JP2008184952A - Variable valve gear for engine - Google Patents

Abstract

An object of the present invention is to improve the returnability of an intake valve timing to a fixed position.
An oil pump (31) that supplies hydraulic oil, and hydraulic oil supply from the oil pump (31) is received by an advance hydraulic chamber (17), and a crankshaft and an intake camshaft (2) A variable valve for an engine having an intake side variable valve timing mechanism (11) capable of advancing the intake valve timing between the most retarded angle position and the most advanced angle position by continuously variably controlling the rotational phase difference. In the apparatus, when the intake valve timing is advanced from the initial position, the response speed is relatively high from the initial position to an intermediate position between the most retarded angle position and the most advanced angle position. Operation from the oil pump (31) to the advance hydraulic chamber (17) from the initial position to the intermediate position and after the intermediate position so that the response speed becomes relatively slow after the intermediate position. oil's Varying the number of the oil supply passage.
[Selection] Figure 1

Description

  The present invention relates to a variable valve operating apparatus for an engine (internal combustion engine).

An engine-driven oil pump that supplies hydraulic oil, and a predetermined intermediate position between the most retarded angle position and the most advanced angle position that is supplied with hydraulic oil from the oil pump, and an intake valve at the fixed position. A fixing mechanism capable of fixing the timing, and the supply of hydraulic oil from the oil pump is received in the advance hydraulic chamber or the retard hydraulic chamber via the advance side oil passage or the retard side oil passage, and the crankshaft An intake side variable valve timing mechanism capable of continuously and variably controlling the rotational phase difference between the intake side camshaft and the intake side camshaft to advance and retard the intake valve timing between the most retarded angle position and the most advanced angle position; In an engine control device comprising retard control means for retarding the intake valve timing to the most retarded position during idling, when the engine stop is predicted, the intake valve timing is adjusted to the most retarded position. Those providing the advance control means to advance into the more the fixed position has been proposed (see Patent Document 1).
JP 2002-309974 A

  By the way, the hydraulic performance of the oil pump driven by the engine changes depending on the oil temperature of the hydraulic oil and the engine rotation speed. It may not be possible to advance the intake valve timing from the most retarded position to the fixed position. That is, the position of the intake valve timing at the start of the engine is determined in advance by engine specifications such as a request from exhaust emission, and the target position determined by the engine specifications is set as a fixed position. If the engine was started this time with the intake valve timing not being advanced to the fixed position at the time of the previous engine stop, the intake valve timing at the time of engine start will be delayed from the target position. Exhaust emissions cannot be obtained.

  Therefore, an object of the present invention is mainly to improve the returnability of the intake valve timing to a fixed position.

  According to the present invention, an oil pump (31) that supplies hydraulic oil and the hydraulic oil supply from the oil pump (31) are received by the advance hydraulic chamber (17), and the rotational phase difference between the crankshaft and the intake camshaft is In the variable valve operating system of the engine, the intake side variable valve timing mechanism (11) that can advance the intake valve timing between the most retarded angle position and the most advanced angle position by continuously controlling the intake valve timing, When the intake valve timing is advanced from the initial position, the response speed is relatively high from the initial position to an intermediate position between the most retarded position and the most advanced angle position. If it passes, the hydraulic fluid from the oil pump (31) to the advance hydraulic chamber (17) from the initial position to the intermediate position and after the intermediate position is set so that the response speed becomes relatively slow. of Varying the number of the oil supply passage.

  The present invention also provides an oil pump for supplying hydraulic oil, and the hydraulic oil supply from the oil pump is received by the advance hydraulic chamber, and the rotational phase difference between the crankshaft and the intake camshaft is continuously variably controlled. In the variable valve gear for an engine having an intake side variable valve timing mechanism capable of advancing the intake valve timing between the most retarded position and the most advanced position, the intake valve timing is advanced from the initial position. In this case, in addition to the hydraulic oil supply oil path from the oil pump to the advance hydraulic chamber, the oil pump may provide an intermediate position between the most retarded position and the most advanced angle position from the initial position. A hydraulic oil is supplied to the advance hydraulic chamber, and a second supply oil passage is provided to stop the supply of hydraulic oil from the oil pump to the advance hydraulic chamber when the intermediate position is passed.

  The present invention also provides an oil pump that supplies hydraulic oil, and the hydraulic oil supply from the oil pump is received by the retarded hydraulic chamber, and the rotational phase difference between the crankshaft and the exhaust camshaft is continuously variably controlled. The exhaust valve timing is retarded from the initial position in a variable valve gear for an engine having an exhaust side variable valve timing mechanism capable of retarding the exhaust valve timing between the most advanced position and the most retarded position. In this case, the response speed is relatively high from the initial position to the intermediate position between the most advanced position and the most retarded position, and the response speed is relatively slow after the intermediate position. In addition, the number of oil supply oil passages from the oil pump to the retarded hydraulic chamber is changed from the initial position to the intermediate position and after the intermediate position.

  The present invention also provides an oil pump that supplies hydraulic oil, and the hydraulic oil supply from the oil pump is received by the retarded hydraulic chamber, and the rotational phase difference between the crankshaft and the exhaust camshaft is continuously variably controlled. The exhaust valve timing is retarded from the initial position in a variable valve gear for an engine having an exhaust side variable valve timing mechanism capable of retarding the exhaust valve timing between the most advanced position and the most retarded position. In this case, in addition to the oil supply passage for the hydraulic oil from the oil pump to the advance hydraulic chamber, the oil pump may provide an intermediate position between the most advanced angle position and the most retarded angle position from the initial position. A hydraulic oil is supplied to the retard hydraulic chamber, and a second supply oil passage is provided for stopping the hydraulic oil supply from the oil pump to the retard hydraulic chamber when the intermediate position is passed.

  According to the present invention, an oil pump that supplies hydraulic oil, and the hydraulic oil supply from the oil pump is received in the advance hydraulic chamber, and the rotational phase difference between the crankshaft and the intake camshaft is continuously variably controlled. An intake valve timing mechanism that can advance the intake valve timing between the most retarded angle position and the most advanced angle position, wherein the intake valve timing is advanced from the initial position. In this case, the response speed is relatively high from the initial position to an intermediate position between the most retarded angle position and the most advanced angle position, and the response speed is relatively slow after the intermediate position. As described above, the number of oil supply oil passages from the oil pump to the advance hydraulic chamber is changed from the initial position to the intermediate position and after the intermediate position, or the intake air When the lube timing is advanced from the initial position, in addition to the hydraulic oil supply oil path from the oil pump to the advance hydraulic chamber, the position between the most retarded angle position and the most advanced angle position from the initial position is set. The second supply oil passage that supplies hydraulic oil from the oil pump to the advance hydraulic chamber until an intermediate position of the oil pump and stops supplying hydraulic oil from the oil pump to the advance hydraulic chamber after the intermediate position. Therefore, the amount of oil supplied to the intake side variable valve timing mechanism from the initial position to the intermediate position can be relatively increased, and the response speed toward the advance angle side is improved. For this reason, even in a region where the hydraulic oil pressure is low (a region where the engine speed is low or a region where the hydraulic oil temperature is high and the hydraulic fluid viscosity is low), the required operating time (for example, immediately before the engine stops) The intake valve timing can be surely advanced to an intermediate position (for example, a fixed position).

  According to the present invention, an oil pump that supplies hydraulic oil, and the hydraulic oil supply from the oil pump is received by the retard hydraulic chamber, and the rotational phase difference between the crankshaft and the exhaust camshaft is continuously variably controlled. An exhaust valve timing mechanism that can retard the exhaust valve timing between the most advanced angle position and the most retarded angle position, wherein the exhaust valve timing is retarded from the initial position. In this case, the response speed is relatively high from the initial position to an intermediate position between the most advanced position and the most retarded position, and the response speed is relatively slow after the intermediate position. As described above, the number of hydraulic oil supply oil paths from the oil pump to the retarded hydraulic chamber is changed from the initial position to the intermediate position and after the intermediate position, or the exhaust When the lube timing is retarded from the initial position, in addition to the hydraulic oil supply oil path from the oil pump to the advance hydraulic chamber, the position between the most advanced angle position and the most retarded angle position from the initial position is determined. The second supply oil passage that supplies hydraulic oil from the oil pump to the retard hydraulic chamber until the intermediate position of the oil pump, and stops supplying hydraulic oil from the oil pump to the retard hydraulic chamber after the intermediate position. Therefore, the amount of oil supplied to the exhaust side variable valve timing mechanism from the initial position to the intermediate position can be relatively increased, and the response speed to the retard side is improved. Therefore, even in areas where the hydraulic oil pressure is low (areas where the engine speed is low or areas where the hydraulic oil temperature is high and hydraulic oil viscosity is low), the exhaust is reliably exhausted to the intermediate position during the required operation. The valve timing can be retarded.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a schematic configuration diagram of a valve timing control device. In FIG. 1, the engine is supplied with hydraulic oil and continuously variably controls the rotational phase difference between the crankshaft and the intake camshaft to advance and retard the intake valve timing. "Intake VTC mechanism") 11 is provided.

  2 and 3 show a schematic configuration of a front cross-sectional structure of the intake VTC mechanism 11. Here, FIG. 2 shows a state when the position of the intake valve timing is at a “most retarded position” described later, whereas FIG. 3 shows a state when the position of the intake valve timing is at a “fixed position” described later. Indicates the state.

  As shown in FIGS. 2 and 3, the internal rotor 12 provided inside the intake VTC mechanism 11 can be rotated integrally with the intake camshaft 2 by being fastened to the tip of the intake camshaft 2 with a bolt or the like. The Three blade bodies (vanes) 13 are formed radially on the outer periphery of the inner rotor 12.

  A housing 15 is provided so as to cover the outer periphery of the inner rotor 12. The housing 15 is fixed to an intake cam sprocket (not shown) by a plurality of mounting bolts (not shown), so that the housing 15 can rotate integrally with the intake cam sprocket. Note that the same number (three) of convex portions 15a as the vanes 13 of the internal rotor 12 are formed on the inner periphery of the housing 15, and individual recesses 15b formed between the adjacent convex portions 15a are provided. A vane 13 is accommodated.

  The tip of the vane 13 is in sliding contact with the inner periphery of the recess 15 b, and the tip of the protrusion 15 a is in sliding contact with the outer periphery of the internal rotor 12. As a result, the internal rotor 12 and the intake camshaft 2, the intake cam sprocket and the housing 15 can be relatively rotated around the same axis.

  In addition, two spaces 17 and 18 are formed in the recess 15 b by being partitioned by the vanes 15. Of these two spaces 17, 18, the space 18 on the rotation direction (arrow α direction) side of the intake camshaft 2 with respect to the vane 13 is referred to as a retard hydraulic chamber, and the space 17 on the opposite side is referred to as an advance hydraulic chamber.

  In the internal rotor 12, there are an oil passage 19 in the camshaft direction communicating with a later-described retarded oil passage P <b> 4, and a radial oil passage 20 communicating with the oil passage 19 and the retarded hydraulic chamber 18. Is formed. Further, a first camshaft direction oil passage 21 communicating with an advance oil passage P5 described later, and a first radial oil passage 22 communicating with the first camshaft direction oil passage 21 and the advance hydraulic chamber 17 are provided. And are formed.

  Further, as shown in FIG. 4, the housing 15 is formed with an accommodation hole 25 along the radial direction. A lock key 26 is accommodated in the accommodation hole 25. The lock key 26 has a function of fixing the inner rotor 12 and the housing 15 to a specific relative position. 4 is not shown in FIG. 1, FIG. 2, and FIG.

  In the intake VTC mechanism 11 configured in this way, the relative phase between the rotating parts 12 and 15 can be freely changed through control of the hydraulic pressure supplied to each part such as the advance hydraulic chamber 17 and the retard hydraulic chamber 18. Or it is held.

  Next, a hydraulic control system that controls the hydraulic pressure supplied to each part of the intake VTC mechanism 11 will be described.

  In FIG. 1, an oil pump 31 is mechanically driven based on the rotational force of a crankshaft, sucks hydraulic oil in an oil pan 32, and supplies hydraulic oil to an oil control valve (OCV) 33 via a supply oil passage P1. Supply.

  The oil control valve 33 is a 4-port valve whose opening degree is controlled based on duty control. In addition to the supply oil path P1, the oil discharge valve P2 and P3 return the working oil to the oil pan 32, and the intake air. A retard oil passage P4 communicating with the retard hydraulic chamber 18 of the VTC mechanism 11 and an advance oil passage P5 communicating with the advance hydraulic chamber 17 are connected to the oil control valve 33. Although not shown, the oil control valve 33 incorporates a spool that is slidably reciprocated, a coil spring that urges the spool, and an electromagnetic solenoid that attracts the spool when a voltage is applied thereto.

  The voltage applied to the electromagnetic solenoid is duty-controlled by the engine controller 61. The attractive force generated by the electromagnetic solenoid changes according to the duty ratio of the applied voltage. The position of the spool is determined by a balance between the attractive force generated by the electromagnetic solenoid and the biasing force of the coil spring.

  As the spool moves, the amount of communication between the retard oil passage P4 and the advance oil passage P5 and the supply oil passage P1 and the discharge oil passages P2 and P3 changes, and the retard oil passage P4 and the advance oil passage. The amount of hydraulic oil supplied to P5 or the amount of hydraulic oil discharged from these oil passages P4 and P5 changes. The engine controller 61 controls the relative movement of the internal rotor 12 and the housing 15 by adjusting the hydraulic pressure in the retard hydraulic chamber 18 and the advanced hydraulic chamber 17 in this manner.

  On the other hand, part of the hydraulic oil sucked by the oil pump 31 is supplied to the oil switching valve (OSV) 34 through the oil passage P6 branched from the supply oil passage P1. Similar to the oil control valve 33, the oil switching valve 34 has a built-in spool that reciprocates by the cooperation of the electromagnetic solenoid and the coil spring. The opening of the oil switching valve 34 is controlled by the duty of the supply voltage to the electromagnetic solenoid by the engine controller 61. This is a 3-port valve. In addition to the oil path P6, the oil switching valve 34 is connected to a discharge oil path P7 for returning the working oil to the oil pan 32 and a lock key control oil path P8 communicating with a predetermined portion in the internal rotor 12. Yes. As with the oil control valve 33, the engine controller 61 controls the operating state of the lock key 26 by adjusting the hydraulic pressure of the hydraulic oil supplied through the lock key control oil passage P8.

  The state where the relative phase of the internal rotor 12 (intake camshaft 2) with respect to the housing 15 (intake cam sprocket) has advanced most in the arrow direction α corresponds to the state in which the intake valve timing has been advanced most. The position of the intake valve timing at this time is referred to as “the most advanced position”. On the other hand, the state in which the relative phase of the internal rotor 12 with respect to the housing 15 is most delayed in the arrow direction α corresponds to the state in which the intake valve timing is most retarded. The position of the intake valve timing at this time is referred to as the “most retarded position” (see FIG. 2). For example, the intake valve closing timing (IVC) is delayed more than the intake bottom dead center at the most retarded position so that the intake valve open period and the exhaust valve open period do not overlap (the overlap is eliminated). ). Also, the intake valve closing timing is brought close to the intake bottom dead center at the most advanced position, thereby increasing the overlap. That is, in the engine of the present embodiment, the intake valve timing (the intake valve closing timing or the intake valve opening timing) is movable between the “most advanced angle position” and the “most retarded angle position”. The lock key 26 fixes the relative phase between the internal rotor 12 and the housing 15 when the intake valve timing determined by the relative phase between the internal rotor 12 and the housing 15 is in an intermediate state within the variable range. The position of the intake valve timing at this time is referred to as a “fixed position” (see FIG. 3).

  Next, the structure and function of the lock key 26 will be described.

  As shown in FIG. 4, the accommodation hole 25 is formed so that the lock key 26 can reciprocate inside.

  On the inner rotor 12 side, a locking hole 12a having a shape that engages with the distal end portion 26a of the lock key 26 is provided. The locking hole 12 a opens in a direction facing the housing 15. Further, the locking hole 12a communicates with the lock key control oil path P8 via a circumferential passage 12b communicating with the locking hole 12a. On the other hand, a spring accommodating hole 28 for accommodating a coil spring 27 is provided at the rear end of the lock key 26. The coil spring 27 urges the lock key 26 accommodated in the accommodation hole 28 from the housing 15 side toward the internal rotor 12 side.

  Here, in a state where hydraulic oil (hydraulic pressure) is not supplied to the lock key control oil passage P8 by the oil switching valve 34, the distal end portion 26a of the lock key 26 is brought into the locking hole 12a by the spring force of the coil spring 27. The relative phase between the internal rotor 12 and the housing 15, that is, the intake valve timing is fixed at a fixed position.

  On the other hand, when a sufficiently high hydraulic pressure is applied through the lock key control oil passage P8, the hydraulic pressure overcomes the spring force of the coil spring 27 and separates the tip end portion 26a of the lock key 26 from the locking hole 12a.

  For example, at the time of starting the engine or immediately after starting, the lock valve 26 fixes the intake valve timing at a fixed position that is in an intermediate state within the variable range of the relative phase of the internal rotor 12 and the housing 15. Thereafter, when the temperature of the hydraulic oil rises and exceeds a predetermined value (the viscosity of the hydraulic oil decreases to some extent), the function of fixing the intake valve timing by the lock key 26 is released based on the hydraulic control of the engine controller 61. The release state is maintained as long as the normal operation state continues.

  Next, the operation control of the intake VTC mechanism 11 by the engine controller 61 will be described.

  The engine controller 61 sequentially updates and calculates the target value of the intake valve timing (target intake valve timing) based on the operating state of the engine ascertained from the detection results of various sensors such as the crank angle sensor 62. The engine controller 61 calculates a duty command value based on a comparison between the actual intake valve timing obtained from the output signals of the crank angle sensor 62 and the cam angle sensor 63 and the target intake valve timing. Further, the engine controller 61 applies a command signal (voltage) having a duty ratio corresponding to the calculated duty command value to the electromagnetic solenoid of the oil control valve 33. By adjusting the opening degree of the oil control valve 33 in this way, the oil pressure in the hydraulic chambers 17 and 18 of the intake VTC mechanism 11 is appropriately adjusted, and the intake VTC mechanism 11 is operated. In the manner as described above, the engine controller 61 controls (feedback control) the operation of the intake VTC mechanism 11 to converge the actual intake valve timing to the target intake valve timing.

  By the way, in order to start the engine with the intake valve timing fixed at a specific phase by using the function of the lock key 26, it is necessary to fix the intake valve timing before the engine starts. However, in the engine in the stopped state, the oil pump 31 driven by the engine output also does not operate, so it is difficult to drive the intake VTC mechanism 11 in this state. Further, it is desirable to optimize the operating state of the engine as much as possible by continuously executing the intake valve timing change control in the operating engine. On the other hand, if the engine stops in the idle state, the hydraulic oil pressure is lost rapidly, so even if you try to advance the intake valve timing from the most retarded position to the fixed position immediately after the engine stops, There is no guarantee that the valve timing will reach its fixed position reliably. If the engine stops without the intake valve timing being able to advance to the fixed position, the exhaust emission at the next start may be significantly deteriorated.

  More specifically, FIG. 5 shows the response speed characteristics of the intake VTC mechanism 11 with respect to the engine speed. It can be seen that the response speed of the intake VTC mechanism 11 is low because the engine speed is low during idling. In this case, since the response speed of the intake VTC mechanism 11 varies depending on the oil temperature, hydraulic pressure, and the amount of oil supplied to the intake VTC mechanism 11, a region where the engine rotational speed is low, such as when idling, In the region where the temperature is high and the viscosity of the hydraulic oil is low, the hydraulic pressure of the hydraulic oil is low, and the response speed of the intake VTC mechanism 11 is reduced.

  Therefore, in this embodiment, the response speed is relatively high from the most retarded position (initial position) to the fixed position (intermediate position between the most retarded position and the most advanced position), and the fixed position (intermediate position). ), The advance oil path P5 and the advance angle from the most retarded position to the fixed position and from the fixed position to the most advanced position (after the initial position) so that the response speed becomes relatively slow. The number of oil passages (hydraulic oil supply oil passages from the oil pump 31 to the advance hydraulic chamber 17) communicating with the hydraulic chamber 17 is changed. That is, two (a plurality) of oil passages that communicate the advance oil passage P5 and the advance hydraulic chamber 17 are formed between the most retarded position and the fixed position.

  First, the first of the two oil passages is the same as the conventional device. That is, as shown in FIGS. 2 and 3, the first camshaft direction oil passage 21 communicating with the advance oil passage P5 and the first camshaft direction oil passage 21 and the advance hydraulic chamber 17 are communicated. This is a first radial oil passage 22.

  On the other hand, the second oil passage newly provided is configured as follows. That is, as shown in FIGS. 2 and 3, the second camshaft direction oil passage 51 communicates with the advance oil passage P5, and the second camshaft direction oil passage 51 communicates with the convex portion of the housing. A second radial oil passage 52 that opens toward the inner periphery of 15a is formed in the inner rotor 12, whereas in the convex portion 15a of the housing, on the radial side surface 15c on the advance hydraulic chamber 17 side. A communication oil passage 53 that opens and opens toward the outer periphery of the inner rotor 12 is formed.

  In this case, the second radial oil passage 52 and the communication oil passage 53 communicate with each other while the intake valve timing is in the fixed position from the most retarded position, and while the intake valve timing is in the most advanced position from the fixed position. The opening diameter on the inner peripheral side of the convex portion 15 a of the second radial oil passage 52, the opening diameter on the outer peripheral side of the inner rotor 12 of the communication oil passage 53, and the convex portion 15 a of the second radial oil passage 52 so as not to communicate with each other. The positional relationship in the circumferential direction between the inner peripheral side opening hole and the opening hole on the outer peripheral side of the inner rotor 12 of the communication oil passage 53 is set.

  Here, the effect of this embodiment is demonstrated.

  With the intake valve timing at the most retarded position (see FIG. 2), the oil switching valve 33 is operated to connect the advance oil path P5 and the supply oil path P1, and the retard oil path P4 and the exhaust oil path. P2 and P3 are connected. Then, the hydraulic oil from the oil pump 31 flows into the advance hydraulic chamber 17 through the first oil passage including the first camshaft direction oil passage 21 and the first radial oil passage 22, and the second The oil also flows into the advance hydraulic chamber 17 via the second oil passage composed of the camshaft direction oil passage 51, the second radial oil passage 52 and the communication oil passage 53. In contrast, the hydraulic oil in the retarded hydraulic chamber 18 is returned to the oil tank 32 through the oil passages 19 and 20, the retarded oil passage P4, and the discharge oil passages P2 and P3. That is, in contrast to the conventional apparatus in which only the first oil passage communicates with the advance hydraulic chamber 17, in this embodiment, a second oil passage communicating with the advance hydraulic chamber 17 is newly provided. Therefore, the response speed of the intake VTC mechanism 11 is larger than that of the conventional device by the amount of the second oil passage, and the vane 13 is advanced to the housing 15 at the increased response speed. In time, the intake valve timing is at a fixed position (see FIG. 3).

  Even after this state has passed, the vane 13 moves toward the advance angle side with respect to the housing 15 and moves toward the most advanced angle position. However, if the intake valve timing passes the fixed position, the second radial oil Since the communication between the passage 52 and the communication oil passage 53 is interrupted, the hydraulic oil flows into the advance hydraulic chamber 17 only from the first oil passage. At this time, the response speed, that is, the same as the conventional device. The vane 13 advances to the most advanced position at the response speed.

  Thus, according to the present embodiment, in contrast to the conventional device in which only the first oil passage communicates with the advance hydraulic chamber 17, in this embodiment, the intake valve timing is greater than the most retarded position. A second oil passage communicating with the advance hydraulic chamber 17 is newly provided only when it is between the fixed position and the response speed of the intake VTC mechanism 11 is increased by the amount of the second oil passage. It becomes larger than the case of the conventional apparatus. As a result, the response speed characteristic of the intake VTC mechanism 11 of the present embodiment is as shown by a solid line in FIG. 6, and according to the present embodiment, the response of the intake VTC mechanism 11 from the most retarded position to the fixed position. The speed is higher than the response speed of the intake VTC mechanism 11 from the fixed position to the most advanced position.

  If the intake VTC mechanism 11 of this embodiment configured as described above is used, the intake valve timing can be advanced to a fixed position when the engine is stopped. Explaining this, when an idle state in which the intake valve timing is at the most retarded position and a preliminary event (e.g., the shift lever position of the automatic transmission is in the P range) prior to stopping the engine is detected, the engine In the controller 61, the oil switching valve 33 is operated to connect the advance oil passage P5 and the supply oil passage P1, and to connect the retard oil passage P4 and the discharge oil passages P2 and P3. Then, as described above, the hydraulic oil from the oil pump 31 flows into the advance hydraulic chamber 17 through the first oil passage including the first camshaft direction oil passage 21 and the first radial oil passage 22. In addition, the fluid flows into the advance hydraulic chamber 17 through the second oil passage including the second camshaft direction oil passage 51, the second radial oil passage 52, and the communication oil passage 53. The hydraulic oil in the retard hydraulic chamber 18 is returned to the oil tank 32 through the oil passages 19 and 20, the retard oil passage P4, and the discharge oil passages P2 and P3. As a result, the vane 13 is advanced to the fixed position with respect to the housing 15 at a higher response speed than in the conventional apparatus.

  Thus, according to the present embodiment (the invention described in claim 1), the oil pump 31 that supplies hydraulic oil and the supply of the hydraulic oil from the oil pump 31 are supplied via the advance oil path P5. The intake valve timing can be advanced between the most retarded angle position and the most advanced angle position by variably controlling the rotational phase difference between the crankshaft and the intake side camshaft 2 received by the advance hydraulic chamber 17. When the intake valve timing is advanced from the most retarded position (initial position) in the variable valve operating system of the engine including the intake VTC mechanism 11 (intake side variable valve timing mechanism), the most retarded position (initial position) ) Until the fixed position (intermediate position between the most retarded angle position and the most advanced angle position), the response speed is relatively fast, and after the fixed position, the response speed is relatively slow. More rigid than corner position (initial position) An oil passage (advanced hydraulic chamber from the oil pump) that connects the advanced oil passage P5 and the advanced hydraulic chamber 17 from the fixed position to the most advanced position (after the intermediate position). The number of the hydraulic oil supply oil passages 17 is changed, that is, the oil that communicates the advance oil passage P5 and the advance hydraulic chamber 17 from the most retarded position (initial position) to the fixed position (intermediate position). The first oil passage composed of the first cam shaft direction oil passage 21 and the first radial oil passage 22, the second cam shaft direction oil passage 51, the second radial oil passage 52, and the communication passage 53. The second oil passage is composed of two oil passages, and an advance oil passage P5 and an advance hydraulic chamber are provided from the fixed position to the most advanced position (after the intermediate position). The first oil passage comprising the first camshaft direction oil passage 21 and the first radial oil passage 22 is communicated with the oil passage 17. Since only become road, it is possible to supply oil amount to the intake VTC mechanism 11 to the fixed location than the most retarded position relative increase, the response speed to correspondingly advance side is improved. For this reason, even in a region where the hydraulic oil pressure is low (a region where the engine speed is low or a region where the hydraulic oil temperature is high and the hydraulic fluid viscosity is low), the required operating time (for example, immediately before the engine stops) The intake valve timing can be surely advanced to an intermediate position (for example, a fixed position).

  On the other hand, the broken line in FIG. 6 shows the response speed characteristic of the conventional intake VTC mechanism. In the conventional intake VTC mechanism, the response speed is constant from the most retarded position to the most advanced position. There is a possibility that the engine may stop while the intake valve timing cannot be advanced to the fixed position in a low speed region or a region where the hydraulic oil temperature is high and the hydraulic fluid viscosity is low.

  In the embodiment, an oil pump that supplies hydraulic oil, and the hydraulic oil supply from the oil pump is received in the advance hydraulic chamber via the advance oil passage, and the rotational phase difference between the crankshaft and the intake camshaft is determined. In a variable valve operating apparatus for an engine, comprising an intake side variable valve timing mechanism capable of continuously varying and controlling the intake valve timing between a most retarded position and a most advanced position, the intake valve timing Is advanced from the initial position to the intermediate position between the most retarded position and the most advanced angle position, the response speed is relatively high, and after the intermediate position, the response speed is increased. The oil passage (the advance angle from the oil pump) that connects the advance oil passage and the advance hydraulic chamber from the initial position to the intermediate position and after the intermediate position is To hydraulic room The number of hydraulic oil supply oil passages) is changed. The oil pump that supplies the hydraulic oil and the hydraulic oil supply from the oil pump are received by the advance hydraulic chamber, and the crankshaft and the intake camshaft A variable valve timing system for an engine having an intake-side variable valve timing mechanism capable of advancing the intake valve timing between a most retarded angle position and a most advanced angle position by continuously variably controlling the rotation phase difference of the intake valve When the intake valve timing is advanced from the initial position, in addition to the hydraulic oil supply oil path from the oil pump to the advance hydraulic chamber, the most retarded angle position and the most advanced angle position from the initial position. The hydraulic oil is supplied from the oil pump to the advance hydraulic chamber up to an intermediate position between the oil pump and the hydraulic pump from the oil pump to the advance hydraulic chamber after the intermediate position. Serving It may be provided in the oil passage.

  In the embodiment, the case where the present invention is applied to the intake VTC mechanism has been described. However, the rotation phase difference between the crankshaft and the exhaust camshaft is continuously variably controlled by the supply of hydraulic oil, and the exhaust valve timing is advanced or retarded. The present invention can also be applied to the exhaust side variable valve timing mechanism (exhaust VTC mechanism). That is, an oil pump that supplies hydraulic oil, and the hydraulic oil supply from the oil pump is received in the retarded hydraulic chamber via the retarded oil passage, and the rotational phase difference between the crankshaft and the exhaust camshaft is continuously measured. In the variable valve operating system for an engine, comprising an exhaust VTC mechanism (exhaust side variable valve timing mechanism) capable of variably controlling the exhaust valve timing between the most advanced position and the most retarded position. When the exhaust valve timing is retarded from the initial position, the response speed becomes relatively faster from the initial position to an intermediate position between the most advanced angle position and the most retarded angle position, and passes the intermediate position. An oil passage (oil pump) that connects the retarded oil passage and the retarded hydraulic chamber from the initial position to the intermediate position and after the intermediate position so that the response speed becomes relatively slow. The number of hydraulic oil supply passages to the retarded hydraulic chamber is changed, or the oil pump that supplies hydraulic oil and the hydraulic fluid supplied from this oil pump are received by the retarded hydraulic chamber, Exhaust VTC mechanism (exhaust side variable valve timing mechanism) capable of delaying exhaust valve timing between the most advanced position and the most retarded position by continuously variably controlling the rotational phase difference between the shaft and the exhaust side camshaft. When the exhaust valve timing is retarded from the initial position, in addition to the hydraulic oil supply oil path from the oil pump to the advance hydraulic chamber, Hydraulic oil is supplied from the oil pump to the retard hydraulic chamber up to an intermediate position between the most advanced angle position and the most retarded angle position, and after the intermediate position, the retard hydraulic pressure is supplied from the oil pump. The supply of hydraulic oil to be able to be provided a second supply passage to stop.

  The initial position in the exhaust VTC mechanism is the most advanced position, whereas the initial position in the intake VTC mechanism is the most retarded position.

  The oil pump is not limited to the engine drive, and may be an electric drive type.

The schematic block diagram of the variable valve operating apparatus of the engine of 1st Embodiment of this invention. The schematic block diagram of the front cross-section of an intake VTC mechanism. The schematic block diagram of the front cross-section of an intake VTC mechanism. The expanded sectional view of a lock key part. The characteristic diagram of the response speed of the intake VTC mechanism with respect to the engine rotation speed. The characteristic diagram of the response speed of the intake VTC mechanism with respect to the intake valve timing.

Explanation of symbols

11 Intake VTC mechanism (Intake side variable valve timing mechanism)
21 1st camshaft direction oil path 22 1st radial direction oil path 31 Oil pump 51 2nd camshaft direction oil path 52 2nd radial direction oil path 53 Connection oil path

Claims (9)

An oil pump for supplying hydraulic oil;
The hydraulic oil supply from the oil pump is received by the advance hydraulic chamber, and the rotational phase difference between the crankshaft and the intake camshaft is continuously variably controlled to control the intake valve timing to the most retarded position and the most advanced position. An intake side variable valve timing mechanism capable of advancing between
When the intake valve timing is advanced from the initial position, the response speed is relatively high from the initial position to an intermediate position between the most retarded position and the most advanced angle position. The number of oil supply oil passages from the oil pump to the advance hydraulic chamber from the initial position to the intermediate position and after the intermediate position is set so that the response speed becomes relatively slow if the A variable valve operating system for an engine characterized by changing the engine. An oil pump for supplying hydraulic oil;
The hydraulic oil supply from the oil pump is received by the advance hydraulic chamber, and the rotational phase difference between the crankshaft and the intake camshaft is continuously variably controlled to control the intake valve timing to the most retarded position and the most advanced position. An intake side variable valve timing mechanism capable of advancing between
When the intake valve timing is advanced from the initial position, in addition to the hydraulic oil supply oil path from the oil pump to the advance hydraulic chamber, the most retarded angle position and the most advanced angle position from the initial position Hydraulic oil is supplied from the oil pump to the advance hydraulic chamber up to an intermediate position between them, and when the intermediate position is passed, the supply of hydraulic oil from the oil pump to the advance hydraulic chamber is stopped. An engine variable valve operating system characterized in that an oil passage is provided.   When the hydraulic oil is supplied and a fixing mechanism capable of fixing the intake valve timing to the fixed position with a predetermined intermediate position between the most retarded angle position and the most advanced angle position as a fixed position, the most retarded angle The variable valve operating apparatus for an engine according to claim 1 or 2, wherein an intermediate position between a position and the most advanced angle position is the fixed position.   The variable valve operating apparatus for an engine according to claim 1 or 2, wherein the initial position is the most retarded position. An oil pump for supplying hydraulic oil;
The hydraulic oil supply from this oil pump is received by the retarded hydraulic chamber, and the rotational phase difference between the crankshaft and the exhaust camshaft is continuously variably controlled to control the exhaust valve timing to the most advanced position and the most retarded position. A variable valve timing system for an engine having an exhaust side variable valve timing mechanism that can be retarded between
When the exhaust valve timing is retarded from the initial position, the response speed is relatively high from the initial position to an intermediate position between the most advanced angle position and the most retarded angle position. The number of hydraulic oil supply oil passages from the oil pump to the retarded hydraulic chamber from the initial position to the intermediate position and after the intermediate position is set so that the response speed becomes relatively slow when it passes. The variable valve operating device for an engine characterized by changing the engine. An oil pump for supplying hydraulic oil;
The hydraulic oil supply from this oil pump is received by the retarded hydraulic chamber, and the rotational phase difference between the crankshaft and the exhaust camshaft is continuously variably controlled to control the exhaust valve timing to the most advanced position and the most retarded position. A variable valve timing system for an engine having an exhaust side variable valve timing mechanism that can be retarded between
When the exhaust valve timing is retarded from the initial position, in addition to the hydraulic oil supply oil path from the oil pump to the advance hydraulic chamber, the most advanced angle position and the most retarded angle position from the initial position Hydraulic oil is supplied from the oil pump to the retard hydraulic chamber until an intermediate position between them, and after the intermediate position, the supply of hydraulic oil from the oil pump to the retard hydraulic chamber is stopped. An engine variable valve operating system characterized in that an oil passage is provided.   The variable valve operating apparatus for an engine according to claim 5 or 6, wherein the initial position is the most advanced angle position. An internal rotor fixed to the intake camshaft;
A housing that is fixed to the intake cam sprocket so as to cover the outer periphery of the inner rotor, and has a concave portion and a convex portion on the inner peripheral side,
The tip of the vane protruding from the inner rotor is in sliding contact with the inner periphery of the concave portion of the housing, and the tip of the convex portion of the housing is in sliding contact with the outer periphery of the inner rotor, so that the inner rotor and the housing are the same. Relative rotation about the axis of
2. The advance hydraulic chamber is a space defined by the vane in the recess of the housing and is a space opposite to the rotation direction of the intake camshaft with respect to the vane. Or the variable valve operating apparatus of the engine of 2. An internal rotor fixed to the exhaust camshaft;
A housing that is fixed to the exhaust cam sprocket so as to cover the outer periphery of the inner rotor, and that has a concave portion and a convex portion on the inner peripheral side,
The tip of the vane protruding from the inner rotor is in sliding contact with the inner periphery of the concave portion of the housing, and the tip of the convex portion of the housing is in sliding contact with the outer periphery of the inner rotor, so that the inner rotor and the housing are the same. Relative rotation about the axis of
7. The retard angle hydraulic chamber is a space defined by the vane in the recess of the housing, and is a space on the rotational direction side of the exhaust camshaft with respect to the vane. The variable valve operating device for an engine according to 1.