JPH1037721A - Valve opening/closing timing controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of an engagement mechanism, by providing the engagement mechanism by which a phase between a rotation transmission member and a camshaft is retained when fluid pressure of fluid in first and second channels is lowered, and retaining the phase between the rotation transmission member and the camshaft only when fluid supply to a fluid operating chamber is stopped. SOLUTION: When an engine is started, hydraulic pressure in a phase advance oil pressure chamber 80 and a phase lag oil pressure chamber 82 is lowered, and when an annular housing 50 and an internal rotor 68 are relatively rotated up to the most phase lag position, the small diametral part 110 of a stepped pin 106 is inserted in a receiving hole 112, and the relative positions of the annular housing 50 and the internal rotor 68 are fixed. Next, when discharge oil becomes sufficient pressure, and the rotation of a camshaft for an intake valve is made in a condition to advance its phase, oil supplied to a phase advance oil passage 84 is supplied to the phase advance oil pressure chamber 80, and also a part of oil is acted upon the inner circumferential side of the small diametral part 110 so as to remove the stepped pin 106 from the receiving hole 112, and the camshaft 34 and the annular housing 50 can be relatively rotated, thereby a phase advance condition can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine in which the rotational force from a crank pulley of an internal combustion engine is varied between a camshaft, which is transmitted via a timing pulley, and a timing pulley in accordance with an operation state. And a valve timing control device for the same.

[0002]

2. Description of the Related Art Conventionally, many valve opening / closing timing controllers for controlling the timing between a timing pulley and a camshaft have been introduced, and as one example, a vane type valve opening / closing timing controller is known.

For example, there is a vane type valve opening / closing timing control apparatus disclosed in Japanese Patent Application Laid-Open No. 1-92504.

[0005] The technique disclosed in this publication is shown in FIGS.
Referring to FIG. 6 which is a cross-sectional view taken along the line C--C of FIG. 6, reference numeral 1 denotes a timing pulley which is driven by a crank pulley of an internal combustion engine (not shown) and is transmitted by an annular belt, an annular chain or a gear. . Reference numeral 4 denotes a camshaft, which is supported on the cylinder head 14 of the engine.
It is fixed to. Two spring receiving holes 2a, 2b are formed in the vane 2 in the axial direction of the camshaft 4, and coil springs 25a, 2b are formed in the receiving holes 2a, 2b.
5b is accommodated, and urges the vane 2 in the direction of the timing pulley 1. In addition, a partition wall 1b is formed on the inner peripheral portion 1a of the timing pulley 1 of the timing pulley 1,
A hydraulic chamber 8 is formed between the partition walls 1b, 1b. The vanes 2 are inserted into the hydraulic chambers 8, and the pressure working chambers 9 and 9 a are formed by the vanes 2 and the outer plate 5.
The outer plate 5 is positioned by the plate 21 and the fixing bolt 20. That is, the camshaft 4 side including the vane 2 and the timing pulley 1 side including the hydraulic chamber 8 are supported so as to be relatively rotatable. This relative rotation is achieved by rotating the vane 2 in the range of the hydraulic chamber 8 provided on the inner peripheral portion of the timing pulley,
The angle can be rotated by the angle θ shown in FIG. The relative rotation between the camshaft 4 and the timing pulley 1 is performed by rotating the vane 2 by hydraulic pressure sucked and discharged to pressure working chambers 9 and 9a provided on both sides of the vane 2. In addition, with respect to the rotation direction indicated by the arrow in FIG. This hydraulic pressure is controlled by a switching valve 15 using an oil pump (not shown) as a hydraulic pressure source. The switching valve 15 slides the valve spool 18 rightward in the figure against the spring 16 by energizing the solenoid 13, and allows the oil discharged from the oil pump to flow from the oil passage 12 to the switching valve 15. Intake, oil path 10, 1
1 adjusts the hydraulic pressure of the hydraulic operating chambers 9 and 9a on both sides of the vane 2.

In the operation of the prior art having such a structure, the oil passage 10 communicates with the pressure working chamber 9 and the oil passage 11 communicates with the pressure working chamber 9a. When the switching valve 15 is controlled to supply oil to the oil passage 10 and increase the oil pressure in the pressure working chamber 9, the vane 2 rotates in the direction indicated by the arrow in FIG. Te vane 2
, And the opening / closing timing of an intake valve or an exhaust valve that opens and closes with the rotation of the camshaft 4 can be advanced. Conversely, when the switching valve 15 is controlled to supply oil to the oil passage 11 and increase the oil pressure in the pressure working chamber 9a, the vane 2 rotates in the direction opposite to the arrow in FIG. The rotation of the vane 2 can be delayed with respect to the pulley 1, and the opening / closing timing of an intake valve or an exhaust valve that opens and closes as the camshaft 4 rotates can be delayed.

A knock pin 22 shown in FIG. 6 is inserted by a biasing force of a spring 23 into a hole 24 provided in the internal rotor 3. The position of this hole 24 is
The end of the relative rotatable range in the oil groove 8 is provided at a position most delayed with respect to the rotation direction of the timing pulley 1. The knock pin 22a is also provided at a position symmetrical to the knock pin 22. When the pin 22 is relatively rotated by an angle θ from the state shown in FIG. I have.

[0007]

In the above prior art, two knock pins 22 and 22a are disposed at the most advanced position and the most retarded position in the phase conversion range of the timing pulley 1 and the camshaft 4, respectively. When the phase between the timing pulley 1 and the camshaft 4 changes and reaches the most retarded position, and the knock pin 22 comes to a position facing the hole 24, the knock pin 2
2 is inserted into the hole 24 to fix the phase between the timing pulley 1 and the camshaft 4. When the hydraulic pressure is controlled in the advance direction from this state, the knock pin 22 is discharged from the hole 24, and when the phase changes to the most advanced position, the knock pin 22a is inserted into the hole 24a, and the timing pulley 1 and the cam shaft 4 Is fixed. That is, in the above-described conventional technology, when the engine rotates to operate the valve opening / closing timing control device, the operation in which the knock pin 22 and the knock pin 22a are inserted into and discharged from the holes 24 and 24a, respectively, is repeated. ing. Therefore,
Dowel pin 22, dowel pin 22a and hole 24, hole 2
The internal rotor 3 constituting 4a is formed using a material capable of ensuring extreme durability, and its configuration requires high reliability.

Further, the dowel pins 22 and 22a are
The main purpose of fixing the phase between the timing pulley 1 and the camshaft 4 by inserting the camshaft 4 into the camshaft 4 is to rotate the camshaft in a state where the oil pressure generated by the oil pump cannot secure a sufficient magnitude such as when starting the engine. This prevents the vane 2 from moving in the hydraulic chamber 8 and coming into contact with the partition wall 1b to generate a tapping sound, thereby preventing generation of abnormal noise and improving the durability of the vane 2. . Therefore, the repeated disengagement of the knock pins 22 and 22a during the normal operation of the engine in which the oil pressure generated by the oil pump is sufficient is the operability of the valve timing control device,
Loss in durability was large.

The present invention discloses a valve opening / closing timing control device which solves the above-mentioned problems of the prior art.

[0010]

In order to solve the above-mentioned problems, the applicants always maintain the engagement mechanism in an open state during normal operation of the engine, and improve the durability of the engagement mechanism. We paid attention to that.

In order to solve the above-mentioned problem, means taken in the invention according to claim 1 includes a rotation transmitting member provided with a partition wall forming a plurality of fluid chambers on an inner peripheral portion, and a vane dividing the fluid chamber. A camshaft for opening and closing the attached intake valve or exhaust valve, and a fluid chamber defined by a vane are a first fluid working chamber and a second fluid working chamber, respectively. A phase variable mechanism for varying the phase with the camshaft, a first flow path for supplying and discharging fluid to and from the first fluid working chamber, a second flow path for supplying and discharging fluid to and from the second fluid working chamber, A valve opening / closing timing control device comprises an engagement mechanism for maintaining the phase of the rotation transmission member and the camshaft when both the fluid pressure in the first flow path and the fluid pressure in the second flow path decrease. It was done. Therefore, only when the supply of fluid to the fluid working chamber is stopped, such as when the engine is stopped, the phase between the rotation transmitting member and the camshaft is held by the engagement mechanism. Durability and reliability can be improved.

According to a second aspect of the present invention, the engaging mechanism is disposed on one of the rotation transmitting member and the camshaft, and the large diameter portion and the small diameter portion are biased by a spring toward the other member. And a receiving hole into which the small diameter portion of the pin formed in the other member is inserted, the fluid in the first flow path acts on the large diameter portion, and the fluid in the second flow path This is to act on the small diameter portion. Therefore, the stepped pin of the engagement mechanism is deactivated by the fluid pressure of one of the fluid in the first flow path and the fluid in the second flow path. When the fluid is supplied to at least one of the fluid in the first flow path and the fluid in the second flow path, the stepped pin is not inserted into the receiving hole, and the stepped pin is inserted into the unnecessary receiving hole. This can be prevented.

According to the third aspect of the present invention, a passage for communicating fluid is formed between the large diameter portion of the stepped pin and the first fluid working chamber adjacent to the stepped pin. Therefore, it is possible to easily form a passage for supplying a fluid to the large diameter portion of the stepped pin.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described with reference to FIGS.

FIG. 1 is a drawing showing a valve timing control apparatus 30 according to a first embodiment of the present invention. As shown in FIG. 1, the valve timing control device 30 is applied to a DOHC engine. An intake valve camshaft 34 and an exhaust halve camshaft 36 rotatably supported are attached to the cylinder head 32. A gear 38 rotatably mounted on the outer periphery of the intake valve camshaft 34 and the exhaust halve camshaft 3
A gear 40 is attached to the outer periphery of the gear 6 so as to be relatively non-rotatable. The gear 38 and the gear 40 mesh with each other to connect the intake valve camshaft 34 and the exhaust halve camshaft 36. I have. The valve timing control device 30 according to the present embodiment is attached to an intake valve camshaft 34 (rotating shaft, hereinafter referred to as a camshaft 34).

The timing pulley 42 is provided with a bolt 4 at the end of the camshaft 34 projecting from the cylinder head 32.
4 and is positioned by a stopper pin 46 and fixed so as not to rotate relatively.

A gear 38,
Front plate housing 48, annular housing 5
0, a rear plate housing 52 is integrally fastened by bolts 54 to form a rotation transmitting member 56, and is mounted to be rotatable relative to the camshaft 14. As shown in FIG. 2, five hydraulic chambers (pressure chambers) 60 are provided between the partition walls 58, 58 inside the annular housing 50 sandwiched between the front plate housing 48 and the rear plate housing 52.
And a support hole 62 cut from the outside of the annular housing 50
Is provided. The support hole 62 has a bottom 64, and a hole 66 having a smaller diameter than the support hole 62 is provided substantially at the center of the bottom 64.
Are formed.

An inner peripheral rotor 68 is fixed to the outer surface of the camshaft 34 by a pin 70 so as not to be relatively rotatable, and is fastened and fixed between the step portion 35 of the camshaft 34 by a nut 72. The five vanes 74 extend radially with their inner peripheral ends locked in vane receiving grooves 76 formed in the inner peripheral rotor 68. A gap 78 is formed on the inner peripheral side of the vane 74 between the vane 74 and the receiving groove 76, and a leaf spring (not shown) is disposed in the gap 78 to urge the vane 74 outward. The vanes 74 define each hydraulic chamber 60 as an advanced hydraulic chamber 80 and a retard hydraulic chamber 82.
And divided into The vane 74 attached to the inner rotor 68 and the advance hydraulic chamber 80 and the retard hydraulic chamber 82 provided in the annular housing 50 form a phase variable mechanism.

Inside the camshaft 34, the advance oil passage 8 communicating with the advance hydraulic chamber 80 and the retard hydraulic chamber 82, respectively.
4 and a retard oil passage 86 are formed. As shown in FIG. 2, two retard oil passages 86 are formed inside the camshaft 34. The advance oil passage 84 and the retard oil passage 86 are respectively formed by an advance oil passage connection ring 88 and a retard oil passage connection ring 9 formed between the camshaft 34 and the cylinder head 32.
It is in communication with the control valve 92 via 0. The control valve 92 is an electromagnetic valve provided with three chambers 92a, 92b, and 92c that are operated by a signal from a central control unit (ECU) 94 that receives information such as the number of revolutions of the engine and the output of the engine. The control valve 92 further includes an oil pan 96
Passage 10 for introducing hydraulic pressure from oil through oil pump 98
0 and a passage 102 for discharging the oil pressure to the oil pan 96.

A phase holding mechanism 104 shown in FIG.
A stepped pin 106 is disposed in the support hole 62 of the annular housing 50 by being biased toward the inner peripheral rotor 68 by a spring 108. The stepped pin 106 has a small-diameter portion 110 and a large-diameter portion 111 having substantially the same diameter as the hole 66 at the tip. When the small diameter portion 110 of the stepped pin 106 coincides with the receiving hole 112 formed in the inner peripheral rotor 68 due to a phase change between the annular housing 50 and the inner peripheral rotor 68 that rotates integrally with the camshaft 34 (the most retarded angle). State), stepped pin 1
The small diameter portion 110 is inserted into the receiving hole 112 by the urging force of the spring 108, so that the phases of the annular housing 50 and the inner peripheral rotor 68 can be fixed. In addition, the engagement of the stepped pin 104 is
The oil is discharged from the receiving hole 112 against the urging force of the spring 108 by the oil pressure from the side 8.

A passage 114 communicates between the retard hydraulic chamber 82 and the vicinity of the bottom 64 of the support hole 62, and can guide the hydraulic pressure of the retard hydraulic chamber 82 into the support hole 62.

FIG. 3 is a drawing of the annular housing 50 and the inner peripheral rotor 68 which rotates integrally with the camshaft 34 in the most advanced state due to a phase change. FIG. 4 shows the state in which the phase holding mechanism 104 is engaged. It is a drawing showing a state.

The operation of the valve timing control device 30 will be described. When the rotation of the timing pulley (not shown) is transmitted to the timing pulley 42 via a chain belt or the like, the rotation of the timing pulley 42 rotates the camshaft 34 integrated with the timing pulley 42 in the direction indicated by the arrow in FIG. At the same time, it is also transmitted to the intake valve camshaft 36 via the inner peripheral rotor 68, the vane 74, the rotation transmitting portion 56 (the gear 38, the front plate housing 48, the annular housing 50, the rear plate housing 52), and the gear 40.

Here, the vane 74 is rotatable in the hydraulic chamber 60, so that the phase of the camshaft 34 can be changed. E depends on engine speed and engine output
The control valve 92 is switched by the CU 94 to change the rotation phase of the camshaft 34 and the camshaft 36 for the intake valve.
Is changed. Specifically, the control valve 92
As shown in FIG. 1, the oil in the passage 100 is supplied to the advance oil passage 84 by making the chamber 90a. Then, the vane 74 is rotated in a direction (clockwise direction) opposite to the arrow shown in FIG.
As shown in (2), the rotation of the intake valve camshaft is advanced compared to the rotation of the camshaft.

Conversely, from the most advanced position shown in FIG. 3, the control valve 92 is switched to the chamber 90c to supply oil to the retard hydraulic chamber 82 via the retard hydraulic passage 86, Is discharged to the oil pan 96 through the advance oil passage 84, and the vane 74 is rotated in the direction of the arrow shown in FIG.
The rotation of the intake valve camshaft 36 can be retarded compared to the rotation of the camshaft 34. Note that the control valve 92 can be switched to the chamber 90b to adjust and hold the hydraulic pressure of the advance hydraulic chamber 80 and the retard hydraulic chamber 82 sandwiching the vane 74, thereby holding the vane 74 at a desired position.

In the present embodiment, the phase of the valve timing control device 30 is converted by oil pressure, but the phase can be converted by a fluid such as air instead of oil.

Next, the phase holding mechanism 1 will be described with reference to FIGS.
The operation of No. 04 will be described.

When the engine is started, that is, when the oil pump 98
During the time period until the discharge oil reaches a sufficient pressure, the hydraulic pressure in the advance hydraulic chamber 80 and the hydraulic pressure in the retard hydraulic chamber 82 decrease, and the vane 74 can be held at a fixed position in the hydraulic chamber 60. It cannot be done. Accordingly, by rotating the camshaft 34 in the direction of the arrow shown in FIGS. 2 to 4, the annular housing 50 and the internal rotor 68 are relatively rotated to the most retarded position shown in FIG. 2 regardless of the position of the vane 74. When the relative rotation to the maximum retard position occurs, the small-diameter portion 11 of the stepped pin 106 is
0 is inserted into the receiving hole 112. Therefore, when the engine is started, the relative position between the annular housing 50 and the internal rotor 68 can be fixed by the stepped pin 106, so that sufficient discharge oil from the oil pump 98 is supplied to the advance hydraulic chamber 80 or the retard hydraulic chamber 82. Even when the vane 74 is not supplied to the hydraulic chamber 60, it is possible to prevent the vane 74 from contacting the wall of the hydraulic chamber 60 and generating a tapping sound, or the vane 74 from contacting the wall of the hydraulic chamber 60 and being deformed. Next, when the oil discharged from the oil pump 98 has a sufficient pressure from the state shown in FIG. 4 and the rotation of the intake valve camshaft 36 is advanced as compared with the rotation of the camshaft 34 as shown in FIG. The oil supplied to the advance oil passage 84 is supplied to the advance hydraulic chamber 80, and a part of the oil is supplied to the small diameter portion 110 of the stepped pin 106.
Of the stepped pin 106 and the spring 108
Is discharged from the receiving hole 112 against the urging force of By discharging the small diameter portion 110 of the stepped pin 106 from the receiving hole 112, the relative rotation between the camshaft 34 and the annular housing 50 becomes possible.

Conversely, in order to make the rotation of the intake valve camshaft 36 the most retarded state from the most advanced state shown in FIG. 3 as compared with the rotation of the camshaft 34 shown in FIG.
6 to the retard hydraulic chamber 82,
Acts on the large-diameter portion 111 of the stepped pin 106 through the passage 114. Therefore, even if there is no oil acting on the tip of the small-diameter portion 110 of the stepped pin 106, the oil acting on the large-diameter portion 111 of the stepped pin 106 through the passage 114 is in the most retarded state shown in FIG. , Stepped pin 10
6 does not engage with the receiving hole 112 of the inner rotor 68.

Thus, during the operation of the engine (while the oil pump 98 discharges a sufficient amount of oil), the phase holding mechanism 104 of the present embodiment
2, the stepped pin 106 is engaged with the receiving hole 112 only when the engine is started (while the oil pump 98 cannot discharge sufficient oil).
Can be greatly reduced, and the durability and reliability of the phase holding mechanism 104 due to aging can be improved.

Further, in the present embodiment, the valve timing control device 30 provided with only one phase holding mechanism 104 is provided. However, the present invention is different from the prior art valve timing control device shown in FIG. The present invention can also be applied to a type in which a phase holding mechanism is provided at each of the most advanced position and the most retarded position, and a type in which a phase holding mechanism is provided at an intermediate position from the most advanced position to the most retarded position.

[0032]

According to the first aspect of the present invention, a rotation transmitting member provided with a partition wall forming a plurality of fluid chambers on the inner peripheral portion, and an intake valve or exhaust having a vane for partitioning the fluid chambers. A camshaft that opens and closes a valve and a fluid chamber defined by a vane are a first fluid working chamber and a second fluid working chamber, respectively, and the phase of the rotation transmitting member and the camshaft is controlled by fluid pressure to the fluid working chamber. A variable phase mechanism that makes variable
A first flow path for supplying and discharging fluid to and from the first fluid working chamber, a second flow path for supplying and discharging fluid to and from the second fluid working chamber, a fluid pressure in the first flow path, and a fluid pressure in the second flow path And the engagement mechanism for maintaining the phase of the rotation transmission member and the camshaft when both fluid pressures decrease, to constitute a valve timing control device. Therefore, only when the oil pump is stopped, such as when the engine is stopped, and the supply of fluid to the fluid working chamber is stopped, the phase between the rotation transmitting member and the camshaft is maintained by the engagement mechanism. The durability and reliability of the engagement mechanism of the device can be improved.

According to the second aspect of the present invention, the engagement mechanism is disposed on one of the rotation transmitting member and the camshaft,
A first flow path comprising: a stepped pin having a large-diameter portion and a small-diameter portion biased by a spring on the other member side; and a receiving hole into which the small-diameter portion of the pin formed on the other member is inserted. Is to act on the large-diameter portion and the fluid in the second flow path acts on the small-diameter portion. Therefore, the stepped pin of the engagement mechanism is deactivated by the fluid pressure of one of the fluid in the first flow path and the fluid in the second flow path. When the fluid is supplied to at least one of the fluid in the first flow path and the fluid in the second flow path, the stepped pin is not inserted into the receiving hole, and the stepped pin is inserted into the unnecessary receiving hole. Can be prevented.

According to the third aspect of the present invention, a passage for communicating fluid is formed between the large diameter portion of the stepped pin and the first fluid working chamber adjacent to the stepped pin. Therefore, a passage for supplying a fluid to the large diameter portion of the stepped pin can be easily formed.

[Brief description of the drawings]

FIG. 1 shows a cross section of a valve timing control apparatus according to a first embodiment of the present invention.

FIG. 2 is a view showing the most retarded state of the AA sectional view of FIG. 1;

FIG. 3 shows a state of the most advanced angle in the sectional view taken along the line AA of FIG. 1;

FIG. 4 is a sectional view taken along the line AA of FIG. 1 and shows a most retarded state at the time of starting the engine.

FIG. 5 shows a cross section of a conventional valve timing control apparatus.

FIG. 6 is a sectional view taken along the line CC of FIG. 5;

[Explanation of symbols]

 Reference numeral 30: valve opening / closing timing control device 34: cam shaft 56: rotation transmitting member 58: partition wall 60: hydraulic chamber (fluid chamber) 74: vane 80: advanced hydraulic pressure Chamber (second fluid working chamber) 82: retard hydraulic chamber (first fluid working chamber) 84: advance oil passage (first flow passage) 86 ... retard oil passage (second) Flow path) 104: phase holding mechanism (engaging mechanism) 106: stepped pin 110: small diameter section 111: large diameter section 112: receiving hole 114: passage

Claims (3)

[Claims] 1. A rotation transmitting member having a partition wall forming a plurality of fluid chambers on an inner peripheral portion, a camshaft for opening and closing an intake valve or an exhaust valve provided with a vane defining the fluid chamber, and the vane. A variable fluid chamber defined as a first fluid working chamber and a second fluid working chamber, respectively, and a phase of the rotation transmitting member and the camshaft being variable by a fluid pressure applied to the fluid working chamber. A first flow path for supplying and discharging the fluid to and from the first fluid working chamber; a second flow path for supplying and discharging the fluid to and from the second fluid working chamber; A valve timing control device comprising an engagement mechanism for maintaining a phase between the rotation transmitting member and the camshaft when both fluid pressures of the flow path and the fluid pressure decrease. 2. The step mechanism according to claim 1, wherein the engaging mechanism is disposed on one of the rotation transmitting member and the camshaft, and has a large-diameter portion and a small-diameter portion biased by a spring toward the other member. A pin, and a receiving hole formed in the other member, into which the small-diameter portion of the pin is inserted, in which the fluid in the first flow path acts on the large-diameter portion, and the fluid in the second flow path has a small diameter. The valve opening / closing timing control device according to claim 1, which acts on a portion. 3. The valve timing control device according to claim 2, further comprising a passage for communicating fluid between a large diameter portion of the stepped pin and a first fluid working chamber adjacent to the stepped pin.