JPH09112222A - Valve timing controller for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the reduction of a whole cost by lightening members and simplifying a joint system during an assembly period. SOLUTION: A rotary timing pulley 1 rotatively driven by an engine, is equipped with a front cover 3 which has a cylindrical main body 1a and a gear 1b arranged along the periphery of the cylindrical main body 1a, and by which an opening 1e at the end of the cylindrical main body 1a is oil-tightly sealed, and a rear cover 7 by which an opening at the other end of the cylindrical main body 1a is oiltightly sealed. The front cover 3 and the rear cover 7 are respectively formed by press molding, one circumferential end 3a of the front cover 3 is pressed into or fixed by caulking to the opening 1e at one end of the cylindrical main body 1a, and the other circumferential end 7b of the rear cover 7 is pressed into or fixed by caulking to the opening at the other end of the cylindrical main body 1a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing control device for variably controlling the opening / closing timing of intake / exhaust valves according to the operating state of an engine.

[0002]

2. Description of the Related Art As is well known, a valve timing control device for an internal combustion engine has a rotating body to which a rotational force is transmitted from a crankshaft of the engine through a timing chain or a timing belt. It consists of a tubular body formed by forging and a gear part, and the gear part by a sprocket or pulley is integrally formed on the outer periphery of the tubular body or is joined to an opening at one end of the tubular body. . Further, it has a cam shaft provided on the outer periphery with a cam for opening the intake valve by the rotational force from the rotating body. One end of the cam shaft is inserted into the cylindrical body coaxially with the rotating body. doing. Further, between the rotating body and the cam shaft, there is provided a cylindrical gear that is a phase converting means for converting the relative rotational phase between the rotating body and the cam shaft by moving in the cam shaft axial direction.

On the other hand, in the rotating body, a front cover and a rear cover, such as a casting, which seals the openings at the front end, which is one end of the cylindrical body, and the rear end, which is the other end, in an oil-tight manner, are made of bolts, screws, or the like. They are connected by fastening means. In the case of a rear cover, one end of the rear cover is coupled using the gear portion, and the rear cover is relatively rotatably fitted to the outer periphery of the cam shaft and compresses and biases the tubular gear that moves by operating hydraulic pressure from the rear side. Holds the spring. (Japanese Patent Laid-Open No. 61-
(268810 publication)

[0004]

By the way, in such a conventional device, since the front cover and the rear cover are both formed by casting or forging, the weight of the entire device is increased and the bolts are increased. Since they are connected by using a fastening means such as a screw or a screw, mechanical processing such as drilling a screw hole is required as a post-processing, which is one of the causes of the increase in manufacturing cost.

An object of the present invention is to realize a reduction in overall cost by reducing the weight of members and simplifying the coupling method during assembly.

[0006]

The present invention has been devised in view of the above-mentioned problems of the prior art. The invention of claim 1 is rotationally driven by an engine to form a cylindrical main body and the cylindrical main body. A cam having a rotating body having a gear portion provided on the outer periphery, and a cam having one end inserted coaxially inside the cylindrical main body to operate an intake / exhaust valve by a rotational force from the rotating body on the outer periphery. A shaft, and a phase conversion means that is interposed between the rotating body and the camshaft, and that converts a relative rotational phase between the rotating body and the camshaft with movement in the camshaft axial direction according to the engine operating state, In a valve timing control device for an internal combustion engine, comprising: a front cover that oil-tightly seals an opening at one end of the tubular body; and a rear cover that is coupled to the opening at the other end of the tubular body. The front cover and the rear The bars are respectively formed by press molding, the peripheral end of the front cover is press-fitted into the opening at one end of the tubular body, and the peripheral end of the rear cover is press-fitted into the opening at the other end of the tubular body. It is characterized by

According to a second aspect of the present invention, the peripheral end portion of the front cover is caulked and fixed to the opening portion at one end of the tubular body, while the peripheral end portion of the rear cover is opened at the other end of the tubular body. It is characterized by being caulked and fixed to the part.

Further, in the invention of claim 3, the front cover and the rear cover are respectively formed to extend to a connecting wall connecting the cylindrical main body and the gear portion, and the connecting wall is provided with the front cover and the front cover. It is characterized in that the rear cover and the rear cover are fastened together.

Therefore, according to the first aspect of the invention, in the tubular main body of the rotating body, both the front cover and the rear cover coupled to the openings at the one end and the other end in the axial direction can be easily worked by press molding. The weight is reduced, and the conventional bolts, screws, etc. are not required for joining, and it is possible to join by press fitting.

According to the invention of claim 2, instead of the press-fitting method of claim 1, the connection can be made by caulking.

Further, according to the invention of claim 3, one end of each of the front cover and the rear cover is extended and formed to a connecting wall for connecting the cylindrical main body of the rotating body and the gear portion, respectively. The front cover and the rear cover can be tightened from both sides of the pin, and the number of joints can be reduced accordingly.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. The apparatus has a timing pulley 1 which is a rotating body to which a rotational force is transmitted from a crankshaft of an engine via a timing belt (not shown). This timing pulley 1 has a cylindrical body 1a.
And the timing belt is wound around the tubular body 1
Gear part 1 connected by a connecting wall 1d on the outer periphery of a
b, and has a front cover 3 and a rear cover 5 which are respectively coupled to one end and the other end of the cylindrical main body 1a.

Further, the camshaft 2 has a camshaft 2 provided on the outer circumference with a cam for opening the intake valve by the rotational force from the timing pulley 1, and the camshaft 2 has a cylindrical sleeve 8 connected to one end thereof. It is inserted coaxially with the timing pulley 1 through the inside of the cylindrical main body 1a.

Further, between the timing pulley 1 and the cam shaft, there is a phase conversion means for converting the relative rotational phase of the timing pulley 1 and the cam shaft 2 by moving in the cam shaft axial direction on these axes. The tubular gear 9 is interposed. The tubular gear 9 is composed of a front gear forming portion 9a and a rear gear forming portion 9b which are divided into two parts in a direction perpendicular to the axis, and helical gears formed on inner and outer peripheral surfaces of both gear forming portions 9a and 9b are The helical inner teeth 1c formed on the inner peripheral surface of the cylindrical main body 1a are meshed with the helical outer teeth 8a formed on the outer peripheral surface of the sleeve 8.
Further, both gear component parts 9a and 9b are connected while being biased in a direction toward each other via a connecting pin 10 and a coil spring 11 in order to absorb a backlash clearance.

In this cylindrical gear 9, hydraulic oil from an oil pump (not shown) acts on the front gear component 9a from the left side in the figure via a pressure chamber provided in the hydraulic pressure supply circuit. A compression spring 13 is pressed and urged from the rear of the side gear component 9b via a piston 12. The volume of the pressure chamber increases or decreases in the axial direction according to the amount of hydraulic oil from the hydraulic pressure supply circuit that changes according to the operating state, and the relative pressure between the oil pressure supplied to the pressure chamber and the spring force of the compression spring 13 The gear wheel 9 can move in the left-right axis direction in the figure. The movement of the cylindrical gear 9 converts the relative rotational phase between the timing pulley 1 and the cam shaft 2.

Here, in the cylindrical main body 1a of the timing pulley 1, a disc-shaped front cover 3 is fixed by press fitting into an opening 1e at the left front end in the figure which is one end thereof. The front cover 3 is formed by press-forming a steel plate or the like, and the opening 1e is oil-tightly sealed by a flange portion 3a provided along a disk-shaped peripheral edge.
A circular mounting hole 3b is provided at the center of the disc. The mounting hole 3b is for incorporating a coupling bolt 14 that connects the sleeve 8 to one end of the camshaft 2. After the assembly, it is closed with a stopper plug 4.

At the rear end on the right side in the figure, which is the other end of the tubular body 1a, a tubular extension member 5 is provided on a connecting wall 1d with the gear portion 1b, and a bolt screw 6 is formed at a flange portion 5b at one end of the body portion 5a. The oil tightness is secured through the O-ring 80. The extension member 5 can be considered as an extension of the tubular main body 1a, and is provided to secure a reciprocating stroke of the piston 12 and a storage space for the compression spring 13.

In the rear end opening 5c of the body portion 5a of the extension member 5 thus combined as an extension portion of the tubular body 1a, a tubular rear cover 7 is fixed by press fitting. This rear cover 7 is also formed by pressing a steel plate or the like, and is press-fitted into the inner peripheral surface of the rear end opening 5c of the extension member 5 by a flange portion 7b formed by bending the U-shaped portion at one end of the body portion 7a. The rear end opening 5c is oil-tightly sealed. The rear cover 7 holds the compression spring 13 in contact with the side surface of the flange portion 7b, and the body portion 7a is relatively rotatably fitted to the outer peripheral surface of the camshaft 2.

In the above embodiment, the only member formed by casting is the timing pulley 1 having the cylindrical main body 1a and the gear portion 1b. Since both the flange cover 3 and the rear cover 7 are formed by press molding, it is possible to adopt a coupling method by press fitting to the cylindrical main body 1a, and it is possible to use fastening means such as bolts and screws as in the conventional case. There is nothing, and there is no need for machining such as pre-drilling and screw hole processing for fastening. Therefore, the manufacturing cost such as the processing cost and the assembly cost of the flange cover 3 and the rear cover 7 is greatly reduced, and the thickness of the press cover is thinned, so that the entire apparatus is considerably reduced.

Next, the operation mode and operation of the above-mentioned structure will be briefly described. For example, in the low engine load range,
An OFF signal (non-energized) is output from the controller to the stepping motor, and most of the hydraulic oil supplied from the oil pump to the pressure chamber via the hydraulic pressure supply passage is discharged to the outside through the drain hole. Therefore, the pressure chamber becomes a low pressure state, and the tubular gear 9 is biased to the maximum forward position (the leftward position in the drawing) by the spring force of the compression spring 13. As a result, the timing pulley 1 and the cam shaft 2 are held at the maximum relative rotational angle position on one side, and the intake valve closing timing is controlled by the maximum retard angle, for example.

When the engine operation shifts to the high load range,
The pressure chamber is sealed and the internal hydraulic pressure is maximized.
Therefore, the piston 12 moves to the right in the figure and pushes the tubular gear 9 to the maximum right. Therefore, the relative rotation angle of the timing pulley 1 and the camshaft 2 is converted to the other side to the maximum, and the closing timing of the intake valve is controlled to the maximum advance side.

In the above embodiment, the front cover 3 and the rear cover 7 which are press-molded in the illustrated shape are shown, but the present invention is not limited to this, and is shown in each of FIGS. 2 and 3 below. The second and third embodiments are also possible. The same members as those of the members shown in the first embodiment of FIG. 1 or the same members will be described with the same members.

First, in the second embodiment shown in FIG.
Instead of the press-fitting front cover 3 and rear cover 7 of the first embodiment, a caulking front cover 20 and rear cover 30 are used, and both of these members are press-molded. Front cover 20
Is caulked and fixed at its peripheral end 21 to an annular caulking groove 1f provided on the inner periphery of the front end opening of the cylindrical body 1a. Further, in the case of the rear cover 30, its peripheral end portion 31
At, the cylindrical body 1a is caulked and fixed to the extension member 5 of the extension portion coupled in the axial direction. That is, an annular caulking groove 5c is provided on the inner periphery of the rear end portion of the body portion 5a of the extension member 5, and the rear cover 30 is caulked at the peripheral end portion 31 therein. The body 32 of the rear cover 30 is fitted to the outer peripheral surface of the camshaft 2 so as to be relatively rotatable.

In the case of the third embodiment shown in FIG. 3, the front cover 40 and the rear cover 50, which are fastened together here, are utilized by utilizing the connecting wall 1d for connecting the cylindrical main body 1a and the gear portion 1b. It is provided. In the case of the front cover 40, a body portion 41 that extends completely up to the connecting wall 1d is formed by completely pressing the outer periphery of the cylindrical body 1a by press molding, and a flange that extends like a collar at the rear end of the body portion 41. Part 4
2 are formed. In this flange portion 42, rivets 60 are fixed by caulking to the outer surface of the connecting wall 1d via an O-ring 81 while ensuring oil tightness. Rivets 6
It is of course possible to use bolt connection instead of 0.

In the case of the rear cover 50, the first
Also, the extension member 5 and the rear cover 7 (or 30) shown in the second embodiment are integrated. That is, the rear cover 50 has a body portion 51, a spring holding portion 52, an extension body portion 53, and a flange portion 54 enlarged in a flange shape, and is press-molded. In the flange portion 54, O is formed on the inner surface of the connecting wall 1d.
It is caulked and secured with oil tightness via the ring 82,
The front cover 40 and the rivets 60 are fastened together as one body from both sides with the connecting wall 1d interposed therebetween. Body 51
Is rotatably fitted to the outer peripheral surface of the camshaft 2 and receives and holds one end of the compression spring 13 on the surface of the spring holding portion 52.

In the third embodiment, the rear cover 5
Retainer bush 7 that is in contact with the spring retaining portion 52 of No. 0
0 is provided, and this retainer bush 70 holds the compression spring 13 by its flange portion 71 as a member that assists the rear cover 50. Further, as is clear from the above, the front cover 40 and the rear cover 50 are connected to the rivet 6 by utilizing the connecting wall 1d on the timing pulley 1 side.
Since the structure is crimped into three bodies by 0, the first
Further, there is an advantage that the connecting portion by press fitting or caulking shown in the second embodiment can be reduced.

[0028]

As is apparent from the above description, claim 1
According to the invention, by forming both the front cover and the rear cover, which are coupled to the openings at the one end and the other end in the axial direction of the cylindrical main body of the rotating body, by press molding,
Compared to conventional casting and forging, it is easier to manufacture and can be made lighter in weight, does not require conventional bolts and screws, and is press-fitted or joined by caulking as in the invention of claim 2,
Overall, the manufacturing cost can be reduced.

According to the third aspect of the present invention, the front cover and the rear cover are fastened together by caulking or the like by utilizing the connecting wall between the cylindrical main body of the rotating body and the gear portion. It is possible to reduce the cost and further reduce the cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a main part showing a second embodiment.

FIG. 3 is a longitudinal sectional view of a main part showing a third embodiment.

[Explanation of symbols]

 1 ... Timing pulley 2 ... Cam shaft 3, 20, 40 ... Front cover 5 ... Extension member 7, 30, 50 ... Rear cover

Claims (3)

[Claims] 1. A rotating body which is rotationally driven by an engine and has a tubular body and a gear portion provided on the outer periphery of the tubular body, and one end of which is coaxially inserted into the tubular body. A camshaft having a cam on its outer periphery for operating the intake and exhaust valves by the rotational force from the rotating body, and the camshaft, which is interposed between the rotating body and the camshaft, moves in the camshaft axial direction according to the engine operating state. Along with the above, phase conversion means for converting the relative rotational phase between the rotating body and the cam shaft, a front cover for oil-tightly sealing the opening at one end of the tubular body, and an opening at the other end of the tubular body. A rear cover connected to the
In the valve timing control device for an internal combustion engine, the front cover and the rear cover are each formed by press molding, and a peripheral end portion of the front cover is press-fitted into an opening portion of one end of the tubular main body, A valve timing control device for an internal combustion engine, wherein a peripheral end portion is press-fitted into an opening portion at the other end of the tubular body. 2. A peripheral end portion of the front cover is crimped and fixed to an opening portion at one end of the tubular body, while a peripheral end portion of the rear cover is crimped and fixed to an opening portion at the other end of the tubular body. The valve timing control device for an internal combustion engine according to claim 1, wherein 3. The front cover and the rear cover are formed to extend to a connecting wall that connects the tubular body and the gear portion, respectively, and the front cover and the rear cover are joined to the connecting wall by co-fastening. The valve timing control device for an internal combustion engine according to claim 1, wherein the valve timing control device is provided.