JP4829562B2 - Direct acting valve lifter for internal combustion engine - Google Patents

Description

  The present invention relates to a cylindrical direct acting valve lifter interposed between a cam constituting a valve mechanism of an internal combustion engine and a valve stem, and in particular, a cam unit in which a high lift cam and a low lift cam are integrated. On the other hand, the present invention relates to a direct acting valve lifter for an internal combustion engine that can adjust the lift amount of the valve in two steps of high and low by switching between a side lifter having a low lift cam sliding contact surface and a center lifter having a high lift cam sliding contact surface.

  As this type of direct acting valve lifter, one disclosed in the following Patent Document 1 is known. Here, as shown in FIG. 11, a cylindrical lifter main body 1 includes a central center lifter 2 having a circular center cam sliding contact surface 2a corresponding to a low lift center cam at the top, and a high lift side cam at the top. Is divided into a cylindrical side lifter 3 having a ring-shaped side cam slidable contact surface 3a, and a first connecting pin 5a is provided between the center lifter 2 and the through holes 4a, 4b extending over the side lifter 3, and the through holes 4b, 4b, Between the 4c, the 2nd connection pin 5b is each arrange | positioned. Reference numeral 6 denotes a spring member for returning the first connecting pin 5a and the second connecting pin 5b to a predetermined position, and reference numeral 7 is interposed between the spring receiver 2b at the bottom of the center lifter 2 and the spring receiver 3b of the side lifter 3, 2 is a spring member that holds 2 at a predetermined position in the vertical direction with respect to the side lifter 3.

If the first connecting pin 5a is in the through hole 4a, the center lifter 2 and the side lifter 3 are separated in the lifter axial direction (the vertical direction in FIG. 11) (the side lifter 3 can sink into the center lifter 2). (The form shown in FIG. 11), and the drive by the center cam (low lift amount) is transmitted to the lifter body 1 through the sliding contact surface 2a. On the other hand, the first connecting pin 5a and the second connecting pin 5b move to the right in FIG. 11 against the urging force of the spring 7 by hydraulic pressure, and the first connecting pin 5a straddles between the through holes 4a and 4b. When the second connecting pin 5b is located between the through holes 4b and 4c, the center lifter 2 and the side lifter 3 are connected in the lifter axial direction via the first connecting pin 5a and the second connecting pin 5b. Thus, the drive by the side cam (high lift amount) is transmitted to the lifter body 1 through the sliding contact surface 3a.
Special table 2002-509219 (FIGS. 1 and 2)

  However, in Patent Document 1, the cylindrical lifter body 1 has a structure in which the center lifter 2, the side lifter 3, the first connection pin 5a, the second connection pin 5b, the spring portion 6 and the spring member 7 are accommodated, and the number of components is reduced. There are many.

  In particular, in order for the lifter to operate smoothly, it is indispensable that the positional relationship between the connecting pin and the through hole coincide with each other with high accuracy. For this purpose, the dimensional accuracy of the pin 5a is not limited to the connecting pin 5a. The dimensional accuracy of the abutting receiver and the second connecting pin 5b, as well as the dimensional accuracy of the through-hole, etc., are required for the hole shape of the lifter main body 1 and all the components assembled to the lifter main body 1, so that much. There was a problem that mass production was difficult and manufacturing cost was high.

  In addition, a spring member 7 for holding the center lifter 2 at a predetermined position in the vertical direction with respect to the side lifter 3 is indispensable between the center lifter 2 and the side lifter 3. When the cam is rotated at a high speed with the side lifter 3 submerged into the center lifter 2), the lift force of the spring member 7 is always applied to increase the sliding friction of the lifter. There was also a problem that there was a risk of being disturbed.

  The present invention has been made in view of the above-described problems of the prior art, and the object thereof is a direct-acting valve lifter interposed between a valve unit and a cam unit in which a high lift cam and a low lift cam are integrated. An object of the present invention is to provide a direct acting valve lifter for an internal combustion engine that has a small number of parts, has a simple structure, can be switched between a high lift and a low lift, and operates smoothly.

In order to achieve the above object, in the direct acting valve lifter for an internal combustion engine according to claim 1, a cylindrical direct acting type interposed between a cam and a valve stem constituting a valve mechanism of the internal combustion engine. in the valve lifter, the cam is high-lift center cam and low lift side cams are constituted by integral, said valve lifter, said a Saidorifuta low lift side cam sliding contact, wherein the high lift center cam sliding A direct-acting valve lifter for an internal combustion engine comprising a center lifter that comes into contact and a hydraulic means that operates the center lifter to switch the valve lift amount between two levels: a cam slide on the top of the cylindrical lifter body. slit for high-lift Sentakamu air shot is provided extending in the moving direction, Saidorifuta with low lift side cam sliding surface on the top portion structure While being, the circular holes extending in a direction perpendicular to the slit in the lifter body provided, circular holes piston Sentarifuta configured in a cylindrical engaging is provided, in the lower part of the circular hole, parallel to the circular hole A bottomed cylindrical slide pin is provided so as to be slidable along a hole provided in the center, and one end is positioned with respect to the cylinder bore, so that the center lifter that contacts the slide pin is removed from the slit. A spring that biases the position is provided inside the slide pin, and the center lifter that receives a hydraulic pressure exceeding the spring force of the spring slides to the position of the slit in the circular hole .

  (Operation) The piston-type center lifter slides along the hole by the acting hydraulic pressure, and when the center lifter is in a position corresponding to the slit, the high lift cam is in sliding contact with the center lifter, and the valve stem has a center lifter and side lifters (lifter body) The high lift amount is transmitted via the. On the other hand, when the center lifter is in a position not corresponding to the slit, the high lift cam is swung in the slit, the low lift cam is slidably contacted with the side lifter, and the low lift amount is transmitted to the valve stem via the side lifter (lifter body). .

  That is, the center lifter slides along the hole by hydraulic pressure, and can adopt a form that can be slidably contacted with the center cam and a form that is not slidably contacted with the center cam.

  Therefore, the valve lifter is mainly composed of a cylindrical lifter body that is a side lifter and a piston-type center lifter that is disposed in the hole of the lifter body and slides by hydraulic pressure. The number of component parts is small, the dimensional tolerance required for each component part is relaxed, and the work of assembling each component part is also simplified.

Also, as in the prior art, since without the spring member for holding vertically a predetermined position relative to the lifter body is Saidorifuta the Sentarifuta, in the low lift mode to the high lift center cam is misses in the slit In addition, since the spring force of the spring member does not act as a load, the smooth operation of the lifter is ensured even during the high rotation operation of the cam in the low lift mode.
Furthermore, since the high-lift center cam sliding contact surface is an arc surface, the length of the sliding contact surface with respect to a predetermined lift amount is shortened, and the size of the center lifter in the cam sliding direction can be reduced accordingly. The degree of freedom in design increases.

According to a second aspect of the present invention, in the cylindrical direct acting type valve lifter interposed between the cam constituting the valve mechanism of the internal combustion engine and the valve stem, the cam includes a high lift center cam and a low lift side cam. The valve lifter is configured to be integrated, and the valve lifter operates the center lifter in order to switch the valve lift amount between two levels: a side lifter with which the low lift side cam is in sliding contact, a center lifter with which the high lift center cam is in sliding contact, and a valve lift amount. A direct-acting valve lifter for an internal combustion engine provided with hydraulic means, wherein a slit for high-lift center cam idle swing extending in the cam sliding direction is provided at the top of the cylindrical lifter body, and a low lift at the top A side lifter having a side cam sliding contact surface is configured, and the lifter body is perpendicular to the slit. A piston-type center lifter that is formed in a cylindrical shape that is provided with an extending circular hole and that engages with the circular hole is provided, contacts the center lifter, and slides along a hole provided in parallel to the circular hole at the lower portion of the circular hole. A movable slide pin is provided, and one end is positioned with respect to the cylinder bore so that a spring for biasing the center lifter to the slit position is provided inside the center lifter. The center lifter that has received a hydraulic pressure exceeding the spring force is configured to slide to a position outside the slit in the circular hole.

  According to a third aspect of the present invention, in the cylindrical direct acting valve lifter interposed between the cam constituting the valve mechanism of the internal combustion engine and the valve stem, the cam includes a high lift center cam and a low lift side cam. The valve lifter is configured to be integrated, and the valve lifter operates the center lifter in order to switch the valve lift amount between two levels: a side lifter with which the low lift side cam is in sliding contact, a center lifter with which the high lift center cam is in sliding contact, and a valve lift amount. A direct-acting valve lifter for an internal combustion engine provided with hydraulic means, wherein a slit for high-lift center cam idle swing extending in the cam sliding direction is provided at the top of the cylindrical lifter body, and a low lift at the top A side lifter having a side cam sliding contact surface is configured, and the lifter body is perpendicular to the slit. An extended circular hole is provided, and a piston-type center lifter configured to be engaged with the circular hole is provided. The center part of the circular hole is slidably disposed along a hole provided in parallel with the circular hole. A hollow spring receiving portion is formed integrally with the center lifter, and one end is positioned with respect to the cylinder bore, so that a spring for biasing the center lifter to a position off the slit is provided inside the spring receiving portion. The center lifter that has received the hydraulic pressure exceeding the spring force of the spring is configured to slide to a position outside the slit in the circular hole.

According to a fourth aspect of the present invention, in the direct acting valve lifter for an internal combustion engine according to any one of the first to third aspects, the width of the slit for swinging the high lift cam substantially matches the width (plate thickness) of the high lift cam. I made it to size.
(Operation) Between the cylindrical lifter main body and the cylinder bore which is the relative sliding surface thereof, it is necessary to provide a detent means such as a vertical groove provided on the cylinder bore side and a protrusion on the lifter main body side engaged with the vertical groove. However, the width of the slit for swinging the high-lift center cam substantially matches the plate thickness of the high-lift center cam. By setting the cam profile so that the center cam always engages with the slit, the center cam The idle swing slit and the high lift center cam function as a detent means for the cylinder bore of the lifter body.

As is clear from the above description, according to the direct acting valve lifter for an internal combustion engine according to claims 1 to 3 , since the number of components of the valve lifter is small, the dimensional tolerance required for each component is alleviated. In addition, the work of assembling each component is also simplified, so that the manufacturing cost of the valve lifter can be greatly reduced, and the valve lifter can be provided at a lower cost.

  Moreover, since the smooth operation of the lifter is ensured even during the high rotation operation of the cam in the low lift mode, which has been a problem in the past because the smooth operation of the lifter is hindered, uneven wear of the valve lifter can be prevented. In addition, since the spring member that holds the lifter for high lift is not required, it is not necessary to consider the rotational speed limitation due to the spring force and the spring stiffness, and the degree of freedom in engine design is increased.

Further , since the size of the center cam in the cam sliding direction can be reduced, the degree of freedom in designing the cam and the valve lifter can be increased.

According to the fourth aspect of the present invention , if the high lift cam is always engaged with the slit for swinging the high lift cam, the lifter body is prevented from rotating with respect to the cylinder bore without providing a separate rotation prevention means between the lifter body and the cylinder bore. Therefore, the structure of the lifter body and the cylinder bore is simplified accordingly.

  Next, embodiments of the present invention will be described based on examples.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a sectional view around a direct acting valve lifter constituting an internal combustion engine valve mechanism according to an embodiment of the present invention. FIG. FIG. 3 is a side view of the valve lifter in a state where the valve lifter is in a position not corresponding to the slit of the side lifter, FIG. 3 is a side view of the valve lifter (viewed from the right side of the valve lifter shown in FIG. 2), and FIG. FIG. 5 is a cross-sectional view of the valve lifter in a state where the center lifter is in a position corresponding to the slit of the side lifter.

  In these drawings, reference numeral 12 denotes an intake port provided in the cylinder head 10 of the automobile engine, reference numeral 14 denotes an intake valve provided in the port 12, and an intake valve stem (valve stem) 15 is an intake port. 12 protrudes into the cylinder bore 11 near 12 and is urged by the compression coil spring 16 in the direction of closing the intake port 12.

  Reference numeral 20 denotes a cam unit 20 in which low lift side cams 24, 24 are integrated on both sides of a high lift center cam 22. The cam unit 20 is disposed above the cylinder bore 11, and between the cam unit 20 and the valve stem 15. A valve lifter 30 that can slide in the bore 11 in the vertical direction is interposed.

  As shown in FIG. 4, the valve lifter 30 is provided with a center cam 22 swinging slit 33 extending in the cam sliding direction at the top, and a side lifter 32 that is a lifter body having a pair of side cam sliding contact surfaces 32a and 32a at the top. A piston-type center lifter 40 slidably disposed in a through-hole 34 provided in the side lifter 32 so as to be orthogonal to the extending direction of the slit 33, and a compression spring for holding the center lifter 40 in a predetermined position 39 is mainly composed. The through hole 34 is formed of a circular hole, the center lifter 40 is formed in a bottomed cylindrical shape that engages with the through hole 34, and the outer peripheral surface of the center lifter 40 is a center cam sliding contact surface 40a.

  Reference numeral 36 denotes a plug that functions as a spring receiver that is press-fitted and fixed in a hole 35 that is provided in parallel with the through-hole 34 near the lower portion on the opening side of the through-hole 34, and a non-rotating pin 37 is provided on the bottomed cylindrical plug 36. The pin 37 engages with the longitudinal groove 11a on the cylinder bore 11 side, and constitutes a detent means for the valve lifter 30 with respect to the cylinder bore 11 (cams 22, 24).

  A bottomed cylindrical slide pin 38 is slidably disposed in the plug 36 in the axial direction, and a compression coil spring 39 is interposed between the plug 36 and the slide pin 38 to plug the center lifter 40. It is energizing in the direction away from the left (left direction in FIG. 2).

  Reference numeral 11b denotes an oil passage provided in the cylinder head 10 and opening at a position opposite to the longitudinal groove 11a of the cylinder bore 11 (a position facing the center lifter 40 of the valve lifter 30). The pressure of the engine oil supplied from the oil passage 11b Thus, the center lifter 40 slides along the through-hole 34 so that the lift amount of the valve 14 is switched.

  That is, when hydraulic pressure (high pressure) is applied to the center lifter 40 via the oil passage 11b, the center lifter 40 slides along the through hole 34 against the spring force of the spring 39, and the center lifter 40 is slit 33 as shown in FIG. , The high lift center cam 22 is in sliding contact with the center lifter 40 (sliding contact surface 40a thereof), and a high lift amount is transmitted to the valve stem 15 via the center lifter 40 and the side lifter 32 (lifter body). The

  On the other hand, when the hydraulic pressure acting on the center lifter 40 is lowered, the center lifter 40 returns to the original position not corresponding to the slit 33 by the spring force of the spring 39, and the high lift center cam 22 is moved into the slit 33 as shown in FIG. And the low lift side cam 24 is in sliding contact with the side lifter 32 (sliding contact surface 32a thereof), and a low lift amount is transmitted to the valve stem 15 via the side lifter 32 (lifter body).

Thus, Sentarifuta 40 slides along the through-hole 34 by oil pressure acting, alternatively a high-lift Sentakamu 2 2 and slidable contact form, and a high-lift Sentakamu 2 2 and not in sliding contact with the form Can be taken.

Further, since the center lifter 40 is formed in a cylindrical shape and the center cam sliding contact surface 40a is an arc surface, the length of the sliding contact surface 40a with respect to a predetermined lift amount is shortened, and the center lifter 40 in the cam sliding direction is accordingly increased. dimensions, i.e. the like can reduce the outer diameter of Sentarifuta 40, the degree of freedom in designing the high-lift Sentakamu 2 2 and the valve lifter 30 goes up.

  6 and 7 show a direct-acting valve lifter for an internal combustion engine according to a second embodiment of the present invention. FIG. 6 is a sectional view of the valve lifter in a state where the center lifter is located at a position corresponding to the slit of the side lifter. It is sectional drawing of the valve lifter in the state where the center lifter was settled in the position which does not correspond to the slit of a side lifter.

  In the first embodiment described above, the rotation prevention means of the valve lifter 30 constituted by the rotation prevention pin 37 on the valve lifter 30 (side lifter 32) side and the vertical groove 11a on the cylinder bore 11 side is provided, but in this embodiment, Since the width d of the center cam idle swing slit 33 is substantially aligned with the width (plate thickness) t of the center cam 22, the profile of the center cam 22 is configured to always engage with the slit 33. 33 and the center cam 22 function as a detent means for the cylinder bore 11 (cam unit 20) of the valve lifter 30, so that the detent means (vertical groove 11a and detent pin 37) as shown in the first embodiment is not required. Accordingly, the structure of the valve lifter 30A and the cylinder bore 11 is also simple.

In the first embodiment, the piston-type center lifter 40 does not correspond to the slit 33 due to the spring force of the compression coil spring 39 as shown in FIG. 2 when no hydraulic pressure (high pressure) acts on the center lifter 40. When the hydraulic pressure (high pressure) is applied to the center lifter 40, the center lifter 40 moves to a position corresponding to the slit 33, as shown in FIG. are configured to switch to the high drive transmission mode lifting center cam 22, in this second embodiment, the switching from the first embodiment is reversed, piston Sentarifuta 40A is hydraulic in Sentarifuta 40A At the beginning of the operation, the position corresponding to the slit 33 is caused by the spring force of the compression coil spring 39 as shown in FIG. Are held in (high driving force transmitting position of the lifting center cam 22), when the hydraulic pressure acting on Sentarifuta 40, as shown in FIG. 7, moved to the position corresponding to the slit 33, side cam for low-lift 24 It is comprised so that it may switch to driving force transmission mode.

  In other words, reference numeral 38A denotes a bottomed cylindrical slide pin disposed in the hole 35. An oil passage 11c provided in the cylinder head 10 is provided at a position facing the slide pin 38A (hole 35) of the valve lifter 30A. It is open. On the opposite side of the through hole 34 from the side where the slide pin 38A is disposed, a cap 44 having a spherical outer surface is disposed, and a compression coil spring 39 is interposed between the cap 44 and the piston type center lifter 40A. The center lifter 40A is in contact with the slide pin 38A and is held at a predetermined position corresponding to the slit 33.

  Specifically, when hydraulic pressure (high pressure) acts on the slide pin 38A through the oil passage 11c, the center lifter 40A slides along the through hole 34 against the spring force of the spring 39A, as shown in FIG. In addition, when the position does not correspond to the slit 33, the high lift center cam 22 swings in the slit 33 and the low lift side cam 24 is slidably contacted with the side lifter 32, and the side lifter 32 (lifter body) is attached to the valve stem 15. A low lift amount is transmitted via On the other hand, when the hydraulic pressure acting on the slide pin 38A is reduced, the spring 39 returns to the original position not corresponding to the slit 33 by the spring force, and as shown in FIG. 6, the high lift center cam 22 slides on the center lifter 40A. A high lift amount is transmitted to the valve stem 15 via the center lifter 40A and the side lifter 32 (lifter body).

  Others are the same as in the first embodiment described above, and therefore, the same reference numerals are given and the redundant description is omitted.

  8 and 9 show a direct acting valve lifter for an internal combustion engine according to a third embodiment of the present invention. FIG. 8 is a cross-sectional view showing a state where the center lifter is in a position not corresponding to the slit of the side lifter. It is sectional drawing which shows the state settled in the position corresponding to a slit.

  The third embodiment is an improvement over the first embodiment described above, but in the first embodiment, the structure in which the spring force of the compression coil spring 39 acts on the piston-type center lifter 40 via the slide pin 38. However, in the third embodiment, the bottomed cylindrical plug 36 provided with the non-rotating pin 37 projecting can slide along the hole 35 provided in the central portion of the through hole 34, A spring receiving portion 41 corresponding to a slide pin that engages with the plug 36 extends from the center portion of the center lifter 40B, and the spring force of the compression coil spring 39 directly acts on the center lifter 40B. The number of components is small.

  Further, since the spring force of the compression coil spring 39 acts on the center portion of the center lifter 40B, the center lifter 40B slides smoothly.

  Others are the same as in the first embodiment described above, and therefore, the same reference numerals are given and the redundant description is omitted.

  In the first to third embodiments described above, the through hole 34 and the center lifter 40 (40A, 40B) are configured in a cylindrical shape, but may be configured in a square shape.

  In the first to third embodiments described above, the piston is slid by the spring force and the oil pressure of the spring. However, by applying the oil pressure to the front and rear of the piston, It is good also as a structure which abbreviate | omitted use.

  In the first to third embodiments described above, the valve lifter constituting the valve mechanism of the intake valve provided in the intake port has been described. However, the valve mechanism of the exhaust valve provided in the exhaust port is described. The present invention can be similarly applied to the valve lifter to be configured.

FIG. 1 is a sectional view around a direct acting valve lifter for an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the valve lifter in a state where the center lifter is in a position not corresponding to the slit of the side lifter. FIG. 3 is a side view of the valve lifter (a view of the valve lifter shown in FIG. 2 viewed from the right side). It is a disassembled perspective view of the valve lifter. FIG. 4 is a cross-sectional view of the valve lifter in a state where the center lifter is housed in a position corresponding to the slit of the side lifter. It is sectional drawing of the direct acting type | mold valve lifter for internal combustion engines which is the 2nd Example of this invention, and is a figure which shows the state which the center lifter was settled in the position corresponding to the slit of a side lifter. It is sectional drawing which shows the state which the center lifter was settled in the position which does not correspond to the slit of a side lifter. It is sectional drawing of the direct acting type | mold valve lifter for internal combustion engines which is the 3rd Example of this invention, and is a figure which shows the state settled in the position which does not correspond to the slit of a side lifter. It is a right view of the valve lifter. It is sectional drawing which shows the state in which the center lifter was settled in the position corresponding to the slit of a side lifter. It is sectional drawing of the conventional valve lifter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cylinder head 11 Cylinder bore 11a Vertical groove 11b, 11c Oil path 14 Intake valve 15 which comprises a valve operating mechanism Valve stem 20 Cam unit 22 which comprises a valve operating mechanism High lift center cam 24 Low lift side cams 30, 30A, 30B Dynamic valve lifter 32 Side lifter (lifter body)
32a Side cam sliding contact surface 33 Center cam idle slit 34 Through hole 39 Compression coil springs 40, 40A, 40B Piston type center lifter 40a Center cam slide contact surface d Center cam idle slit width t Center cam width (plate thickness)

Claims (4)

In direct-acting valve lifter of interposed a cylindrical between the cam and the valve stem constituting a valve mechanism of an internal combustion engine, the cam is high-lift center cam and low lift side cams are integrated is configured, the valve lifter, the a Saidorifuta low lift side cam sliding contact, and Sentarifuta which the high lift center cam in sliding contact with the hydraulic means for operating the Sentarifuta to switch the valve lift in two stages of high and low A direct acting valve lifter for an internal combustion engine comprising:
Said cylindrical lifter body slit for high-lift Sentakamu whiff extending cam sliding direction on top of is provided with Saidorifuta is configured with a low-lift side cam sliding surface on the top, the lifter body Provided with a circular hole extending in a direction perpendicular to the slit,
A piston-type center lifter configured in a cylindrical shape that engages with the circular hole is provided,
At the bottom of the circular hole, a bottomed cylindrical slide pin is provided that is slidably disposed along a hole provided in parallel with the circular hole.
A spring that biases the center lifter that contacts the slide pin to a position off the slit by positioning one end with respect to the cylinder bore is provided inside the slide pin,
A direct acting valve lifter for an internal combustion engine, wherein a center lifter that receives a hydraulic pressure exceeding a spring force of a spring slides to a slit position in a circular hole . In a cylindrical direct acting valve lifter interposed between a cam and a valve stem constituting a valve mechanism of an internal combustion engine, the cam is configured by integrating a high lift center cam and a low lift side cam. The valve lifter includes a side lifter with which the low lift side cam is slidably contacted, a center lifter with which the high lift center cam is slidably contacted, and hydraulic means for operating the center lifter to switch the valve lift amount between two levels of high and low. A direct acting valve lifter for an internal combustion engine,
A slit for high-swing center cam idle swing extending in the cam sliding direction is provided at the top of the cylindrical lifter body, and a side lifter having a low-lift side cam sliding contact surface is formed at the top. A circular hole extending in a direction perpendicular to the slit is provided,
A piston-type center lifter configured in a cylindrical shape that engages with the circular hole is provided,
In contact with the center lifter, a slide pin is provided at the lower part of the circular hole so as to be slidable along a hole provided in parallel with the circular hole.
By positioning one end with respect to the cylinder bore, a spring for biasing the center lifter to the position of the slit is provided inside the center lifter,
A direct acting valve lifter for an internal combustion engine , wherein a center lifter that has received a hydraulic pressure exceeding the spring force of a spring slides through a slide pin to a position outside the slit in a circular hole . In a cylindrical direct acting valve lifter interposed between a cam and a valve stem constituting a valve mechanism of an internal combustion engine, the cam is configured by integrating a high lift center cam and a low lift side cam. The valve lifter includes a side lifter with which the low lift side cam is slidably contacted, a center lifter with which the high lift center cam is slidably contacted, and hydraulic means for operating the center lifter to switch the valve lift amount between two levels of high and low. A direct acting valve lifter for an internal combustion engine,
A slit for high-swing center cam idle swing extending in the cam sliding direction is provided at the top of the cylindrical lifter body, and a side lifter having a low-lift side cam sliding contact surface is formed at the top. A circular hole extending in a direction perpendicular to the slit is provided,
A piston-type center lifter configured in a cylindrical shape that engages with the circular hole is provided,
In the center of the circular hole, a hollow spring receiving portion that is slidably disposed along a hole provided in parallel with the circular hole is formed integrally with the center lifter,
By positioning one end with respect to the cylinder bore, a spring for biasing the center lifter to a position off the slit is provided inside the spring receiving portion,
A direct acting valve lifter for an internal combustion engine , characterized in that a center lifter that receives a hydraulic pressure exceeding the spring force of a spring slides in a circular hole to a position off the slit .   4. The direct acting type for an internal combustion engine according to claim 1, wherein a width of the slit for swinging the high lift center cam substantially matches a width (plate thickness) of the center cam for high lift. Valve lifter.

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