JP3116929B2 - Assembling method of variable valve timing mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing of an engine valve which is driven to open and close by changing the relative rotational phase of a camshaft with respect to a crankshaft which is an output shaft of an internal combustion engine. The present invention relates to a method of assembling a variable valve timing mechanism that makes variable.

[0002]

2. Description of the Related Art Conventionally, there has been known a variable valve timing mechanism for varying the valve timing of an engine valve in accordance with the operating state of an internal combustion engine in order to improve the performance of the internal combustion engine. As such a variable valve timing mechanism, for example, a mechanism described in Japanese Patent Application Laid-Open No. 9-324611 is known.

The configuration of such a variable valve timing mechanism will be described with reference to FIGS. FIG. 8 is a front sectional view of the variable valve timing mechanism, and FIG.
FIG. 10 shows a sectional structure taken along line VIII-VIII, and FIG. 10 shows an exploded perspective structure of the variable valve timing mechanism.

As shown in FIGS. 8 to 10, the variable valve timing mechanism includes a sprocket 15 which is drivingly connected to a crankshaft, a housing 16 which is fastened integrally with the sprocket 15 and a cover 17. , At the tip of the camshaft 11.

Camshaft 1 for opening and closing an engine valve
The inner rotor 12 is fixed to the front end of the unit 1 by a center bolt 14 so as to be integrally rotatable. Internal rotor 12
Are provided with a plurality (four in this example) of vanes 13 extending in the radial direction with respect to the axis of the camshaft 11.

A housing 16 having a substantially hollow cylindrical shape is externally fitted to the outer diameter of the inner rotor 12. A plurality of grooves (recesses) 19 for accommodating the respective vanes 13 are formed in the inner diameter of the housing 16. Between the adjacent concave portions 19, convex portions 20 for defining these are extended toward the axis of the camshaft 11.

A sprocket 15 is rotatably mounted at the distal end of the camshaft 11 and at the base end of the housing 16. The sprocket 15 is drivingly connected to a crankshaft (not shown) as an engine output shaft via a chain, and rotates in synchronization with the shaft.
In addition, a cover 17 is mounted on the distal end side of the housing 16. These sprocket 15 and housing 1
6. The cover 17 is fastened by mounting bolts 18 so as to rotate integrally with the camshaft 11.

The space inside the concave portion 19 is closed by the cover 17 and the sprocket 15, and is divided by the vane 13 into two spaces 21 and 22. These spaces 21 and 22 are pressure chambers into which hydraulic oil for relatively rotating the internal rotor 12 and the housing 16 is introduced. The pressures of the hydraulic oil in the pressure chambers 21 and 22 act on both side surfaces of the vane 13, respectively. This vane 13
The difference between the forces based on the pressures acting on both side surfaces is the driving force for relatively rotating the internal rotor 12 and the housing 16.

In this variable valve timing mechanism, the relative rotation phase between the camshaft 11 and the sprocket 15 is changed by appropriately rotating the internal rotor 12 and the housing 16 by controlling the hydraulic pressure of the two pressure chambers 21 and 22. That is, the rotation timing of the camshaft 11 with respect to the crankshaft can be changed to make the valve timing of the engine valve variable.

On the other hand, in this variable valve timing mechanism, the tip of the vane 13 and the tip of the projection 20 that separates adjacent recesses 19 in the housing 16 are provided with:
A seal member 28 is provided. Each seal member 28
Are arranged in grooves formed at the tip of the vane 13 and the tip of the projection 20 together with the leaf spring 29. The leaf spring 29
The seal member 28 is urged radially with respect to the axis of the camshaft 11 to constantly press the seal member 28 against the inner diameter of the concave portion 19 or the outer diameter of the internal rotor 12. In this manner, the sliding portion between the tip of the vane 12 and the inner diameter of the concave portion 19 and the sliding portion between the distal end of the convex portion 20 and the outer diameter of the internal rotor 12 are blocked by the seal member 28, so that each of the pressure chambers 21 and
Leakage of hydraulic oil between 22 is prevented.

Further, as shown in FIG. 10 , in this variable valve timing mechanism, the internal rotor 12 is accommodated in a space surrounded by the sprocket 15, the housing 16, and the cover 17. Then, the sprocket 15 and the housing 16 and the cover 1 are
7, the internal rotor 12 is temporarily fixed so as to be sandwiched between the sprocket 15 and the cover 17, and the variable valve timing mechanism is assembled. The variable valve timing mechanism thus assembled is then fastened to the camshaft 11.

[0012]

However, in the variable valve timing mechanism having such a structure, the internal rotor 12 and the housing 16 are relatively rotated about the same axis, so that the internal rotor 12 and the housing 16 can be assembled. The internal rotor 12 and the housing 16 need to be adjusted (aligned) so that their axes are aligned.

However, at the time of the assembling, the inner rotor 12 is housed in the space surrounded by the sprocket 15, the housing 16, and the cover 17 as described above.
2 cannot be referred to from outside.

Conventionally, the above alignment is performed by using the inner rotor 12.
And the outer diameter of the housing 16 as a reference. However, when such an assembling method is adopted, the following inconveniences cannot be ignored.

That is, since the inner diameter of the housing 16 is slidably contacted with the inner rotor 12, high precision is naturally required for the processing in view of the function as a variable valve timing mechanism. The outer diameter of the housing 16 does not require particularly high-precision machining, similarly from the functional aspect of the variable valve timing mechanism. However, when assembling the variable valve timing mechanism, the outer diameter of the housing 16 must be naturally secured with high accuracy in the processing since it is used as a reference for the alignment. In addition, it is also difficult to ensure processing accuracy with coaxiality with respect to the inner and outer diameter surfaces of the housing 16 in the first place.

As described above, the difficulty in aligning the inner rotor 12 and the housing 16 is one of the causes of lowering the assembling accuracy and increasing the processing cost when assembling the variable valve timing mechanism.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of assembling a variable valve timing mechanism that can easily assemble with high accuracy.

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
To, the invention described in claim 1, a housing is drivingly connected to one of the camshaft for opening and closing the valve of the output shaft and the engine of the internal combustion engine, the same as this in the housing
The output shaft and the cam
Together and an internal rotor which is drivingly connected to the other shaft, the pressure chamber on the side of the vane by partitioning a plurality of recesses formed radially inside the housing at vanes formed on the internal rotor A variable valve timing mechanism, wherein the housing and the internal rotor are relatively rotated based on pressure control of the formed pressure chamber to vary valve timing of an engine valve driven to be opened and closed by the camshaft; A method of assembling the internal rotor to a cam shaft of the internal rotor into a holding shaft vertically held in a base, and fixing the internal rotor horizontally on the base. And mounting the housing on the horizontally fixed internal rotor, and connecting the bottom of the recess with the vane. A seal member that seals pressure leakage between the pressure chambers at least between the end portion and at least between the distal end portion of the concave portion and the base circle portion of the internal rotor, and presses the seal member against the opposing wall surface Attaching the urging member to be energized, autonomously aligning the housing and the internal rotor based on the urging force of the urging member, and positioning the housing on the base in the aligned state. And assembling the housing and the internal rotor.

According to the above method, it is possible to easily and appropriately perform alignment between the housing and the internal rotor based on the urging force of the urging member and assembling of the housing and the internal rotor in the aligned state. it can.

[0026] The invention of claim 2, claim 1
In the assembling method of the variable valve timing mechanism described above, when the centered housing is fixedly held on the base, (1) a step of pressing the aligned housing on the base from the upper surface of the housing with an upper clamp; The gist of the present invention is to sequentially execute a step of holding the housing from the side surface with a natural clamp while holding the housing from the upper surface, and a step of releasing the pressing by the upper clamp.

When the housing is held and fixed from the side, if the balance of the holding force is broken even a little, the position of the axis of the housing is shifted. On the other hand, in a state where the housing is pressed and fixed on the base from the upper surface, the upper clamp is present on the upper surface of the housing, so that it is difficult to perform an assembling operation of the internal rotor. In this regard, according to the above method, the housing is held from the side while being pressed down from the upper surface by the upper clamp, thereby making it possible to fix and hold the housing while preventing displacement of the axis. Since the housing can be opened, the axial center of the housing can be easily and reliably fixed and held, and the assembling work between the housing and the internal rotor performed thereafter can be easily performed.

Further, the invention according to claim 3, claim 1
Or in the assembling method of the variable valve timing mechanism according to 2, in a state where the housing is fixedly held on the base, the holding shaft is rotated to relatively rotate the aligned housing and the internal rotor, The gist of the present invention is that the method further includes a step of judging an improper or improper assembling of the housing and the inner rotor according to the turning torque at the time of the relative turning.

According to the above-mentioned method, it is possible to easily perform the assembling by performing autonomous alignment by the urging force of the urging member, and to detect the improper or erroneous assembling based on the rotation torque. The assembling accuracy can be improved.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying a method and an apparatus for assembling a variable valve timing mechanism according to the present invention will be described in detail below. Also in this embodiment, it is assumed that the variable valve timing mechanism to be assembled has basically the same structure as that illustrated in FIGS.

First, the internal rotor 12 and sprocket 15 of the variable valve timing mechanism, the housing 16,
An apparatus for assembling the cover 17 will be described with reference to FIGS.

This device is a base 41 for performing an assembling operation.
And a holding shaft 42 rotatably disposed on the base 41.
And three natural clamps 4 each provided
3 and an upper clamp 44.

Here, the inner diameter of the internal rotor 12 is fitted and fixed to the holding shaft 42. By fixing the internal rotor 12 in this manner, the position of the axis can be fixedly held. The inner diameter of the rotor 12 is a part that requires high processing accuracy because it is inserted into the tip of the camshaft when it is fastened to the camshaft. Also,
The holding shaft 42 rotates with the same axis as the rotor 12 while holding the axis of the internal rotor 12.

The natural clamp 43 fixes and holds the axis of the housing 16 by holding the housing 16 in the outer diameter direction. This natural clamp 43 is provided around the axis of the holding shaft 42.
0 ° intervals, and the outer diameter of the housing 16 is 3
By holding in the direction, the axis is fixedly held.

Further, the upper clamp 44 fixes the housing 16 to the base 41 by pressing the housing 16 toward the base 41 from above. By fixing the housing 16 on the base 41 in this manner, its axis can be fixed and held more firmly.

On the other hand, as shown in FIG. 2, the holding shaft 42 is drivingly connected to a driving device 45 such as an electric motor, and can be driven to rotate. The driving torque when rotating the holding shaft 42 by the driving device 45 is measured by a torque measuring device 46. From the magnitude of the measured driving torque, the sliding resistance at the time of relative rotation of the internal rotor 12 and the housing 16 can be grasped.

Next, a procedure for assembling the variable valve timing mechanism using the above-described apparatus will be described with reference to FIGS. First, as shown in FIG. 3, after disposing the sprocket 15 on the base 41,
The inner diameter of the rotor 2 is inserted into the holding shaft 42, and the axis of the rotor 12 is fixed and held. Further, the housing 1 is attached to the inner rotor 12.
6 is fitted outside. At this stage, the axis of the internal rotor 12 does not match the axis of the housing 16.

Thereafter, a seal member 28, a leaf spring 29, and the like are mounted in respective grooves formed at the ends of the vane 13 and the convex portion 20, respectively. At this time, the housing 16 is not fixed, and its axis is movable.
Since the leaf springs 29 are arranged substantially point-symmetrically about the axis of the internal rotor 12, when the axis of the rotor 12 coincides with the axis of the housing 16, the urging force of all the leaf springs 29 is reduced. Become balanced. Therefore, by allowing the axis of the housing 16 to move freely, the leaf spring 29
The housing 16 is moved by the urging force of the above, so that the axis of the internal rotor 12 and the axis of the housing 16 coincide. In this way, the alignment between the internal rotor 12 and the housing 16 is performed autonomously.

After the centering of the inner rotor 12 and the housing 16 is performed by the urging force of the leaf spring 29 in this manner, the housing 16 is directed to the base 41 by the upper clamp 44 from above the housing 16 as shown in FIG. By pressing and fixing, the axis is fixed and held. Since the axis of the internal rotor 12 is already fixed and held by the holding shaft 42, the axis of the internal rotor 12 is aligned with the axis of the housing 16 by the fixed holding of the housing 16 by the upper clamp 44. Will be retained.

Thereafter, as shown in FIG. 5, the three natural clamps 43 are pressed against the fixedly held housing 16 from the outer diameter side and are held in three directions, whereby the axial center of the housing 16 is held. Furthermore, it is firmly held. At this time, since the axis of the housing 16 is fixed and held by the upper clamp 44 in advance, even if there is some imbalance in the pressing force of the natural clamps 43, the position of the axis of the housing 16 is maintained. It does not shift.

After the axis of the housing 16 is fixed and held by the upper clamp 44 and the natural clamp 43 in this manner, the upper clamp 44 is retracted from the upper surface of the housing 16 as shown in FIG. In this state, the holding shaft 42 is rotated by the driving device 45 to rotate the internal rotor 12 relative to the housing 16. Then, the driving torque of the driving device 45 in the relative rotation is measured by the torque measuring device 46.

At this time, if there is a problem in centering or a problem in assembling each member, the internal rotor 12 and the housing 1
The driving torque of the driving device 45 increases because the sliding resistance with the motor 6 increases and the relative rotation cannot be performed smoothly. Therefore, the above problem can be determined from the value of the driving torque. Here, if the drive torque at this time is equal to or greater than a predetermined value, it is determined that the assembly is defective or incorrectly assembled,
Repeat the above assembly.

On the other hand, if it is confirmed that the drive torque is at an appropriate value and the assembly is performed properly, the cover 17 is placed on the upper surface of the housing 16 as shown in FIG. With 18, the sprocket 15, the housing 16 and the cover 17 are fastened and fixed. Thus, the inner rotor 12 is temporarily fixed between the cover 17 and the sprocket 15 in a state where the inner rotor 12 is aligned with the housing 16.

The above procedure completes the assembly of the variable valve timing mechanism. The variable valve timing mechanism assembled in this manner is then replaced with the center bolt 14
As a result, it is mounted on the camshaft 11 of the internal combustion engine (FIG. 9).

According to the method of assembling the variable valve timing mechanism of the present embodiment described above, many excellent effects listed below can be obtained. (1) By using the biasing force of the leaf spring 29 provided in the variable valve timing mechanism, the axis of the internal rotor 12 and the axis of the housing 16 are autonomously made to coincide with each other. The wicking can be performed easily and reliably.

(2) A leaf spring 2 originally provided in the variable valve timing mechanism for sealing hydraulic oil.
Since 9 is used for the above-described alignment, it is not necessary to add a new structure, member, or the like for the alignment.

(3) Regarding the outer diameter of the housing 16 which is not directly used for the alignment, it is not necessary to increase the height of the housing 16 or the precision, so that it is possible to suppress an increase in processing cost and processing steps.

(4) After assembling, the internal rotor 12 and the housing 16 are relatively rotated, and the driving torque is measured, so that an assembling failure or an erroneous assembling can be detected easily and accurately.

The above embodiment can be implemented by changing the procedure or the configuration of the variable valve timing mechanism to be assembled as follows. In the above embodiment, the housing 16 is fixed, and the internal rotor 12 is rotated to determine the assembly failure. However, the determination may be performed by fixing the internal rotor 12 and rotating the housing 16.

The seal member 28 and the leaf spring 29 may be provided on only one of the vane 13 and the projection 20. The urging member for urging the seal member 28 is not limited to the leaf spring 29. As long as the seal member 28 can be urged in the radial direction of the axis, the member may be changed to, for example, an elastic body such as a coil spring or rubber, or a member urged based on fluid pressure, magnetic force, or the like. Further, the seal member 28 itself may be made of an elastic member such as rubber, and may press the rotating body on the other side by using its own elastic force as an urging force. In this case, the configuration is such that the seal member also functions as a biasing member. Even in the case of such a change, the centering can be performed autonomously by the urging force of the urging member.

Also, the inner rotor 12 or the housing 16 can slide the vanes 13 and the protrusions 20 in the radial direction.
, And these may be pressed by a biasing member against a rotating body on the other side. In this case, the configuration is such that the vanes and the convex portions also serve as the sealing member. Even in the case of such a change, the centering can be performed autonomously by the urging force of the urging member.

In the above embodiment, after alignment, it is determined whether the assembly is defective or erroneous, based on the sliding resistance of the relative rotation, and then the sprocket 15, the housing 16, and the cover 17 are fastened with the mounting bolts 18. However, the determination of the improper assembling or the erroneous assembling may be performed at any time after the alignment, or may be performed after the bolt 18 is fastened. In this case, it is possible to obtain the effects according to the effects (1) to (3) as well as the effect (4).

In the above embodiment, the autonomous centering by the urging force of the leaf spring 29, the internal rotor 12 and the housing 1
Although the determination of the improper assembly or the erroneous assembly based on the relative rotation with respect to 6 is continuously performed, these steps may be performed separately.

When the autonomous alignment is performed by the urging force of the urging member, the holding shaft 42 is simply
What is necessary is just to hold and fix the position of the axis center of the internal rotor 12, and does not need to be able to rotate integrally with the internal rotor 12. In this case, the housing 16 may be fixed, and the axis of the inner rotor 12 may be freely moved to perform autonomous centering by the urging force of the urging member. In this case, the same effects as the effects (1) to (3) can be obtained.

On the other hand, when it is determined that the assembly is defective or erroneous based on the relative rotation, the variable valve timing mechanism without the seal member 28 and the leaf spring 29 (biasing member) is also required. Can be applied. Also in this case, the same effect as the above (4) can be obtained.

In this embodiment, the case where the assembling method according to the present invention is applied to the variable valve timing mechanism in which the inner rotor 12 has four vanes 13 has been described. However, the variable valve timing mechanism having three or less vanes or five or more vanes is described. The present invention can be similarly applied to a valve timing mechanism.

Also, in the present embodiment, the present invention is applied to a so-called vane type variable valve timing mechanism in which the valve timing is made variable based on hydraulic control introduced into pressure chambers 21 and 22 provided on both sides of the vane 13. Although the case where the assembling method according to the present invention is applied has been described, the variable valve timing mechanism of another type is also housed in a housing that is drivingly connected to one and the other of the engine output shaft and the camshaft and the housing. If the variable valve timing mechanism includes an internal rotor, the autonomous alignment based on the urging force of the urging member for urging the internal rotor in the radial direction of the housing, or the relative rotation between the housing and the internal rotor It is possible to apply the determination of the improper or incorrect assembly based on the rotation torque at the time.

The technical ideas other than those described in the claims understood from the above-described embodiments of the present invention will be described below together with their effects. (1) A housing which has the same rotation axis and is drivingly connected to one and the other of an output shaft of an internal combustion engine and a camshaft for driving a valve of the engine to open and close, and an internal rotor housed in the housing. A variable valve timing mechanism for varying the valve timing of an engine valve that is opened and closed by the camshaft based on a change in the relative rotational phase of the housing and the internal rotor, wherein the internal rotor is assembled to the housing. Then, the centered housing and the internal rotor are relatively rotated, and a defective or incorrect assembly between the housing and the internal rotor is determined according to a rotation torque at the time of the relative rotation. How to assemble the variable valve timing mechanism.

According to the above method, the housing and the internal rotor are relatively rotated, and the determination is made in accordance with the rotation torque, whereby it is possible to easily and appropriately detect a defective assembly or a wrong assembly. Further, the detection can be performed even when the state of the internal rotor and the housing cannot be directly grasped.

[0060]

[0061]

[0062]

[0063]

According to the invention described in 請 Motomeko 1 according to the present invention, assembled with them housing and the inner rotor in the state centering or, which is the alignment between the housing and the inner rotor based on the biasing force of the biasing member Can be easily and appropriately performed.

According to the second aspect of the present invention, the housing is clamped from the side while being pressed from the upper surface by the upper clamp, so that the housing can be fixed and held while preventing displacement of the axis. Since the upper surface can be opened and the upper surface thereof can be opened, the axial center of the housing can be easily and reliably fixed and held, and the assembling work of the housing and the internal rotor performed thereafter can be easily performed.

According to the third aspect of the present invention, the assembly can be easily performed by autonomously adjusting the center by the urging force of the urging member. By detecting the assembling, the assembling accuracy can be improved.

[0066]

[Brief description of the drawings]

FIG. 1 is a plan view showing the configuration of an apparatus for assembling a variable valve timing mechanism.

FIG. 2 is a side sectional view showing the configuration of the apparatus.

FIG. 3 is a sectional view showing an assembling procedure of the variable valve timing mechanism.

FIG. 4 is a sectional view showing a procedure for assembling the variable valve timing mechanism.

FIG. 5 is a sectional view showing an assembling procedure of the variable valve timing mechanism.

FIG. 6 is a sectional view showing the procedure for assembling the variable valve timing mechanism.

FIG. 7 is a sectional view showing an assembling procedure of the variable valve timing mechanism.

FIG. 8 is a sectional view showing a front sectional structure of the variable valve timing mechanism.

FIG. 9 is a sectional view showing a sectional structure along line VIII-VIII in FIG. 8;

FIG. 10 is a perspective view showing an exploded perspective structure of a variable valve timing mechanism.

[Explanation of symbols]

11 camshaft, 12 internal rotor, 13 vane, 15 sprocket, 16 housing, 17 cover, 18 mounting bolt, 19 concave, 20 convex, 21 pressure chamber, 22 pressure chamber, 28 ... Seal member,
29: leaf spring, 41: base, 42: holding shaft, 43: natural clamp, 44: upper clamp, 45: drive unit, 46: torque measuring instrument.

Claims (3)

(57) [Claims] 1. A within a housing which is drivingly connected to one of the camshaft for opening and closing the valve of the output shaft and the engine combustion engine, the same rotation axis and which in the housing
And housed in the other of the output shaft and the camshaft.
Together and an internal rotor which is drivingly connected, to form a pressure chamber on the side of the vane by partitioning by said formed a plurality of recesses formed radially inside the housing to the internal rotor vanes, said A variable valve timing mechanism that relatively rotates the housing and the internal rotor based on pressure control of the formed pressure chamber to vary valve timing of an engine valve that is opened and closed by the camshaft; A step of fitting a mounting shaft of the internal rotor to the camshaft into a holding shaft vertically held in the base, and fixing the internal rotor horizontally on the base; The housing is mounted on the internal rotor fixed to the inner rotor, and a gap between the bottom of the recess and the tip of the vane is provided. A sealing member for sealing a pressure leak between the pressure chambers at at least one between a tip end of the concave portion and a base circle portion of the internal rotor, and an urging member for urging the sealing member against an opposing wall surface Attaching the housing and the internal rotor autonomously based on the urging force of the urging member; fixing and holding the housing on the base in the aligned state; And assembling the internal rotor with the variable valve timing mechanism. 2. When the centered housing is fixedly held on the base, (1) a step of pressing the housing from above on the base with an upper clamp, and (2) pressing from the top of the housing. a step of sandwiching from the side surface of the housing at Natural clamped state, (3) a method of assembling of claim 1, wherein the variable valve timing mechanism, wherein the step of releasing the pressing by the upper clamp, the sequential execution. 3. A method of assembling of the variable valve timing mechanism according to claim 1 or 2 wherein, while fixing holding the housing on the base, the housing being the alignment by rotating the holding shaft and The variable valve timing mechanism further comprising a step of relatively rotating the internal rotor, and determining a defective or incorrect assembly between the housing and the internal rotor according to the rotational torque at the time of the relative rotation. Assembly method.