JPH05272316A - Engine valve timing control device - Google Patents

Abstract

PURPOSE:To provide an engine valve timing control device by which the valve timing can be set precisely according to an engine operating condition and engine output torque can be increased uniformly over a wide rotation area. CONSTITUTION:A valve timing control device 27, which transmits rotation of an air intake side timing pulley 23 to an air intake side cam shaft 21 and switches their rotational phases to/from each other, is provided in an engine CE. In this valve timing control device 27, an approximately cylindrical hollow outer member 31, the first and the second approximately ring shape helical pistons 32 and 33 and an approximately cylindrical inner member 29 are arranged in this order acdjacently to each other in concentrically circular form toward the inside from the diametrical directional outside. Supply/discharge conditions of an oil pressure to the first and the second helical pistons 32 and 33 are switched to/from each other by a hydraulic means A, so that rotational phases to the air intake side timing pulley 23 of the air intake side cam shaft 21 can be switched in four stages of 0 deg., 10 deg., 20 deg. and 30 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine valve timing control device.

[0002]

2. Description of the Related Art Generally, an engine is provided with a valve mechanism (valve mechanism) for opening and closing an intake valve or an exhaust valve at a predetermined timing. And in an engine equipped with such a valve mechanism, the optimum opening / closing timing of the intake valve or the exhaust valve depends on the operating state of the engine,
For example, it changes according to the engine speed, engine load, and the like. Therefore, various valve timing control devices that change the opening / closing timing of the intake valve or the exhaust valve according to the operating state of the engine have been proposed.

An engine provided with an intake side camshaft and an exhaust side camshaft separately, for example, a DOH
In the C engine, a valve timing control device is often used in which the opening / closing timing of the intake valve or the exhaust valve is changed by changing the rotational phase of the intake camshaft or the exhaust camshaft.
As one of such valve timing control devices, a valve timing control device using a hydraulic helical piston has been conventionally known (for example, the actual opening 1-113).
111, Japanese Utility Model Publication No. 2-54307).

In the conventional valve timing control device using such a hydraulic helical piston, a hollow substantially cylindrical outer member having inner teeth formed on its inner peripheral portion is usually connected to a timing pulley, and is connected to a camshaft. And a substantially cylindrical inner member having outer teeth formed on its outer peripheral portion, an outer gear meshing with the inner teeth is formed on the outer peripheral surface, and an inner gear meshing with the outer teeth is formed on the inner peripheral surface. The helical piston of is arranged. Here, at least one of a gear set in which the inner teeth of the outer member mesh with the outer gear or a gear set in which the outer teeth of the inner member mesh with the inner gear is a helical gear set that causes relative rotation by relative displacement in the axial direction. It Further, a hydraulic means for displacing the helical piston in the camshaft axial direction by an on / off operation is provided, and when hydraulic pressure is applied to the helical piston by this hydraulic means, the helical piston is displaced in the camshaft axial direction. Then, relative rotation is generated between the outer member and the inner member, the rotation phase between the timing pulley and the cam shaft is changed, and the opening / closing timing of the intake valve or the exhaust valve is switched.

[0005]

By the way, in a conventional engine provided with such a valve timing control device for the intake side camshaft, for example, a medium-sized engine is usually used.
In the high speed range, the hydraulic pressure of the helical piston is released,
The intake valve opening / closing timing is in a predetermined basic state (advance angle 0)
On the other hand, in the low speed range, hydraulic pressure is applied to the helical piston to advance the valve opening / closing timing by a predetermined value (for example, at a crank angle of 30
°). However, when the opening / closing timing of the intake valve is switched in this manner, the maximum output torque of the engine is kept high in the high speed region and the low speed region, respectively, but the maximum output torque drops in the intermediate region between them, that is, in the medium speed region. There is a problem that a so-called torque valley is generated. The present invention has been made to solve the above-mentioned conventional problems, and it is possible to uniformly increase the maximum output torque of the engine over a wide rotation range and prevent the occurrence of torque troughs. An object is to provide a valve timing control device.

[0006]

To achieve the above object, the first invention is a substantially ring-shaped helical gear having an outer gear on the outer peripheral surface and an inner gear on the inner peripheral surface, at least one of which is a helical gear. With a piston,
A hollow, substantially cylindrical outer member, which is rotationally driven by a crankshaft and has inner teeth that mesh with the outer gear of the helical piston on the inner periphery, and external teeth that are connected to the camshaft and mesh with the inner gear of the helical piston on the outer periphery. Urging for switching valve timing by changing the rotational phase between the outer member and the inner member by displacing the substantially cylindrical inner member provided with and the helical piston in the camshaft axial direction by on / off operation. In a valve timing control device for an engine provided with means, a plurality of sets of helical pistons and biasing means for operating the helical pistons are provided between the outer member and the inner member, and the operation of these helical pistons is provided. Helical piston control that switches the valve timing in multiple stages by switching the state Means to provide a valve timing control apparatus for an engine, characterized in that is provided.

According to a second aspect of the invention, in the engine valve timing control device according to the first aspect of the invention, the helical pistons are arranged concentrically adjacent to each other in the radial direction in the hollow portion of the outer member, and in the radial direction. The inner member is arranged in the hollow portion of the innermost helical piston, the inner teeth of the outer member mesh with the outer gear of the radially outermost helical piston, and the two adjacent helical pistons have a radially outer helical gear. (EN) Provided is a valve timing control device for an engine, characterized in that an inner gear of a piston meshes with an outer gear of a helical piston radially inside, and an inner gear of a helical piston radially innermost meshes with outer teeth of an inner member. ..

According to a third aspect of the invention, in the valve timing control device for an engine according to the second aspect, only two helical pistons are provided, the helical piston arranged on the radially outer side and the other helical piston. Provided is a valve timing control device for an engine, wherein a piston and a piston are arranged so as to face each other so that the directions in which hydraulic pressure is applied are opposite to each other.

According to a fourth aspect of the present invention, in the engine valve timing control device according to the third aspect, the helical piston control means is arranged radially outward when the valve timing is switched from the basic state to the predetermined state. A valve timing control device for an engine, wherein the first-stage switching operation is performed by operating the helical piston.

According to a fifth aspect of the present invention, in the engine valve timing control device according to the third or fourth aspect of the invention, the first stage switching operation is performed when the valve timing is switched from the basic state to a predetermined state. A valve timing control device for an engine, wherein a rotational phase conversion angle of a helical piston is set to be smaller than a rotational phase conversion angle of another helical piston.

According to a sixth aspect of the present invention, in the engine valve timing control device according to the third or the fourth aspect of the present invention, when the valve timing is switched from the basic state to the predetermined state, the switching operation is performed in the first stage. A valve timing control device for an engine, characterized in that the helical piston is formed so as to receive hydraulic pressure from the outside of the engine, and the other helical piston is formed so as to receive hydraulic pressure from the inside of the engine. provide.

According to a seventh aspect of the invention, in the valve timing control device for an engine according to the sixth aspect, when the valve timing is switched from the basic state to a predetermined state, the helical piston that performs the switching operation in the first stage is , Is formed so that hydraulic oil is supplied from the outside of the engine,
Provided is a valve timing control device for an engine, wherein the other helical piston is formed so that hydraulic oil is supplied from the inside of the engine.

According to an eighth aspect of the present invention, in the engine valve timing control device according to the second aspect of the present invention, a return spring is provided for returning each helical piston to its basic position when the hydraulic oil is released. (EN) Provided is a valve timing control device for an engine, wherein an end of the spring, which is not in contact with the helical piston, is fixed to the outer member side.

[0014]

EXAMPLES Examples of the present invention will be specifically described below.
As shown in FIG. 2, the engine CE draws the air-fuel mixture from the intake port 2 into the combustion chamber 3 when the intake valve 1 is opened, and compresses the air-fuel mixture with the piston 4 to spark plug.
Ignition / combustion is performed (not shown), and when the exhaust valve 5 is opened, the combustion gas is discharged to the exhaust passage 7 via the exhaust port 6. Along with this, the piston 4 reciprocates in the cylinder axis direction, and the reciprocating motion of the piston 4 is rotated by the connecting rod 8, the crank pin (not shown) and the crank arm (not shown). It is adapted to be transmitted to the crankshaft 9 while being converted.

In order to supply air to the engine CE, an intake passage 11 communicating with the intake port 2 is provided, and the intake passage 11 has an accelerator pedal (not shown).
A throttle valve 12 that is opened and closed in conjunction with is interposed. Further, a fuel injection valve 13 that injects fuel into the air is provided facing the intake passage 11 on the downstream side of the throttle valve 12.

A spring 16 is provided at the upper end of the intake valve 1.
Is engaged with the peripheral surface (cam surface) of the intake side cam 15 via the HLA 14. And intake valve 1
Is basically opened and closed by the intake side cam 15 at a predetermined timing in synchronization with the crankshaft 9. Similarly, the upper end portion of the exhaust valve 5 is urged by the spring 19 and is passed through the HLA 17 to the exhaust side cam 1
8 is engaged with the peripheral surface. The exhaust valve 5 is opened and closed by the exhaust cam 18 at a predetermined timing in synchronization with the crankshaft 9.

The intake side cam 15 is the intake side camshaft 21.
The exhaust side cam 18 is attached to the exhaust side cam shaft 22. The intake-side camshaft 21 has a valve timing control device 27 which will be described later.
Via the intake side timing pulley 23, while the exhaust side camshaft 22 is connected to the exhaust side timing pulley 2
It is connected to 4. A crank pulley 25 is coaxially attached to the crankshaft 9, and a timing belt 26 is wound around the crank pulley 25, the intake side timing pulley 23, and the exhaust side timing pulley 24, and both timing pulleys 23, 24 are It is adapted to be driven by the crankshaft 9.

As described above, the intake side camshaft 21
Between the intake side timing pulley 23 and the intake side timing pulley 23, a hydraulic helical piston type valve timing control device 27 that switches the opening / closing timing of the intake valve 1 in four stages is provided. Next, the valve timing control device 27 will be described in detail with reference to FIGS. 1, 3, and 4. However, for convenience sake, the leftward direction in FIGS. 1 and 4 is simply referred to as “front” because it is the front side of the engine. , The right direction is simply called "rear". Further, the radially outer side of the substantially columnar valve timing control device 27 or the intake side camshaft 21 is simply referred to as “outer side”, and the radially inner side is simply referred to as “inner side”.

As shown in FIG. 1, the valve timing control device 27 includes a substantially cylindrical inner member 29 substantially coaxially attached to the front end portion of the intake camshaft 21 by using an attachment bolt 30. An outer member 31 having a hollow cylindrical shape and connected to the intake side timing pulley 23, and an outer member 3
1 and the inner member 29, the hydraulic type 1st and 2nd helical pistons 32 and 33, which are arranged in a substantially annular space, and the hydraulic pressure for supplying and discharging hydraulic oil to and from the 1st and 2nd helical pistons. And means A. Since only the intake side will be substantially described below, the intake side camshaft 21 is simply referred to as the "camshaft 21" and the intake side timing pulley 23 is simply referred to as the "timing pulley 23" unless otherwise required. That.

The valve timing control device 27 transmits the rotation of the timing pulley 23 to the camshaft 21 through the outer member 31, the first helical piston 32, the second helical piston 33 and the inner member 29 in this order.
By the hydraulic means A, the first and second helical pistons 32, 3
3 changes the hydraulic pressure supply / discharge pattern to change the rotation phase between the outer member 31 (timing pulley 23) and the inner member 29 (camshaft 21) to open / close the intake valve 1 (see FIG. 2). The timing is switched in 4 steps.

The outer member 31 is an assembly having a hollow and generally cylindrical shape as a whole, and is substantially formed into a substantially cylindrical outer cylinder portion 31b which constitutes a main body thereof and a rear end portion of the outer cylinder portion 31b. It is composed of a support portion 31c attached and rotatably supported by the cylinder head 28. And the outer cylinder part 3
A timing pulley 23 is attached to the outer peripheral portion of 1b, and helical inner teeth 31a (helical teeth) having a predetermined inclination are formed on the other inner peripheral portion.

The hydraulic first helical piston 32 is formed in a substantially ring shape and is concentrically housed in the hollow portion of the outer member 31. Then, the first helical piston 32
A helical first outer gear 32a that meshes with the inner teeth 31a of the outer member 31 is formed on the outer peripheral surface of the, while the helical first inner gear 3 having a predetermined inclination is formed on the inner peripheral surface.
2b is formed. This first helical piston 32
Is fitted into the first hydraulic chamber 35 formed in the outer member 31 (outer cylinder portion 31b) such that the surface to which hydraulic pressure is applied (pressure receiving surface) is located on the front side. A first return spring 36 that constantly biases the first helical piston 32 in a forward direction is provided. The rear end portion of the first return spring 36 is fixed to the outer member 31 (support portion 31c) in order to prevent vibration or rattling noise due to backlash.

Here, the first helical piston 32 has the first helical piston 32 when the hydraulic pressure is not applied to the first hydraulic chamber 35.
The return spring 36 is held in the basic position by the urging force (FIG. 1 shows this state), and the first hydraulic chamber 35
When the hydraulic pressure is applied to the inside, the hydraulic pressure causes the first return spring 36 to withdraw to a predetermined position against the urging force of the first return spring 36, and when the hydraulic pressure is released, the first return spring 36 returns the basic position. ing. That is, the first helical piston 32 is binary in the front-rear direction (camshaft axis direction) corresponding to the supply and discharge of hydraulic pressure.
Displaces (on / off).

The hydraulic second helical piston 33 has a smaller diameter than the first helical piston 32 and is formed in a substantially ring shape, and is concentrically housed in the hollow portion of the first helical piston 32. And the second helical piston 33
The outer peripheral surface of the second helical outer gear 33a meshes with the first inner gear 32b of the first helical piston 32.
And a helical second inner gear 33b having a predetermined inclination is formed on the other inner peripheral surface. The second helical piston 33 is arranged so that the pressure receiving surface is located on the rear side, that is, the first helical piston 32 faces the axial direction of the camshaft, and the outer member 31 (support portion 31c) and the inner member 29 are connected to each other. It is fitted in the second hydraulic chamber 37 formed between the two. A second return spring 38 that constantly biases the second helical piston 33 backward is provided. This second return spring 3
The front end portion of 8 has an outer member 31 (outer cylinder portion 31) in order to prevent vibration or gear rattling noise due to backlash.
It is fixed to b).

Here, the second helical piston 33 is held at the basic position by the urging force of the second return spring 38 when no hydraulic pressure is applied to the second hydraulic chamber 37 (FIG. 1 shows this state. The second hydraulic chamber 3
When a hydraulic pressure is applied inside 7, the hydraulic pressure causes the second return spring 38 to move forward to a predetermined position against the urging force of the second return spring 38, and when the hydraulic pressure is released, the basic position is restored. That is, the second helical piston 33 is binaryly displaced in the front-rear direction in response to the supply and discharge of hydraulic pressure.

The inner member 29 is formed in a substantially cylindrical shape, and
It is housed in the hollow portion of the helical piston 33. Further, on the outer peripheral portion of the inner member 29, helical outer teeth 29a that mesh with the second inner gear 33b of the second helical piston 33 are formed. The front end opening of the inner member 29 is closed by the front plate 34.

The hydraulic means A will be described below. To the first hydraulic chamber 35, in order, first and second camshaft internal hydraulic passages 41 and 42 formed in the camshaft 21, a bolt internal hydraulic passage 43 formed in the fastening bolt 30, and an inner member. An inner member hydraulic passage 44 formed at the front of 29;
The hydraulic oil (hydraulic pressure) is supplied and discharged from the front side via an outer member internal hydraulic passage 45 formed in the outer member 31 (outer cylinder portion 31b). On the other hand, hydraulic oil is supplied to and discharged from the rear side to the second hydraulic chamber 37 via a third camshaft internal hydraulic passage 46 formed in the camshaft 21. With such an arrangement of the hydraulic passages 41 to 46, the number of places requiring sealing is extremely reduced, and the sealing performance of the valve timing control device 27 is improved. Further, each hydraulic passage 41 to 46 is formed by excavating the meat portion of the cam shaft 21, the fastening bolt 30, the inner member 29, and the outer member 31, and a pipe line for supplying and discharging hydraulic oil is particularly required. Therefore, the valve timing control device 27 is made compact.

Then, the first camshaft internal hydraulic passage 41
Hydraulic oil is supplied to and discharged from the hydraulic mechanism 52 through the first hydraulic oil supply passage 51. In the first hydraulic oil supply passage 51, a first solenoid valve 53 is provided. .. Here, the first solenoid valve 53 is on / off controlled by the control unit 56, and when the first solenoid valve 53 is turned on, hydraulic oil (hydraulic pressure) is supplied from the hydraulic mechanism 52 to the first hydraulic chamber 35. .. On the other hand,
When the first solenoid valve 53 is turned off, the hydraulic oil (hydraulic pressure) in the first hydraulic chamber 35 is released to the first release passage 58. Similarly, the third camshaft internal hydraulic passage 46
Hydraulic oil is supplied to and discharged from the hydraulic mechanism 52 through the second hydraulic oil supply passage 54. In the second hydraulic oil supply passage 54, a second solenoid valve controlled by the control unit 56 is supplied. 55 is provided.
When the second solenoid valve 55 is turned on,
Hydraulic oil is supplied from the hydraulic mechanism 52 to the second hydraulic chamber 37,
When turned off, the hydraulic oil in the second hydraulic chamber 37 is released to the second release passage 59.

The power transmission mechanism from the outer member 31 to the inner member 29 or the rotational phase conversion mechanism between the members 30, 29 will be described below. As shown in FIGS. 3 and 4, the outer member 31, the first helical piston 32, the second helical piston 33, and the inner member 29 are concentrically adjacent to the former hollow portion in this order. They are arranged in a positional relationship such that they are housed. Then, as described above, the members adjacent to each other in the radial direction are engaged with each other by meshing the helical gears at the adjacent portions. Since the members 31, 32, 33, 29 are arranged concentrically in this way, the valve timing control device 27 has a compact structure. Here, the inner teeth 31a of the outer member 31 and the first outer gear 32a of the first helical piston 32 that mesh with each other are left-hand screw type helical gears and have the same inclination angle, and the first teeth of the first helical piston 32 that mesh with each other are the same. 1 inner gear 32
b and the second outer gear 33a of the second helical piston 33 are right-hand screw type helical gears and have the same inclination angle, and the second helical piston 33 of the second helical piston 33 meshes with each other.
The inner gear 33b and the outer teeth 29a of the inner tooth member 29 are left-handed helical gears and have the same inclination angle.

Here, when hydraulic pressure is applied to the first hydraulic chamber 35 (see FIG. 1) and the first helical piston 32 is displaced rearward from the basic position as shown by arrow X, the internal teeth 31a and the first outer gear 32a. By the action of the first helical piston 32, the second helical piston 33, and the inner member 2
9 and 9 rotate in the arrow Y direction relative to the outer member 31 by a conversion angle θ ₁ corresponding to the piston displacement amount and the inclination angle. At the same time, by the action of the first inner gear 32b and the second outer gear 33a, the second helical piston 33 and the inner member 29 are converted relative to the first helical gear 32 in accordance with the piston displacement amount and the inclination angle. Rotate in the direction of arrow Y by angle θ ₂ . Therefore,
The inner member 29 is relatively (θ ₁ +
Rotate in the Y direction by θ ₂ ). That is, the camshaft 21
(See FIG. 1) advances the timing pulley 23 (see FIG. 1) by a crank angle of (θ ₁ + θ ₂ ).

On the other hand, when hydraulic pressure is applied to the second hydraulic chamber 37 (see FIG. 1) and the second helical piston 33 is displaced forward from the basic position as shown by the arrow Z, the first inner gear 32b and the second outer gear 33a. By this action, the second helical piston 33 and the inner member 29 rotate in the arrow Y direction relative to the first helical piston 32 by the conversion angle θ ₃ corresponding to the piston displacement amount and the inclination angle. At the same time, the second inner gear 33b and the outer teeth 2
By the action of 9a, the inner member 29 rotates in the arrow Y direction relative to the second helical gear 33 by the conversion angle θ ₄ corresponding to the piston displacement amount and the inclination angle. Therefore, the inner member 29 is relatively positioned with respect to the outer member 31.
Rotate in the Y direction by (θ ₃ + θ ₄ ). That is, the camshaft 21 (see FIG. 1) advances by (θ ₃ + θ ₄ ) with respect to the timing pulley 23 (see FIG. 1).

Further, the first and second hydraulic chambers 35 and 37 (see FIG. 1)
When the first and second helical pistons 32 and 33 are displaced as indicated by arrows X and Z, respectively, the two types of rotation of the inner member 29 in the Y direction are added. , The inner member 29 relative to the outer member 31,
Rotate in the Y direction by (θ ₁ + θ ₂ + θ ₃ + θ ₄ ). That is,
The camshaft 21 (see FIG. 1) is the timing pulley 23.
The angle is advanced by (θ ₁ + θ ₂ + θ ₃ + θ ₄ ) with respect to (see FIG. 1). Then, in the present embodiment, each gear 31
The inclination angles of a, 32a, 32b, 33a, 33b and 29a and the displacement amounts of the first and second helical pistons 32 and 33 are determined by the camshaft 21 (Fig. 1) is advanced by 10 ° (θ ₁ + θ ₂ = 1
0 °), when the hydraulic pressure is applied to the second helical piston 33, the camshaft 21 (see FIG. 1) advances by 20 °.
It is set as (θ ₃ + θ ₄ = 20 °). Therefore, when hydraulic pressure is applied to both helical pistons 32 and 33, the camshaft 21 (see FIG. 1) advances by 30 °. It should be noted that when the hydraulic pressure is not applied to both helical pistons 32 and 33, it is in the basic state, and in this state, the advance amount of the camshaft 21 (see FIG. 1) is zero. When the displacement amounts of the first and second helical pistons 32 and 33 are set to be equal, θ ₂ and θ ₃ are equal to each other. In addition, θ ₁ + θ ₂ = 10 °, θ ₃ + θ ₄ = 20 °
As long as the above relationship is satisfied, some of the meshing portions may mesh with each other by simple spline fitting (conversion angle 0 °).

Hereinafter, a valve timing control method by the valve timing control device 27 by the control unit 56 will be described with reference to FIGS. In the present embodiment, when the advance amount is increased in multiple stages from the state where the advance amount is 0, first, in the first stage, hydraulic pressure is applied only to the first helical piston 32, and the advance amount becomes 10 °. ..
Subsequently, in the second stage, hydraulic pressure is applied only to the second helical piston 33, and the advance amount becomes 20 °. Furthermore, in the third stage, hydraulic pressure is applied to both helical pistons 32 and 33,
The amount of advance becomes 30 °. In this way, the advance angle of the first step is
The conversion angle performed by the first helical piston 32 having a large pressure receiving area and by the first helical piston 32.
Since the (advance amount) is set small (10 °), the responsiveness at the time of advancing is enhanced.

The advance amount of the camshaft 21 is set to 0 °, 10 °,
An example of the characteristics of the maximum output torque of the engine CE with respect to the engine speed N at 20 ° and 30 ° is shown by curves G ₄ , G ₃ , G ₂ , and G ₁ in FIG. 5, respectively. As is clear from FIG. 5, the advance amount is 3 in the region of N ≦ N ₁ (low speed region).
The maximum output torque is the largest when 0 ° and N ₁ <
In the region of N ≦ N ₂ (medium speed region, low speed portion), the maximum output torque is largest when the advance amount is 20 °, and N ₂ <N ≦ N ₃
The maximum output torque when the advance amount is 10 ° is the largest in the region (high speed region of the medium speed region), and the maximum output torque when the advance amount is 0 in the region of N> N ₃ (high speed region) Is the largest.

Therefore, in this embodiment, basically, N>
In the region of N ₃ , both solenoid valves 53, 55 are turned off, and the advance amount of the camshaft 21 (intake valve 1) is set to 0 without applying hydraulic pressure to the hydraulic chambers 35, 37. N ₂ <N
In the region of ≦ N ₃ , only the first solenoid valve 53 is turned on and the hydraulic pressure is supplied only to the first hydraulic chamber 35 so that the advance amount of the camshaft 21 is 10 °. N ₁ <N
In the region of ≦ N ₂ , only the second solenoid valve 55 is turned on to supply the hydraulic pressure only to the second hydraulic chamber 37.
The advance amount of 1 is set to 20 °. In the region of N ≦ N ₁ , the first and second solenoid valves 53, 55 are turned on,
Hydraulic pressure is supplied to the first and second hydraulic chambers 35 and 37 so that the advance amount of the camshaft 21 is set to 30 °. According to such a valve timing control method, the maximum output torque is evenly increased over a wide rotation range, and a valley of torque does not occur.

[0036]

According to the first aspect of the invention, since a plurality of helical pistons are provided between the outer member and the inner member, the valve opening / closing timing can be achieved by preferably switching the operating state of each helical piston. Can be switched in multiple stages. Therefore, the opening / closing timing of the valve can be finely set, and the output torque of the engine can be uniformly increased over a wide operating range. In addition, there is no torque valley in the medium speed range.

According to the second invention, basically the same action and effect as the first invention can be obtained. Furthermore, since the outer member, each helical piston, and the inner member are arranged concentrically while effectively utilizing the hollow portion of each member, the arrangement of each member becomes easy, and the valve timing control device is compact. Be converted.

According to the third invention, basically the same action and effect as the second invention can be obtained. Furthermore, when both helical pistons are arranged facing each other and hydraulic pressure is applied,
Since the valve timing control devices are displaced toward each other, the length of the valve timing control device in the piston displacement direction is shortened, and the valve timing control device is made more compact.

According to the fourth invention, basically, the same action and effect as the third invention can be obtained. Further, since the switching operation of the valve timing of the first stage is performed by the outer helical piston having a large pressure receiving area, the responsiveness at the time of switching the valve timing is enhanced.

According to the fifth invention, basically, the same operation and effect as those of the third or fourth invention can be obtained. further,
Since the switching operation of the valve timing of the first stage is performed by the helical piston having the smaller conversion angle, the responsiveness when switching the valve timing is further enhanced.

According to the sixth invention, basically, the same operation and effect as those of the third or fourth invention can be obtained. further,
Since the helical piston that performs the switching operation in the first stage is formed so as to receive the hydraulic pressure from the outside of the engine, the load from the return spring of the helical piston to the valve timing control device is reduced, and the valve timing is reduced. The durability of the control device is improved.

According to the seventh invention, basically, the same action and effect as the sixth invention can be obtained. Further, the helical piston that performs the switching operation in the first stage is formed so that the hydraulic oil is supplied from the outside of the engine, and the other helical piston is supplied with the hydraulic oil from the inside of the engine. Since the valve timing control device is formed, the number of places requiring sealing is reduced and the sealing performance of the valve timing control device is improved. Further, the hydraulic means is made compact.

According to the eighth invention, basically the same action and effect as the second invention can be obtained. Further, since one end of the return spring is fixed to the outer member side, vibration or rattling noise due to backlash is prevented.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional plan view around a valve timing control device of an engine equipped with a valve timing control device according to the present invention.

FIG. 2 is an elevation sectional view of an engine including a valve timing control device according to the present invention.

FIG. 3 is a schematic elevational view of a valve timing control device.

FIG. 4 is a schematic side view of a valve timing control device.

FIG. 5 is a diagram showing a characteristic of a maximum output torque of an engine with respect to an advance amount and an engine speed. .

[Explanation of symbols]

 CE ... Engine A ... Hydraulic means 1 ... Intake valve 9 ... Crankshaft 15 ... Intake side cam 21 ... Intake side camshaft 27 ... Valve timing control device 29 ... Inner member 29a ... Outer teeth 31 ... Outer member 31a ... Inner teeth 32 ... 1st helical piston 33 ... 2nd helical piston 32a, 33a ... 1st, 2nd outer gear 32b, 33b ... 1st, 2nd inner gear 36, 38 ... 1st, 2nd return spring 56 ... Control unit

Front page continuation (72) Inventor Ichiro Hirose, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor, Noriro Mito, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Corporation ( 72) Inventor Isamu Iguchi 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Motor Corporation

Claims (8)

[Claims] 1. A substantially ring-shaped helical piston having an outer gear on an outer peripheral surface and an inner gear on an inner peripheral surface, at least one of which is a helical gear, and a helical piston rotatably driven by a crankshaft, and the helical piston on an inner peripheral portion. A substantially hollow cylindrical outer member having internal teeth that mesh with the outer gear, and a substantially cylindrical inner member having outer teeth that are connected to the cam shaft and that mesh with the inner gear of the helical piston on the outer periphery, and the helical piston. In a valve timing control device for an engine, which is provided with an urging means for switching the valve timing by changing the rotational phase between the outer member and the inner member by displacing in the camshaft axial direction by on / off operation Operate the helical piston and the helical piston between the outer member and the inner member. Biasing means and is provided with a plurality of sets that, and the valve timing control apparatus for an engine, wherein a helical piston control means is provided for switching the valve timing in a multi-stage by switching the operating states of these helical piston. 2. The engine valve timing control device according to claim 1, wherein in the hollow portion of the outer member, the helical pistons are sequentially arranged concentrically adjacent to each other in the radial direction and at the innermost side in the radial direction. The inner member is arranged in the hollow portion of the helical piston, the inner teeth of the outer member mesh with the outer gear of the radially outermost helical piston, and the inner gear of the radially outer helical piston is formed between two adjacent helical pistons. And a radially inner outer gear of a helical piston mesh with each other, and an inner gear of the radially innermost helical piston meshes with an outer tooth of an inner member. 3. The engine valve timing control device according to claim 2, wherein only two helical pistons are provided, and the helical piston disposed on the radially outer side and the other helical piston are provided. A valve timing control device for an engine, wherein the valve timing control devices are arranged so as to face each other so that the directions in which hydraulic pressure is applied are opposite to each other. 4. The engine valve timing control device according to claim 3, wherein, when the helical piston control means switches the valve timing from the basic state to a predetermined state, the helical piston located on the outer side in the radial direction. A valve timing control device for an engine, characterized in that a first-stage switching operation is performed by operating the valve timing control device. 5. The engine valve timing control device according to claim 3 or 4, wherein one of the helical pistons performs a first stage switching operation when switching a valve timing from a basic state to a predetermined state. The valve timing control device for an engine, wherein the rotational phase conversion angle of is set smaller than the rotational phase conversion angle of the other helical piston. 6. A valve timing control device for an engine according to claim 3 or 4, wherein a helical piston that performs a switching operation at a first stage when switching a valve timing from a basic state to a predetermined state. Is formed to receive hydraulic pressure from the outside of the engine, and the other helical piston is formed to receive hydraulic pressure from the inside of the engine. 7. The valve timing control device for an engine according to claim 6, wherein when the valve timing is switched from a basic state to a predetermined state, the helical piston that performs the switching operation in the first stage is outside the engine. A valve timing control device for an engine, characterized in that the hydraulic oil is supplied from one side, and the other helical piston is formed so that the hydraulic oil is supplied from the inside of the engine. 8. The engine valve timing control device according to claim 2, further comprising return springs for returning each helical piston to a basic position when hydraulic oil is released. A valve timing control device for an engine, wherein an end portion that does not come into contact with the helical piston is fixed to an outer member side.