JP4831098B2 - Valve timing adjustment device - Google Patents

Description

  The present invention controls a valve timing adjustment device (hereinafter referred to as VVT) that controls the advance angle of a camshaft of an internal combustion engine (hereinafter referred to as an engine) by hydraulic control and varies the opening and closing timing of at least one of an intake valve and an exhaust valve. Name).

The prior art will be described with reference to FIG. 5 (the reference numerals in the figure are common to the embodiments described later).
The VVT is attached to the camshaft of the engine and has a variable valve timing mechanism (hereinafter referred to as VCT) 2 that can continuously change the valve opening and closing timing, and a hydraulic control means 3 that hydraulically controls the operation of the VCT 2. And an ECU (engine control unit: control device) 4 for electrically controlling an oil flow control valve (hereinafter referred to as OCV) 22 provided in the hydraulic pressure control means 3. (For example, refer to Patent Documents 1 and 2).

  The VCT 2 includes an input side rotor 5 that is rotationally driven by the crankshaft of the engine and an output side rotor 6 that rotationally drives the camshaft of the engine, and the advance chamber A (the output side rotor 6 is displaced to the advance side). The output-side rotor 6 is rotated relative to the input-side rotor 5 by the hydraulic pressure applied to the hydraulic chamber) and the retarding chamber B (the hydraulic chamber that displaces the output-side rotor 6 to the retarding side). This adjusts the amount of advance of the camshaft.

Here, under a low temperature, the viscosity of the oil increases, and the passage resistance of the filter 23 that filters the oil increases.
For this reason, immediately after start-up, particularly immediately after start-up in a low temperature environment such as winter, the oil pressure generated by the oil pump 21 becomes difficult to flow through the filter 23 and to the OCV 22 and VCT 2 (specifically, the advance chamber A and the retard chamber B). Is delayed, and the responsiveness of the advance amount adjustment by VCT2 is delayed.
Specifically, the VCT 2 at the start of the engine is such that the output side rotor 6 is set to the most retarded angle, and a stopper pin 14 (reference numeral, see FIG. 3) provided on the output side rotor 6 Since it is in a state of being fitted to the stopper bush 17 (reference numeral, see FIG. 3), the displacement state of the output side rotor 6 is advanced by moving the stopper pin 14 into the advanced angle chamber A by increasing the hydraulic pressure in the advanced angle chamber A. In order to cancel and further advance the output-side rotor 6, it is necessary to increase the hydraulic pressure in the advance chamber A, and the response speed to the advance side becomes slow immediately after the low temperature start.
JP 2001-27107 A JP 2005-54797 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a VVT capable of preventing deterioration of responsiveness due to oil viscosity.

[Means of Claim 1]
The hydraulic control means of the VVT employing the means of claim 1 can supply the oil that bypasses the filter to the advance chamber or the retard chamber by opening the sub valve.
In other words, the control device that controls the opening and closing of the sub-valve opens the sub-valve when the oil viscosity is high, such as during cold start, thereby increasing the hydraulic pressure supply capacity of the advance chamber or retard chamber. Responsiveness of the angular amount adjustment (adjustment from the retard angle side to the advance angle side, and adjustment from the advance angle side to the retard angle side) can be enhanced.

The sub valve switches the communication state between the sub oil passage and the advance chamber.
As a result, even when the oil viscosity is high, such as during cold start, the hydraulic pressure supply capacity of the advance chamber can be increased by opening the sub valve, and the VCT can be varied toward the advance side with good responsiveness. be able to.

The sub valve is provided integrally with the OCV.
Thereby, the increase in a number of parts can be suppressed and a cost rise can be suppressed.

The OCV and the sub valve are driven by a common electromagnetic actuator and include a return spring that resists the driving force of the electromagnetic actuator. The OCV and the sub valve advance from the main oil passage when the energization of the electromagnetic actuator is stopped. The hydraulic pressure is supplied to the chamber, and the hydraulic pressure is supplied from the sub oil passage to the advance chamber.
Thereby, the hydraulic pressure can be supplied to the advance chamber without energizing the electromagnetic actuator. That is, even when the oil viscosity is high, such as when starting cold, and the valve (for example, spool in a spool valve) is sluggish, the hydraulic pressure can be quickly supplied to the advance chamber. It is possible to prevent a delay in the advance of hydraulic pressure in the advance chamber due to a delay in movement, that is, deterioration in the advance response.

[Means of claim 2 ]
The sub-valve in the VVT employing the means of claim 2 does not open after the engine is warmed up.
In other words, the control device that controls the opening and closing of the sub-valve prohibits the opening of the sub-valve when it is determined that the engine has been warmed up based on the temperature of the engine coolant or the elapsed time after the engine is started. As a result, oil that does not pass through the filter is supplied to the VCT side only when the viscosity of the oil is high, and the rate at which oil that does not pass through the filter is supplied to the VCT side can be kept small.

The VVT outputs an output side rotor for rotationally driving an engine camshaft with respect to an input side rotor that is rotationally driven by an engine crankshaft, and an output to an advance side chamber for hydraulically driving the output side rotor. VCT including a retard chamber that drives the side rotor to the retard side by hydraulic pressure, and hydraulic control means including an OCV that supplies and discharges the hydraulic pressure generated by the oil pump to the advance chamber and the retard chamber.
The hydraulic control means includes a sub-oil passage through which the oil pressure generated by the oil pump bypassing the filter is guided, in addition to the main oil passage that guides the oil pressure generated by the oil pump that has passed through the filter that filters oil to the OCV. A sub valve for switching the communication state between the sub oil passage and the advance chamber or the retard chamber is provided.
The sub valve is provided integrally with the OCV and switches the communication state between the sub oil passage and the advance chamber.
The OCV and the sub-valve are driven by a common electromagnetic actuator and include a return spring that resists the driving force of the electromagnetic actuator.
The OCV and the sub-valve supply hydraulic pressure from the main oil passage to the advance chamber and supply hydraulic pressure from the sub oil passage to the advance chamber when the energization of the electromagnetic actuator is stopped.

A first embodiment to which the present invention is applied will be described with reference to FIGS.
(Explanation of VVT)
First, the structure of the VVT will be described with reference to FIGS.
The VVT is attached to the engine camshaft (intake valve, exhaust valve, intake / exhaust combined camshaft) 1 and can continuously change the opening / closing timing of at least one of the intake valve and the exhaust valve. VCT 2, hydraulic control means 3 for controlling the operation of VCT 2 by hydraulic pressure, and ECU 4 for electrically controlling hydraulic control means 3.

(Explanation of VCT2)
The VCT 2 is provided with an input side rotor (housing rotor) 5 that is driven to rotate in synchronization with the crankshaft of the engine, and an output side that is provided so as to be rotatable relative to the input side rotor 5 and rotates integrally with the camshaft 1. The rotor (vane rotor) 6 is provided, and the output side rotor 6 is driven to rotate relative to the input side rotor 5 by a hydraulic actuator configured in the input side rotor 5 to advance the camshaft 1. It changes to the side or retarded side.

The input-side rotor 5 is sandwiched in the axial direction between a sprocket 7 that is rotationally driven by a crankshaft of an engine via a timing belt, a timing chain, or the like, a substantially ring disk-shaped front plate 8, and the sprocket 7 and the front plate 8. The three parts with the shoe housing 9 are coupled by a plurality of bolts 10 and rotate integrally with the sprocket 7. Note that the front plate 8 and the shoe housing 9 may be formed of a single component.
As shown in FIG. 4, the shoe housing 9 has a plurality of (four in this embodiment) shoes 9a as partition members in the inner diameter direction, and a substantially fan-shaped recess is formed between the shoes 9a. In addition, the input side rotor 5 rotates clockwise in FIG. 4, and this rotation direction is an advance angle direction.

The output-side rotor 6 is positioned at the end of the camshaft 1 so as to rotate integrally with the knock pin 11, and then fixed to the end of the camshaft 1 by the center bolt 12. Rotate.
The output-side rotor 6 includes a plurality of (four in this embodiment) vanes 6a that divide a substantially fan-shaped recess formed between the shoes 9a into an advance chamber A and a retard chamber B, and output The side rotor 6 is provided to be rotatable within a predetermined angle with respect to the input side rotor 5.
The advance chamber A is a hydraulic chamber for driving the vane 6a to the advance side by hydraulic pressure, and is formed in a substantially fan-shaped recess on the side opposite to the rotation direction of the vane 6a. Conversely, the retard chamber B is a hydraulic chamber for driving the vane 6a to the retard side by hydraulic pressure. A seal member 13 that slides on the inner peripheral surface of the shoe housing 9 is provided on the outer peripheral surface of each vane 6a to block communication between the advance chamber A and the retard chamber B.

The VCT 2 includes a stopper pin 14 for engaging the output side rotor 6 with the input side rotor 5 at the most retarded position.
The stopper pin 14 has a substantially cylindrical bar shape, and is slidably inserted in the axial direction into a substantially circular stopper insertion hole 15 formed in one of the four vanes 6a so as to penetrate in the axial direction. Yes. The stopper pin 14 is biased toward the sprocket 7 by a spring 16 and is provided so as to be fitted in a stopper bush 17 press-fitted and fixed to the sprocket 7 at the most retarded position. A tapered portion is formed in the fitting portion between the stopper pin 14 and the stopper bush 17 so that the stopper pin 14 can be smoothly fitted into the stopper bush 17.

A first stopper releasing oil chamber 18 formed between the tip of the stopper pin 14 on the right side in FIG. 3 and the sprocket 7 communicates with the advance chamber A, and the stopper pin 14 is driven by the hydraulic pressure applied to the advance chamber A. 3 is pushed back to the left side in FIG. 3 to release the fitting between the stopper pin 14 and the stopper bush 17.
Further, the stopper pin 14 is provided with a large diameter on the left side in FIG. 3, and the second stopper release oil chamber 19 formed between the step portion of the stopper pin 14 and the stopper insertion hole 15 is a retard chamber. The stopper pin 14 is pushed back to the left side in FIG. 3 by the hydraulic pressure applied to the retard chamber B, and the fitting between the stopper pin 14 and the stopper bush 17 is released.

(Description of hydraulic control means 3)
Next, the hydraulic control means 3 will be described with reference to FIGS.
The hydraulic pressure control means 3 supplies and discharges oil from the advance chamber A and the retard chamber B, generates a hydraulic pressure difference between the advance chamber A and the retard chamber B, and connects the output side rotor 6 to the input side rotor 5. OCV 22 is a means for relatively rotating the oil, and supplies oil (hydraulic pressure) pumped from an oil pump (hydraulic pressure generating source) 21 driven by a crankshaft or the like to the advance chamber A or the retard chamber B. Prepare.

(Background of Example 1)
Oil increases in viscosity as temperature decreases. For this reason, the viscosity of the oil is high under a low temperature environment such as immediately after the engine is started in winter, and the passage resistance of the filter 23 that filters the oil increases. As a result, immediately after starting in a low temperature environment, the oil pressure generated by the oil pump 21 hardly flows in the filter 23, the oil pressure supply from the filter 23 → OCV22 → VCT2 is delayed, and the responsiveness of the advance amount adjustment is delayed.
In particular, when the engine is started, the VCT 2 has the output side rotor 6 set to the most retarded angle, and the stopper pin 14 is in a state of being fitted to the stopper bush 17 of the input side rotor 5. In order to displace 6 to the advance side, it is necessary to release the fitting state of the stopper pin 14 by increasing the hydraulic pressure, and further to increase the hydraulic pressure in the advance chamber A in order to drive the output side rotor 6 to the advanced side. Immediately after starting at low temperature, the response speed toward the advance side becomes slow.

(Characteristics of Example 1)
In order to solve the above problem, in the hydraulic control means 3 of the first embodiment, as shown in FIG. 1, as shown in FIG. 1, the main oil passage that guides the generated hydraulic pressure of the oil pump 21 that has passed through the filter 23 that filters oil to the OCV 22 In addition to 24, a sub oil passage 25 through which the oil pressure generated by the oil pump 21 bypassing the filter 23 is guided is provided, and a sub valve 26 for switching the communication state between the sub oil passage 25 and the advance chamber A is provided.
The sub valve 26 of this embodiment is provided integrally with the OCV 22.

An example of the OCV 22 in which the sub valve 26 is integrated will be described.
The OCV 22 includes a sleeve 31 and a spool 32. The spool valve 34 biases the spool 32 to the right side in FIG. 1 by the return spring 33, and drives the spool 32 to the left side in FIG. 1 against the biasing force of the return spring 33. This is an electromagnetic spool valve that is coupled to the electromagnetic actuator 35.

  The sleeve 31 has a substantially cylindrical shape, and has a plurality of input / output ports. Specifically, the sleeve 31 of the first embodiment has a main oil passage that communicates with an oil discharge port of the oil pump 21 through an insertion hole that slidably supports the spool 32 in the axial direction and a filter 23 that filters oil. 24, a main hydraulic pressure supply port that communicates with the sub hydraulic passage 25 that bypasses the filter 23 and communicates with the oil discharge port of the oil pump 21, and a main hydraulic advance chamber communication port that communicates with the advance chamber A , The sub-advance chamber communication port communicating with the advance chamber A, the retard chamber communication port communicating with the retard chamber B, and the oil is discharged to the outside of the spool valve 34 (for example, the engine cam chamber) A drain port returning to 36 is formed. The main advance chamber communication port and the sub advance chamber communication port are joined by an oil passage formed in the engine and communicate with the advance chamber A.

  The main hydraulic pressure supply port, the sub hydraulic pressure supply port, the main advance chamber communication port, the sub advance chamber communication port, the retard chamber communication port, and the drain port described above are holes formed on the side surface of the sleeve 31. FIG. From the left side (the side different from the electromagnetic actuator 35) to the right side, the drain port, the retard chamber communication port, the main hydraulic pressure supply port, the main advance chamber communication port, the drain port, the sub hydraulic pressure supply port, the sub advance chamber A communication port is formed.

The spool 32 includes four large-diameter portions (lands) for blocking a port having an outer diameter that substantially matches the inner diameter of the sleeve 31 (the diameter of the insertion hole).
Between each large-diameter portion, from the left side to the right side in FIG. 1, a small-diameter portion for a retarded-chamber drain that changes the communication state of the plurality of input / output ports according to the axial position of the spool 32, main hydraulic pressure supply A small-diameter portion for the advance, a small-diameter portion for the advance chamber drain, and a small-diameter portion for supplying the sub hydraulic pressure are formed.

The positional relationship between each port of the sleeve 31 and each large-diameter portion and each small-diameter portion of the spool 32 is provided so that four switching states can be achieved according to the axial displacement position of the spool 32.
Specifically, the spool 32 is controlled by energization control of the electromagnetic actuator 35. The I setting position shown in FIG. 2A, the II setting position shown in FIG. 2B, and the III setting shown in FIG. The position is set to the IV setting position shown in FIG. In addition, the arrow line in FIG. 2 shows the flow of oil.

  2A is a default state in which the energization of the electromagnetic actuator 35 is stopped and the spool 32 is stopped on the right side in the drawing by the urging force of the return spring 33, and the main hydraulic pressure supply port and the main advance angle are set. The chamber communication port communicates with the sub hydraulic pressure supply port and the sub advance chamber communication port to supply the oil in the main oil passage 24 and the sub oil passage 25 to the advance chamber A, and the retard chamber communication port. Is a set position (rapid advance position) where the hydraulic pressure in the retard chamber B is drained by communicating with the drain port.

In the second set position shown in FIG. 2 (b), the energization state of the electromagnetic actuator 35 is switched to low energization, and the spool 32 is displaced from the first set position to the left side by a small amount to block the sub advance chamber communication port. This is the setting position to perform.
That is, in the second setting position, the main hydraulic pressure supply port communicates with the main advance chamber communication port, only the oil in the main oil passage 24 is supplied to the advance chamber A, and the retard chamber communication port becomes the drain port. This is a set position (normal advance angle position) where the hydraulic pressure of the retard chamber B is drained by communication.

  In the third setting position shown in FIG. 2 (c), the energization state of the electromagnetic actuator 35 is switched to the middle energization, and the spool 32 is further displaced from the second setting position to the left side in the figure, thereby the retarding chamber communication port, the main At the set position (holding position: no oil is supplied to VCT2) where the advance angle chamber communication port and the sub advance angle communication port are closed at the large diameter portion and the hydraulic pressure of the advance angle chamber A and the retard angle chamber B is maintained. is there.

  In the IV setting position shown in FIG. 2D, the energization state of the electromagnetic actuator 35 is switched to high energization, and the spool 32 is further displaced from the above-mentioned III setting position to the left side in the drawing by the driving force of the electromagnetic actuator 35. The spool 32 is in a full stroke state stopped on the left side in the figure, the main hydraulic pressure supply port and the retard chamber communication port communicate with each other, only the oil in the main oil passage 24 is supplied to the retard chamber B, and the main advance chamber This is a set position (normally retarded position) where the communication port is connected to the drain port to drain the hydraulic pressure in the advance chamber A. Also at this time, the sub-advance chamber communication port is closed.

(Description of ECU 4)
The ECU 4 is a known computer. The ECU 4 determines the I to IV setting positions based on the engine operation state (including the occupant operation state) read by various sensors and the program stored in the memory. A VVT control function for controlling the duty ratio of the energization amount (supply current amount) of the OCV 22 so as to obtain the set position is provided. That is, the ECU 4 controls the hydraulic pressure of the advance chamber A and the retard chamber B by setting the OCV 22 to any of the first to IV setting positions by controlling the energization amount of the OCV 22, and the camshaft 1 The advance phase (advance amount) is controlled to an advance phase corresponding to the engine operating state.

In the VVT control function of the ECU 4, the engine is not warmed up immediately after the engine is started (for example, within a predetermined time after the engine is started or the engine cooling water temperature is equal to or lower than a predetermined temperature), that is, a cold start. When the oil viscosity is high and the output-side rotor 6 is displaced to the advance side, a rapid advance program is provided to de-energize the electromagnetic actuator 35 and set the OCV 22 to the above-mentioned first setting position. ing.
Thus, even if the oil viscosity is high, hydraulic pressure is supplied to the advance chamber A from both the main oil passage 24 and the sub oil passage 25 when the condition for displacement toward the advance angle is satisfied. That is, the sub valve 26 is opened and the sub hydraulic pressure supply port and the sub advance chamber communication port are communicated, so that the oil discharged from the oil pump 21 that has not passed through the filter 23 can be supplied to the advance chamber A. .

Further, the VVT control function of the ECU 4 is in a state where the engine has been warmed up (for example, after a predetermined time after the engine is started or when the engine coolant temperature is higher than a predetermined temperature), that is, when the oil viscosity is low. A sub-valve closing program for prohibiting the OCV 22 from being set to the I-th setting position is provided.
As a result, when the oil viscosity is low, the sub-valve 26 is kept closed even if the condition for displacement toward the advance angle is satisfied, and the oil that has not passed through the filter 23 after warming up is moved to the VCT 2 side. There is no flow failure.

(Explanation of VVT operation at engine start)
When the engine is stopped, the stopper pin 14 is fitted to the stopper bush 17. In the cranking state of the engine, the hydraulic pressure is not sufficiently supplied from the oil pump 21, so the stopper pin 14 remains fitted to the stopper bush 17 and the camshaft 1 is held at the most retarded position.
When the engine starts (complete explosion), the discharge hydraulic pressure of the oil pump 21 increases. However, when the oil is cold, the viscosity of the oil is high and the filter 23 inhibits the flow of the oil. However, when the spool 32 is not moved (that is, the non-energized state of the electromagnetic actuator 35 is maintained even after the engine is started), the OCV 22 is maintained at the I setting position so that the main oil passage 24 and the sub oil Hydraulic pressure is supplied to the advance chamber A through the passage 25.
Then, the hydraulic pressure in the first and second stopper release oil chambers 18 and 19 rises rapidly and the stopper pin 14 comes out of the stopper bush 17 so that the output side rotor 6 can rotate relative to the input side rotor 5. become. Then, when the hydraulic pressure in the advance chamber A becomes larger than the hydraulic pressure in the retard chamber B, the output side rotor 6 is displaced toward the advance side relative to the input side rotor 5, and the camshaft 1 is advanced.

When the output side rotor 6 reaches the target phase, the ECU 4 sets the OCV 22 to the third setting position, holds the drive hydraulic pressure of the advance chamber A and the retard chamber B, and holds the output side rotor 6 at the target phase. .
Thereafter, when the output side rotor 6 is further displaced to the advance side in a state where the oil viscosity is high, the ECU 4 sets the OCV 22 to the I setting position, and conversely, the output side rotor 6 is set to the retard side. When displacing, the ECU 4 sets the OCV 22 to the IV setting position.
Further, when the output side rotor 6 is displaced to the advance side in the state where the warm-up has progressed and the oil viscosity has decreased, the ECU 4 sets the OCV 22 to the second setting position, and conversely, the output side rotor 6 is delayed. When displacing to the corner side, the ECU 4 sets the OCV 22 to the IV setting position.

(Effect of Example 1)
As described above, the VVT of the first embodiment is such that the discharge hydraulic pressure of the oil pump 21 bypassing the filter 23 is adjusted to advance the advance chamber A by opening the sub valve 26 when the viscosity of the oil is high, such as at low temperature start. To be supplied. In this way, the hydraulic pressure is supplied to the advance chamber A without hindering the oil flow by the filter 23, whereby the VCT 2 can be varied to the advance side with good responsiveness.
Moreover, since the sub valve 26 is provided integrally with the OCV 22, an increase in the number of parts can be suppressed, and an increase in cost can be suppressed.

Furthermore, the OCV 22 with the sub valve 26 provided integrally is set to the I setting position by the action of the return spring 33 when the electromagnetic actuator 35 is deenergized, and supplies hydraulic pressure from the main oil passage 24 to the advance chamber A. The hydraulic oil is supplied from the sub oil passage 25 to the advance chamber A.
Thereby, the hydraulic pressure can be supplied to the advance angle chamber A without energizing the electromagnetic actuator 35. That is, even when the viscosity of the oil is high, such as when starting at a low temperature, and the movement of the spool 32 is slow, the hydraulic pressure can be quickly supplied to the advance chamber A without moving the spool 32. As a result, it is possible to prevent a delay in the hydraulic pressure increase in the advance chamber A due to a response delay of the spool 32 caused by the high viscosity of the oil, and to prevent a deterioration in the advance response due to the response delay of the spool 32.

On the other hand, the sub valve 26 is provided by the ECU 4 so as not to open after the engine is warmed up. That is, when the ECU 4 determines that the engine is warmed up and determines that the viscosity of the oil has decreased, the opening of the sub valve 26 is prohibited. As a result, oil that does not pass through the filter 23 is supplied to the VCT2 side only when the viscosity of the oil is high, and the rate at which oil that does not pass through the filter 23 is supplied to the VCT2 side can be kept small.
Further, the opening of the sub valve 26 is achieved only when the spool 32 is in the default position. Even if the spool valve 34 is switched after the warm-up is completed, the sub valve 26 is temporarily (in the moment) switched during the switching. ) Do not open. For this reason, the malfunction that the oil which does not pass the filter 23 in the middle of switching is supplied to the VCT2 side can be avoided.

[Modification]
In the above embodiment, the OCV 22 and the sub valve 26 are provided by the spool valve 34. However, the valve structure is not limited, and the OCV 21 or the sub valve 26 having another valve structure (such as a rotary valve) may be used. good.

In the above-described embodiment, the example in which the VCT 2 is provided on the camshaft 1 has been described. However, the VCT 2 may be provided on another part such as an engine crankshaft.
In the above embodiment, the input side rotor 5 is divided into four substantially fan-shaped concave portions by the four shoes 9a, and the four vanes 6a are provided on the outer peripheral portion of the output side rotor 6. The number and the number of vanes 6a may be any number as long as it is one or more in terms of configuration, and the number of shoes 9a and vanes 6a may be other numbers.
In the above embodiment, the housing rotor (input-side rotor 5) rotates synchronously with the crankshaft, and the vane rotor (output-side rotor 6) rotates integrally with the camshaft 1, but conversely the vane rotor and the crankshaft. The housing rotor may be configured to rotate integrally with the camshaft 1 by synchronous rotation.

(Example 1) which is the schematic of a hydraulic control means. (Example 1) which is switching explanatory drawing of OCV with which the subvalve was integrated. (Example 1) which is the schematic of VVT using the cross section along the axial direction of VCT. (Example 1) which is explanatory drawing of VCT seen from the axial direction. It is the schematic of VVT (conventional example).

Explanation of symbols

1 Camshaft 2 VCT (Variable valve timing mechanism)
3 Hydraulic control means 4 ECU
5 Input side rotor 6 Output side rotor 21 Oil pump 22 OCV (oil flow control valve)
23 Filter 24 Main oil path 25 Sub oil path 26 Sub valve 33 Return spring 35 Electromagnetic actuator A Advance angle chamber B Delay angle chamber

Claims (2)

With respect to an input side rotor that is rotationally driven by a crankshaft of the internal combustion engine, an advance angle chamber that drives an output side rotor that rotationally drives the camshaft of the internal combustion engine to an advance side by hydraulic pressure, and the input side rotor A variable valve timing mechanism including a retard chamber that drives the output-side rotor to the retard side by hydraulic pressure;
In a valve timing adjusting device comprising a hydraulic control means having an oil flow control valve for supplying and discharging hydraulic pressure generated by an oil pump to the advance chamber and the retard chamber,
The hydraulic control means guides the generated hydraulic pressure of the oil pump that bypasses the filter in addition to the main oil path that guides the generated hydraulic pressure of the oil pump that has passed through a filter that filters oil to the oil flow control valve. With a sub oil passage,
A sub valve for switching the communication state between the sub oil passage and the advance chamber or the retard chamber ;
The sub valve is provided integrally with the oil flow control valve, and switches the communication state between the sub oil passage and the advance chamber,
The oil flow control valve and the sub valve are driven by a common electromagnetic actuator and have a return spring that resists the driving force of the electromagnetic actuator.
The oil flow control valve and the sub-valve supply hydraulic pressure from the main oil passage to the advance angle chamber and supply hydraulic pressure from the sub oil passage to the advance angle chamber when energization of the electromagnetic actuator is stopped. A valve timing adjustment device. In the valve timing adjustment device according to claim 1 ,
The valve timing adjusting device according to claim 1, wherein the sub-valve does not open after the internal combustion engine is warmed up.

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