JP2019027319A - Variable valve mechanism of internal combustion engine - Google Patents

Abstract

To switch a valve driving state without disposing a switching pin and a pin holding portion inside of a driving arm.SOLUTION: In a variable valve mechanism of an internal combustion engine including a driving arm 30 having a receiving portion 37 and driving a valve 70 when oscillated, and a lost arm 20 oscillated by being pressed by a cam 10, oscillating the driving arm 30 together when received by the receiving portion 37, and conducting lost motion when not received by the receiving portion 37, the receiving portion 37 is disposed on the driving arm 30 in a manner free from displacement, and includes a slide supporting mechanism 40 for supporting the lost arm 20 to the driving arm 30 slidably in an arm longitudinal direction, and a slide operation device 50 for sliding the lost arm 20 to a receiving position p1 to be received by the receiving portion 37 and an out position p2 not to be received according to the slide supporting mechanism 40.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a variable valve mechanism that drives a valve of an internal combustion engine and changes the drive state of the valve in accordance with the operating state of the internal combustion engine.

  The variable valve mechanism of Patent Documents 1 and 2 drives a valve when it swings, and swings while being pressed by a cam and a driving arm (outer arm) provided with a receiving portion (switching pin) displaceable therein, A drive arm is swung together when received by the receiving portion, and a lost arm (inner arm) that becomes a lost motion when not received by the receiving portion is provided. The variable valve mechanism displaces the receiving portion (switching pin) between a receiving position that protrudes from the drive arm and receives the lost arm, and a disengagement position that retreats into the drive arm and does not receive the lost arm. To switch the driving state of the valve.

US Pat. No. 6,925,978 US Pat. No. 7,661,400

  In the above structure, since there is a switching pin and a pin holding part that holds the switch pin so as to be slidable inside the drive arm, it is costly to form the switching pin and the pin holding part. Therefore, an object of the present invention is to enable switching of the driving state of the valve without providing a switching pin or a pin holding portion inside the driving arm.

  In order to solve the above problems, a variable valve mechanism for an internal combustion engine according to the present invention includes a receiving portion, and when it swings, a drive arm that drives the valve and a cam that presses and swings are received by the receiving portion. In the variable valve mechanism of the internal combustion engine provided with a lost arm that causes a lost motion if it cannot be received by the receiving portion, the receiving portion is provided so as not to be displaced to the driving arm. In contrast, a slide support mechanism that supports the lost arm so as to be slidable in the arm length direction, and a slide operation device that slides the lost arm into a receiving position that can be received by the receiving portion and a receiving position that cannot be received according to the slide support mechanism. It is provided. The receiving portion is not displaced with respect to the drive arm as described above, but may be rotated with respect to the drive arm.

  Although the slide support mechanism is not particularly limited, a long hole formed in the lost arm or the drive arm and extending in the arm length direction, and a swinging shaft of the lost arm inserted through the long hole so as to be slidable in the arm length direction, The aspect comprised by is illustrated.

  According to the present invention, the receiving portion is provided so as not to be displaced to the drive arm, and the driving state of the valve is switched by displacing the lost arm between the receiving position and the disengagement position. There is no need to provide a switching pin (slidable receiving portion) or a pin holding portion for holding the switching pin so as to be slidable. Therefore, the drive arm can be reduced in weight and simplified, and the manufacturing cost of the drive arm can be reduced.

FIG. 1A is a side sectional view showing a state in which the lost arm is slid to the receiving position in the variable valve mechanism of the first embodiment, and FIG. 1B is a side sectional view showing a state in which the lost arm is displaced to the disengaged position. It is. FIG. 2A is a perspective view showing a lost arm body of the variable valve mechanism, and FIG. 2B is a perspective view showing a lost arm and a drive arm. FIGS. 3A to 3C are side sectional views showing the variable valve mechanism when the lost arm is slid from the receiving position to the disengaged position. 4A to 4C are side cross-sectional views showing the variable valve mechanism when the lost arm is slid from the disengaged position to the receiving position. FIG. 5A is a side sectional view showing a state in which the lost arm is slid to the receiving position in the variable valve mechanism of the second embodiment, and FIG. 5B is a side sectional view showing a state in which the lost arm is displaced to the disengaged position. It is. FIG. 6A is a perspective view showing a lost arm body of the variable valve mechanism, and FIG. 6B is a perspective view showing a lost arm and a drive arm. 7 (a) to 7 (c) are side cross-sectional views showing the variable valve mechanism when the lost arm is slid from the receiving position to the disengaged position. 8A to 8C are side cross-sectional views showing the variable valve mechanism when the lost arm is slid from the disengaged position to the receiving position.

Although the aspect of a slide actuator is not specifically limited, The following aspect is illustrated.
[I] The slide operating device is provided separately from the drive arm and the lost arm, and is provided with one actuator that receives the lost arm and presses it toward the position side, and is provided separately from the drive arm and the lost arm to disengage the lost arm. And the other actuator that presses to the position side, the lost arm is pressed by one actuator and not pressed by the other actuator, is slid to the receiving position, and is not pressed by one actuator, but is pressed by the other actuator. An aspect configured to slide to a disengaged position.
[Ii] The slide operating device includes an actuator that is separated from the drive arm and the lost arm and presses the lost arm toward the disengaged position side, and a return spring that biases the lost arm toward the position side. A mode in which the lost arm is slid to the disengaged position by the pressing, and the lost arm is slid to the position by the urging force of the return spring by releasing the pressing.

  In the above {i] and [ii], the actuator is provided separately from the drive arm and the lost arm because the arm can be reduced in weight and simplified. On the other hand, the spring may be provided separately from the drive arm and the lost arm, but is preferably provided on the drive arm or the lost arm. Because the spring is light, it is more advantageous to install it on one of the arms and simplify the overall structure of the variable valve mechanism than to provide both arms with a slight weight reduction. .

The following aspect is illustrated as a more specific aspect of said [ii].
[Iia] The drive arm is provided with a guide on which the lost arm can come into contact with the lost arm when the cam nose acts during the lost motion where the lost arm is arranged at the disengaged position. At the time of operation, the actuator is pressed against the actuator by the urging force of the return spring, so that it is kept in the disengaged position against the urging force. At the time of the nose action of the cam, it is pressed against the guide by the urging force of the return spring. A mode (Example 2) configured so as to be maintained against the disengaged position.
[Iib] At the time of lost motion in which the lost arm is disposed at the disengaged position, the lost arm is pressed against the actuator by the urging force of the return spring both during the cam base circle action and the nose action. (Example 1) It is comprised so that it may be maintained in a removal position against this urging | biasing force by continuing the said press, and the cancellation | release of the said press is controlled so that it may be performed at the time of a base circle action.

  According to [iia], even if the pressing by the actuator is released during the nose action during the lost motion, the lost arm swings while being maintained at the disengaged position by the guide, and slides to the receiving position during the base circle action. Therefore, it is not always necessary to release the pressure when the base circle is applied, and the pressure can be released at any timing including the time of the nose action. Therefore, the control of the actuator is simplified and the switching time can be shortened. On the other hand, according to [iib], such a guide becomes unnecessary.

  Although the specific mode of the drive arm is not particularly limited, the drive arm includes a receiving pin, and the portion on the return direction side of the rocking direction of the lost arm on the outer peripheral surface of the receiving pin constitutes the receiving portion, The aspect by which the part by the side of the dislocation position in the outer peripheral surface of a pin comprised the guide is illustrated.

  The actuator is not particularly limited, but an actuator provided with an electromagnetic solenoid, a hydraulic mechanism, a motor mechanism, or the like is exemplified.

The driving state of the valve when the lost arm slides to each of the receiving position and the disengagement position is not particularly limited, but the following mode is exemplified.
[A] A mode in which when the lost arm slides to the receiving position, the valve is driven according to the cam profile, and when the lost arm slides to the disengaged position, the driving is stopped.
[A] The variable valve mechanism includes a first cam that is the cam, and a second cam that drives the drive arm and has a nose lower than the first cam. When the lost arm slides to the receiving position, A mode in which the valve is driven in accordance with the profile of the cam and the valve is driven in accordance with the profile of the second cam when the lost arm slides to the disengaged position.

  The variable valve mechanism of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the configuration of the embodiment, and can be appropriately modified and embodied without departing from the spirit of the invention.

  FIG. 1A is a side cross-sectional view showing a state in which the lost arm 20 is slid to the arm tip side in the variable valve mechanism 1 of the first embodiment, and FIG. It is side surface sectional drawing which shows the state slid to the end side. FIGS. 1A and 1B are views of the variable valve mechanism 1 cut from the lateral center of the lost arm 20 as viewed from the side. The variable valve mechanism 1 opens and closes the valve 70 in cooperation with the valve spring by intermittently pressing the valve 70 of the internal combustion engine to which the valve spring (not shown) is attached. The variable valve mechanism 1 includes a cam 10 provided on a camshaft 9, a lost arm 20 that is swung when pressed by the cam 10, a drive arm 30 that drives a valve 70 when swung, and a drive arm 30. On the other hand, a slide support mechanism 40 that supports the lost arm 20 so as to be slidable in the arm length direction and a slide operation device 50 that slides the lost arm 20 in the arm length direction according to the slide support mechanism 40 are provided.

  The camshaft 9 is a shaft extending in the width direction of the lost arm 20 and is turned on once every two revolutions of the internal combustion engine. The cam 10 includes a base circle 11 having a circular cross-sectional shape and a nose 12 protruding from the base circle 11.

  The lost arm 20 includes a lost arm main body 21 and a roller 25 that is rotatably attached to a distal end portion of the lost arm 20 via a roller shaft 27 and a bearing 26. The time when the base circle 11 abuts on the roller 25 is when the base circle acts, and the time when the nose 12 abuts is when the nose acts. The lost arm 20 swings when the base circle 11 and the nose 12 abut against the roller 25 alternately.

  The lower surface of the drive arm base 31 is provided with a hemispherical recess 32 that is recessed upward, and the hemispherical recess 62 at the upper end of the plunger 61 of the lash adjuster 60 is inserted into the hemispherical recess 32, thereby 30 is supported by the plunger 61 so as to be swingable. A receiving portion 37 with which the lost arm 20 can come into contact is formed on the upper surface of the drive arm tip portion 35, and the stem end of the valve 70 is in contact with the lower surface of the drive arm tip portion 35.

  The slide support mechanism 40 has a long hole 42 formed in the lost arm 20 extending in the arm length direction, and is provided in the drive arm 30 so as to be slidable in the hole length direction (the arm length direction). The swing arm 43 of the lost arm 20 is configured. When the lost arm 20 slides to the arm tip side, the tip part comes into contact with the receiving part 37 of the drive arm 30 from above. The position where the contact comes into contact is the receiving position p1. Further, when the lost arm 20 is slid to the proximal side of the arm, the tip portion does not come into contact with the receiving portion 37 of the drive arm 30. The position where the contact does not occur is the disengagement position p2.

  The slide operating device 50 is a device that slides the lost arm 20 to the receiving position p1 and the disengaged position p2, and includes a return spring 52 that biases the lost arm 20 toward the receiving position p1 (arm tip side), and the lost arm. And an actuator 56 that presses 20 toward the disengagement position p2 (arm base end side). The return spring 52 includes a coil portion 54 that is externally fitted to a spring retainer 51 provided on the drive arm 30, a spring base portion 53 that extends from the base end of the coil portion 54 and contacts the drive arm 30, and a coil portion 54. And a spring tip 55 that extends from the tip and contacts the lost arm 20. The actuator 56 includes a body 57 and a rod 58 inserted into the body 57. Inside the body 57 is an electromagnetic solenoid (not shown) for feeding the rod 58 out of the body 57 when the actuator 56 is turned on, and for retracting the rod 58 into the body 57 when the actuator 56 is turned off. A spring (not shown) is installed.

  FIG. 2A is a perspective view showing the lost arm main body 21. The lost arm main body 21 includes a lost arm side portion 23 arranged in parallel in the left-right direction and a lost arm base portion 22 that connects base ends of the left and right lost arm side portions 23 to each other. A shaft hole 28 for attaching a roller shaft is provided through the front part of the left and right lost arm side parts 23. The long hole 42 penetrates the base side of the left and right lost arm side portions 23.

  FIG. 2B is a perspective view showing the lost arm 20 and the drive arm 30. The lost arm 20 is an inner arm disposed inside the drive arm 30, and the drive arm 30 is an outer arm disposed outside the lost arm 20. The drive arm 30 includes left and right drive arm side portions 33 arranged on the left and right sides of the lost arm 20, a drive arm tip portion 35 connecting the tip portions of the drive arm side portion 33, and left and right drive arm side portions 33. And a drive arm base 31 that connects the base ends of the two. The swing shaft 43 and the spring retainer 51 are attached so as not to be displaced to the base end side so as to penetrate the base end side of the left and right drive arm side portions 33 in the width direction.

  FIG. 3 shows a case where the lost arm 20 is slid from the receiving position p1 to the disengaged position p2. Specifically, as shown in FIG. 3A, the actuator 56 is turned on from the state where the lost arm 20 is disposed at the receiving position p1 by turning the actuator 56 off. The actuator 56 may be turned on at any time during the base circle action and the nose action. However, since the load is applied between the lost arm 20 and the receiving portion 37 during the nose action, the lost arm 20 It cannot slide and therefore the rod 58 cannot be extended. Therefore, in any case, the lost arm 20 slides to the disengagement position p2 when the rod 58 is extended during the base circle action as shown in FIG. 3 (b).

  When the lost arm 20 slides to the disengagement position p2, as shown in FIG. 3C, the lost arm 20 switches to a resting state in which the lost arm 20 swings (lost motion) with respect to the drive arm 30. After the lost arm 20 slides to the disengagement position p2, the lost arm 20 resists the urging force by being pressed against the rod 58 by the urging force of the return spring 52 during both the base circle action and the nose action. And maintained at the disengagement position p2.

  FIG. 4 shows when the lost arm 20 is slid from the disengagement position p2 to the receiving position p1. Specifically, as shown in FIG. 4 (a), the actuator 56 is turned on to turn the lost arm 20 into the disengagement position p2 (at the time of lost motion), and when the base circle is actuated in FIG. 4 (b). As shown, the actuator 56 is turned OFF and the rod 58 is retracted. As a result, the lost arm 20 slides to the receiving position p <b> 1 by the urging force of the return spring 52. This slide (actuator 56 is OFF) is controlled so that it is always performed when the base circle acts. Therefore, the distal end of the lost arm side portion 23 does not collide with the drive arm tip portion 35 from the arm proximal end side (displacement position p2 side).

  When the lost arm 20 slides to the receiving position p1, as shown in FIG. 4 (c), the tip of the lost arm side portion 23 pushes down the receiving portion 37 of the drive arm 30, so that both arms 20, 30 are moved. The drive state that swings together is switched. FIG. 4C shows a state where both arms 20 and 30 swing to the maximum lift direction side to lift the valve 70 to the maximum. Even in this state, the upper end of the distal end of the lost arm side portion 23 is applied on the extended line of the rod 58 in the feeding direction. Therefore, when the lost arm 20 is slid again to the disengagement position p2, the actuator 56 can be turned on at an arbitrary timing as described above. However, as described above, even if the actuator 56 is turned on during the nose action, the lost arm 20 always slides during the base circle action.

  According to the present embodiment, the receiving portion 37 is provided so as not to be displaced to the drive arm 30, and the driving state of the valve 70 is switched by displacing the lost arm 20 to the receiving position p1 and the disengagement position p2. In addition, there is no need to provide a switching pin (slidable receiving portion) or a pin holding portion for holding it slidably inside the drive arm 30. Therefore, the drive arm 30 can be reduced in weight and simplified, and the manufacturing cost of the drive arm 30 can be reduced.

  Next, Example 2 will be described. The present embodiment is different from the first embodiment in the following points and is the same in other points. FIG. 5A is a side cross-sectional view showing a state in which the lost arm 20 is slid to the arm tip side in the variable valve mechanism 2 of the present embodiment, and FIG. It is side surface sectional drawing which shows the state slid to the end side. 5 (a) and 5 (b) are views of the variable valve mechanism 2 cut from the lateral center of the lost arm 20 and viewed from the side. A receiving pin 36 is attached to the tip of the drive arm side portion 33. The upper part of the outer peripheral surface of the receiving pin 36 constitutes a receiving part 37. Further, the arm base end side (displacement position p2 side) portion of the outer peripheral surface of the receiving pin 36 constitutes a guide 38 with which the lost arm 20 abuts during the lost motion.

  FIG. 6A is a perspective view showing the lost arm main body 21, and FIG. 6B is a perspective view showing the lost arm 20 and the drive arm 30. The receiving pin 36 is attached so as not to be displaced to the tip portion so as to penetrate the tip portion of the left and right drive arm side portions 33 in the width direction. The receiving pin 36 may be rotatable or non-rotatable with respect to the tip portion of the drive arm side portion 33.

  FIG. 7 shows the case where the lost arm 20 is slid from the receiving position p1 to the disengaging position p2. Specifically, as shown in FIG. 7A, the actuator 56 is turned on from the state where the lost arm 20 is disposed at the receiving position p1 by turning the actuator 56 off. The actuator 56 may be turned on at any time during the base circle action and the nose action. However, since the load is applied between the lost arm 20 and the receiving portion 37 during the nose action, the lost arm 20 It cannot slide and therefore the rod 58 cannot be extended. Therefore, in any case, the lost arm 20 slides to the disengagement position p2 when the rod 58 is extended during the base circle action as shown in FIG. 7B. At the time of the base circle action after the sliding, the lost arm 20 is pressed against the rod 58 by the urging force of the return spring 52, and is maintained at the disengagement position p2 against the urging force.

  When the lost arm 20 slides to the disengagement position p2, as shown in FIG. 7C, the lost arm 20 is switched to a resting state in which the lost arm 20 swings (lost motion) with respect to the drive arm 30. During the nose action, the lost arm 20 is pressed against the guide 38 (the arm proximal end side of the receiving pin 36) by the urging force of the return spring 52, and is maintained at the disengaged position p2 against the urging force.

  FIG. 8 shows when the lost arm 20 is slid from the disengagement position p2 to the receiving position p1. Specifically, as shown in FIG. 8A, the actuator 56 is turned off and the rod 58 is retracted. This retraction may be performed during the base circle action of the cam 10 or during the nose action, but this figure shows the case where it is performed during the nose action. In this case, the lost arm 20 is pressed against the guide 38 (the arm proximal end side of the receiving pin 36) by the urging force of the return spring 52, so that the lost arm 20 resists the urging force until the base circle is operated. Thus, it swings (lost motion) with respect to the drive arm 30 while being maintained at the disengagement position p2. Therefore, only the rod 58 is retracted first. When the base circle acts, the lost arm 20 slides to the receiving position p1 (arm tip side) by the urging force of the return spring 52 as shown in FIG. 8B. Therefore, the distal end of the lost arm side portion 23 does not collide with the drive arm tip portion 35 from the arm proximal end side.

  When the lost arm 20 slides to the receiving position p1, as shown in FIG. 8C, the tip of the lost arm side portion 23 pushes down the receiving portion 37 (the upper surface of the receiving pin 36) of the drive arm 30. Thus, the arm 20 and 30 are switched to a driving state in which the arms 20 and 30 swing together.

  According to the present embodiment, since the guide 38 is provided, the lost arm 20 is maintained at the disengaged position p2 by the guide 38 even when the actuator 56 is turned off and the pressing is released during the nose action during the lost motion. It swings while sliding to the receiving position p1 when the base circle acts. Therefore, it is not always necessary to turn off the actuator 56 at the time of the base circle action, and the actuator 56 can be turned off at any timing including the time of the nose action. Therefore, the control of the actuator 56 is simplified, the switching time can be shortened, and switching at a higher rotation is possible.

For example, the first and second embodiments may be modified as follows.
[Modification 1] Instead of providing the guide 38 on the receiving pin 36, the guide 38 may be provided on the drive arm tip 35 or the drive arm side 33.
[Modification 2] Instead of providing a long hole 42 in the lost arm body 21 and attaching the swing shaft 43 to the drive arm 30 so as not to displace it, the swing arm 43 is attached to the lost arm body 21 so as not to be displaced and driven. A long hole 42 may be provided in the arm 30.
[Modification 3] When the lost arm 20 slides to the disengagement position p2 by providing the camshaft 9 with a second cam that drives the drive arm 30 having a nose lower than that of the cam 10, instead of entering a resting state, You may make it be in the 2nd drive state which drives the valve 70 according to the profile of a 2nd cam.

1 Variable valve mechanism (Example 1)
2 Variable valve mechanism (Example 2)
DESCRIPTION OF SYMBOLS 10 Cam 20 Lost arm 30 Drive arm 36 Receiving pin 37 Receiving part 38 Guide 40 Slide support mechanism 42 Long hole 43 Oscillating shaft 50 Slide operating device 52 Return spring 56 Actuator 70 Valve p1 Receiving position p2 Detaching position

Claims (6)

A drive arm (30) comprising a receiving part (37) and driving the valve (70) when swung;
When the cam (10) is pressed and swings and is received by the receiving part (37), the drive arm (30) is swung together, and if it is not received by the receiving part (37), the lost arm (20) is in lost motion. In a variable valve mechanism for an internal combustion engine,
A slide support mechanism (40) provided so that the receiving portion (37) is not displaced to the drive arm (30), and the lost arm (20) is slidably supported to the drive arm (30) in the arm length direction; According to the slide support mechanism (40), there is provided a slide operating device (50) for sliding the lost arm (20) to a receiving position (p1) received by the receiving portion (37) and a disengaged position (p2) not received. A variable valve mechanism for an internal combustion engine.   The slide support mechanism (40) has a long hole (42) formed in the lost arm (20) or the drive arm (30) and extending in the arm length direction, and is slidable in the arm length direction in the long hole (42). The variable valve mechanism for an internal combustion engine according to claim 1, comprising a swinging shaft (43) of the lost arm (20) inserted therethrough.   The slide actuating device (50) is provided separately from the drive arm (30) and the lost arm (20) to press the lost arm (20) toward the disengaged position (p2), and the lost arm ( 20) a return spring (52) that urges the receiving position (p1) toward the receiving position (p1), and by pressing the actuator (56), the lost arm (20) is slid to the disengaged position (p2). 3. The variable valve mechanism for an internal combustion engine according to claim 1, wherein the lost arm (20) is slid to the position (p1) by being released by the urging force of the return spring (52). The drive arm (30) is provided with a guide (38) with which the lost arm (20) can come into contact with the nose of the cam (10) during the lost motion when the lost arm (20) is arranged at the disengagement position (p2). ,
In the lost motion, the lost arm (20) is pressed against the actuator (56) by the urging force of the return spring (52) when the cam (10) is in the base circle action, so that the lost arm (20) is moved away from the urging force. When the nose action of the cam (10) is maintained, it is pressed against the guide (38) by the urging force of the return spring (52) and is maintained at the disengaged position (p2) against the urging force. The variable valve mechanism for an internal combustion engine according to claim 3, configured as described above. At the time of the lost motion in which the lost arm (20) is arranged at the disengagement position (p2), the lost arm (20) has a return spring (52) both during the base circle action and the nose action of the cam (10). ) Is pressed against the actuator (56) by the urging force, and is kept in the pressing position so as to be maintained at the disengaged position (p2) against the urging force.
The variable valve mechanism for an internal combustion engine according to claim 3, wherein the release of the pressing is controlled so as to be performed when the base circle acts.   The drive arm (30) includes a receiving pin (36), and a portion on the return direction side of the swinging direction of the lost arm (20) on the outer peripheral surface of the receiving pin (36) forms a receiving portion (37). The variable valve mechanism for an internal combustion engine according to claim 4, wherein a portion of the outer peripheral surface of the receiving pin (36) on the side of the disengagement position (p2) constitutes a guide (38).

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