JPH04175430A - Valve opening and closing timing control device - Google Patents

Abstract

PURPOSE:To set the valve opening and closing timing at an optimum desired timing constantly by controlling linearly a rotation phase converting means to convert the rotation phase of a camshaft with two oil pressure control valves which are duty-controlled. CONSTITUTION:An electronic control device 12 calculates the control object value of a camshaft 14 depending on the operation condition of the engine 11. And the valve opening and closing timing of the present condition is detected by the output signals of a crank position sensor 15 and a cam position sensor 16, and it is compared with the control object value to determine the rotation phase converting amount of the camshaft 14. Furthermore, the electronic control device 12 duty-controls the first and the second oil pressure control valves 24 and 25. When the valve opening and closing timing is advanced from the present condition, for example, the first oil pressure control valve 24 is controlled after the second oil pressure control valve 25 is fully closed. As a result, a high pressure oil discharged from the second hydraulic pump 22 is fed to an operation line 28, and this pressure operates to an oil pressure chamber 37. Consequently, a ring-form piston 31 is moved to convert the rotation phase of a timing pulley 30 and the camshaft 14.

Description

[Detailed description of the invention] [Object of the invention] (Industrial application field) The present invention relates to a valve opening/closing timing control device, which linearly controls the valve opening/closing timing of an engine according to various engine conditions. It is something.

(Prior art) As the prior art related to the present invention, for example, JP-A-62-
There is one disclosed in Publication No. 3111.

This conventional valve opening/closing timing control device 80 will be explained based on FIG. A ring-shaped piston means 83 having a helical spline formed in each portion is engaged with the ring-shaped piston means 83.

Further, a timing belt 86 is engaged with the outer circumferential surface of the timing boot I781, and is driven by a crankshaft (not shown) of an engine (not shown).

Here, the transmission member 82 is fixed to the camshaft 85 by a port 84, so that they do not rotate relative to each other.

Further, the piston means 83 is divided into two parts in the axial direction, and a spring 86 is inserted between them, thereby forming a so-called scissor gear. As a result, it is possible to reduce the meshing noise caused by backlash, etc., generated between the respective helical splines when the rotational torque is transmitted between the timing boot means 83 and the transmission member 82.

Further, a pressure receiving plate 87 disposed on the right side of the piston means 83 in the figure moves together with the piston means 83, and moves the piston means 83 left and right in the figure according to the oil pressure of the hydraulic line 88.

Here, a spring 90 is disposed in a space 89 on the right side of the piston means 83 in the figure, and moves the piston means 83 to the initial position (
(the leftmost position in the figure).

(Problem to be Solved by the Invention) However, in the conventional valve opening/closing timing control device 80 described above, the hydraulic pressure supplied to the hydraulic line 88 is only controlled at 0N10FF by a hydraulic control valve (not shown), and therefore, the valve opening/closing timing control device 80 There are only two periods.

However, in recent years, there has been a demand for improved engine performance, and it is preferable that the valve opening/closing timing is always maintained at an optimal arbitrary timing.

Therefore, the technical object of the present invention is to enable a valve opening/closing timing to be set at any timing in a valve opening/closing timing control device.

[Structure of the invention]

(Means for Solving the Problems) The technical means of the present invention taken to solve the above-mentioned technical problems of the present invention is to combine a valve timing control device with an engine having a camshaft and a crankshaft, A first sensor that detects the rotational position of the camshaft, a second sensor that detects the rotational position of the crankshaft, a hydraulic pump that is driven by the crankshaft, and a hydraulic pump that is disposed on the camshaft and changes the rotational phase of the camshaft. It has a rotational phase changing means, a hydraulic line that connects the hydraulic pump and the rotational phase changing means, a hydraulic control means disposed on the hydraulic line, and an electronic control device that controls the hydraulic control means. The device is configured such that the output signals of the first and second sensors are input, and the rotational phase changing means is linearly controlled by the hydraulic control means.

(Function) According to the above-mentioned technical means of the present invention, the rotational phase changing means is not controlled ON10F F as in the past, but is linearly controlled, so that the valve opening/closing timing is always set at an optimal arbitrary timing. be done.

(Example) Hereinafter, an example embodying the technical means of the present invention will be described based on the accompanying drawings.

A valve timing control device 10 is disposed in an engine 11, and almost all operations thereof are controlled by an electronic control device 12. The engine 11 includes a crankshaft 13 and a camshaft 1 that is driven by the crankshaft 13 via a transmission means (for example, a belt member such as a belt or a cogged belt, a gear member, etc.) (not shown).
4, and the rotational position of each shaft 13, 14 is detected by a crank position sensor (second sensor) 15 and a cam position sensor (first sensor) 16, respectively.

Here, the electronic control device 12 includes a crank position sensor (second sensor) 15 and a cam position sensor (first sensor) 16.
In addition to the output signals, for example, an engine oil temperature signal, an engine load signal, an engine rotation speed signal, etc. are input.

Oil for lubricating the engine 11 is always stored in an oil pan 17 disposed at the bottom of the engine 11 body, and when the enshiff 11 is in operation, a first hydraulic pump (hydraulic pump) 18 driven by the crankshaft 13 is used. As a result, oil is pumped to various parts of the engine 11 via the hydraulic circuit 19.

Note that this hydraulic circuit 19 is provided with an oil filter 20, a relief valve 21, and the like.

A second hydraulic pump (hydraulic pump) 22 , which is also driven by the crankshaft 13 , sucks oil from the hydraulic circuit 19 and discharges the oil to the hydraulic control means 23 .

The hydraulic control means 23 includes a first hydraulic control valve 24 and a second hydraulic control valve 25, and is duty-controlled by the electronic control device 12. First port 2 of first hydraulic control valve 24
4a is a discharge line (hydraulic line) of the second hydraulic pump 22
26, a second port) 24b communicates with an operating line (hydraulic line) 28 connected to the rotational phase changing means 27, and a third port 24C communicates with the first boat 25a of the second hydraulic control valve 25, and the second hydraulic pressure The second port 25b of the control valve 25 communicates with the oil pan 17.

Further, a relief valve 29 is provided in the discharge line 26 .

The rotational phase changing means 27 is disposed at one end of the camshaft 14, transmits the rotational torque of the crankshaft 13 to the camshaft 14, and changes the rotational phase of the camshaft 14. An intake/exhaust valve (not shown) is engaged with the camshaft 14, and as the camshaft 14 rotates, the intake/exhaust valve opens and closes an intake/exhaust passage.

The timing pulley 30 is inserted into the camshaft 14 so as to be rotatable relative to the camshaft 14, and the above-mentioned transmission means is engaged on its outermost circumferential surface 30a. Further, a helical spline 30c is formed on the inner outer peripheral surface 30b of the timing pulley 30, and a helical spline 31a is formed on the inner peripheral surface of the ring-shaped piston (piston means) 31 so as to mesh with the helical spline 30c. There is.

Further, a helical spline 31b is formed on the outer peripheral surface of the ring-shaped piston 31, and this helical spline 31
A helical spline 32a is formed on the inner peripheral surface of the transmission member 32 so as to mesh with the transmission member 32b.

Furthermore, the transmission member 32 is fixed to the camshaft 14 through a cover 34 that is integrally fixed thereto with a bolt 35 and a pin 44 so that it cannot rotate relative to the camshaft 14 .

Therefore, the ring-shaped piston 31 moves along each helical spline 30 in the left-right direction in the drawing in the space 33 formed between the timing pulley 30 and the transmission member 32, which are located apart from each other.
c, 31a, 31b, and 32a.

Here, a spring (spring means) 36 is disposed on the right side of the ring-shaped piston 31 in the space 33, and moves the ring-shaped piston 31 to an initial position (a position where the left end of the ring-shaped piston 31 in the figure abuts the cover 34). I am encouraging this.

Further, a hydraulic chamber 37 is formed at a position where the left end of the ring-shaped piston 31 in the drawing and the right end of the cover 34 in the drawing are opposed to each other.
It communicates with the aforementioned operating line 28 via a passage 14a within the camshaft 14.

Here, the oil acting on the hydraulic chamber 37 is transferred to the operating line 28.
Each helical spline 30
The oil that leaked into the space 33 through c. A passage 30d is formed therein.

Further, the flange portion 3°e of the timing boob I730 is press-fitted, while the inner circumferential portion of the damper case 38 comes into sliding contact with the outer circumferential surface of the transmission member 32 via the seal ring 39. Here, annular grooves are formed in the illustrated right side surface of the damper case 38 and the flange portion 32b of the transmission member 32 to form a labyrinth portion 40 which is spaced apart from each other and engages with the flange portion 32b of the transmission member 32. encapsulated to form viscous damper means 41.

Moreover, 42 and 43 are seal rings (cooperating with the seal ring 39) for sealing in viscous fluid.

The operation of the valve timing control device IO having the above configuration will be explained below.

First, when the electronic control unit 12 detects the operating state of the engine 11 using an engine rotation speed signal or the like, it calculates the camshaft 140 control target value so as to achieve the optimal valve opening/closing timing (
PID calculation, etc.).

Next, the electronic control unit 12 detects the current valve opening/closing timing based on the output signals of the crank position sensor 15 and the cam position sensor 16, and determines the rotational phase change amount of the camshaft 14 by comparing it with the control target value.

Therefore, the electronic control device 12 performs duty control on the first hydraulic control valve 24 and the second hydraulic control valve 25.

For example, if you want to advance the valve opening/closing timing from the current one,
Fully close the second hydraulic control valve 25 (duty ratio, open: closed = O
:100/first port 25a and second port 25b are out of communication), and then the first hydraulic control valve 24 is controlled with the calculated duty ratio. Therefore, a second
The high-pressure oil discharged by the oil cliff pump 22 is supplied, and the pressure acts on the hydraulic chamber 37, so that the ring-shaped piston 31 moves to the right in the figure against the biasing force of the spring 36, and the timing boot IJ30 The rotational phase between the camshaft 14 and the camshaft 14 is changed. Therefore, the valve opening/closing timing is advanced.

When the amount of change in the rotational phase reaches the target value, the first hydraulic control valve 24 as well as the second hydraulic control valve 25 are fully closed to keep the operating line 28 in a sealed state and maintain the amount of change in the rotational phase. do.

Here, since the oil in the operating line 28 leaks from various parts, the phase tends to change gradually.

Therefore, the electronic control device 12 performs feedback control using the hydraulic control means 23 by constantly detecting the valve opening/closing timing.

Further, the camshaft 14 receives fluctuating torque in both positive and negative directions by valve springs (not shown) disposed in the intake and exhaust valves to move the ring-shaped piston 31 in the axial direction (left and right directions in the figure) to change the rotational phase. However, since the viscous damper means 41 absorbs the fluctuating torque, no change occurs in the rotational phase.

On the other hand, in order to retard the valve opening/closing timing from the current timing, the first hydraulic control valve 24 is fully opened (the first port 24a and the second boat 24b-third boat 24c are not in communication with each other), and then,
The second hydraulic control valve 25 is controlled using the calculated duty ratio. Therefore, as the hydraulic pressure acting on the hydraulic chamber 37 is reduced, the ring-shaped piston 31' moves to the left in the figure due to the biasing force of the spring 36, changing the rotational phase of the timing pulley 30 and the camshaft 14. . Therefore,
The valve opening/closing timing is delayed.

When the amount of change in the rotational phase reaches the target value, both the first hydraulic control valve 24 and the second hydraulic control valve 25 are fully closed to keep the operating line 28 in a sealed state and maintain the amount of change in the rotational phase. do. Note that the subsequent feedback control is as described above.

As described above, the electronic control device 12 always controls the camshaft 1
4 and the crankshaft 13 (upright position is detected, and the rotational phase changing means 27 is linearly controlled so that the valve opening/closing timing is optimal according to engine conditions such as engine speed, engine load, and engine oil temperature. Therefore, the valve opening/closing timing is not binary as in the conventional case, but can be set at any timing.

In this embodiment, the viscous damper means is shown as having a labyrinth groove, but it may be of a plate type, and is not particularly limited to a labyrinth groove.

〔Effect of the invention〕

As described above, in the present invention, by linearly controlling the rotational phase changing means using two duty-controlled hydraulic control valves, it is possible to always set the valve opening/closing timing to an optimal arbitrary timing.

Further, by disposing the viscous fluid damper means in the rotational phase changing means, it is possible to effectively absorb the fluctuating torque that the camshaft receives from the valve spring.

[Brief explanation of the drawing]

FIG. 1 shows a configuration diagram of a valve timing control device 10 according to an embodiment of the present invention. FIG. 2 shows a sectional view of a prior art valve timing control device 80. lO... Valve opening/closing timing control device, 11... Engine, 12... Electronic control device, I3... Crankshaft, 14... Camshaft, 15... Crank position sensor (second sensor) , 16... cam position sensor (first sensor), 18...
1st hydraulic pump (hydraulic pump), 22... 2nd hydraulic pump (hydraulic pump), 23... hydraulic control means, 24... 1st hydraulic control valve, 25... 2nd hydraulic control valve, 26...Discharge line (hydraulic line), 27...Rotation phase changing means, 28...Operation line (hydraulic line), 30...Timing pulley, 32...Transmission member, 36...Spring (spring means), 41...
viscous damper means,

Claims (3)

[Claims] (1) An engine having a camshaft and a crankshaft, a first sensor that detects the rotational position of the camshaft, a second sensor that detects the rotational position of the crankshaft, and a hydraulic pressure driven by the crankshaft. a pump, a rotational phase changing means disposed on the camshaft and changing the rotational phase of the camshaft, a hydraulic line connecting the hydraulic pump and the rotational phase changing means, and a hydraulic line disposed on the hydraulic line. and an electronic control device that controls the hydraulic control device, and the electronic control device receives at least the output signals of the first and second sensors, and controls the rotational phase by the hydraulic control device. A valve opening/closing timing control device characterized by linearly controlling a changing means. (2) The hydraulic control means is configured to control the first
2. The valve opening/closing timing control device according to claim 1, comprising: a first hydraulic control valve; and a second hydraulic control valve. (3) The rotational phase changing means engages with a timing pulley via a piston means, and urges a transmission member fixed to the camshaft and the piston means to an initial position. Claim: comprising: a spring means; and a viscous damper means disposed between the timing pulley and the transmission member.
1) The valve opening/closing timing control device described above.