JP5585832B2 - Valve timing control device - Google Patents

Description

  The present invention relates to a valve opening / closing timing control device including a housing that rotates synchronously with a drive shaft of an internal combustion engine, and an internal rotor that is disposed coaxially with the housing and is rotatable relative to the housing.

  An example of such a valve opening / closing timing control device is disclosed in Patent Document 1. In the valve opening / closing timing control apparatus described in Patent Document 1, an internal rotor (in the literature, “internal main body”) is fixed to a camshaft by a shaft core member (in the literature, “clamping screw”), and the internal rotor and cam Two axially separated passages are formed between the shaft and the shaft.

  In the valve timing control device having the above-described configuration, the inner rotor and the shaft core member must be formed of a material having a similar linear expansion coefficient in order to suppress leakage of oil supplied to the valve timing control device. There is. On the other hand, since it is a necessary condition that the screw portion of the shaft core member has sufficient strength, a high-strength material is generally used for the shaft core member. As a result, when the shaft core member is inserted into the center hole of the internal rotor and screwed to the camshaft, it is necessary to prevent damage to the internal rotor due to the high-strength shaft core member. Accordingly, the inner rotor needs to be made of a material having the same linear expansion coefficient and the same strength as the shaft core member.

Japanese Patent No. 3965051

  However, except for avoiding damage due to the shaft core member, there is not much need for high strength in the internal rotor, rather it becomes difficult to work by using high strength material, and problems such as weight increase and cost increase occur Therefore, there is room for improvement in this respect.

  In view of the above circumstances, an object of the present invention is to provide a valve timing control device that does not require the use of a high-strength material for an internal rotor.

A first characteristic configuration of the valve timing control device according to the present invention includes a housing that rotates synchronously with a drive shaft of an internal combustion engine, an internal rotor that is disposed coaxially with the housing and is rotatable relative to the housing, An advance angle chamber and a retard angle chamber formed between the housing and the internal rotor, a driven shaft that transmits rotation of the internal rotor, and the internal rotor and the driven shaft are disposed between the internal rotor and the driven shaft. comprising an intermediate member which rotates the rotor and synchronized with the driven shaft, a, it is the space between the inner rotor before and SL driven shaft forming a first oil passage communicating with the advance chamber, of the driven shaft A second oil passage extending from the shaft core in the radially outward direction through the space and the inside of the inner rotor and communicating with the retarding chamber is formed from the shaft core of the driven shaft through the inside of the intermediate member. extending radially outward, said first oil passage Serial wherein between the second oil path intermediate member around the entire circumference in the axial direction in the inner rotor provided abutment portion abutting, said first oil passage and the second oil passage, said abutment It exists in the point arrange | positioned so that a part may be pinched | interposed in the said axial direction .

  According to this structure, since the space which comprises a part of intermediate member and 1st oil path is provided between an internal rotor and a driven shaft, an internal rotor does not contact a driven shaft. Therefore, even if the driven shaft is a high-strength material, it is not necessary to use a high-strength material for the internal rotor in order to prevent damage due to contact with the driven shaft. In addition, since the intermediate member is provided with an abutting portion that abuts the inner rotor over the entire circumference in the axial direction between the first oil passage and the second oil passage, the oil in the first oil passage and the second oil passage The oil in the road is not mixed in the gap between the internal rotor and the intermediate member, and the controllability of the valve timing control device is not impaired. In this configuration, the driven shaft may be a bolt that fastens the internal rotor to the camshaft, the camshaft itself, or another member.

  The second characteristic configuration is that the intermediate member is made of a material having a linear expansion coefficient closer to the driven shaft than the internal rotor or the same linear expansion coefficient as the driven shaft.

  It is desirable that the gap between the driven shaft and the intermediate member in the assembled state be as narrow as possible in order to minimize oil leakage in the gap while allowing the driven shaft to be inserted into the intermediate member. However, even if the gap is narrow at the time of assembly at normal temperature, the valve opening / closing timing control device is at a high temperature during actual operation. Therefore, if the linear expansion coefficients of both members are greatly different, the gap may be increased. Therefore, if the intermediate member is made of a material having a linear expansion coefficient closer to the driven shaft than the internal rotor or the same linear expansion coefficient as the driven shaft as in the present configuration, the driven shaft and the intermediate member have the same degree even in a high temperature environment. It can suppress that it expand | swells and the clearance gap between both members spreads.

  The third characteristic configuration is that the hydraulic oil that flows through the second oil passage and is supplied to the internal rotor passes through the outer peripheral side of the driven shaft and can be supplied via the intermediate member.

  According to this configuration, hydraulic oil can be supplied to the internal rotor via the second oil passage without changing or processing an existing driven shaft. Therefore, when the intermediate member is newly provided, the existing driven shaft can be used, and the cost increase can be suppressed.

  According to a fourth characteristic configuration, the driven shaft and the intermediate member are made of iron, and the inner rotor is made of aluminum.

  As in this configuration, when the driven shaft and the intermediate member are made of iron, both have high strength and the same linear expansion coefficient, so when the driven shaft is inserted into the intermediate member, While avoiding the risk of damage to the intermediate member, it is possible to prevent the gap between the driven shaft and the intermediate member from expanding even under a high temperature environment. Further, by using an aluminum material as the internal rotor, it is easy to process the internal rotor, and it is effective in terms of weight reduction and cost reduction.

  A fifth characteristic configuration is that the driven shaft is a camshaft, and the intermediate member is press-fitted into the camshaft.

  If the intermediate member is press-fitted into the camshaft that is the driven shaft as in this configuration, it is possible to prevent a gap from being generated between the driven shaft and the intermediate member, so that oil leakage in the gap can be prevented. .

  According to a sixth characteristic configuration, the driven shaft is a bolt that is screwed onto a camshaft, and a control valve that switches between communication and non-communication of the first oil passage and the second oil passage is housed inside the bolt. There is in point.

  If the control valve that switches between communication and non-communication of the first oil passage and the second oil passage is housed inside the bolt that is the driven shaft as in this configuration, the valve opening / closing timing control device can be downsized, The mountability to the engine can be improved.

It is sectional drawing which shows the whole structure of a valve timing control apparatus. It is II-II sectional drawing in FIG. It is detail drawing which shows the state of OCV at the time of advance angle control. It is detail drawing which shows the state of OCV at the time of retard control. It is a disassembled perspective view which shows the structure of a valve opening / closing timing control apparatus. It is sectional drawing which shows the whole structure of the valve timing control apparatus in another embodiment.

  Hereinafter, an embodiment in which the present invention is applied as a valve opening / closing timing control device on an intake valve side in an automobile engine will be described with reference to the drawings. In the present embodiment, the automobile engine corresponds to an “internal combustion engine”.

〔overall structure〕
As shown in FIG. 1, this valve opening / closing timing control device is disposed coaxially with a housing 1 that rotates synchronously with a crankshaft (not shown) as a “drive shaft”, and is rotatable relative to the housing 1. Internal rotor 2. An intermediate member 6 is provided between the internal rotor 2 and the OCV bolt 5 as a “driven shaft” that transmits the rotation of the internal rotor 2. The camshaft 101 is a rotating shaft of a cam (not shown) that controls opening and closing of the intake valve of the engine, and rotates in synchronization with the internal rotor 2, the OCV bolt 5, and the intermediate member 6. The camshaft 101 is rotatably assembled to a cylinder head of an engine (not shown).

[Housing and internal rotor]
The housing 1 is assembled by assembling a front plate 11 opposite to the side to which the camshaft 101 is connected, an external rotor 12 that is externally mounted on the internal rotor 2, and a rear plate 13 that is integrally provided with a timing sprocket 15. Composed. An inner rotor 2 is accommodated in the housing 1, and a fluid pressure chamber 4 is formed between the inner rotor 2 and the outer rotor 12 as described later.

  When the crankshaft is rotationally driven, the rotational driving force is transmitted to the timing sprocket 15 via the power transmission member 102, and the housing 1 is rotationally driven in the rotational direction S shown in FIG. As the housing 1 rotates, the internal rotor 2 rotates in the rotational direction S to rotate the camshaft 101, and the cam provided on the camshaft 101 pushes down the intake valve of the engine to open it.

  As shown in FIG. 2, a plurality of projecting portions 14 projecting in the radially inward direction are formed on the outer rotor 12 so as to be spaced apart from each other along the rotational direction S, so that the space between the inner rotor 2 and the outer rotor 12 is increased. A fluid pressure chamber 4 is formed. The protruding portion 14 also functions as a shoe for the outer peripheral surface of the inner rotor 2. A protrusion 21 is formed on the outer peripheral surface of the internal rotor 2 on the portion facing the fluid pressure chamber 4. The fluid pressure chamber 4 is divided into an advance chamber 41 and a retard chamber 42 along the rotation direction S by the protrusion 21. In the present embodiment, the fluid pressure chamber 4 is configured to have four locations, but the present invention is not limited to this.

  Oil is supplied to and discharged from the advance chamber 41 and the retard chamber 42, or the supply and discharge of the oil is shut off, and hydraulic pressure is applied to the protruding portion 21. In this way, the relative rotational phase is displaced in the advance angle direction or the retard angle direction, or held at an arbitrary phase. The advance direction is a direction in which the volume of the advance chamber 41 is increased, and is indicated by an arrow S1 in FIG. The retarding direction S2 is a direction in which the volume of the retarding chamber 42 increases, and is indicated by an arrow S2 in FIG. The relative rotation phase when the volume of the advance chamber 41 is maximized is the most advanced phase, and the relative rotation phase when the volume of the retard chamber 42 is maximized is the most retarded phase.

[Lock mechanism]
The valve opening / closing timing control device restricts the relative rotational movement of the inner rotor 2 with respect to the housing 1, thereby locking the relative rotational phase of the inner rotor 2 with respect to the housing 1 between a most advanced angle phase and a most retarded angle phase. A lock mechanism 8 that can be restricted to the phase is provided. By restraining the relative rotational phase to the lock phase in a situation where the oil pressure of the oil immediately after engine startup is not stable, the rotational phase of the camshaft 101 with respect to the rotational phase of the crankshaft is properly maintained, and stable engine rotation is achieved. Can be realized.

  As shown in FIG. 2, the lock member 81 is configured to be movable along the axial direction, and is engaged with a lock groove (not shown) formed in the front plate 11 or the rear plate 13 by a biasing member (not shown). By being held in the state, the locked state is maintained. The lock oil passage 82 formed in the internal rotor 2 connects the lock mechanism 8 and the advance oil passage 43, and when the advance angle control is performed, hydraulic pressure is applied to the lock mechanism 8. As a result, the lock member 81 moves out of the lock groove against the urging force of the urging member, and the locked state is released.

[OCV (oil control valve)]
As shown in FIG. 1, in this embodiment, an OCV 51 as a “control valve” is disposed coaxially with the camshaft 101. The OCV 51 includes a spool 52, a spring 53 that biases the spool 52, and an electromagnetic solenoid 54 that drives the spool 52. Since the electromagnetic solenoid 54 is a known technique, a detailed description thereof will be omitted.

  The spool 52 is accommodated in an accommodation space 5a formed at the tip of the OCV bolt 5, and is slidable in the axial direction inside the accommodation space 5a. The OCV bolt 5 is formed with a male screw portion 5 b, and the male screw portion 5 b is screwed to the female screw portion 101 a of the camshaft 101, whereby the OCV bolt 5 is fixed to the camshaft 101.

  The spring 53 is disposed in the inner part of the accommodation space 5 a and constantly urges the spool 52 to the side opposite to the camshaft 101. When power is supplied to the electromagnetic solenoid 54, a push pin 54 a provided on the electromagnetic solenoid 54 presses the rod portion 52 a formed on the spool 52. As a result, the spool 52 slides toward the camshaft 101 against the urging force of the spring 53. The OCV 51 is configured so that the position of the spool 52 can be adjusted by adjusting the duty ratio of the power supplied to the electromagnetic solenoid 54. The amount of power supplied to the electromagnetic solenoid 54 is controlled by an ECU (electronic control unit) (not shown).

[Intermediate member and washer member]
As shown in FIG. 5, the intermediate member 6 is formed in a cylindrical shape and is internally provided on the camshaft 101 side (right side in the drawing) of the internal rotor 2. A washer member 7 is housed on the opposite side (right side in the figure) of the internal rotor 2 to the camshaft 101. In the state where the intermediate member 6 and the washer member 7 are installed in the inner rotor 2 and the housing 1 (not shown in FIG. Screw on. Then, as shown in FIG. 1, the intermediate member 6 and the internal rotor 2 abut on the entire circumference in the axial direction, and the abutting portion A is formed.

  The washer member 7 has a function of increasing the fastening force of the OCV bolt 5 to the camshaft 101, but the washer member 7 is not an essential component in the present invention. In addition, a member having the same function can be formed in another shape, and can be provided in another position.

(Oil channel configuration)
As shown in FIG. 1, the oil stored in the oil pan 61 is pumped up by a mechanical oil pump 62 that is driven by transmission of the rotational driving force of the crankshaft, and is supplied to a supply oil passage 45 described later. Is done. Then, the supply of oil to the advance oil passage 43 and the retard oil passage 44, and the shutoff of supply / discharge are switched by the control of the OCV 51.

  As shown in FIGS. 1 and 2, an advance oil passage 43 as a “first oil passage” connected to each advance chamber 41 is provided with a through hole 43 a formed in the OCV bolt 5, the OCV bolt 5 and the internal rotor. 2 and a through hole 43 c formed in the internal rotor 2. Further, a retard oil passage 44 as a “second oil passage” connected to each retard chamber 42 includes a through hole 44 a formed in the OCV bolt 5, a through hole 44 b formed in the intermediate member 6, and the internal rotor 2. And the through-hole 44c formed in. Further, a supply oil passage 45 for supplying oil to the advance chamber 41 or the retard chamber 42 has a passage 45 a formed in the camshaft 101, a passage 45 b formed in the intermediate member 6, and a through hole formed in the OCV bolt 5. 45c.

  The oil flowing through the supply oil passage 45 first flows into an annular groove 52 b formed on the outer peripheral surface of the spool 52. As shown in FIG. 1, when the annular groove 52 b does not communicate with the through hole 43 a and the through hole 44 a formed in the OCV bolt 5, no oil is supplied to the advance chamber 41 and the retard chamber 42. In this state, the through hole 43a is configured not to communicate with the through hole 52c formed in the spool 52, so that the oil in the advance chamber 41 has the advance oil passage 43, the through hole 52c, the accommodation space 5a, and It is not discharged out of the apparatus via the discharge hole 52d. Similarly, in this state, since the through hole 44a is configured not to communicate with the accommodation space 5a, the oil in the retardation chamber 42 passes through the retardation oil passage 44, the accommodation space 5a, and the discharge hole 52d. It is not discharged outside the device. That is, when a predetermined amount of power is supplied to the electromagnetic solenoid 54 and the OCV 51 is controlled so as to hold the spool 52 in the position shown in FIG. 1, the oil supply / discharge to the advance chamber 41 and the retard chamber 42 is interrupted, The relative rotational phase is maintained.

  When power is not supplied to the electromagnetic solenoid 54, the spool 52 is held at the position shown in FIG. In this state, the annular groove 52b of the spool 52 communicates with the through hole 43a formed in the OCV bolt 5 and does not communicate with the through hole 44a. At the same time, the through hole 44a communicates with the accommodation space 5a. Therefore, the oil supplied to the supply oil passage 45 is supplied to the advance chamber 41 via the advance oil passage 43, and the oil in the retard chamber 42 is the retard oil passage 44, the accommodating space 5a, and the discharge hole 52d. It is discharged out of the device via At this time, the relative rotation phase is displaced in the advance direction S1 by the hydraulic pressure acting on the advance chamber 41.

  When maximum power is supplied to the electromagnetic solenoid 54, the spool 52 is held at the position shown in FIG. 4 against the urging force of the spring 53. In this state, the annular groove 52b of the spool 52 communicates with the through hole 44a formed in the OCV bolt 5 and does not communicate with the through hole 43a. At the same time, the through hole 43a communicates with a through hole 52c formed in the spool. Accordingly, the oil supplied to the supply oil passage 45 is supplied to the retard chamber 42 via the retard oil passage 44, and the oil in the advance chamber 41 is the advance oil passage 43, the through hole 52c, the accommodation space 5a, And it is discharged out of the apparatus via the discharge hole 52d. At this time, the relative rotational phase is displaced in the retarding direction S2 by the hydraulic pressure acting on the retarding chamber 42.

〔effect〕
In the valve timing control apparatus configured as described above, since the intermediate member 6 and the space 43b are provided between the OCV bolt 5 and the internal rotor 2, the OCV bolt 5 does not contact the internal rotor 2. Therefore, even if the OCV bolt 5 is a high-strength material, it is not necessary to use a high-strength material for the internal rotor 2 in order to prevent damage due to contact with the OCV bolt 5. For example, using an aluminum material as the internal rotor 2 facilitates processing of the internal rotor 2 and is effective in terms of weight reduction and cost reduction.

  In addition, since the intermediate member 6 is provided between the advance oil passage 43 and the retard oil passage 44, the contact portion A is provided to contact the inner rotor 2 over the entire circumference in the axial direction. And the oil in the retarded oil passage 44 are not mixed in the gap between the internal rotor 2 and the intermediate member 6, and the controllability of the valve opening / closing timing control device is not impaired.

  Furthermore, if a material having a linear expansion coefficient that is the same as or close to the linear expansion coefficient of the OCV bolt 5 is used as the intermediate member 6, the OCV bolt 5 and the intermediate member 6 expand to the same extent even in a high temperature environment, and both members It can suppress that the clearance gap between them spreads. As a result, oil leakage in the gap between the OCV bolt 5 and the intermediate member 6 can be suppressed, and the controllability of the valve opening / closing timing control device can be maintained. For example, if both the OCV bolt 5 and the intermediate member 6 are made of iron, it is desirable because they have the same linear expansion coefficient while satisfying the strength requirements. In addition, since each member is fastened by the OCV bolt 5 in the axial direction, even if each member expands in a high temperature environment, a gap is hardly generated in the contact portion A.

[Another embodiment]
Another embodiment of the present invention will be described with reference to FIG. Since the basic configuration of the valve timing control device is the same as that of the previous embodiment, differences from the previous embodiment will be mainly described. In addition, the same code | symbol is attached | subjected about the same member as previous embodiment.

  In the present embodiment, the camshaft 101 passes through the center hole of the inner rotor 2 in the axial direction, and is configured as a “driven shaft” in the present invention. An internal space 101 b into which the bolt 91 is inserted is formed at the tip of the camshaft 101. The bolt 91 has a male threaded portion 91 a formed therein. The male threaded portion 91 a is screwed into the female threaded portion 101 a of the camshaft 101, thereby fixing the internal rotor 2 housed in the housing 1 to the camshaft 101. The

  Unlike the previous embodiment, the OCV 51 is disposed closer to the oil pump 62 than the valve opening / closing timing control device. That is, before the oil flows into the valve opening / closing timing control device, the OCV 51 is switched to supply the advance oil passage 73 or the retard oil passage 74 to be described later. In the present embodiment, the supply oil passage in the previous embodiment is not formed in the valve opening / closing timing control device.

  An advance oil passage 73 as a “first oil passage” connected to each advance chamber, a passage 73a formed in the camshaft 101, a space 73b formed between the camshaft 101 and the internal rotor 2, and an internal And a through hole 73 c formed in the rotor 2. Further, a retard oil passage 74 as a “second oil passage” connected to each retard chamber is formed in a passage 74 a formed in the camshaft 101, a passage 74 b formed in the intermediate member 6, and the internal rotor 2. And a through hole 74c.

  In the valve timing control apparatus configured as described above, since the intermediate member 6 and the space 73b are provided between the camshaft 101 and the internal rotor 2, the camshaft 101 does not contact the internal rotor 2. Therefore, even if the camshaft 101 is a high-strength material, it is not necessary to use a high-strength material for the internal rotor 2 in order to prevent damage due to contact with the camshaft 101. Further, since the contact portion A where the inner rotor 2 and the intermediate member 6 are contacted over the entire circumference in the axial direction is provided, the oil in the advance oil passage 73 and the oil in the retard oil passage 74 are transferred to the inner rotor. 2 and the intermediate member 6 are not mixed with each other, and the controllability of the valve timing control device is not impaired.

  The intermediate member 6 not only contacts the inner rotor 2 at the contact portion A over the entire circumference in the axial direction, but also contacts the camshaft 101 at the contact portion B over the entire circumference in the axial direction. As shown in FIG. 6, when the passage 74 b formed in the intermediate member 6 is connected to the passage 74 a formed in the cam shaft 101 in the axial direction, a gap is generated between the intermediate member 6 and the cam shaft 101. However, since the oil in the advance oil passage 73 and the oil in the retard oil passage 74 are not mixed, the controllability of the valve opening / closing timing control device is not impaired. In this case, there is little need to use a material having a linear expansion coefficient that is the same as or close to the linear expansion coefficient of the camshaft 101 as the intermediate member 6, and the degree of freedom in selecting the material of the intermediate member 6 is increased.

  In the present embodiment, the intermediate member 6 can be press-fitted into the camshaft 101 in advance before assembling the internal rotor 2, thereby eliminating the gap between the camshaft 101 and the intermediate member 6. be able to. Therefore, when a gap is generated between the camshaft 101 and the intermediate member 6, the oil passage configuration is such that the oil in the advance oil passage 73 and the oil in the retard oil passage 74 are mixed. By press-fitting the intermediate member 6 into the camshaft 101, it is possible to prevent the controllability of the valve opening / closing timing control device from being lowered.

Other Embodiment
(1) The valve opening / closing timing control device according to the present invention may be applied to a valve opening / closing timing control device on the exhaust valve side.
(2) The lock mechanism may not be provided, or the configuration of the lock mechanism may be different from that of the above embodiment.
(3) The oil passage configuration may be different from the above embodiment as long as the function of the valve timing control device is not hindered.
(4) The “driven shaft” in the present invention may be a member other than the OCV bolt or the camshaft.
(5) The shape and arrangement of the intermediate member may be different from those in the above embodiment.

  The present invention can be used for a valve opening / closing timing control device of an automobile or other internal combustion engine.

1 Housing 2 Internal rotor 5 OCV bolt (driven shaft)
6 Intermediate member 43 Advance oil passage (first oil passage)
43b space (a space constituting a part of the first oil passage)
44 Retardation oil passage (second oil passage)
44b Through hole (passage constituting part of second oil passage)
51 OCV (Control valve)
73 Advance oil passage (first oil passage)
73b space (a space constituting a part of the first oil passage)
74 Retardation oil passage (second oil passage)
74b passage (passage constituting a part of the second oil passage)
101 Camshaft (driven shaft)
A Contact part

Claims (6)

A housing that rotates synchronously with the drive shaft of the internal combustion engine;
An inner rotor disposed coaxially with the housing and rotatable relative to the housing;
An advance chamber and a retard chamber formed between the housing and the inner rotor;
A driven shaft for transmitting rotation of the internal rotor;
An intermediate member disposed between the inner rotor and the driven shaft and rotating synchronously with the inner rotor and the driven shaft;
A space is formed between the inner rotor before and SL driven shaft, a first oil passage communicating with the advance chamber, through the interior of the space and the inner rotor from the axis of the driven shaft radially A second oil passage extending in a direction and communicating with the retard chamber extends from the axial center of the driven shaft in the radially outward direction through the inside of the intermediate member , and the first oil passage and the second oil passage A contact portion is provided between the oil passage and the intermediate member that contacts the inner rotor over the entire circumference in the axial direction ;
The first oil passage and the second oil passage are valve opening / closing timing control devices arranged so as to sandwich the contact portion in the axial direction .   The valve opening / closing timing control device according to claim 1, wherein the intermediate member is made of a material having a linear expansion coefficient closer to the driven shaft than the internal rotor or the same linear expansion coefficient as the driven shaft.   3. The valve opening / closing timing control according to claim 1, wherein the hydraulic oil that flows through the second oil passage and is supplied to the internal rotor passes through the outer peripheral side of the driven shaft and can be supplied via the intermediate member. apparatus.   The valve opening / closing timing control device according to any one of claims 1 to 3, wherein the driven shaft and the intermediate member are made of an iron material, and the inner rotor is made of an aluminum material.   The valve opening / closing timing control device according to any one of claims 1 to 4, wherein the driven shaft is a camshaft, and the intermediate member is press-fitted into the camshaft.   The driven shaft is a bolt that is screwed onto a camshaft, and a control valve that switches between communication and non-communication of the first oil passage and the second oil passage is housed inside the bolt. The valve opening / closing timing control device according to any one of the above.

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