JP5985889B2 - Valve operating device and rocker arm - Google Patents

Description

  The present invention relates to a valve gear and a rocker arm used in an internal combustion engine such as an automobile or a motorcycle.

A valve operating device for an internal combustion engine includes a rocker arm for operating a valve by a rotating cam (see Patent Document 1). The rocker arm is sometimes called a finger follower.
As a support structure of the rocker arm, there is a structure that does not have a rocker shaft for supporting the rocker arm, in addition to a rocker arm that is rotatably supported by the rocker shaft at an intermediate position in the longitudinal direction of the rocker arm.

  In the case of the latter without the rocker shaft, the rocker arm is supported at one end in the longitudinal direction from below (opposite side of the cam) by the lash adjuster, and at the other end in the longitudinal direction by the valve (opposite side of the cam). Supported by. The clearance (valve clearance) between the valve and the rocker arm is adjusted to 0 by the lash adjuster.

  The cam for operating the valve is disposed so as to contact the rocker arm from above the rocker arm. Thereby, the cam contact surface of the rocker arm and the cam are in surface contact, and the posture of the rocker arm is stabilized.

JP 2011-140927 A JP 2006-152911 A

  Conventionally, in a valve gear that does not have a rocker shaft for supporting a rocker arm, only one rocker arm and one lash adjuster are used for one valve.

  However, since the two valves on the intake side / exhaust side are often arranged in parallel, two pairs of valves on the left and right can be operated simply by using one rocker arm and one lash adjuster. If it is possible, the structure of the valve operating device is simplified and the cost can be reduced.

  Here, in order to operate two valves by one rocker arm, a valve bridge connected to the two valves is provided, for example, in Patent Document 2. By driving the valve bridge connected to the two valves by one rocker arm, the two valves can be operated by one rocker arm.

  However, conventionally, a valve bridge is used only for a valve operating device having a rocker shaft for supporting a rocker arm, as shown in Patent Document 2, to support the rocker arm. The valve bridge was not used in the valve operating apparatus that does not have the rocker shaft.

  In a valve operating apparatus that does not have a rocker shaft for supporting a rocker arm, as described above, the rocker arm is supported by the lash adjuster and the valve from the lower side (opposite side of the cam), and the upper cam ( Attitude control is performed by a cam piece or a sub cam). For this reason, in order to adjust the valve clearance (tuppet clearance) between the rocker arm and the valve tip (upper end) to zero, one lash adjuster and one rocker arm are required for each of the two valves in the pair. Met.

  In other words, the height of each pair of valves may not be the same due to manufacturing errors and other factors (temperature, dynamic behavior, etc.), so appropriate valve clearance (tuppet clearance) for different height valves In order to adjust to the above, it is necessary to provide a rocker arm for each of the pair of valves, which hinders the simplification of the valve gear.

  In view of this, the present invention provides a valve operating apparatus that does not have a rocker shaft for supporting a rocker arm, and allows the structure of the valve operating apparatus to be simplified while allowing differences in the tip positions of the pair of valves due to manufacturing errors. The purpose is to plan.

(1) The present invention is a valve operating apparatus including a rocker arm that operates a valve by a rotating cam, and the rocker arm receives a force from the cam and is operated from a side opposite to the cam by a valve clearance adjuster. A rocker arm body that is supported, and a valve bridge that is supported by a pair of valves from the opposite side of the cam, and the rocker arm virtually connects the tip positions of the pair of valves that support the rocker arm. From the opposite side of the cam by the pair of valves and the valve clearance adjuster in a state in which an inclination of a part or the whole of the rocker arm due to the inclination of the straight line with respect to the axial direction of the cam is allowed. A valve operating device that is supported.

In the present invention, the rocker arm receives force from the cam and is supported from the opposite side of the cam by the valve clearance adjuster and the valve bridge, so that the rocker shaft is unnecessary.
And even if there is a difference in the tip position of each pair of valves that support the rocker arm, the rocker arm adjusts the tappet clearance to zero for each pair of valves by tilting a part or the whole of the rocker arm. can do.
Therefore, the structure of the valve operating device can be simplified while allowing a manufacturing error in the height of the pair of valves.

(2) In the rocker arm, a virtual line connecting the tip positions of the pair of valves supporting the rocker arm is inclined with respect to the axial direction of the cam. It is preferable to be configured to be allowed to tilt with respect to the main body.
In this case, when there is a difference in the tip positions of the pair of valves supporting the rocker arm, the valve bridge can be inclined with respect to the rocker arm body.

(3) In the rocker arm, a virtual line connecting the tip positions of the pair of valves that support the rocker arm is inclined with respect to the axial direction of the cam, so that the valve bridge is connected to the rocker arm. It is preferable that a joint portion for connecting the rocker arm main body and the valve bridge is provided so as to allow tilting with respect to the main body.
In this case, the valve bridge can be inclined with respect to the rocker arm body with the joint portion as a fulcrum.

(4) The joint part is preferably a spherical joint part.

(5) The joint portion can change a contact position between the rocker arm body and the valve bridge in a longitudinal direction of the rocker arm body in accordance with the operation of the rocker arm body driven by the cam. It is preferable to be configured as described above.

(6) The rocker arm allows an inclination of the entire rocker arm due to an imaginary line connecting the tip positions of the pair of valves supporting the rocker arm being inclined with respect to the axial direction of the cam. In this state, the pair of valves and the valve clearance adjuster are supported from the opposite side of the cam, and the rocker arm body has a contact portion that receives a force from the cam, and the contact portion is the cam It is preferable that the center portion of the contact portion has an R shape that protrudes toward the cam rather than both ends of the contact portion in a direction parallel to the rotation axis.
In this case, even if the entire rocker arm is tilted, a stable contact state between the rocker arm and the cam can be maintained.

(7) It is preferable that at least a part of the rocker arm body is integrally formed with the valve bridge. In this case, the rocker arm body can be tilted according to the tilt of the valve bridge.

(8) In the rocker arm, a portion of the valve bridge and the rocker arm main body formed integrally with the valve bridge is formed by bending a single plate member having a predetermined shape. preferable. In this case, it becomes easy to manufacture a rocker arm having a valve bridge.

(9) The present invention from another viewpoint is a rocker arm that is used as the rocker arm in the valve gear according to any one of (1) to (8).

  According to the present invention, even with a rocker arm that is not supported by a rocker shaft, manufacturing errors in the height of the pair of valves can be allowed, and the structure of the valve gear can be simplified.

It is a perspective view of the valve gear which concerns on 1st Embodiment. It is a perspective view of the rocker arm concerning a 1st embodiment. It is a right view of the valve gear which concerns on 1st Embodiment. It is a top view of the valve gear which concerns on 1st Embodiment (a cam is abbreviate | omitted). (A) is the VV sectional view taken on the line of FIG. 4, (b) is an enlarged view of the contact part in (a), (c) is explanatory drawing of the rotating roller whose outer peripheral surface is flat. is there. It is an expanded view of the support body which comprises a rocker arm main body. It is a perspective view of the valve gear which concerns on 2nd Embodiment. It is a top view of the valve gear which concerns on 2nd Embodiment (a cam is abbreviate | omitted). It is the IX-IX sectional view taken on the line of FIG. It is a perspective view of the valve gear which concerns on 3rd Embodiment. (A) is the XI-XI sectional view taken on the line of FIG. 10, (b) is an enlarged view of the contact part in (a). (A) is sectional drawing of the joint part in the direction orthogonal to Fig.11 (a), (b) is a figure which shows the change of the contact position P2 in (a). It is sectional drawing equivalent to Fig.11 (a) about the valve gear which concerns on the modification of 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<First embodiment>
1-6 has shown the valve gear 1 which concerns on 1st Embodiment. The valve gear 1 has a rocker arm 11 that operates valves (valve stems) 61 and 62 that are paired in an internal combustion engine by the rotational force of a cam 5.

  The rocker arm 11 includes a rocker arm main body 3 and a valve bridge 4. In the first embodiment, the rocker arm body 3 and the valve bridge 4 are integrally connected.

In the valve operating apparatus 1, the rocker shaft which supports a rocker arm is not provided.
The rocker arm body 3 receives a force from the cam 5 rotating with the rotation of the cam rotation shaft 51 from above, and is lowered by a lash adjuster 7 (fulcrum P1) on one end side in the longitudinal direction B of the rocker arm body 3. It is supported from the opposite side of the cam 5.
The valve bridge 4 is provided on the other end side in the longitudinal direction B of the rocker arm body 3. The valve bridge 4 is formed long in a direction A (a direction in which a pair of left and right valves 61 and 62 supporting the valve bridge 4 are arranged) orthogonal to the longitudinal direction B of the rocker arm body 3. Thereby, the valve bridge 4 can connect the front-end | tips of a pair of valve | bulb 61,62 in bridge | crosslinking form.

In this manner, the rocker arm 11 is supported from below (on the opposite side of the cam 5) by the pair of left and right valves 61 and 62 in the valve bridge 4 portion, and is lowered by the lash adjuster 7 in the rocker arm main body 3 portion ( It is supported from the opposite side of the cam 5).
Therefore, as a whole, the rocker arm 11 is supported from below (opposite side of the cam 5) at three locations of the pair of left and right valves 61 and 62 and the lash adjuster 7. Therefore, the cam 5 is in contact from above, so that a state in which posture control is performed can be obtained without a rocker shaft.

In addition, although the hydraulic lash adjuster is used as the lash adjuster 7 of this embodiment, you may use a mechanical lash adjuster. The lash adjuster 7 can automatically adjust the valve clearance (tuppet clearance) between the rocker arm 11 and the valves 61 and 62 to zero.
Further, instead of the lash adjuster 7 that can automatically adjust the valve clearance, means for manually adjusting the valve clearance such as a screw nut may be used. In the case of means for manually adjusting the valve clearance such as a screw nut, the valve clearance can be adjusted to a predetermined amount (not necessarily 0).
Thus, what supports the rocker arm main body 3 at the fulcrum P1 is not limited to the lash adjuster 7, but may be a valve clearance adjuster that adjusts the valve clearance.

  The rocker arm body 3 includes a rotating roller 2 that functions as a contact portion that receives a force from the rotating cam 5, and a support body 30 that rotatably supports the rotating roller 2.

The support 30 is configured integrally with a pair of left and right side walls 31, 32 facing each other with a predetermined interval, and a connecting portion 33 serving as a bottom between the pair of side walls 31, 32. .
The rotating roller 2 is disposed between the left and right side walls 31 and 32. The rotating roller 2 has support shafts 20a that protrude on both sides in the axial direction. The rotating roller 2 is configured such that its outer peripheral side is rotatable with respect to the support shaft 20a. Fitting holes 31 a and 32 a into which the support shaft 20 a of the rotating roller 2 is fitted are formed in the left and right side walls 31 and 32. The rotation roller 2 is rotatably supported with respect to the support body 30 by fitting the support shaft 20a of the rotation roller 2 into the fitting holes 31a and 32a.

In the rocker arm 11, the rotary roller 2 is disposed between a portion 33a (fulcrum P1) supported by the lash adjuster 7 and a portion (valve bridge 4) supported by the pair of valves 61 and 62. .
Therefore, when the rocker arm 11 receives a pressing force from the cam 5 via the rotating roller 2, the valve bridge 4 side is downward (cam) with a portion (a pivot portion described later) 33a supported by the lash adjuster 7 as a fulcrum P1. (Opposite side of 5). When the valve bridge 4 is pushed down, the pair of valves 61 and 62 can simultaneously move downward to perform an opening / closing operation.

  The connecting portion 33 of the support 30 has a pivot portion (support portion) 33 a so as to be supported from below (the opposite side of the cam 5) by the lash adjuster 7. The pivot portion 33a swells upward (cam side) from the connecting portion 33 and is formed in a hemispherical shape. The lash adjuster 7 has a hemispherical tip 72 biased upward (cam side) by hydraulic pressure or the like with respect to the inner surface side of the pivot portion 33a that is recessed in a hemispherical shape when viewed from below (opposite the cam 5). Thus, they are in contact with the bottom side (see FIG. 3). That is, a spherical joint structure is adopted as a connection between the pivot portion 33a and the tip portion 72 of the lash adjuster 7.

  The valve bridge 4 is formed integrally with the connecting portion 33 of the support 30 and has a pair of abutting portions 41 and 42 with which the flat tips 61a and 62a of the pair of valves 61 and 62 abut. ing.

  The valve bridge 4 includes a wall portion 43 that rises along the longitudinal direction B of the valve bridge 4 on the distal end side in the longitudinal direction B of the rocker arm 4. The wall 43 is formed to rise by bending a plate member constituting the valve bridge 4. In the first embodiment, the wall portion 43 is formed in a range from one abutting portion 41 to the other abutting portion 42, but the wall portion 43 has a shorter length in the longitudinal direction. Or it may be longer. By providing the wall portion 43 on the valve bridge 4, the strength of the valve bridge 4 is reinforced.

  As shown in FIGS. 5A and 5B, the contact portions 41 and 42 have convex contact curved surfaces 41 a and 42 a that protrude toward the valves 61 and 62 of the valve bridge 4.

  Each of the contact curved surfaces 41a and 42a is a downward R surface having a constant curvature. The R surfaces 41a and 42a constituting the contact curved surface are such that the central portion in the longitudinal direction A (the direction in which the pair of valves 61 and 62 are arranged) A of the valve bridge 4 is lower than both end portions in the same direction A. The protrusion has a large crown shape.

  Since the contact surfaces that contact the flat tips 61a, 62a of the pair of valves 61, 62 are downward convex curved surfaces 41a, 42a, the tips 61a, 62a of the pair of valves 61, 62, respectively, as will be described later. Even when the positions of are different, the tips 61a and 62a of the pair of valves 61 and 62 can be stably brought into contact with each other.

  Further, in the first embodiment, there is no one that restricts the change in the contact position of the convex curved surfaces 41 a and 42 a with respect to the valve tips 61 a and 62 a in the longitudinal direction of the rocker arm body 3. Therefore, as shown in FIG. 3, the convex curved surfaces 41a and 42a slide (slide) with respect to the valve tips 61a and 62a as the rocker arm body 3 driven by the cam 5 swings up and down. The contact positions of the curved surfaces 41a and 42a and the valve tips 61a and 62a change.

  As described above, in the first embodiment, the contact state between the valve bridge 4 and the valves 61 and 62 corresponds to the valves 61 and 62 as the rocker arm body 3 swings up and down around the fulcrum P1. The rocker arm 11 is allowed to move (slide) in the contact position of the valve bridge 4 with respect to the rocker arm valve tip 61a, 62a, and the rocker arm 11 can be inclined according to the difference in position between the rocker arm valve tips 61a and 62a.

  In the first embodiment, the contact curved surfaces 41a and 42a are flat in the longitudinal direction B of the rocker arm 11, but the center of the contact curved surfaces 41a and 42a may be curved downwardly projecting in the direction B. Good. That is, the contact curved surfaces 41a and 42a may be downward hemispheres. When the contact curved surfaces 41a and 42a are downward hemispherical surfaces, the contact curved surfaces 41a and 42a may have different curvatures in the directions A and B.

  Further, as shown in FIGS. 4 and 5A, the outer peripheral surface 21 of the rotating roller 2 serving as a contact portion that receives the force from the cam 5 is in the axial direction of the rotating roller 2 (parallel to the rotating shaft 51 of the cam). Direction; a direction parallel to direction A), the central portion in the axial direction of the outer peripheral surface 21 has an R shape (crown shape) that protrudes in the roller outer diameter direction (cam 5 side) from both axial end portions of the outer peripheral surface. ing. The R shape of the outer peripheral surface 21 may or may not have a constant curvature throughout the R shape.

Now, the height positions of the tips 61a and 62a of the pair of valves 61 and 62 may differ due to manufacturing errors of the valves.
Here, when the height positions of the pair of valve tips 61 a and 62 a are aligned, a line (virtual line) connecting the pair of valve tips 61 a and 62 a is parallel to the axial direction A of the cam rotation shaft 51. become. Therefore, for example, when the cam rotation shaft 51 is set in the horizontal direction, if the height positions of the pair of valve tips 61a and 62a are aligned, a line connecting the pair of valve tips 61a and 62a (virtual line) ) Is also horizontal.
On the other hand, if the height positions of the pair of valve tips 61 a and 62 a are different, a line (virtual line) connecting the pair of valve tips 61 a and 62 a extends in the axial direction A of the cam rotation shaft 51. On the other hand, it is inclined and non-parallel.

  In the rocker arm 11 according to the first embodiment, even if the height positions of the pair of valves 61 and 62 are different from each other, the pair of contact curved surfaces 41a and 42a in the valve bridge 4 are different from each other in the pair of valves 61 and 62. In conformity with the height position, the valve clearances (tuppet clearances; gaps between the contact curved surfaces 41a and 42a and the tips 61a and 62a of the valves 61 and 62) in the two valves 61 and 62 may be zero. it can.

  That is, the rocker arm 11 according to the first embodiment is not supported by the rocker shaft, and the outer peripheral surface of the rotating roller 2 has an R shape in which the central portion in the axial direction of the rotating roller 2 protrudes. It is allowed to tilt left and right around the portion 33a (spherical joint) supported by the lash adjuster 7.

  Here, as shown in FIG.5 (c), when the outer peripheral surface 21 of the rotating roller 2 is flat in the axial direction (direction parallel to the direction A) of the rotating roller 2, the outer peripheral surface 21 of the rotating roller 2 is Similarly, the entire axial direction contacts the cam 5 which is flat in the axial direction. Then, the posture of the rocker arm 11 is restricted by the cam 5 that is flat in the axial direction, and takes an inclined posture even if the height positions of the tips 61a and 62a of the pair of valves 61 and 62 are different. Becomes difficult. If the rocker arm 11 is not tilted to the left and right, the valve clearance (tuppet clearance) does not become zero for the valve having the lower tip 61a, 62a in the pair of valves 61, 62.

  Further, in the case of the rotating roller 2 having an outer circumferential shape that is flat in the axial direction shown in FIG. 5C, the entire rocker arm 11 is different in the height positions of the tips 61a and 62a of the pair of valves 61 and 62, respectively. If tilted to fit, the valve clearance (tuppet clearance) will be zero for each of the pair of valves 61,62. However, the outer peripheral surface 21 of the flat rotating roller 2 is not preferable because only the end portion in the axial direction is biased against the cam 5 and the contact state between the cam 5 and the rotating roller 2 becomes unstable.

  On the other hand, in the rocker arm 11 according to the first embodiment, the outer peripheral surface 21 of the rotating roller 2 has an R shape in which the central portion in the axial direction of the rotating roller 2 protrudes toward the cam 5. The contact structure between 2 and the cam 5 is in a contact state between an R shape (curved surface shape) and a flat surface. Therefore, the rocker arm 11 can be smoothly tilted to the left and right so as to be adapted to the difference in the height positions of the tips 61a and 62a of the pair of valves 61 and 62, respectively. And even if the rocker arm 11 is tilted to the left and right, the rotary roller 2 having the R shape with the axial center portion protruding maintains the state in which the axial center portion stably contacts the cam 5. Can do.

  Further, in the first embodiment, the positions of the tips 61a and 62a of the pair of valves 61 and 62 are different, so that the valve bridge 4 is smoothly tilted to the left and right, and the surface direction of the valve bridge 4 is Even if it becomes no longer orthogonal to the longitudinal direction of 61, 61, the contact surfaces that contact the flat tips 61a, 62a of the pair of valves 61, 62 are downward convex curved surfaces 41a, 42b. , 62 can be stably brought into contact with the flat tips 61a, 62a.

Thus, in 1st Embodiment, the contact state of the rotating roller 2 with respect to the cam 5, and the contact state with respect to the valves 61 and 62 are contact of the convex curve with respect to a flat surface. Therefore, the entire rocker arm 11 is allowed to tilt left and right with the pivot portion (support portion) 33a as a fulcrum.
Further, the rocker arm 11 is stably supported from below by the pair of valves 61 and 62 and the lash adjuster 7 and is sandwiched by the upper cam 5 so that the entire rocker arm 11 is inclined to the left and right. However, the movement for operating the valves 61 and 62 can be performed while maintaining a stable posture as a whole.

Further, the rocker arm 11 according to the first embodiment is advantageous because the support body 30 constituting a part of the rocker arm body 3 is integrally formed with the valve bridge 4, so that the number of parts is reduced.
Further, since the support 30 and the valve bridge 4 are integrally formed, as shown in FIG. 6, a single plate member formed in a predetermined shape so as to include a portion that becomes the support 30 and the valve bridge 4. By bending 101 along the dotted lines M1, M2, and M3 shown in FIG. 6, both the support 30 and the valve bridge 4 can be obtained.
That is, the support 30 and the valve bridge 4 can be obtained simply by adding a process such as a bending process for forming the valve bridge 4 in the process of performing the bending process for forming the support body 30.

<Second Embodiment>
7 to 9 show the valve gear 1 according to the second embodiment. In the second embodiment, the rocker arm body 3 constituting the rocker arm 11 and the valve bridge 4 are formed separately.

The rocker arm body 3 has a pivot portion (support portion) 35 that swells in a hemispherical shape toward the upper side (cam side) and is recessed in a hemispherical shape when viewed from below at the distal end portion connected to the valve bridge 4. ing.
As shown in FIG. 9, the pivot portion 35 has a concave spherical surface 35a that is recessed upward (cam side) when viewed from below. The valve bridge 4 has a convex spherical portion 45 that protrudes toward the concave spherical surface 35a at an intermediate position between the contact portions 41 and 42 (a central position in the longitudinal direction of the valve bridge 4). The convex spherical surface 45 may be formed on the rocker arm main body, and the concave spherical surface 35 a may be formed on the valve bridge 4.

  In the valve operating apparatus 1 according to the second embodiment, the rocker arm body 3 and the valve bridge 4 are connected by a joint portion including a convex spherical portion 45 and a concave spherical surface 35a. This joint portion is a spherical joint portion in which the convex spherical portion 45 is inserted into the concave spherical surface 35a.

  A clearance that allows the inclination of the valve bridge 4 is secured between the rocker arm body 3 and the valve bridge 4 except for the joint portion.

  Therefore, the valve bridge 4 can be inclined with respect to the rocker arm body 3 via the joint portion.

  Further, in the second embodiment, the rotation roller 2 included in the rocker arm body 3 has an outer peripheral surface 21 that is not in an R shape in which the central portion in the axial direction protrudes in the outer diameter direction as in the first embodiment, but in the axial direction. As a result, it is formed flat. Therefore, the entire outer circumferential surface 21 of the rotating roller 2 is in contact with the cam 5 which is also flat in the axial direction.

  The configuration of the rocker arm body 3 of the second embodiment is the same as the configuration of the rocker arm body 3 of the first embodiment except for the points described above as the second embodiment.

Similar to the first embodiment, the valve bridge 4 of the second embodiment has a pair of contact portions 41 and 42 with which the flat tips 61a and 62a of the pair of valves 61 and 62 contact.
As shown in FIG. 9, the contact portions 41 and 42 have convex spherical surfaces 41a and 42a protruding downward.
Since the contact surfaces that contact the flat tips 61a and 62a of the pair of valves 61 and 62 are downward convex convex spherical surfaces 41a and 42a, respectively, as in the first embodiment, Even when the positions of the tips 61a and 62a are different, the tips 61a and 62a of the pair of valves 61 and 62 can be stably brought into contact with each other.

  Also in the second embodiment, there is nothing that regulates the change in the contact position of the convex curved surfaces 41a, 42a with respect to the valve tips 61a, 62a in the longitudinal direction of the rocker arm body 3. Therefore, as in the first embodiment, the convex curved surfaces 41a and 42a slide (slide) with respect to the valve tips 61a and 62a as the rocker arm body 3 driven by the cam 5 swings up and down. The contact position between the convex curved surfaces 41a and 42a and the valve tips 61a and 62a changes.

  Therefore, also in the second embodiment, the contact state between the valve bridge 4 and the valves 61 and 62 is caused by the up and down swinging motion of the rocker arm body 3 with the fulcrum P1 as the swing center. The movement of the contact position of the valve bridge 4 with respect to (slide) is allowed, and the inclination of the valve bridge 4 corresponding to the difference in the positions of the rocker arm valve tips 61a and 62a is allowed.

  That is, in the valve gear 1 of the second embodiment, when the height positions of the pair of valves 61 and 62 are different, the valve bridge 4 that is a separate body from the rocker arm body 3 is The rocker arm body 3 is tilted to the left and right with the joint portion as a fulcrum so as to match the height positions of the valves 61 and 62. By tilting the valve bridge 4, the pair of contact curved surfaces 41 a and 42 a in the valve bridge 4 can make the valve clearances (tuppet clearances) in the two valves 61 and 62 both zero.

  In the second embodiment, since the outer peripheral surface 21 of the rotating roller 2 is flat when viewed in the axial direction, the posture of the rocker arm body 3 is in a state regulated by the cam 3 in a horizontal state. Therefore, in the second embodiment, the rocker arm 11 is such that the portion of the valve bridge 4 is partially inclined to the left and right with respect to the rocker arm body 3 whose posture is regulated with the joint portion as a fulcrum.

  Further, in the second embodiment, the positions of the tips 61a and 62a of the pair of valves 61 and 62 are different, so that the valve bridge 4 can be smoothly inclined to the left and right, and the surface direction of the valve bridge 4 Even if it becomes no longer orthogonal to the longitudinal direction of 61, 61, the contact surfaces that contact the flat tips 61a, 62a of the pair of valves 61, 62 are the convex convex spherical surfaces 41a, 42b. The flat tips 61a and 62a of 61 and 62 can be stably brought into contact with each other.

As described above, in the second embodiment, the valve bridge 4 can be partially inclined in the rocker arm 11 corresponding to the difference in the positions of the tips 61a and 62a of the pair of valves 61 and 62. The inclination of the main body 3 can be avoided. Since the rocker arm body 3 does not tilt, the stable contact state between the cam 5 and the rotating roller 2 can be maintained even if the outer peripheral surface of the rotating roller 2 is flat in the axial direction.
The rocker arm 11 is maintained in a state where the rocker arm 11 is stably supported from below by the pair of valves 61 and 62 and the lash adjuster 7 by partially tilting the valve bridge 4 portion.

  Moreover, in 2nd Embodiment, it has the rotation control parts 101 and 102 which control that the valve bridge 4 rotates horizontally around the axis C parallel to the longitudinal direction of the valves 61 and 62 centering on the joint part. .

The rotation restricting portions 101 and 102 are provided on the valve bridge 4. The rotation restricting portions 101 and 102 are arranged at lateral positions on both sides (left and right sides) in the width direction on the distal end side of the rocker arm body 3. The rotation restricting portions 101 and 102 may be provided on the rocker arm main body 3 side.
The rotation restricting portions 101 and 102 allow the inclination of the valve bridge 4 to cope with the difference in the positions of the tips 61a and 62a of the pair of valves 61 and 62, but the valve valve bridge 4 is largely horizontal around the axis C. In order to prevent the rotation, the side walls 31 and 32 of the rocker arm body 3 are provided with a clearance.

  By providing the rotation restricting portions 101 and 102, even if the rocker arm main body 3 and the valve bridge 4 are connected by the spherical joint portion, the movement allowed for the valve bridge 4 is limited to the tilt to the left and right. can do.

<Third Embodiment>
10 to 12 show the valve gear 1 according to the third embodiment. Also in the third embodiment, similarly to the second embodiment, the rocker arm main body 3 constituting the rocker arm 11 and the valve bridge 4 are formed as separate bodies.

  The third embodiment is different from the second embodiment in the structure of the joint part that connects the rocker arm body 3 and the valve bridge 4 and the structure of the rotation restricting parts 101 and 102. Points that are not particularly described in the third embodiment are the same as those in the second embodiment.

The joint portion of the third embodiment includes a convex spherical surface (convex curved surface) 36 that protrudes from the distal end portion of the rocker arm body 3 toward the valve bridge 4, and a receiving surface (R groove) 50 that is recessed downward in the valve bridge 4. , Is composed of.
The receiving surface 50 is a surface with which the convex spherical surface 36 abuts. As shown in FIG. 12, the receiving surface 50 has a contact position P <b> 2 of the convex spherical surface 36 in the longitudinal direction of the rocker arm body 3 in accordance with the vertical rocking motion of the rocker arm body 3 with the pivot point P <b> 1 as the rocking center. The rocker arm body 3 has a predetermined length in the longitudinal direction B so as to be changeable in the direction B.
The receiving surface 50 may be formed on the rocker arm body 3 and the convex spherical surface (convex curved surface) 36 may be formed on the valve bridge 4.

  In the third embodiment, the rotation restricting portions 101 and 102 are not provided at the positions where the rotation restricting portions 101 and 102 are provided in the second embodiment. Instead, on the valve 61 and 62 side surfaces of the abutting portions 41 and 42, the top ends 61a and 62a of the valves 61 and 62 can be inserted from below (opposite side of the cam 5). Concave portions 41b and 42b which are recessed toward the cam 5 side) are formed. The distal ends 61a and 62 of the pair of valves 61 and 62 are inserted into the recesses 41b and 42b, so that the outer peripheral surfaces of the valves 61 and 612 and the inner peripheral surfaces of the recesses 41b and 42b come into contact with each other. , Horizontal rotation around the axis C is prevented. That is, the concave portions 41 b and 42 b function as a rotation restricting portion of the valve bridge 4.

  In the third embodiment, the convex spherical surfaces 41a and 42a in the pair of contact portions 41 and 42 that contact the tips 61a and 62a of the pair of valves 61 and 62 are recessed portions 41b that are recessed upward (cam side). , 42b.

  In the third embodiment, since the valves 61 and 62 are inserted into the recesses 41 b and 42 b of the valve bridge 4, as the rocker arm body 3 driven by the cam 5 moves up and down, The contact positions of the valve tips 61 a and 62 a are restricted from changing in the longitudinal direction of the rocker arm body 3.

Instead, as shown in FIG. 12, in the third embodiment, the contact position P <b> 2 between the rocker arm body 3 and the valve bridge 4 causes the rocker arm body 3 driven by the cam 5 to swing up and down. Accordingly, the rocker arm body 3 can be changed in the longitudinal direction.
That is, the contact position P <b> 2 of the convex spherical surface 36 changes along the longitudinal direction B of the receiving surface 50 as the rocker arm body 3 swings up and down around the fulcrum P <b> 1.
Therefore, in the third embodiment, the contact state between the rocker arm main body 3 and the valve bridge 4 is the same as the rocker arm main body 3 and the rocker arm main body 3 swinging up and down with the fulcrum P1 as the rocking center. The movement (sliding) of the contact position P2 with the valve bridge 4 is allowed, and the inclination of the valve bridge 4 corresponding to the difference in the positions of the rocker arm valve tips 61a and 62a is allowed.

<Modification of Third Embodiment>
FIG. 13 shows a modification of the third embodiment. In this modification, the structure of the joint portion is different from that of the third embodiment. In this modified example, the rocker arm body 3 is formed with a pivot portion 35 having a concave spherical surface 35a similar to that of the second embodiment, and the valve bridge 4 has a receiving surface (R groove) similar to that of the third embodiment. 50 is formed. A spherical body 90 is disposed between the concave spherical surface 35 a and the receiving surface 50.

In this modification, the concave spherical surface 35a, the receiving surface 50, and the spherical body 90 constitute a joint portion.
Note that the joint structure shown in FIG. 13 can also be applied to the second embodiment.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the contact portion with which the cam 5 contacts in the rocker arm main body 3 does not need to be the rotating roller 2 and may be a slipper portion.

1 Valve operating device 2 Rotating roller 3 Rocker arm body 4 Valve bridge 5 Cam 7 Rush adjuster (valve clearance adjuster)
11 Rocker Arm 30 Support 61, 62 Valve 61a, 62a Tip

Claims (6)

A valve operating apparatus having a rocker arm that operates a valve by a rotating cam,
The rocker arm is
A rocker arm body that receives force from the cam and is supported from the opposite side of the cam by a valve clearance adjuster;
A valve bridge supported from the opposite side of the cam by a pair of valves;
With
The rocker arm is
In a state in which a virtual line connecting the tip positions of each of the pair of valves supporting the rocker arm is allowed to tilt partially or entirely of the rocker arm due to being tilted with respect to the axial direction of the cam, Supported from the opposite side of the cam by the pair of valves and the valve clearance adjuster ;
The rocker arm body and the valve bridge are connected to allow the valve bridge to be tilted with respect to the rocker arm body by the fact that the virtual line is inclined with respect to the axial direction of the cam. With a joint,
The joint portion is configured so that a contact position between the rocker arm body and the valve bridge can be changed in a longitudinal direction of the rocker arm body in accordance with the operation of the rocker arm body driven by the cam. The valve operating device. The joint part is
A convex curved surface provided on one of the rocker arm body and the valve bridge;
A receiving surface provided on the other of the rocker arm main body and the valve bridge, on which the convex curved surface abuts so that the convex curved surface can be changed in the longitudinal direction of the rocker arm main body.
The valve gear according to claim 1. The rocker arm is in a state where an imaginary line connecting the tip positions of the pair of valves that support the rocker arm is tilted with respect to the axial direction of the cam and the entire rocker arm is allowed to tilt. , Supported from the opposite side of the cam by the pair of valves and the valve clearance adjuster,
The rocker arm body has a contact portion that receives a force from the cam,
The valve operating device according to claim 1, wherein the contact portion has an R shape in which a central portion of the contact portion protrudes toward the cam side than both end portions of the contact portion in a direction parallel to the rotation axis of the cam. . The valve gear according to claim 3 , wherein at least a part of the rocker arm body is integrally formed with the valve bridge. The rocker arm, the valve bridge and the portion are integrally formed of the valve bridge and said rocker arm body, a single plate member to bending according to claim 4, wherein is formed by having a predetermined shape Valve operating device. A rocker arm, wherein the rocker arm is used as the rocker arm in the valve gear according to any one of claims 1 to 5 .

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