JP2002030908A - Valve timing control device for internal combustion engine - Google Patents

Abstract

(57) [Summary] [Problem] To reduce the weight of a vane member without incurring rotational imbalance of the vane member while ensuring sufficient operating torque by using a vane member provided with three or more blade portions. In addition, a sufficient relative rotation angle between the vane member and the housing member can be ensured. SOLUTION: A blade portion 17 provided with a lock pin 36 is provided.
a, and the circumferential width of one blade 17b located on the opposite side of the blade 17a with respect to the rotation axis o from the circumferential width of the remaining blades 17c, 17d. Form widely. The blade portion 17a provided with the lock pin 36 is balanced with the blade portion 17b located symmetrically therewith.

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 (hereinafter referred to as "internal combustion engine").
Let's say "engine". The present invention relates to a valve timing control device for controlling the opening / closing timing of the intake valve and the exhaust valve according to the operating conditions.

[0002]

2. Description of the Related Art By rotating a mounting angle between a driving force transmitting member such as a timing pulley or a chain sprocket which rotates synchronously with a crankshaft of an engine and a camshaft having a driving cam on an outer periphery, an intake valve and a suction valve are rotated. 2. Description of the Related Art A valve timing control device for variably controlling the opening / closing timing of an exhaust valve has been proposed, and this technique is disclosed in, for example, JP-A-9-60507.

In the valve timing control device described in this publication, a vane member having a plurality of blades protruding radially outward is integrally attached to an end of a cam shaft, and the vane member is connected to a driving force transmitting member. The vane member is housed inside the integral housing member, and an advance hydraulic chamber and a retard hydraulic chamber are provided inside the housing member. The opening / closing timing of the intake valve and the exhaust valve is changed by changing the rotation phase of the driving force transmission member and the camshaft.

In such a so-called vane type valve timing control device, when the supply hydraulic pressure is low, for example, when the rotation speed of the engine is low, the pressure in the hydraulic chamber loses the reaction force received from the intake valve and the exhaust valve, and the vane It is known that a member is pushed by its reaction force. In order to cope with this, in the valve timing control device described in the above publication, a lock pin is provided on one blade portion of the vane member so as to be able to advance and retreat, and the vane member and the housing member are in the set relative rotation position. In the above, the tip of the lock pin is fitted into the lock hole of the housing member to prevent the vane member from being pushed back.

In this valve timing control device, the torque required to rotate the vane member and the housing member relative to each other is determined by the product of the pressure receiving area of the blade and the oil pressure. The pressure-receiving area related to this torque increases in proportion to the number of blades if the size of the pressure-receiving surface of each blade is the same, so that the torque enough to reliably overcome the reaction force of the engine valve during operation is obtained. In the case where an attempt is to be made, it is usually dealt with by increasing the number of blades.

[0006]

However, if the number of blades of the vane member is simply increased, the weight of the vane member is greatly increased, and the number of blades is increased along with the number of blades. Since a corresponding number of partition walls must be provided, the pivot angle between the vane member and the housing member is reduced accordingly.

As a countermeasure for this, it is conceivable to reduce the circumferential width of each blade to suppress an increase in the weight and to increase the rotation angle. At least the blade on which the lock pin is disposed is provided with the lock pin. Since a width that can be securely held must be ensured, if the width of the other blades is reduced while leaving the blades, a rotational imbalance of the entire vane member occurs. Since the valve timing control device always rotates at a high speed together with the camshaft, the rotational imbalance causes various problems such as generation of vibration and deterioration of durability of the bearing portion.

Accordingly, the present invention reduces the weight of the vane member while ensuring sufficient operating torque by using a vane member having three or more blade portions, without causing rotational unbalance of the vane member. Further, it is an object of the present invention to provide a valve timing control device for an internal combustion engine which can ensure a sufficient relative rotation angle between a vane member and a housing.

[0009]

SUMMARY OF THE INVENTION In order to solve this problem, an invention according to claim 1 is a drive force transmitting member driven by a crankshaft of an internal combustion engine, and a drive for operating an engine valve on an outer periphery. A camshaft that has a cam and is mounted so that the driving force transmission member can rotate relative to one another as needed, and that receives power from the driving force transmission member and is driven to rotate; and the driving force transmission member and the camshaft. A housing member rotatable integrally with one of the camshafts; a housing member housed in the housing member; the housing member rotatably integrated with the other one of the driving force transmitting member and the camshaft; A vane member having at least one blade portion, an advance hydraulic chamber and a retard hydraulic pressure provided in the housing member and rotating the vane member by hydraulic pressure A hydraulic suction / discharge means communicating with the advance hydraulic chamber and the retard hydraulic chamber, and selectively absorbing and discharging hydraulic pressure to and from these hydraulic chambers; and an internal combustion engine mounted on one of the vanes of the vane member so as to be able to advance and retreat. A lock pin fitted into a lock hole of the housing member in accordance with the operation state of the internal combustion engine, and a circumferential width of a blade portion provided with the lock pin, The circumferential width of one blade portion located on the opposite side with respect to the rotation axis is formed to be wider than the circumferential width of the remaining blade portions.

In the case of the present invention, since the circumferential width of the blade portion provided with the lock pin and the blade portion located on the opposite side of the rotary shaft with respect to the rotary shaft is widened, the weight balance of the both blade portions is maintained. . Further, since the circumferential width of the remaining blade portion is reduced, the weight of the entire vane member is reduced, and the relative rotation angle between the vane member and the housing member is ensured.

According to the second aspect of the present invention, the circumferential width of the blade provided with the lock pin is larger than the circumferential width of the blade located on the opposite side of the blade with respect to the rotary shaft. It was made wider.

A space for accommodating the lock pin and a mechanism for urging the lock pin must be provided on the blade portion on which the lock pin is provided. Since a fitting hole must be provided at the position where the lock pin is provided, the blade portion on which the lock pin is disposed is reduced in weight by these amounts. However, in the case of the present invention, since the blade portion provided with the lock pin is secured to be wider than the circumferential width of the blade portion located on the opposite side with respect to the rotation shaft, both blade portions are more accurately Weight balanced.

According to a third aspect of the present invention, the moment of inertia of the blade provided with the lock pin is substantially equal to the moment of inertia of the blade located on the opposite side of the blade with respect to the rotary shaft. .

In the case of the present invention, not only the weight balance of the two blades but also the moment of inertia substantially match, so that the center of gravity of the vane member matches the center of rotation.

According to a fourth aspect of the present invention, the vane member is provided with four blades, and the blade provided with the lock pin and the one blade having a wide width in the circumferential direction are arranged symmetrically with respect to the rotation axis. The remaining two blades having a narrow width in the direction are arranged symmetrically with respect to an axis connecting the blade provided with the lock pin and the blade arranged symmetrically therewith.

In the present invention, the weight balance on the left and right of the axis connecting the two wide blades is maintained by the two narrow blades.

According to a fifth aspect of the present invention, the two blades having a narrow circumferential width are arranged so as to be biased toward the blade having a wide circumferential width where no lock pin is provided.

In the case of the present invention, the weight can be balanced by three blades with respect to the blade provided with the lock pin.

[0019]

Next, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a camshaft on the intake side of the engine. The camshaft 1 is rotatably supported by a cylinder head (not shown) via a bearing, and a drive cam (not shown) for opening and closing an intake valve as an engine valve is provided on an outer periphery of a main portion thereof. I have. The valve timing control device 2 according to the present invention includes the camshaft 1
At one end.

The valve timing control device 2 includes a chain sprocket 4 as a driving force transmitting member that is rotationally driven by a crankshaft via a timing chain (not shown), and the chain sprocket 4 is formed on the outer periphery on the rear side. A housing member 5, the camshaft 1 assembled at one end so that the housing member 5 can rotate as required, and the camshaft 1.
A vane member 7 integrally assembled to one end of the housing member 5 and rotatably housed inside the housing member 5; a hydraulic suction / discharge means 8 for rotating the vane member 7 forward and reverse by hydraulic pressure according to the operating state of the engine; A rotation restricting means 9 is provided for restricting return of the vane member 7 due to rotation fluctuation torque acting on the camshaft 1 in accordance with an operation state.

The housing member 5 has a substantially cylindrical housing body 10 and a front cover 12 connected to front and rear end faces of the housing body 10 by bolts 11.
And a rear cover 13, the housing body 10
As shown in FIG. 1, four partition walls 14 each having a trapezoidal cross section protrude from the inner peripheral surface at intervals of approximately 90 °.

On the other hand, the vane member 7 has a substantially cylindrical body 16 and four blades 17a, 17b, 17c, 17d radially protruding from an outer peripheral surface of the body 16. The body 16 is arranged at the axial position of the housing member 10, and the blades 17 a to 17 d are arranged between the adjacent partition walls 14 of the housing member 5. And
An advancing hydraulic chamber 18 is provided between one side surface of each of the blade portions 17a to 17d of the vane member 7 and the partition wall 14 opposed thereto, and the other side surface of each of the blade portions 17a to 17d and the partition wall opposed thereto. Between 14 is a retard hydraulic chamber 19.
Therefore, in this device, a total of four pairs of the advance hydraulic chamber 18 and the retard hydraulic chamber 19 are provided.

A first concave portion 20 opening on the front side and a second concave portion 21 opening on the rear side are formed in the axial center of the body 16 of the vane member 7, respectively. Second recess 21
The end of the camshaft 1 is fitted to the partition wall 22, and the end of the camshaft 1 is connected to the partition wall 22 separating the first recess 20 and the second recess 21 by bolts 23. The head of the bolt 23 is disposed in the first recess 20, and the end of the first suction / discharge hole 24 formed from the axis of the bolt 23 to the head is opened in the first recess 20. It has become. On the other hand, an end of a second suction / discharge hole 25 formed in the camshaft 1 is opened on the outer peripheral surface of the camshaft 1 fitted in the second recess 21. And the first
A first radial hole 26 communicating with each of the advance hydraulic chambers 18 is opened in the concave portion 20, and the second radial portion 26 of the second concave portion 21 is opened.
A second radial hole 27 communicating with each of the retard hydraulic chambers 19 is opened at a position corresponding to the end of the suction / discharge hole 25. Therefore, each of the advance hydraulic chamber 18 and the retard pressure chamber 19 communicates with the first suction / discharge hole 26 and the second suction / discharge hole 27 via the first recess 20 and the second recess 21, respectively.

The hydraulic suction / discharge means 8 includes a first hydraulic passage 28 connected to the first suction / discharge hole 24 for sucking / discharging hydraulic pressure to / from the advance hydraulic chamber 18 and a retard hydraulic chamber 19 connected to the second suction / discharge hole 25.
The hydraulic passages have two systems, a second hydraulic passage 29 that sucks and discharges hydraulic pressure, and a supply passage 30 and a drain passage 31 are provided in each of the two hydraulic passages 28 and 29 with an electromagnetic switching valve 32 for switching the passage. Connected through. In the supply passage 30,
An oil pump 34 for feeding oil in the oil pan 33 is provided, and an end of the drain passage 31 communicates with the inside of the oil pan 33. The electromagnetic switching valve 32 is controlled by a controller 35.
5, various signals indicating the operating state of the engine are input.

On the other hand, the rotation restricting means 9 mechanically controls the relative rotation between the housing member 5 and the vane member 7 when the rotation of the vane member 7 is controlled to the retard side when the engine is started. As shown in an enlarged view in FIG. 3, a lock pin 36 is accommodated and supported in one vane portion 17a of the vane member 7 so as to be able to advance and retreat in the axial direction. The spring member 37 biasing (in the direction of the front cover 12) and the inner surface of the front cover 12 (the side wall of the housing member 5) are arranged at set positions, and the vane member 7 is positioned at a maximum retard angle with respect to the housing member 5. And a lock hole 38 into which the tip of the lock pin 36 is fitted at a position displaced in the direction shown in FIG.

The lock pin 36 is formed in a bottomed cylindrical shape having a tapered portion at the tip, and is slidably received in a shaft hole 39 formed in one blade 17 a of the vane member 7. The shaft hole 39 accommodates the spring member 37 for urging the lock pin 36 in the protruding direction and a spring support pin 40 for supporting one end of the spring member 37, and the back of the lock pin 36 in which the spring member 37 is interposed. The space communicates with the atmosphere.

On the other hand, the lock hole 38 is
Instead of being directly processed on the front cover 12
And a bottomed cylindrical guide bush 42 made of a material having high abrasion resistance is press-fitted and fixed in the mounting hole 41 formed at the set position. The guide bush 42 has a suction / discharge hole (not shown) for communicating the bottom of the guide bush 42 with the advance hydraulic chamber 18.
The hydraulic pressure of the advance hydraulic chamber 18 acts on the tip.

In the valve timing control device 2 according to the present invention, the four blade portions 17a to 17d of the vane member 7 are formed with the following settings.

That is, as shown in FIG. 4, the vane member 7 has one blade portion 17b arranged symmetrically with respect to the rotation axis (o) with respect to the blade portion 17a on which the lock pin 36 is arranged, and the other two blades 17b are arranged. Are arranged in line symmetry with respect to an axis p connecting the blades 17a and 17b, and slightly displaced toward the blade 17b. The blades 17a and 17b have their circumferential widths L ₁ and L _{2 set} to the remaining blades 17a and 17b.
The widths c and 17d are set wider than the circumferential widths L ₃ and L ₄ . Also, the circumferential width L ₁ of the blade portion 17a is widely set than the circumferential width L ₂ of the blade portion 17b of the symmetrical position, the remainder of the blade portion 17c, the circumferential width L ₃ of the 17d, L ₄ are both the same (See the following equation (1)).

[0031]

L ₁ > L ₂ > L ₃ = L ₄ (1) Here, the circumferential width L ₁ of the blade portion 17a is inevitably wide due to the provision of the lock pin, but is symmetrical therewith. blade portion 17b in the position, is likewise circumferential width L ₂ in order to take the weight balance of the blade portion 17a is set widely. The remaining blade portions 17c and 17d have circumferential widths L3 and L4 smaller than those of the blade portions 17a and 17b.

A shaft hole 39 for accommodating the lock pin 36, the spring member 37 and the like is formed in the blade portion 17a.
Furthermore, since the lock hole 38 is formed in the portion corresponding to the lock pin 36 of the housing member 10, if the blade 17b is set to have the same circumferential width L ₁ = L ₂ as the blade 17a, the blade 1
The weight on the 7b side becomes heavy. For this reason, in this embodiment, the shaft hole 39 and the lock hole 3 of the blade portion 17a are
8, the circumferential width L ₂ of the blade portion 17b is considered.
There is set wider than the circumferential width L ₁ of the blade portion 17a. The blades 17a and 17b have substantially the same moment of inertia so that the center of gravity of the vane member 7 coincides with the rotation axis o.

In this structure, when hydraulic oil is not sufficiently supplied from the oil pump 34 when the engine is started, or when high-pressure hydraulic oil is supplied to the retard hydraulic chamber 19 by operating the electromagnetic switching valve 32, the vane member 7 is located at the most retarded position shown in FIG. 1 with respect to the housing member 5, and the lock pin 36 of the rotation restricting means 9
Of the guide bush 42 is fitted into the lock hole 38 of the guide bush 42, and the vane member 7 and the housing member 5 are mechanically connected. For this reason, the rotational driving force input to the chain sprocket 4 from a crankshaft (not shown) is transmitted to the camshaft 1 via the housing member 5 and the vane member 7 which are mechanically connected in the most retarded state,
The intake valve is opened and closed at a retard timing through a drive cam (not shown).

When the vane member 7 is rotationally displaced to the most retarded side, the lock pin 36 mechanically couples the housing member 5 and the vane member 7 as described above. Even when the fluctuating torque is input to the camshaft 1 from the above, the vane member 7 does not rotate relative to the housing member 5, and therefore, there is no problem such as the rattling noise of the vane member 7.

In this state, the advance hydraulic chamber 18 communicates with the supply passage 30 and the retard hydraulic chamber 19 communicates with the drain passage 31 under the control of the electromagnetic switching valve 32 by the controller 35. High-pressure hydraulic oil is introduced into the chamber 18, and at this time, the high-pressure hydraulic oil is also introduced into the tip end (lock hole 38) of the lock pin 36. At this time, the lock pin 36 receives the pressure of the high-pressure hydraulic oil, retreats against the urging force of the spring member 37, and releases the rotation regulation of the housing member 5 and the vane member 7.

On the other hand, each blade 17a-1 of the vane member 7
7d receives a differential pressure between the advance hydraulic chamber 18 and the retard hydraulic chamber 19,
The whole vane member 7 rotates in the advance direction (toward the retard hydraulic chamber 19) with respect to the housing member 5, and stops at the most advanced position. Thereby, the chain sprocket 4 and the camshaft 1 rotate relatively, and the rotation phase of the camshaft 1 with respect to the chain sprocket 4 is controlled to the advanced side.

Although the valve timing control device 2 operates as described above, the vane member 7 receives hydraulic pressure at the four blade portions 17a to 17d at the time of operation, so that reliable operation can be obtained with a large operating force. it can. Further, in the device 2, when providing the four blade portions 17a to 17d of the vane member 7, the circumferential widths L ₁ and L of the blade portion 17a provided with the lock pin 36 and the blade portion 17b axially symmetric with the lock pin 36 are provided. ₂ is set to be wide, and the circumferential widths L ₃ and L ₄ of the remaining two blades 17 c and 17 d are set to be narrow. Therefore, the weight of the entire vane member 7 can be reduced, and the housing member 5 can be reduced. Wide relative rotation angle with respect to.

The blade 17b, which is axially symmetric with respect to the blade 17a, has a slightly smaller circumferential width than the blade 17a in consideration of the hollow portion such as the shaft hole 39 and the lock hole 38 on the blade 17a side. In addition, since the moments of inertia of the two blade portions 17a and 17b are substantially matched, the rotational balance around the axis o is well maintained.

Further, in the device 2 of this embodiment, the remaining blade portions 17c and 17d are also arranged in line with the axis p interposed therebetween, so that the weight balance with the axis p interposed therebetween is also maintained well. ing. Also, both wings 17
Since c and 17d are protruded toward the blade 17b side, the amount of expansion of the circumferential width of the blade 17b for balancing with the blade 17a on the lock pin 36 side is reduced,
There is an advantage that the weight of the entire vane member 7 can be further reduced.

Although an example in which a vane member having four blade portions is applied has been described above, the number of blade portions of the vane member used in the apparatus according to the present invention is arbitrary if three or more. good.

[0041]

As described above, the invention according to claim 1 is
Basically, since a vane member having three or more blade portions is used, a sufficient operating torque can be ensured, and the blades provided with the lock pins and the blades located on the opposite side of the rotary shaft with respect to the rotary shaft. By increasing the circumferential width of the portion, it is possible to maintain the weight balance of these two blades, and since the circumferential width of the remaining blades is reduced, the weight of the entire vane member can be reduced, A sufficient relative rotation angle between the vane member and the housing member can be secured.

According to the second aspect of the present invention, the vane portion provided with the lock pin and the symmetrical vane portion can be completely balanced in consideration of the accommodation space of the lock pin and the like. It can be higher than the rotational balance of the members.

According to the third aspect of the present invention, the center of gravity of the vane member can be made substantially coincident with the center of rotation by making the moments of inertia of the two blades substantially coincide with each other, so that the rotational balance of the vane member is further enhanced. be able to.

According to a fourth aspect of the present invention, the weight balance on the left and right sides of the axis connecting the two wide blades is reduced by the narrow width.
Since it can be maintained by the blades, the rotational balance of the vane member can be further enhanced.

According to the fifth aspect of the present invention, since the weight of the blade provided with the lock pin can be balanced by the three blades, the circumference of the blade provided at a position symmetrical to the blade provided with the lock pin can be achieved. By reducing the width in the direction, the weight of the entire vane member can be further reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along the line AA of FIG. 2 showing one embodiment of the present invention.

FIG. 2 is an exemplary sectional view of the embodiment, taken along line BB of FIG. 1;

FIG. 3 is a partially enlarged cross-sectional view showing the same embodiment.

FIG. 4 is a sectional view of a vane member showing the same embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Camshaft 2 ... Valve timing control device 4 ... Chain sprocket (driving force transmission member) 5 ... Housing member 7 ... Vane member 8 ... Hydraulic suction / discharge means 18 ... Advance hydraulic chamber 19 ... Retard hydraulic chamber 17a, 17b, 17c , 17d: blade part 36: lock pin 38: lock hole

Claims (5)

[Claims] 1. A driving force transmitting member driven by a crankshaft of an internal combustion engine, and a driving cam on an outer periphery for operating an engine valve so that the driving force transmitting member can relatively rotate as required. A camshaft assembled and driven to rotate by receiving power from the driving force transmitting member; a housing member rotating integrally with one of the driving force transmitting member and the camshaft; A vane member that is housed and rotates integrally with the other of the driving force transmission member and the camshaft and that has three or more blades protruding radially outward; The advancing hydraulic chamber and the retarding hydraulic chamber for rotating the vane member are communicated with the advancing hydraulic chamber and the retarding hydraulic chamber. A hydraulic pressure suction / discharge means for selectively sucking / discharging oil pressure, and a lock pin which is attached to one of the vanes of the vane member so as to be able to advance and retreat, and is fitted into a lock hole of a housing member according to an operation state of the internal combustion engine. In the valve timing control device for an internal combustion engine, the circumferential width of the blade provided with the lock pin and the circumferential width of one blade positioned on the opposite side of the blade with respect to the rotary shaft are defined as: A valve timing control device for an internal combustion engine, wherein the valve timing control device is formed wider than a circumferential width of the remaining blade portion. 2. The method according to claim 1, wherein a circumferential width of the blade portion provided with the lock pin is wider than a circumferential width of the blade portion located on the opposite side of the blade portion with respect to the rotary shaft. The valve timing control device for an internal combustion engine according to claim 1, wherein 3. A wing provided with a lock pin and a wing located on the opposite side of the wing with respect to the wing axis with respect to the wing about the same moment of inertia. 3. The valve timing control device for an internal combustion engine according to claim 2. 4. The vane member is provided with four blade portions, the blade portion provided with the lock pin and one blade portion having a large circumferential width are arranged symmetrically with respect to the rotation axis, and the remaining two blades having a small circumferential width are provided. The internal combustion engine according to any one of claims 1 to 3, wherein the plurality of blades are arranged symmetrically with respect to an axis connecting the blade provided with the lock pin and the blade arranged symmetrically therewith. Engine valve timing control device. 5. The internal combustion engine according to claim 4, wherein the two blades having a narrow circumferential width are arranged so as to be shifted toward a blade having a wide circumferential width where no lock pin is provided. Valve timing control device.