JP2010255576A - Reed valve for cam phaser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the strength irregularity and maximally utilize the material strength by taking into consideration of the orientation dependency of the strength with respect to the rolling direction of the material in a reed valve of a cam torque actuator (CTA). <P>SOLUTION: A plurality of reed valves 91, 92 provided in an oil path 57 in a CTA 63 for switching the oil path is formed in a valve plate 26 with a rolling process applied in a predetermined rolling direction so that the longitudinal directions thereof linking their base ends 91c, 92c and free ends 91a, 92a, respectively are parallel with each other or the longitudinal directions intersect with each other at a 30° or less intersection angle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reed valve that is used to open and close an oil passage of a cam phase varying device provided in an engine of an automobile or the like.

  For gasoline engines, diesel engines, and HCCI (Homogeneous Charge Compression Ignition) engines, intake and exhaust valves are used according to operating conditions to improve output and fuel consumption and reduce harmful exhaust gas components. The one equipped with a variable valve device that changes the lift amount and valve opening timing is widely used. As a variable valve operating device, there is a conventional variable valve lift control device (hereinafter referred to as VLC) that variably controls the valve lift stepwise or steplessly, and cam phase (valve opening timing). A valve timing control device (Variable Timing Control device: hereinafter referred to as VTC) is also known.

  The VTC includes a hydraulic actuator suitable for high-speed operation (Oil Pressure Actuated phaser: hereinafter referred to as OPA) and a cam torque actuator suitable for low-speed operation (cam torque-driven phase variable mechanism (Cam). Torque Actuated phaser) (hereinafter referred to as CTA) and vane type installed at the end of the camshaft, and the CTA has an advance chamber or retard chamber and a spool valve. A pair of check valves (reed valves) provided for opening and closing the communicating oil passages are provided on the valve plate (see Patent Document 1).

Japanese Patent Publication No. 2005-147153

  By the way, the above-mentioned CTA reed valve is generally formed of a stainless steel plate or the like (rolled material), and the strength of this type of plate has direction dependency with respect to the rolling direction. However, in the above prior art, the rolling direction of the plate material is not considered at all when the reed valve is manufactured. That is, in the above prior art, the two reed valves provided on the valve plate are greatly different from each other in the longitudinal direction (that is, the intersecting angle in the longitudinal direction is set to about 60 °). There was a problem that there was a large variation in strength between them. In particular, since the reed valve used in CTA has a high frequency of opening and closing operations and high reliability is required, it is desirable to reduce such a variation in strength as much as possible.

  The present invention has been devised in view of such problems of the prior art, and is a reed valve provided in a plurality of oil passages in a cam phase variable device, and the effect of strength change depending on the rolling direction of the plate material. It is an object of the present invention to provide a reed valve that can effectively reduce variations in strength by suppressing the above.

  A first invention made to solve the above problems is a reed valve (91, 92) provided in a plurality of oil passages (57) in the cam phase varying device (63) and used to open and close the oil passages. The plurality of reed valves are formed on a single plate (26) that has been rolled along a predetermined rolling direction, and each has a base end (91c, 92c) and a free end (91a, 92a). The longitudinal direction connecting the two is parallel, or the longitudinal direction intersects with an intersection angle of 30 ° or less.

  According to a second aspect of the present invention, the plurality of reed valves includes two leads whose longitudinal direction is parallel to the rolling direction, or whose bisector of the crossing angle of the longitudinal direction substantially coincides with the rolling direction. It can be set as the structure which is a valve | bulb.

  Further, as a third invention, a plurality of reed valves are provided in an oil passage in the cam phase varying device and used for opening and closing the oil passage, wherein the plurality of reed valves are rolled along a predetermined rolling direction. Each plate is formed from a processed plate material, and the crossing angle between the longitudinal direction connecting each base end and the free end and the rolling direction can be substantially equal.

  As a fourth aspect of the invention, the longitudinal direction and the rolling direction can be substantially matched.

According to the first aspect of the present invention, when a plurality of reed valves are provided on one plate in the cam phase varying device, the longitudinal directions of the respective reed valves are made parallel or the longitudinal directions intersect each other by 30 ° or less. By intersecting with an angle and suppressing the influence of the strength change depending on the rolling direction of the plate material, there is an excellent effect that the variation in strength between the reed valves can be effectively reduced.
According to the second aspect of the invention, the longitudinal direction of the two reed valves is parallel to the rolling direction, or the bisector of the crossing angle of the longitudinal direction is substantially coincident with the rolling direction, so that the rolling direction It is possible to make maximum use of the strength of the plate material having the direction dependency on (that is, increase the strength of each reed valve).
According to the third aspect of the invention, when a plurality of reed valves are provided in the cam phase varying device, the crossing angle between the longitudinal direction of the reed valve and the rolling direction is made substantially equal and depends on the rolling direction of the plate material. By suppressing the influence of the strength change, the strength variation between the reed valves can be effectively reduced.
Further, according to the fourth aspect of the invention, the longitudinal direction of the reed valve and the rolling direction of the plate material are substantially matched to make maximum use of the strength of the plate material having direction dependency with respect to the rolling direction (that is, each It is possible to increase the strength of the reed valve.

The principal part perspective view of the engine which concerns on 1st Embodiment. 1 is an exploded perspective view of a VTC actuator according to a first embodiment. Schematic configuration diagram of a VTC actuator according to the first embodiment Plan view of valve plate (reed valve) according to the first embodiment Schematic diagram showing the advance operation of the VTC actuator according to the first embodiment. The figure which shows the relationship between the angle with respect to the rolling direction of the longitudinal direction of the reed valve which concerns on 1st Embodiment, and intensity | strength. The figure which shows the relationship between the crossing angle with respect to the rolling direction of the bisector in the crossing angle (theta) of two reed valves which concern on 1st Embodiment, and the ratio of the mutual strength difference with respect to a maximum strength difference. Plan view of a reed valve according to the second embodiment

<< Configuration of First Embodiment >>
<Overall configuration>
An engine E shown in FIG. 1 is a DOHC four-valve type four-cycle in-line four-cylinder gasoline engine mounted on an automobile. The cylinder head 1 has two intake valves 2 and two exhaust valves 3 for each cylinder, and intake and exhaust thereof. An intake camshaft 4 and an exhaust camshaft 5 that drive the valves 2 and 3 are provided. Both camshafts 4 and 5 are rotationally driven at a rotational speed ½ that of the crankshaft 10 via the crank sprocket 6, the cam chain 7, the intake cam sprocket 8, and the exhaust cam sprocket 9. The crankshaft 10 is connected to the piston 12 via a connecting rod 11 and drives an oil pump 14 installed obliquely downward via a chain 13.

  The cylinder head 1 and the cylinder block 15 are formed with a hydraulic oil supply oil passage 16 for supplying hydraulic oil (engine oil) from the oil pump 14 to the VTC actuators 20 and 21 described later. The cylinder head 1 is provided with a normally open type electromagnetic shut valve 17, and when the electromagnetic shut valve 17 is operated, the supply form of hydraulic oil to the VTC actuators 20 and 21 is switched.

  An intake side VTC actuator 20 is attached to the front end of the intake camshaft 4, and an exhaust side VTC actuator 21 is attached to the front end of the exhaust camshaft 5. An intake side cam angle sensor 18 is installed at the rear end of the intake camshaft 4, and an exhaust side cam angle sensor 19 is installed at the rear end of the exhaust camshaft 5. An intake side VLC mechanism 75 is interposed between the intake camshaft 4 and the intake valve 2, and an exhaust side VLC mechanism 76 is interposed between the exhaust camshaft 5 and the exhaust valve 3.

  In addition, the automobile has various controlled devices (electromagnetic shut-off) attached to the engine E based on output information from various sensors (both cam angle sensors 18 and 19, an accelerator sensor (not shown), an intake air sensor, a crank angle sensor, etc.). An engine ECU 70 that determines the control amount of the valve 17, both VTC actuators 20 and 21, both VLC mechanisms 75 and 76, a fuel injection valve and an ignition coil (not shown), and outputs a drive current is installed.

<VTC actuator>
As shown in FIG. 2, the exhaust-side VTC actuator 21 rotates in synchronization with the crankshaft, and is rotatably held in a housing 22 having an exhaust cam sprocket 9 formed on the outer periphery thereof. A rotor 23 whose rear end surface is fastened to the front end of the camshaft 5 and rotates integrally therewith, a front plate 24 covering the front surface of the housing 22, a back plate 25 covering the rear surface of the housing 22, and an inner side of the front plate 24, A valve plate 26 on which reed valves 91a and 92a (see FIG. 4) are formed; a valve plate cover 27 for fixing the valve plate 26 to the rotor 23; a bias spring 28 for relatively rotating the housing 22 and the rotor 23 in the retard direction; Axes of exhaust camshaft 5 and rotor 23 A spool valve 29 installed, a linear solenoid 31 that drives the spool valve 29 by being controlled by the engine ECU 70, a lock pin 33 held by the rotor 23, and a lock pin spring that urges the lock pin 33 toward the back plate 25 34, a bypass valve 36 held by the rotor 23, a bypass valve spring 37 for urging the bypass valve 36 toward the front plate 24, and the like are used as constituent elements. The spool valve 29 includes a valve sleeve 38 held at the shaft center of the exhaust camshaft 5 and the rotor 23, a spool 39 slidably fitted in the valve sleeve 38, and the spool 39 attached to the linear solenoid 31 side. And a return spring 40 that is energized.

  As shown in FIG. 3, a first vane 41, a second vane 42, and a third vane 43 are erected on the outer periphery of the rotor 23, while these vanes 41 to 43 are provided on the inner periphery of the housing 22. First to third vane chambers 45 to 47 are formed that are accommodated so as to be relatively rotatable with an angle (that is, between the most advanced angle position and the most retarded angle position). In the present embodiment, the first vane 41 and the first vane chamber 45 are components of the first OPA 61, the second vane 42 and the second vane chamber 46 are components of the second OPA 62, and the third vane 43 and the second vane chamber 46. The 3-vane chamber 47 is a component of the CTA 63.

  The first and second vane chambers 45 and 46 are partitioned by the first and second vanes 41 and 42 into OPA-side advance chambers 45a and 46a and OPA-side retard chambers 45b and 46b, respectively. The hydraulic oil from the spool valve 29 is supplied to the OPA side advance chambers 45a and 46a through the OPA side advance oil passages 51 and 52, and is also supplied to the OPA side retard oil passages 53 and 54 through the OPA side retard oil passages 53 and 54. It is supplied to the corner chambers 45b and 46b. The third vane chamber 47 is partitioned by the third vane 43 into a CTA-side advance chamber 47a and a CTA-side retard chamber 47b. The CTA side advance chamber 47a and the CTA side retard chamber 47b communicate with the spool valve 29 through the first CTA oil passage 55 and the second CTA oil passage 56, respectively. The OPA side advance oil passages 51 and 52 are connected to the electromagnetic shut-off valve 17 via the hydraulic oil discharge passages 81 to 83, as will be described later.

  The first vane 41 accommodates a lock pin 33 and a lock pin spring 34 (see FIG. 2), and only when the hydraulic oil is not supplied to the lock pin release oil passage, The tip of the lock pin 33 is fitted into the lock hole 25 a formed in the back plate 25 by the spring force. The lock hole 25a is formed at a position where the lock pin 33 is inserted when the rotor 23 is in the most retarded phase with respect to the housing 22.

<Reed valve>
As shown in FIG. 4, a substantially disc-shaped valve plate 26 made of stainless steel sheet steel (cold rolled stainless steel sheet) has a pair of identical shapes (laterally symmetric shapes) so that the center portion is hollowed out. Reed valves 91 and 92 are formed. The reed valves 91 and 92 close the oil passages by circular valve bodies 91a and 92a provided at free ends. Further, when the oil passage is opened, the valve body support pieces 91b and 92b that support the valve bodies 91a and 92a are elastically deformed with the base ends 91c and 92c as fixed fulcrums, so that the valve bodies 91a and 92a are displaced to the open side ( That is, it is displaced in a direction substantially perpendicular to the paper surface of FIG.

  The reed valves 91 and 92 are arranged so that the longitudinal directions (dashed lines X1 and X2 in FIG. 4) connecting the valve bodies 91a and 92a and the base ends 91c and 92c are parallel to each other. As will be described later, the longitudinal directions of the reed valves 91 and 92 are not necessarily parallel to each other. In this case, it is preferable that the reed valves 91 and 92 intersect at an intersection angle of 30 ° or less. Here, the longitudinal direction of the reed valves 91 and 92 is parallel to the rolling direction of the valve plate 26 (see arrow R in FIG. 4), but the longitudinal directions of the reed valves 91 and 92 intersect each other. In this case, the bisector of the crossing angle θ in the longitudinal direction (one-dot chain line X3 in FIG. 4) is arranged so as to substantially coincide with the rolling direction of the valve plate 26. In addition, the “longitudinal direction” of the reed valve in this specification is a direction connecting the base end and the free end, and does not strictly mean a direction in which the reed valve has a long dimension.

<< Operation of First Embodiment >>
Hereinafter, the operation of the present embodiment will be described with further reference to FIGS. During normal operation of the engine E, the engine ECU 70 repeatedly executes normal operation control of both the VTC actuators 20 and 21 with a predetermined control interval (for example, 10 ms). When the normal operation control is started, the engine ECU 70 determines the target cam phase of both the camshafts 4 and 5 based on the various operation information described above, and then supplies the drive current for realizing the target cam phase to the two VTC actuators 20, 21 to the linear solenoid 31 as appropriate. Further, the engine ECU 70 executes feedback control of the cam phase for both the camshafts 4 and 5 based on the output signals of both the cam angle sensors 18 and 19.

  For example, when the exhaust camshaft 5 is advanced during operation of the engine E, the engine ECU 70 moves the spool 39 to the advance position (rightward in the figure) by the linear solenoid 31 as shown in FIG. Then, the hydraulic oil supplied from the oil pump 14 via the hydraulic oil supply oil passage 16 flows into the OPA side advance chambers 45a and 46a via the spool 39 and the OPA side advance oil passages 51 and 52, The first and second vanes 41 and 42 are rotated relative to the advance side. The hydraulic oil in the OPA side retarding chambers 45b and 46b is discharged to the outside from the left side of the spool 39 through the OPA side retarding oil passages 53 and 54.

  On the other hand, in the CTA 63, the second CTA oil passage 56 and the central oil passage 57 communicate with each other via the spool 39 moved to the advance position. Then, an advance cam torque acts on the exhaust camshaft 5 and the valve element 92a of the reed valve 92 opens each time the rotor 23 rotates relative to the housing 22 in the advance side. The hydraulic oil flows into the CTA side advance chamber 47a and relatively rotates the third vane 43 to the advance side. When the retard side cam torque is applied, the valve bodies 91a, 92a of the reed valves 91, 92 are closed, and the cam phase is maintained without moving the hydraulic oil.

  By the operation of the first and second OPAs 61 and 62 and the CTA 63, the rotor 23 rotates relative to the housing 22 in the clockwise direction in the drawing, and the exhaust camshaft 5 advances. The hydraulic oil is supplied to the CTA 63 until the CTA 63 is satisfied at the start of operation of the engine E. Further, during normal operation of the engine E, no driving current is supplied to the electromagnetic shut valve 17 (the hydraulic oil supply oil passages 16a and 16b are communicated), and the electromagnetic shut valve 17 is held by the hydraulic oil from the oil pump 14 and is also bypass valve 36. Moves to the front plate 24 side and interrupts the flow of hydraulic oil between the communicating oil passages 43c and 43d.

  The strength (tensile strength, yield point, etc.) of the stainless steel sheet steel constituting the reed valves 91 and 92 is highly directional dependent on the rolling direction during rolling. Therefore, the relationship between the crossing angle θ in the longitudinal direction of the reed valves 91 and 92 with respect to the rolling direction (hereinafter referred to as the reed valve rolling angle) and the strength of the reed valves 91 and 92 is, for example, as shown in FIG. . In FIG. 6, the strength of the reed valves 91 and 92 is maximum when the reed valve rolling angle is 0 deg (that is, when the bending axis of the valve body support pieces 91b and 92b during elastic deformation intersects the rolling direction perpendicularly). It takes a value and decreases as the rolling angle increases, and takes the minimum value when the rolling angle of the reed valve is 90 deg.

  Further, the reed valve 91 with respect to the maximum strength difference shown in FIG. 6 and the crossing angle of the bisector of the reciprocal angle θ of the reed valve with respect to the rolling direction (hereinafter referred to as the rolling angle of the reciprocal angle bisector of the reed valve) , 92 (that is, the degree of decrease in intensity from the maximum value in FIG. 6) is, for example, as shown in FIG. FIG. 7 shows the relationship between a plurality of crossing angles (hereinafter referred to as crossing angles of the reed valves) of 10 to 50 degrees in the longitudinal direction of the reed valves 91 and 92.

  Here, the ratio of the strength difference between the reed valves 91 and 92 to the maximum strength difference tends to increase as the crossing angle of the reed valves increases. In addition, with respect to each crossing angle 10 ° to 50 of the reed valve, the ratio of the strength difference between the reed valves 91 and 92 with respect to the maximum strength difference is the minimum value when the rolling angle of the reciprocal angle bisector of the reed valve = 0 deg. And increases as the rolling angle increases to take a maximum value, and then decreases to a minimum value. Therefore, in order to maintain the ratio of the strength difference between the reed valves 91 and 92 with respect to the maximum strength difference (the ratio of the strength difference is 50% or less), the crossing angle of the reed valves needs to be 30 ° or less. There is.

  As described above, in the CTA 63, when a plurality of (here, two) reed valves 91 and 92 are provided on one valve plate 26, the longitudinal directions of the reed valves 91 and 92 are parallel to each other, or Since the longitudinal direction intersects with an intersecting angle of 30 ° or less, the influence of the strength change depending on the rolling direction of the valve plate 26 can be suppressed, and the strength variation between the reed valves 91 and 92 is effective. Can be reduced.

  Further, in the CTA 63, the longitudinal direction of the two reed valves 91 and 92 is parallel to the rolling direction, or the bisector of the crossing angle of the longitudinal direction is made coincident with the rolling direction. It is possible to make maximum use of the strength of the plate material having the property (that is, increase the strength of the reed valves 91 and 92).

<< Second Embodiment >>
In the CTA according to the second embodiment of the present invention, as shown in FIG. 8, the reed valves 91 and 92 are not formed integrally with one valve plate 26 as described above, but are provided as separate members. . In FIG. 8, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the second embodiment, items not particularly mentioned below are the same as those in the first embodiment.

  As shown in FIG. 8, the reed valves 91 and 92 are bolted to the rotor 23 via bolt holes 91d and 92d instead of being fixed by the valve plate cover 27 (see FIG. 2). Since the reed valves 91 and 92 are formed as separate members from a thin stainless steel plate (plate material), it is not necessary to consider the crossing angle of the reed valves as in the first embodiment. When the reed valves 91 and 92 are manufactured, the rolling angles of the reed valves 91 and 92 are made equal. Thereby, it becomes possible to suppress the influence of the strength change of the reed valves 91 and 92 depending on the rolling direction of the stainless steel sheet, and the variation in strength between the reed valves 91 and 92 can be effectively reduced. In particular, if the rolling angle of the reed valves 91 and 92 is set to zero (that is, the longitudinal direction and the rolling direction are made coincident), the strength of the stainless steel sheet having direction dependency with respect to the rolling direction is maximized. It is possible to use (that is, increase the strength of each reed valve 91, 92).

DESCRIPTION OF SYMBOLS 1 Cylinder head 4 Intake camshaft 5 Exhaust camshaft 8 Intake cam sprocket 9 Exhaust cam sprocket 10 Crankshaft 15 Cylinder block 16 Hydraulic oil supply oil path 17 Electromagnetic shut valve 20 VTC actuator 21 Exhaust side VTC actuator 22 Housing 23 Rotor 25a Lock hole 26 Valve plate (plate material)
29 Spool valve 33 Lock pin 36 Bypass valve 41 First vane 42 Second vane 43 Third vane 45 First vane chamber 45a OPA side advance chamber 45b OPA side retard chamber 46 Second vane chamber 46a OPA side advance chamber 46b OPA side retarding chamber 47 Third vane chamber 47a CTA side advance chamber 47b CTA side retarding chamber 48 Inner opening 49 Outer opening 55 First CTA oil passage 56 Second CTA oil passage 57 Central oil passage 63 CTA (cam phase variable device)
65 outer peripheral surface 66 inner peripheral surface 70 engine ECU
81 Hydraulic oil discharge passage 91 Reed valve 91a Valve body (free end)
91c Base end 92 Reed valve
92a Valve body (free end)
92c base

Claims (4)

A plurality of oil passages in the cam phase variable device are provided for opening and closing the oil passage,
The plurality of reed valves are formed on a single plate that has been rolled along a predetermined rolling direction, and the longitudinal directions connecting the respective base ends and free ends are parallel or the longitudinal direction is 30. A reed valve of a cam phase varying device characterized by intersecting at an angle of intersection of less than or equal to °.   The plurality of reed valves are two reed valves in which the longitudinal direction is parallel to the rolling direction or the bisector of the crossing angle of the longitudinal direction substantially coincides with the rolling direction. The reed valve of the cam phase varying apparatus according to claim 1. A plurality of oil passages in the cam phase variable device are provided for opening and closing the oil passage,
The plurality of reed valves are each formed from a plate material that has been rolled along a predetermined rolling direction, and the crossing angle between the longitudinal direction connecting the base end and the free end and the rolling direction is substantially equal. A reed valve for a cam phase varying device.   The reed valve of the cam phase varying device according to claim 3, wherein the longitudinal direction and the rolling direction substantially coincide with each other.

Images