflowing is not limited to hydraulic oil, but may be water, chemical liquid, or other fluids.

The present invention is not limited to the above-mentioned embodiment, and can be implemented in various forms without departing from the spirit of the invention.

10 Valve timing adjustment device,
20 Housing (rotating body),
30 vane rotor (rotating body),
70 (701-704) Check valve unit (ball check valve),
71 bush (valve seat member), 712 inlet, 713 valve seat,
72 Sleeve,
76 ball valve body, 77 valve spring (valve biasing member),
78 Spacer (regulating portion), 79 Inclined wall (regulating portion).

Claims (7)

a cylindrical sleeve (72) arranged parallel to a rotation axis (O) of the rotating body (20, 30) at a position offset from the rotation axis;
A ball valve body (76) accommodated in the sleeve and slidable in the axial direction of the sleeve;
a valve seat member (71) provided at one axial end of the sleeve, the valve seat member having an inlet (712) through which a fluid can flow, and a valve seat (713) formed annularly around the inlet and on which the ball valve element can be seated;
a valve biasing member (77) that biases the ball valve body toward the valve seat;
Equipped with
A ball check valve in which the central axis (Ps) of the valve seat is shifted radially outwardly of the rotor with respect to the central axis (Pc) of the sleeve by an eccentricity amount (δ) equivalent to the one-sided clearance between the inner diameter of the sleeve and the outer diameter of the ball valve body at the portion where the ball valve body is accommodated. In a radial cross section of the sleeve including the center of the ball valve body,
2. The ball check valve according to claim 1, wherein the sleeve has one or more outlets (75) through which the fluid flowing in from the inlet flows out, the outlets being formed in a portion other than the area with which the ball valve body contacts or is in close proximity during rotation of the rotating body. In a radial cross section of the sleeve including the center of the ball valve body,
2. The ball check valve according to claim 1, wherein the sleeve has an inner wall on a side farther from the rotary shaft having a radius (Rw) equal to a radius (Rb) of the ball valve body. a cylindrical sleeve (72) arranged parallel to a rotation axis (O) of the rotating body (20, 30) at a position offset from the rotation axis;
A ball valve body (76) accommodated in the sleeve and slidable in the axial direction of the sleeve;
a valve seat member (71) provided at one axial end of the sleeve, the valve seat member having an inlet (712) through which a fluid can flow, and a valve seat (713) formed annularly around the inlet and on which the ball valve element can be seated;
a valve biasing member (77) that biases the ball valve body toward the valve seat;
Equipped with
The central axis (Ps) of the valve seat coincides with the central axis (Pc) of the sleeve,
A ball check valve in which a regulating portion (78, 79) is provided on the inner wall of the sleeve at the portion where the ball valve body is housed, for regulating the movement of the ball valve body due to centrifugal force while the rotating body is rotating and for maintaining the center of the ball valve body on the central axis of the sleeve. In a radial cross section of the sleeve including the center of the ball valve body,
The ball check valve according to claim 4, wherein the regulating portion is composed of a pair of inclined walls (79) that are symmetrical with respect to a straight line (Y) connecting the rotation axis and the center of the ball valve body, and that are formed so that the spacing between them becomes narrower radially outward. A valve timing control device for controlling an opening/closing timing of an intake valve (4) or an exhaust valve (5) driven to open and close by a driven shaft (3) of an engine (1) by changing a rotational phase between the drive shaft (2) and the driven shaft (3), comprising:
a housing (20) having a cylindrical portion (221) and a plurality of partition walls (23) protruding radially inward from the cylindrical portion, the housing (20) rotating together with one of the drive shaft or the driven shaft;
a vane rotor (30) having a boss portion (31) provided coaxially with the cylindrical portion of the housing and a plurality of vane portions (32) protruding radially from the boss portion, the vane portions being accommodated in the housing so as to be rotatable between the partition portions, rotating together with the other of the drive shaft or the driven shaft, and rotating relatively to the housing by hydraulic pressure of hydraulic oil supplied to a plurality of hydraulic chambers (201, 202) formed between the partition portions and the vane portions;
a check valve unit (70) that opens and closes in parallel to a rotation axis (O) of the housing and the vane rotor at a position offset from the rotation axis (O) and prevents backflow of hydraulic oil from the hydraulic chamber to a hydraulic oil supply source (8);
Equipped with
The check valve unit is configured as a ball check valve according to any one of claims 1 to 5, and a center of the ball valve body is positioned on the central axis of the valve seat during rotation of the housing and the vane rotor. The check valve unit is inserted into a check valve unit insertion hole (37) formed in an end surface of the vane rotor such that the valve seat member is on the opening side,
A position mark (81, 82) indicating an assembly position of the check valve unit is provided on the valve seat member or across the valve seat member and the outer edge of the check valve unit insertion hole, or
7. The valve timing adjusting device according to claim 6, wherein the valve seat member and the vane rotor are provided with positioning portions (83) that prevent the valve seat member and the vane rotor from being assembled at any position other than a specific position.

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