JPWO2019049810A1 - Hydraulic control valve and valve timing control device for internal combustion engine - Google Patents

Abstract

In the valve timing control device of an internal combustion engine, the phase changing mechanism 3 includes a tubular peripheral wall, a valve body 27 having a supply port 32, a retard port 33, and an advance port 34 formed through the peripheral wall in the radial direction. A spool valve 28 that is slidably arranged inside the peripheral wall and opens and closes each port according to the moving position, and is wound so as to cover each of the ports, and the peripheral length L of one hole edge is 1.07 mm or more. A filtration filter 53 to 55 having a plurality of circular mesh holes 53a to 55a having a hole diameter D of 0.34 mm or more is provided. As a result, it is possible to suppress the occurrence of an oil film in each mesh hole and suppress the occurrence of inadvertent unlocking.

Description

The present invention relates to a hydraulic control valve and a valve timing control device for an internal combustion engine.

As a means for controlling the opening and closing of the oil passage of oil, which is provided in the internal combustion engine of an automobile and is the operating source of various systems, changing the flow direction of oil, and controlling the flow rate and pressure, for example, Patent Document 1 below. The described hydraulic control valve is known.

In this hydraulic control valve, a filtration filter that collects foreign matter in oil passing through each port is arranged on the outer circumference of a tubular valve body. In this filtration filter, a thin stainless steel plate is used as a base material, and mesh holes, which are a plurality of fine holes, are formed in most of the parts except both ends by so-called etching processing.

Japanese Unexamined Patent Publication No. 2012-247021

By the way, in a hydraulic valve timing control device that controls the opening / closing timing of an intake valve or an exhaust valve of an internal combustion engine, a part of the oil in the hydraulic circuit enters the oil pan after the engine is stopped for a long time. It is returned and air is accumulated in the hydraulic circuit.

On the other hand, when the above-mentioned hydraulic control valve is applied to this valve timing control device, there is a possibility that an oil film may stick to each of the mesh holes due to the surface tension of the oil when the engine is stopped.

Then, the air in the hydraulic circuit is pushed out to the retard hydraulic chamber or the advance hydraulic chamber by the oil pumped from the oil pump when the engine is started. After that, air enters the other hydraulic chamber through the clearance and is returned from the hydraulic chamber to the hydraulic control valve, but in this hydraulic control valve, the oil film of each mesh hole makes it difficult to discharge to the outside.

Therefore, the compressed air in the hydraulic circuit may be supplied to the pressure receiving chamber for unlocking the lock mechanism to inadvertently pull out the lock pin from the lock hole, and the pin lock state may be released.

One object of the present invention is a hydraulic pressure capable of suppressing the occurrence of inadvertent unlocking by suppressing the generation of an oil film in each mesh hole and ensuring the air flowability in the hydraulic control valve. The purpose is to provide a control valve.

A preferred embodiment of the present invention includes, among other things, a filter having a plurality of mesh holes arranged so as to cover an opening in the valve body and having a peripheral length of one hole edge set to 1.07 mm or more. It is characterized by that.

According to a preferred embodiment of the present invention, it is possible to suppress the occurrence of inadvertent unlocking due to compressed air when the engine is started.

It is an overall block diagram which shows 1st Embodiment of the valve timing control device of the internal combustion engine to which the hydraulic control valve which concerns on this invention is applied. FIG. 5 is a cross-sectional view taken along the line AA of FIG. 1 showing a locking mechanism provided in the present embodiment. It is an exploded perspective view of the hydraulic control valve provided in this embodiment. It is a vertical cross-sectional view of the hydraulic control valve provided in this embodiment. It is a perspective view which shows the valve body which attached the filtration filter used in this embodiment. It is an enlarged view which shows the mesh hole of the filtration filter. It is a line graph which shows the relationship between the pore diameter of the mesh hole and the number of oil film formation holes in the experiment of this embodiment. It is an enlarged view which shows the mesh hole of the filtration filter used in 2nd Embodiment. It is an enlarged view which shows the mesh hole of the filtration filter used in 3rd Embodiment.

Hereinafter, an embodiment in which the hydraulic control valve according to the present invention is applied to a valve timing control device for an internal combustion engine will be described with reference to the drawings.

FIG. 1 is an overall configuration diagram of a valve timing control device for an internal combustion engine to which a hydraulic control valve according to the present invention is applied, and FIG. 2 is a sectional view taken along line AA of FIG. 1 showing a locking mechanism provided in the present embodiment. is there.

As shown in FIG. 1, the valve timing control device includes a timing sprocket 1 which is a drive rotating body, a camshaft 2 on the intake side which is provided so as to be rotatable relative to the timing sprocket 1, a timing sprocket 1 and a camshaft. It includes a phase changing mechanism 3 that converts the relative rotation phase of 2, a locking mechanism 4 that locks the phase changing mechanism 3 at the most retarded phase position, and a hydraulic circuit 5 that operates the phase changing mechanism 3.

The timing sprocket 1 is formed through a disk-shaped sprocket body 1a, a gear portion 1b provided on the outer periphery of the sprocket body 1a around which a timing chain (not shown) is wound, and the center of the sprocket body 1a. The camshaft 2 has a bearing hole (not shown) that is rotatably supported on the outer periphery of one end of the camshaft 2. Further, in the sprocket body 1a, female threads are formed at four positions on the outer peripheral portion in the circumferential direction at equal intervals in the circumferential direction.

The timing sprocket 1 is adapted to transmit rotational force from the crankshaft via a timing chain wound around the gear portion 1b.

Further, the timing sprocket 1 (sprocket body 1a) is configured as a rear cover that liquidally closes the rear end opening of the housing 6 described later.

The drive rotating body may be a timing pulley in which a rotational force is transmitted by a timing belt.

The camshaft 2 is rotatably supported on a cylinder head (not shown) via a plurality of cam bearings. The camshaft 2 is provided with a plurality of egg-shaped rotary cams on the outer periphery that open an intake valve (not shown) against the spring force of a valve spring. Further, in the direction of the internal axial center of one end of the cam shaft 2, there is an insertion hole into which the cam bolt 13 described later is inserted, and a female screw hole formed on the tip end side of the insertion hole into which the cam bolt 13 is screwed. ing.

The phase changing mechanism 3 is fastened and fixed from the axial direction via a housing 6 having an operating chamber formed therein and a valve body 27 described later at one end of the camshaft 2, and is rotatably housed in the housing 6. The vane rotor 7 and a plurality of (four in this embodiment) first operating chambers, a retard operating chamber 9, and a second operating chamber, an advance operating chamber 10, in which the operating chambers of the housing 6 are partitioned, are provided. I have. Each of the retard actuating chamber 9 and the advance angle actuating chamber 10 is partitioned by four shoes 8 projecting from the inner peripheral surface of the housing body 11 described later and vanes 15a to 15d of the vane rotor 7.

The housing 6 is formed by press molding and, for example, a cylindrical housing body 11 integrally formed of a so-called sintered metal material formed by sintering a powder metal, and closes the front end opening of the housing body 11. It is composed of a front cover 12 (see FIG. 4) and a timing sprocket 1 (sprocket body 1a) as a rear cover that closes the rear end opening.

The housing body 11 formed in a cylindrical shape has four shoes 8 projecting from the inner peripheral surface at substantially equal intervals in the circumferential direction. In the internal axial direction of each shoe 8, four bolt insertion holes 11a into which four bolts 13a are inserted are formed through in the present embodiment.

The front cover 12 has a relatively large-diameter insertion hole (not shown) formed through the center thereof. Further, the front cover 12 has side clearances between the insertion hole on the inner peripheral surface 12a and a portion other than the outside of the insertion hole and one opposite side surface of the vane rotor 7, respectively. It is designed to seal the inside. Further, the front cover 12 is formed through four bolt insertion holes (not shown) into which each bolt 13a is inserted at four locations in the circumferential direction of the outer peripheral portion.

The timing sprocket 1, the housing body 11, and the front cover 12 are axially connected by four bolts 13a that are inserted into the bolt insertion holes 11a and the like and screwed into the female threads of the timing sprocket 1.

The vane rotor 7 is also integrally formed of a sintered metal material, and is radially projected from a rotor portion 14 located at the center and an outer peripheral surface of the rotor portion 14 at approximately 90 ° equidistant positions in the circumferential direction. It is composed of two vanes 15a to 15d.

The rotor portion 14 is formed in a relatively large-diameter cylindrical shape, and a bolt insertion hole 14a into which the cam bolt 13 is inserted is formed through the rotor portion 14 in the central internal axial direction, and the rotor portion 14 is rotated to one end of the cam shaft 2 by the cam bolt 13. It is fixed from the axial direction.

The vanes 15a to 15d are formed so that their radial protrusion lengths are relatively short, and each of the vanes 15a to 15d is arranged between the shoes 8. Further, the three second to fourth vanes 15b to 15d other than the one first vane 15a are formed to be relatively thin with substantially the same width in the circumferential direction. The first vane 15a is formed to have a large width in the circumferential direction, and a part of the lock mechanism 4 is provided inside.

Sealing members 16a and 16b for sealing between the inner peripheral surface of the housing body 11 and the outer peripheral surface of the rotor portion 14 are provided on the outer peripheral surfaces of the vanes 15a to 15d and the tip of each shoe 8, respectively. ..

Further, when the vane rotor 7 rotates relative to the retard side (counterclockwise direction) from the position shown in FIG. 1, one side surface of the first vane 15a abuts on the opposite side surface 8a of the one shoe 8 facing the vane rotor 7, and the maximum delay is achieved. The rotation position on the corner side is regulated. Further, when the rotation is relative to the advance side (clockwise direction), the other side surface of the first vane 15a also comes into contact with the opposite side surface 8b of the other shoe 8 and the rotation position on the maximum advance angle side is regulated. It has become.

The retard angle actuating chamber 9 and the advance angle actuating chamber 10 described above are provided between both side surfaces of the vanes 15a to 15d in the forward and reverse rotation directions and both side surfaces of the shoe 8. Each retard operating chamber 9 and each advance operating chamber 10 is a hydraulic circuit 5 via four retard passage holes 17 and advance passage holes 18 formed inside the rotor portion 14 substantially in the radial direction. It communicates with each of them.

The lock mechanism 4 holds the vane rotor 7 at the rotation position on the most retarded angle side with respect to the housing 6.

That is, as shown in FIGS. 1 and 2, the lock mechanism 4 has a lock hole 19 formed by a hole forming portion 19a at a predetermined position on the inner surface of the timing sprocket 1 and an internal shaft of the first vane 15a of the vane rotor 7. A pin accommodating hole 20 formed through in the direction, a lock pin 21 provided in the pin accommodating hole 20 so as to be movable back and forth, and a head-shaped tip portion 21a to be inserted into and removed from the lock hole 19, and the lock pin 21. The coil spring 22 that urges the lock hole 19 and the hydraulic pressure that is formed and supplied in the lock hole 19 causes the lock pin 21 to move backward from the lock hole 19 against the spring force of the coil spring 22 to lock. The second release formed between the first release pressure receiving chamber 23a to be released, the step surface 21b formed on the outer peripheral surface of the lock pin 21, and the step portion 20a formed on the inner peripheral surface of the pin accommodating hole 20. It is mainly composed of a pressure receiving chamber 23b and first and second lock passages 24a and 24b for supplying and discharging hydraulic pressure to the first and second release pressure receiving chambers 23a and 23b.

The lock hole 19 is formed in a conical shape having a diameter larger than the outer diameter of the tip portion 21a of the lock pin 21 via the hole forming portion 19a. Further, the lock hole 19 is formed at a position corresponding to the rotation position on the most retarded angle side of the vane rotor 7 on the inner surface of the sprocket body 1a.

The tip surface of the tip portion 21a of the lock pin 21 receives the hydraulic pressure supplied to the first release pressure receiving chamber 23a, or the stepped surface 21b receives the hydraulic pressure supplied to the second release pressure receiving chamber 23b. By these hydraulic pressures, they move backward and come out of the lock hole 19 to be unlocked. Hydraulic pressure is supplied to the first release pressure receiving chamber 23a from one retard angle operating chamber 9 via the first lock passage 24a. Hydraulic pressure is supplied to the second release pressure receiving chamber 23b from one advance angle operating chamber 10 via the second lock passage 24b.

Further, when hydraulic pressure is not supplied to the pressure receiving chambers 23a and 23b of the lock pin 21, the tip portion 21a of the lock pin 21 enters the inside of the lock hole 19 due to the spring force of the coil spring 22. As a result, the vane rotor 7 is locked with respect to the housing 6. As described above, this lock position is the rotation position on the most retarded side of the vane rotor 7 with respect to the housing 6.

The back pressure chamber 20b formed on the rear end side of the lock pin 21 communicates with the outside through the air vent holes 12b and 12c formed through the side end surface of the first vane 15a and the front cover 12. As a result, good slidability of the lock pin 21 is ensured.

As shown in FIG. 1, the hydraulic circuit 5 is provided with an oil pump 25 for discharging hydraulic pressure from a discharge passage 25a to a supply passage (not shown) and a rotor portion 14 in the internal axial direction, depending on the engine operating state. A hydraulic control valve 26 for switching the flow paths of the retard passage holes 17 and the advance passage holes 18 with respect to the supply passage and the discharge passage 49 is provided.

The supply passage is formed in the bearing portion of the cylinder head and the camshaft 2, and the upstream portion communicates with the discharge passage 25a of the oil pump 25, and the downstream side is each retard passage hole 17 and each advance passage hole 18. It communicates with.

As the oil pump 25, a general type, for example, a vane type or a trochoid type is used.

FIG. 3 is an exploded perspective view of the hydraulic control valve 26 provided in the present embodiment, FIG. 4 is a vertical sectional view of the hydraulic control valve 26, and FIG. 5 is a perspective view of a valve body provided in the hydraulic control valve.

As shown in FIGS. 1, 3 and 4, the hydraulic control valve 26 is formed through a cylindrical valve body 27 made of a metal material such as an aluminum alloy material and the valve body 27 in the internal axial direction. A sliding hole 27a, a spool valve 28 slidably arranged in the sliding hole 27a, a valve spring 29 for urging the spool valve 28 to the right in FIG. 4, and a valve spring for the spool valve 28. It is mainly composed of a solenoid portion 30 that pushes out to the left against the spring force of 29.

As shown in FIG. 4, the valve body 27 is housed and arranged in, for example, a columnar valve hole 01 formed in a cylinder block. Further, the valve body 27 is formed with a drain hole 31 communicating with the discharge passage 49 in the center of the end wall 27b on the one end side.

Further, the valve body 27 is formed with a supply port 32, which is an opening communicating with the discharge passage 25a of the oil pump 25, penetrating along the radial direction at a substantially central position in the axial direction of the peripheral wall. Further, on the side portion of the supply port 32 on the solenoid portion 30 side, a retard angle port 33, which is an opening communicating with the retard angle passage hole 17, is formed through along the radial direction. Further, an advance angle port 34, which is an opening communicating with the advance angle passage hole 18, is formed through the side portion on the end wall 27b side along the radial direction. Further, the supply port 32, the retard port 33, and the advance port 34 are formed with three first to third groove grooves 32a, 33a, and 34a on the outer peripheral side, respectively.

The first to third groove grooves 32a to 34a are formed by cutting out the peripheral walls of the valve body 27 in an annular shape. Therefore, as shown in FIG. 5, four annular protrusions 27d, 27e, 27f, and 27g are formed on both sides of each of the groove grooves 32a to 34a, respectively. Further, on the annular bottom surface of each groove groove 32a to 34a, rectangular plate-shaped protrusions 32b, 33b, 34b are provided so as to avoid the ports 32 to 34. The protrusions 32b to 34b are provided at the same positions in the circumferential direction of the annular bottom surfaces of the groove grooves 32a to 34a.

Further, the valve body 27 is fitted and fixed with an oil seal 35 whose outer peripheral portion is in bullet contact with the inner peripheral surface of the valve hole 01 in an annular seal groove formed on the outer peripheral surface of the peripheral wall on the solenoid portion 30 side. Further, in the valve body 27, a seal ring 36 is fitted and fixed in an annular holding groove formed on the inner peripheral side of the outer end surface of the cylindrical rear end peripheral wall 27c.

The spool valve 28 is integrally formed of a metal material such as an aluminum alloy material. Further, as shown in FIGS. 3 and 4, the spool valve 28 is formed in a cylindrical shape, and is formed in a substantially symmetrical shape about a radial line X extending in a direction perpendicular to the axis at the center of the axis. Further, the spool valve 28 is formed through a drain passage 28a, which is an oil passage communicating with the drain hole 31 in the internal axial direction. Here, the above-mentioned "almost symmetrical shape" includes those in which the shapes of the annular first and second land portions 38 and 39 are different from each other.

The spool valve 28 has a cylindrical first shape that slides on the inner peripheral surface of the sliding hole 27a of the valve body 27 on both ends of the central small-diameter shaft portion 37 to change the opening area of each of the ports 32 to 34. It has 1st and 2nd land portions 38 and 39. Further, on the outer periphery of the small diameter shaft portion 37, a cylindrical annular groove 37a that cooperates with the inner peripheral surface of the sliding hole 27a to form a passage is formed. Further, first and second annular concave grooves 38a and 39a communicating with both ends of the drain passage 28a are formed on the outer portions of both land portions 38 and 39. The bottom walls of the annular recesses 38a and 39a are formed through the first and second communication holes 38b and 39b that communicate with the drain passage 28a. The first and second communication holes 38b and 39b are formed through each of the first and second communication holes 38b and 39b in a cross shape, and four of each are provided.

Further, the spool valve 28 integrally has annular first and second guide portions 40 and 41 on the outer sides of the annular recessed grooves 38a and 39a in the axial direction. The outer diameters of both guide portions 40 and 41 are set to be the same as those of the land portions 38 and 39, and slide on the inner peripheral surface of the sliding hole 27a to guide the entire spool valve 28. ..

The first guide portion 40 is formed in the shape of an internal solid disk. On the other hand, the second guide portion 41 is formed to have a substantially U-shaped vertical cross section, and a communication hole 41a for communicating the drain hole 31 and the drain passage 28a is formed therein. Further, the valve spring 29 is held in a slightly compressed state between the bottom surface of the second guide portion 41 and the bottom surface of the end wall 27b of the valve body 27. The spool valve 28 is urged in the direction of the solenoid portion 30 by the spring force of the valve spring 29.

As shown in FIGS. 3 and 4, the solenoid portion 30 includes a cylindrical casing 42 made of a magnetic material, a cylindrical coil 43 fixed to the inner peripheral side of the casing 42 via a bobbin 43a, and a casing. A magnetic material bracket 44 welded and fixed to substantially the center of the outer peripheral surface of the 42 in the axial direction, and a magnetic material which is a fixed iron core fixed to the inner peripheral side of the coil 43 via a bottomed cylindrical cap sleeve 45. It is mainly composed of a cylindrical portion 46 and a plunger 48 which is a movable iron core slidable in the axial direction inside a holding member 47 of a magnetic material held on the tip end side of the cylindrical portion 46.

The casing 42 holds the shape by rolling a flat plate into a cylindrical shape and engaging an unexpected uneven portion having an opposed end portion. Further, the casing 42 is integrally provided with four claws 42a for caulking and fixing to the valve body 27 at one end edge in the axial direction. On the other hand, on the other end edge, four claw portions 42b for caulking and fixing to the connector portion 51, which will be described later, are integrally provided. At the rear end of the casing 42, a connector 51 that is electrically connected to the engine control unit (ECU) 50 via a harness is provided.

The coil 43 is de-energized by the control current energized from the ECU 50.

The bracket 44 fixes the entire hydraulic control valve 26 to the cylinder block, and is integrally formed by press forming to form a rectangular arc-shaped base portion 44a and a fixing portion 44a integrally formed on the outer edge of the base portion 44a. It is composed of an arm 44b. The base portion 44a is fixed to the outer peripheral surface of the casing 42 by welding. The fixing arm 44b is formed through a bolt insertion hole 44c into which an unexpected bolt fixed to the cylinder block is inserted.

The cap sleeve 45 is formed of a stainless steel material into a thin-walled cylindrical shape, and its axial length is formed so as to cover a part of the cylindrical portion 46 and the holding member 47. Further, the cap sleeve 45 is formed in a stepped diameter shape and has a bottomed small diameter portion 45a that covers the cylindrical portion 46 and a large diameter portion 45b that is arranged on the valve body 27 side and covers a part of the holding member 47. It is composed of a flange portion 45c integrally provided on the front end side of the large diameter portion 45b.

Further, in the cap sleeve 45, the inner peripheral surface of the flange portion 45c is in pressure contact with the front end surface of the bobbin 43a.

The holding member 47 has a substantially cylindrical main body 47a and a flange portion 47b integrally provided at the front end portion of the main body 47a on the valve body 27 side. Further, the holding member 47 is formed through a guide hole 47c for sliding and guiding the plunger 48 in the internal axial direction.

The front end surface of the flange portion 47b is elastically in contact with the seal ring 36 held by the valve body 27 in the axial direction, whereby the inside of the guide hole 47c is sealed.

Further, an oil seal 52 is arranged in a sandwiched state between the back surface of the flange portion 47b and the flange portion 45c of the cap sleeve 45. As a result, the inside of the cap sleeve 45 is sealed.

The plunger 48 is formed in a substantially T-shaped vertical cross section, and has a disk portion 48a and a rod portion 48b protruding from the center of one end surface of the disk portion 48a. Further, the plunger 48 is formed with a through hole 48c for ensuring mobility in the direction of the internal axial center. Further, in the plunger 48, the tip edge of the rod portion 48b is in contact with the outer surface of the first guide portion 40 of the spool valve 28 from the axial direction. The plunger 48 presses and moves the spool valve 28 to the left in FIG. 4 against the spring force of the valve spring 29 by exciting the cylindrical portion 46 or the like by energizing the coil 43.

The connector portion 51 has a tubular portion 51a inserted and fixed inside the casing 42, and a female connector 51b protruding from the rear end of the tubular portion 51a. Each one end of a pair of terminal pieces (not shown) embedded in the tubular portion 51a is connected to the coil 43. On the other hand, each of the other end portions 51c exposed to the outside is connected to the terminal of the male connector on the ECU 50 side.

In the ECU 50, an internal computer detects a crank angle sensor (engine rotation speed detection), an air flow meter, an engine water temperature sensor, an engine temperature sensor, a throttle valve opening sensor, and a cam that detects the current rotation phase of the camshaft 2. Information signals from various sensors such as angle sensors are input to detect the current engine operating state. This controls the drive of the engine. Further, as described above, the ECU 50 outputs a control current to the coil 43 or cuts off the energization to control the moving position of the spool valve 28, and selectively switches and controls each of the ports 32 to 34. There is.

That is, the solenoid unit 30 moves the spool valve 28 to three positions in the front-rear axial direction by the relative pressure between the control current of the ECU 50 and the valve spring 29. That is, by moving the valve body 27 to three positions, the supply, retard, and advance ports 32, 33, and 34 of the valve body 27 are relatively communicated or cut off. At the same time, the advance angle port 34 or the retard angle port 33 is communicated with the drain hole 31 and the drain passage 28a. Further, the supply port 32 is configured to block the communication between the retard port 33 and the advance port 34.

As shown in FIGS. 3 to 5, filtration filters 53, 54, and 55 are mounted on the annular bottom surfaces of the groove grooves 32a to 34a of the valve body 27 described above, respectively.

Each of the filtration filters 53 to 55 is formed by rolling a thin metal plate made of stainless steel, for example, into an annular shape, and a plurality of mesh holes 53a to 55a are formed in an inner portion excluding the outer peripheral portion. ..

That is, each of the filtration filters 53 to 55 is formed in an annular shape having the same shape by bending a thin elongated stainless metal plate material having a thickness of about 0.1 mm. Further, the terminal portions 53b to 55b of each of the filtration filters 53 to 55 are bent and formed in a rectangular cross section that bulges outward.

Further, each of the filtration filters 53 to 55 is fixed so that the respective width length W is formed to be slightly smaller than the width length of each groove groove 32a to 34a and covers the entire annular bottom surface of each groove groove 32a to 34a. Have been placed. That is, they are arranged and fixed so as to cover the supply port 32, the retard port 33, and the advance port 34.

Further, the filtration filters 53 to 55 are engaged with the terminal portions 53b to 55b covering the protrusions 32b, 33b, 34b of the groove grooves 32a to 34a described above. As a result, the filtration filters 53 to 55 are positioned in the circumferential direction with respect to the groove grooves 32a to 34a, and are fixed to the valve body 27. In each of the filtration filters 53 to 55, the valve body 27 is positioned in the axial direction by the facing side surfaces between the protrusions 27d to 27g.

FIG. 6 is an enlarged view showing a part of each mesh hole 53a to 55a of the filtration filters 53 to 55.

Each of the plurality of mesh holes 53a to 55a is formed into a circular shape by so-called etching processing, each having substantially the same hole diameter D, and the peripheral length L of the same hole edge is set to a unique length.

That is, as for the hole diameters D of the mesh holes 53a, 54a, 55a and the peripheral length L of the hole edges, as shown in Tables 1 and 7, the inventor of the present application considers the formation of an oil film due to surface tension. It is defined based on the results of the experiment.

Table 1 shows the number of holes (pieces) in which an oil film was formed by changing the hole diameter D (mm) and the peripheral length L (mm) of the mesh holes.

FIG. 7 shows the number of oil films formed on the vertical axis with respect to the hole diameter D of the mesh holes on the horizontal axis.

In the experiment, a single evaluation product of a thin metal plate simulating a filtration filter was used, and a product having a wall thickness of 0.1 mm was used.

As an experimental method, the evaluation product alone was immersed in oil for 30 seconds, and then the evaluation product was taken out of the oil and pressure (air) was applied to the mesh holes. Then, the number of mesh holes on which the oil film was formed was counted.

As the evaluation conditions, an oil type of 0 W-20 was used, the oil temperature was normal temperature (about 20 ° C.), the pressure on the mesh hole was 50 kPa, and this pressure was such that the lock pin 21 came out of the lock hole 19. It is equivalent to the size to unlock.

In the following, the evaluation product alone will be referred to as a filtration filter 53, and each mesh hole 53a of the filtration filter 53 will be described.

As shown in Table 1 and FIG. 7, the hole diameter D (mm) of the mesh hole 53a is set to 11 different sizes from 0.2 to 0.59, and the peripheral length L (mm) of the hole edge is set. Different sizes of 0.628 to 1.854 were set corresponding to the hole diameter D.

As a result of making the hole diameter D and the peripheral length L of the mesh holes 53a different from each other, the number of oil films formed on the mesh holes 53a by surface tension (number of oil film holes) is shown at the bottom of Table 1. The number of mesh holes 53a used in the experiment was 30.

Looking at the experimental results shown in Table 1 and FIG. 7, the mesh holes 53a having a hole diameter D of 0.2 mm to 0.32 mm and a peripheral length L of 0.628 mm to 1.005 mm formed an oil film. The number was 30 to 17.

However, when the pore diameter D was 0.34 mm or more and the maximum was 0.59 mm, and the peripheral length L was 1.068 mm or more and the maximum was 1.854 mm, the number of oil films formed was zero.

From this experiment, it was found that if at least the peripheral length L of one mesh hole 53a is set to 1.068 mm or more, an oil film is not formed and the open state is always maintained. That is, it was found that the surface tension in one mesh hole 53a becomes small and it becomes difficult to form an oil film.

Therefore, in the present embodiment, the hole diameter D of one mesh hole 53a is set to a size within a range of 0.34 mm or more and a maximum of 0.59 mm. Further, the peripheral length L is set to a length within a range of 1.068 mm or more and a maximum of 1.854 mm.

Further, as described above, the hole diameter D of one mesh hole 53a is set to a size within a range of 0.34 mm or more and a maximum of 0.59 mm, but within this range, one side is further set. The size is set so that foreign matter of a 2 mm cube cannot pass through. Normally, foreign matter such as metal contamination mixed in oil does not have a great influence on the sliding of the spool valve 28 of the hydraulic control valve 26 when the size is about 2 mm or less, but when one side is about 2 mm or more. If there is, the operation of the spool valve 28 may be affected by biting or the like.

Therefore, in the present embodiment, the lengths of the pore diameter D and the peripheral length L are set to a size that does not form an oil film and that does not allow foreign matter having a side of 2 mm or more to pass through.

Then, in the present embodiment, the peripheral length L is set to 1.07 mm. The reason why only the circumference L is specified is that the circumference L has the greatest influence on the formation of the oil film in relation to the surface tension.

Since the peripheral length L also increases as the hole diameter D increases, both D and L are in a proportional relationship, so that the hole diameter D can be specified.

Further, in this experiment, since the filter 53 having a wall thickness of 0.1 mm was used, if the peripheral length of the mesh hole 53a is 1.07 mm or more, the thickness of the filter 53 is the mesh hole 53a. The value obtained by multiplying the circumference of is 0.107 mm ² or more. As a result, the surface tension can be reduced. Therefore, it becomes difficult to form an oil film in each mesh hole 53a.
[Operation of valve timing control device of this embodiment]
Hereinafter, the operation of the valve timing control device provided in the present embodiment will be briefly described. When the engine is stopped, the oil pump 25 is also stopped, hydraulic oil is not supplied from the discharge passage 25a, and the ECU 50 is transferred to the coil 43. It becomes a non-energized state without energization.

Therefore, as shown in FIG. 4, the spool valve 28 is held at the moving position of the first position in the maximum right direction by the spring force of the valve spring 29.

Next, when the engine starts starting, the oil pump 25 is also driven to pump hydraulic oil into the discharge passage 25a. The hydraulic oil that has flowed into the supply passage from the discharge passage 25a flows into the annular groove 37a of the spool valve 28 from the supply port 32 through the first groove groove 32a of the hydraulic control valve 26 and the first filtration filter 53. From here, it flows into the retard port 33, passes through the second filtration filter 54, flows into the second groove groove 33a, and further flows into each retard passage hole 17 from here into each retard operating chamber 9. Be supplied. Therefore, the hydraulic pressure in each retard angle operating chamber 9 rises.

At the same time, the spool valve 28 is in a state of communicating each advance passage hole 18, the second annular recess 39a, and the second communication hole 39b via the advance port 34. Therefore, the hydraulic oil in each advance angle operating chamber 10 flows from the advance angle passage hole 18 through the third filtration filter 55 and each advance angle port 34 from the second annular recess 39a into the second communication hole 39b. From here, it flows into the drain passage 28a and is discharged from the drain hole 31 into the oil pan OP. Therefore, each advance operating chamber 10 is in a low pressure state.

Therefore, the vane rotor 7 is maintained at the most retarded relative rotation position. Therefore, the intake valve is in a state where the opening / closing timing is controlled to the retard side. This improves the startability of the engine.

Further, at this time, the same hydraulic pressure as the retard angle operating chamber 9 is supplied to the first release pressure receiving chamber 23a via the first lock passage 24a, but at the initial stage of cranking, the inside of the first release pressure receiving chamber 23a. Oil pressure does not rise. Therefore, the lock pin 21 is in a state in which the tip portion 21a enters the lock hole 19 and is locked. Therefore, it is possible to suppress fluttering of the vane rotor 7 due to the alternating torque generated on the camshaft 2.

After that, when the hydraulic pressure supplied to the first release pressure receiving chamber 23a via the first lock passage 24a becomes high, the lock pin 21 moves backward against the spring force of the coil spring 22 and moves backward with respect to the lock hole 19. The locked state is released. As a result, the vane rotor 7 is released from the rotation regulation and becomes free.

Next, when the amount of energization from the ECU 50 to the coil 43 increases with the change in the engine operating state, the spool valve 28 is pushed out by the plunger 48 and slightly moves to the left from the state shown in FIG.

In this state, the retard port 33 and the advance port 34 are blocked (closed) by the first land portion 38 and the second land portion 39, and the retard actuating chamber 9 and the advance angle actuating chamber 10 are closed. The supply or discharge of hydraulic oil is stopped. Therefore, the hydraulic oil is held in each retard operating chamber 9 and each advance operating chamber 10.

Therefore, the intake valve is controlled so that the valve timing is in the intermediate phase position between the latest angle and the most advanced angle. Therefore, for example, it is possible to stabilize the engine rotation during steady operation and improve fuel efficiency.

Further, when the amount of energization to the coil 43 becomes larger, the spool valve 28 moves further to the left in FIG. In this state, the first land portion 38 of the spool valve 28 opens the retard angle port 33 to communicate the retard angle port 33 with the first annular recess 38a and the first communication hole 38b. At the same time, the spool valve 28 communicates the supply port 32 with the annular groove 37a and the advance angle port 34.

Therefore, the hydraulic oil in each retard angle operating chamber 9 flows from each retard angle passage hole 17 through the retard angle port 33 into the first annular recess 38a and the first communication hole 38b, and from here, the drain passage. It is quickly discharged into the oil pan OP through 28a and each drain hole 31.

At the same time, the hydraulic oil pumped from the oil pump 25 is supplied from the supply port 32 to the advance operating chambers 10 through the advance passage holes 18 through the annular groove 37a, the advance port 34 and the filtration filter 55.

Therefore, the internal pressure of each retard angle operating chamber 9 decreases, while the internal pressure of each advance angle operating chamber 10 increases.

Therefore, the vane rotor 7 rotates clockwise from the solid line position in FIG. 1 and relatively rotates toward the maximum advance angle side. As a result, the opening / closing timing of the intake valve becomes the most advanced phase, the valve overlap with the exhaust valve becomes large, the intake filling efficiency becomes high, and the output torque of the engine can be improved.

Then, as described above, when the oil pump 25 operates with the start of the engine and the hydraulic pressure is discharged to the discharge passage 25a, the air accumulated in the hydraulic circuit 5 due to the hydraulic pressure is first discharged to the hydraulic control valve 26. It flows into each retard angle operating chamber 9 through. After that, the air in one retard angle operating chamber 9 flows into the first release pressure receiving chamber 23a from the first lock passage 24a of the lock mechanism 4. However, since this air pressure is not large, the lock pin 21 is not moved backward against the spring force of the coil spring 22.

Further, the air flowing into each retard angle operating chamber 9 flows into each advance angle operating chamber 10 through the clearance of each portion and is returned to the hydraulic control valve 26 from each advance angle passage hole 18.

Here, when an oil film is formed in each mesh hole 55a of the third filtration filter 55, air cannot pass through the mesh hole 55a, so that the pressure in each advance passage hole 18 and each advance operating chamber 10 is increased. To rise.

That is, as is clear from the above experimental results, the size of each hole diameter D and peripheral length L of each mesh hole 55a is the size at which an oil film is formed by surface tension (hole diameter D is 0.2 mm to 0.32 mm). When the peripheral length L is set to a size of 0.628 mm to 1.005 mm), the air flowing into each advance passage hole 18 is suppressed by the third filtration filter 55. It ends up.

Therefore, the air pressure in one advance operating chamber 10 is supplied to the second release pressure receiving chamber 23b through the second lock passage 24b, and a high air pressure acts on the lock pin 21. Therefore, the lock pin 21 may move backward against the spring force of the coil spring 22 and the tip portion 21a may inadvertently come out of the lock hole 19. As a result, the vane rotor 7 may flutter and generate an abnormal noise.

In particular, when the engine is started to cool down in a cold region, the viscosity of the oil (lubricating oil) is high, so that the surface tension at each mesh hole 53a (54a, 55a) is high. Therefore, an oil film is likely to be formed.

On the other hand, in the present embodiment, as described above, the hole diameter D and the peripheral length L of the mesh hole 53a are set to a size at which an oil film is not formed due to surface tension. Therefore, the air that has passed through the advance passage holes 18 from the advance actuating chambers 10 quickly passes through the mesh holes 55a of the third filtration filter 55 without being blocked from flowing. From here, it flows into the drain passage 28a through each advance port 34, the second annular recess 39a, and the second communication hole 39b, and is quickly discharged from the drain hole 31 to the outside air.

Therefore, the inflow of air into the second release pressure receiving chamber 23b is suppressed, and the lock pin 21 is prevented from inadvertently coming out of the lock hole 19. As a result, it is possible to sufficiently suppress the occurrence of fluttering and tapping sound of the vane rotor 7.

Further, in the present embodiment, since the mesh holes 53a to 55a of the filtration filters 53 to 55 are formed in a circular shape, they can be relatively easily formed by etching. Further, since it has a circular shape, the yield of the filtration filters 53 to 55 is also improved.
[Second Embodiment]
FIG. 8 shows a second embodiment of the present invention, in which the mesh holes 53a to 55a of the filtration filters 53 to 55 are formed in a substantially regular triangular shape.

That is, the filtration filters 53 to 55 are formed in a cylindrical shape by a thin metal plate having a thickness of about 0.1 mm, and the mesh holes 53a to 55a are formed by etching, as in the first embodiment.

Each of the mesh holes 53a to 55a is formed in a substantially regular triangular shape in a plan view, and all of them are formed in the same shape. Further, the mesh holes 53a to 55a are set to have a peripheral length L of 1.068 mm or more and a maximum of 1.854 mm.

Further, the mesh holes 53a are arranged so that the tops of the mesh holes 53a and 53a'that are adjacent to each other in the vertical direction in the drawing are opposite to each other.

Therefore, according to this embodiment, since the peripheral length L of each mesh hole 53a is set to a specific length, the surface tension becomes small and it becomes difficult to form an oil film. Therefore, this embodiment also has the same effect as that of the first embodiment.

Further, in this embodiment, since the mesh holes 53a are formed in opposite directions, the yield during processing of the thin metal material is improved. Therefore, the manufacturing cost can be reduced.
[Third Embodiment]
FIG. 9 shows a third embodiment, and the basic configuration is the same as that of the first embodiment, but the shapes of the mesh holes 53a to 55a are formed in a hexagonal shape.

That is, each of the filtration filters 53 to 55 is formed in a cylindrical shape by a thin metal plate having a thickness of about 0.1 mm, as in the first embodiment.

Further, each of the mesh holes 53a to 55a formed by the etching process has a substantially regular hexagonal shape (honeycomb shape) in a plan view, and all have the same shape. Each of the mesh holes 53a to 55a has a peripheral length L of 1.068 mm or more and is set to a maximum of 1.854 mm.

Therefore, this embodiment also has the same effects as those of the first embodiment, and since it has a regular hexagonal honeycomb structure, the strength of the entire filtration filters 53 to 55 is increased.

The present invention is not limited to the configuration of each of the above-described embodiments. For example, in each of the above-described embodiments, the valve timing control device is applied to the intake valve side, but the present invention is applied to the exhaust valve side. It is also possible. In this case, the air in the hydraulic circuit 5 at the time of starting the engine flows from each advance operating chamber 10 into each retard operating chamber 9 through the clearance of each part. From here, even when passing through each mesh hole 54a of the second filtration filter 54 through the retarded passage hole 17, since no oil film is formed, air can be quickly discharged to the outside air.

Further, for example, the wall thickness of the filtration filter can be set to be thicker or thinner than 0.1 mm.

Further, the shapes of the mesh holes 53a to 55a can be formed into a pentagonal shape, an elliptical shape, or the like. In this case as well, the circumference L is set within the above-mentioned range, and is set to a size that does not allow passage of a contaminant having a side of 2 mm or more.

Further, in each embodiment, the hydraulic control valve 26 is applied to the valve timing control device, but it can also be applied to other devices other than the valve timing control device.

As the hydraulic control valve based on the embodiment described above, for example, the one described below can be considered.

As one aspect thereof, a valve body having a tubular peripheral wall and an opening formed through the peripheral wall in the radial direction is slidably arranged inside the peripheral wall, and the valve body is slidably arranged inside the peripheral wall. It includes a spool valve that opens and closes the opening, and a filter that is wound so as to cover the opening and has a plurality of mesh holes having a peripheral length of one hole edge set to 1.07 mm or more.

More preferably, the mesh hole has a size that prevents foreign matter of a cube having a side of 2 mm from passing through.

More preferably, the value obtained by multiplying the wall thickness dimension of the filter by the peripheral length of the mesh hole is 0.107 mm ² or more.

The surface tension is affected by the surface area, and in this experiment, a filter with a wall thickness and width of 0.1 mm was used. Therefore, if the circumference of the mesh hole is 1.07 mm or more, it should be 0.107 mm ² or more. Become. As a result, the surface tension can be reduced.

More preferably, the filter is formed of a metal plate as a base material.

More preferably, each of the mesh holes is formed in the metal plate by etching.

More preferably, the filter is configured by forming the plurality of mesh holes in the metal plate.

More preferably, each of the mesh holes is formed in a circular shape.

More preferably, each of the mesh holes is formed in a triangular shape.

More preferably, each of the mesh holes is formed in a hexagonal shape.

More preferably, the plurality of openings are provided in the peripheral wall, and the plurality of openings are arranged so that the filter covers the plurality of openings through mesh holes.

In another preferred embodiment, the rotational force from the crankshaft is transmitted and is fixed to the camshaft while being relatively rotatable inside the housing and the housing having an operating chamber inside, and the operating chamber is first. A vane rotor having a vane partitioning the operating chamber and the second operating chamber, a phase changing mechanism for changing the relative rotation phase of the housing and the camshaft according to the engine operating state, and a vane rotor provided between the housing and the vane rotor. When the internal pressure of the working chamber is lower than the predetermined value, the relative rotation between the housing and the vane rotor is restricted, and when the internal pressure of the operating chamber is higher than the predetermined value, the relative rotation regulation between the housing and the vane rotor is released. A valve timing control device for an internal combustion engine equipped with a lock mechanism.
The phase changing mechanism is slidably arranged inside a valve body having a tubular peripheral wall and an opening formed through the peripheral wall in the radial direction, and the peripheral wall according to a moving position. It includes a spool valve for opening and closing an opening, and a filter having a plurality of mesh holes arranged so as to cover the opening and having a peripheral length of one hole edge set to 1.07 mm or more.

More preferably, the hole diameter of the mesh hole is such that a cubic foreign matter having a side of 2 mm cannot pass through.

More preferably, the value obtained by multiplying the wall thickness dimension of the filter by the peripheral length of the mesh hole is 0.107 mm ² or more.

Claims (13)

A valve body having a tubular peripheral wall and an opening formed through the peripheral wall in the radial direction.
A spool valve that is slidably arranged inside the peripheral wall and opens and closes the opening according to the moving position.
A filter having a plurality of mesh holes arranged so as to cover the opening and having a peripheral length of one hole edge set to 1.07 mm or more.
A hydraulic control valve for an internal combustion engine, which is characterized by being equipped with. The hydraulic control valve for an internal combustion engine according to claim 1.
The mesh hole is a hydraulic control valve for an internal combustion engine, characterized in that a cubic foreign matter having a side of 2 mm cannot pass through. The hydraulic control valve for an internal combustion engine according to claim 2.
A hydraulic control valve for an internal combustion engine, characterized in that a value obtained by multiplying the wall thickness dimension of the filter by the peripheral length of the mesh hole is 0.107 mm ² or more. The hydraulic control valve for an internal combustion engine according to claim 1.
The filter is a hydraulic control valve for an internal combustion engine, characterized in that the filter is formed of a metal plate as a base material. The hydraulic control valve for an internal combustion engine according to claim 1.
Each of the mesh holes is a hydraulic control valve of an internal combustion engine, characterized in that the metal plate is formed by etching. The hydraulic control valve for an internal combustion engine according to claim 4.
The filter is a hydraulic control valve for an internal combustion engine, characterized in that the filter is formed by forming the plurality of mesh holes in the metal plate. The hydraulic control valve for an internal combustion engine according to claim 1.
A hydraulic control valve for an internal combustion engine, wherein each of the mesh holes is formed in a circular shape. The hydraulic control valve for an internal combustion engine according to claim 1.
A hydraulic control valve for an internal combustion engine, wherein each of the mesh holes is formed in a triangular shape. The hydraulic control valve for an internal combustion engine according to claim 1.
A hydraulic control valve for an internal combustion engine, wherein each of the mesh holes is formed in a hexagonal shape. The hydraulic control valve for an internal combustion engine according to claim 3.
A hydraulic control valve for an internal combustion engine, characterized in that the plurality of openings are provided in the peripheral wall, and the plurality of openings are arranged so that the filter covers the plurality of openings through mesh holes. A housing that transmits the rotational force from the crankshaft and has an operating chamber inside,
A vane rotor having a vane fixed to a camshaft while being relatively rotatable inside the housing and having a vane that divides the working chamber into a first working chamber and a second working chamber.
A phase change mechanism that changes the relative rotation phase of the housing and camshaft according to the engine operating condition,
Provided between the housing and the vane rotor, when the internal pressure of the working chamber is lower than the predetermined value, the relative rotation of the housing and the vane rotor is restricted, and when the internal pressure of the working chamber is higher than the predetermined value, the relative rotation is restricted. A locking mechanism that releases the relative rotation restriction between the housing and the vane rotor,
It is a valve timing control device for an internal combustion engine equipped with
The phase change mechanism is
A valve body having a tubular peripheral wall and an opening formed through the peripheral wall in the radial direction.
A spool valve that is slidably arranged inside the peripheral wall and opens and closes the opening according to the moving position.
A filter having a plurality of mesh holes arranged so as to cover the opening and having a peripheral length of one hole edge set to 1.07 mm or more.
A valve timing control device for an internal combustion engine, which is characterized by being equipped with. The valve timing control device for an internal combustion engine according to claim 11.
A valve timing control device for an internal combustion engine, characterized in that the hole diameter of the mesh hole is large enough to prevent foreign matter of a cube having a side of 2 mm from passing through. The valve timing control device for an internal combustion engine according to claim 12.
A valve timing control device for an internal combustion engine, wherein a value obtained by multiplying the wall thickness of the filter by the peripheral length of the mesh hole is 0.107 mm ² or more.

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