TWI498475B - Engine valve actuator - Google Patents

Description

Engine valve actuator

The present invention relates to an engine valve actuator, and more particularly to an engine valve actuator of a single rocker shaft design.

The engine's intake and exhaust actuations have a large impact on performance, so the design of the intake/exhaust valve actuators requires considerable consideration. For example, the valve actuator disclosed in the Republic of China Patent Publication No. TW I285704 includes two rocker arms, two rocker shafts and two torsion springs, wherein the two rocker arms are pivotally disposed on the two rocker shafts. In each rocker/rocker shaft assembly shown in FIG. 1, one of the above-mentioned torsion springs 92 is sleeved on the rocker arm shaft 90 with a spiral section 921, and is abutted at an extending end 922. The arm 91 applies a pre-force. Since the torsion spring 92 is a flexible member, the axial positioning of the rocker arm 91 is not sufficiently accurate in this design; moreover, when the torsion spring 92 is completely destroyed, the rocker arm 91 completely loses axial positioning.

There is also a valve actuator with a single rocker shaft design which has the advantages of reduced number of required hole machining, reduced number of parts, and reduced assembly steps. For example, the Republic of China Patent Publication No. TW I315366 discloses a valve actuation device including a cylinder head, a camshaft, a rocker shaft, an intake rocker arm and an exhaust rocker arm, wherein an intake valve and an exhaust valve are provided in the cylinder head. The valve, the camshaft is supported by the cylinder head by bearings. The rocker shaft is arranged parallel to the camshaft and is also supported on the cylinder head. The intake rocker arm and the exhaust rocker arm form a connection of the camshaft to the intake valve and the exhaust valve. This type of valve actuator uses only a single rocker arm The shaft supports the two rocker arms, and each rocker arm has a large size, so that it has a considerable moment of inertia, so that the valve gap change of the hot and cold car often causes the valve to open abnormal sound.

SUMMARY OF THE INVENTION One object of the present invention is to provide an engine valve actuator that can inhibit the generation of abnormal sounds of a valve while using a single rocker shaft.

Another object of the present invention is to provide an engine valve operating device that can ensure the axial positioning of the rocker arm when the torsion spring is normally actuated or even destroyed.

To achieve the above object, the engine valve actuator of the present invention includes a camshaft seat, a camshaft assembly and a rocker arm mechanism. The camshaft seat is provided with a pair of camshaft support holes and a pair of rocker arm support holes above the camshaft support holes.

The camshaft assembly includes a camshaft, an intake cam and an exhaust cam, wherein the camshaft is rotatably carried on the two camshaft support holes, and the intake cam and the exhaust cam are fixed on the camshaft.

The rocker arm mechanism includes a rocker arm shaft, an intake rocker arm, an exhaust rocker arm, and a torsion spring. The rocker arm shaft is carried on the support arm of the two rocker arm shafts, and the air intake rocker arm and the exhaust rocker arm are coaxially pivoted on the rocker arm shaft. The torsion spring comprises a spiral section, a first extension section and a second extension section, wherein the spiral section is sleeved on the rocker arm shaft and is disposed on the intake rocker arm and the exhaust rocker arm in the direction of the rocker arm axis The first extension section and the second extension section are extended from opposite ends of the spiral section to abut the intake rocker arm and the exhaust rocker arm, respectively. Intake rocker arm and exhaust rocker arm The rocker arm shaft direction respectively protrudes from one of the first bumps and the second bumps.

With the above structural design, the inlet and exhaust rocker arms use only one common rocker shaft and one torsion spring, which saves the number of parts and costs, and also reduces the number of rocker shaft hole machining and the number of overall assembly steps. Increase in production rate.

Preferably, the two-bump length design conforms to: when the first bump corresponds to the top second bump, the spiral section of the torsion spring is not clamped by the intake rocker arm and the exhaust rocker arm, and the two bumps The combination serves to limit the amount of axial movement between the intake rocker arm and the exhaust rocker arm. The above two bumps may be located on the outer side of the spiral segment and not in contact with the spiral segment, or may be located inside the spiral segment.

The engine valve actuator of the present invention may further include a flap. The blocking piece includes a fixing section and a stopping section. The fixing section is fixed to the cam shaft seat, and the stopping section extends from the fixing section and overlaps one of the pair of camshaft supporting holes. The stop section can function to limit the amount of axial displacement of the camshaft assembly. The flap is, for example, an L-shaped flap.

The rocker arm shaft can be recessed with a fixing hole on the outer peripheral surface, and a bolt is inserted into the fixing hole through the fixing portion of the blocking piece and the top surface of the cam shaft seat, so that not only the blocking piece but also the rocker arm shaft is locked. It can also play a role in limiting the axial displacement and rotation of the rocker shaft.

The camshaft assembly may further include a bearing system embedded in one of the pair of camshaft support holes and carrying the camshaft, and the stop section is corresponding to the axial displacement of the restraining bearing. The intake rocker arm and the exhaust rocker arm may be roller type rocker arms.

Referring to Figures 2 to 4, respectively, a perspective view of an engine cylinder head, an exploded view, and an enlarged view of a rocker arm mechanism of a preferred embodiment. The figure shows a part of a locomotive engine, which mainly comprises a cylinder head body 10, a camshaft seat 11, a camshaft assembly 20, a rocker arm mechanism 30 and a pair of valve devices 40 (only shown in the figure) one of them). The top surface of the cylinder head body 10 is a joint surface 101 for engaging a cylinder head (not shown). The camshaft seat 11 described above is located within the range enclosed by the joint surface 101. A fin structure 102 is formed on the outer side of the cylinder head body 10.

The camshaft seat 11 is fixed to the cylinder head body 10 and includes two independent and oppositely disposed seat half bodies 111, 112. Each of the half bodies 111, 112 is provided with a cam shaft support hole 12, 13 and a rocker shaft support hole 14, 15, and the rocker shaft support holes 14, 15 are located above the cam shaft support holes 12, 13.

The camshaft assembly 20 mainly includes a camshaft 21, an intake cam 22, an exhaust cam 23 and two bearings 24, 25, wherein the two bearings 24, 25 are embedded in the corresponding camshaft support holes 12, 13, and Both ends of the cam shaft 21 are respectively placed on the bearings 24, 25, and thus rotatably carried on the aforementioned cam shaft support holes 12, 13. The intake cam 22 and the exhaust cam 23 are fixed relative to the camshaft 21, and the intake cam 22 is responsible for pushing an intake rocker arm 32 of the rocker arm mechanism 30, and the exhaust cam 23 is responsible for pushing the rocker arm mechanism 30. An exhaust rocker arm 33.

The rocker arm mechanism 30 includes a rocker arm shaft 31, an intake rocker arm 32, an exhaust rocker arm 33, and a torsion spring 34 that is carried by the rocker arm shaft support holes 14, 15. Both the intake rocker arm 32 and the exhaust rocker arm 33 include a pivot hole 320, 330, a driven end 322, 332 and a valve actuating end 323, 333 through which the rocker arm shaft 31 passes. The pivot holes 320, 330 are such that the intake rocker arm 32 and the exhaust rocker arm 33 are coaxially pivoted to the rocker shaft 31. The two driven ends 322, 332 are selectively pushed up corresponding to the two cams 22, 23, respectively, and the valve actuating ends 323, 333 respectively correspond to the two valve means 40 (intake valve and exhaust valve) to selectively move the two valve means 40 .

The torsion spring 34 includes a spiral section 341, a first extension 342 and a second extension 343. The spiral section 341 is sleeved on the rocker shaft 31, and the first extension 342 and the second extension 343 are respectively spiral. The opposite ends of the segment 341 extend, and the two extensions 342, 343 are substantially dome-shaped and are respectively hooked on the valve actuating ends 323, 333 of the intake rocker arm 32 and the exhaust rocker arm 33, as shown in FIG. At the time of assembly, the position of the spiral section 341 of the torsion spring 34 is interposed between the intake rocker arm 32 and the exhaust rocker arm 33 in the direction of the rocker arm shaft 31. The torsion spring 34 provides a pre-stress to the two rocker arms 32, 33, causing the rocker arms 32, 33 to contact the valve means 40 at the cam base angular position, but not in contact with the cams 22, 23 but maintaining a gap to prevent the valve Device 40 turns on the abnormal sound.

In addition, the intake rocker arm 32 and the exhaust rocker arm 33 respectively protrude from the direction of the rocker arm shaft 31 with a corresponding first bump 321 and a second bump 331 , and the two bumps 321 , 331 are opposite to each other. .

As shown in FIG. 6, the embodiment is designed such that the axial length of the spiral segment 341 is smaller than the sum of the axial lengths of the two bumps 321, 331. Even if the first bump 321 corresponds to the second protruding block 331, the spiral segment 341 is not affected. The intake rocker arm 32 is biased by the biasing force of the exhaust rocker arm 33, and the combination of the two bumps 321, 331 serves to limit the amount of axial movement between the two rocker arms 32, 33. In addition, the positions of the two bumps 321, 331 are designed on the outer side of the spiral segment 341 and are not in contact with the spiral segment 341. Of course, the position of the two bumps 321, 331 can also be designed inside the spiral segment 341, which is not special. limited.

It can be seen from the above that the engine valve operating device of the present invention can drive the intake valve and the exhaust valve by using only one rocker shaft, two rocker arms and a torsion spring, and the purpose of preventing the abnormal sound of the valve opening. Compared with the conventional double rocker shaft design, one rocker shaft and one torsion spring are saved, and the processing steps of one rocker shaft hole are also reduced, which has advantages in parts cost and manufacturing speed. In addition, the arrangement of the two projections 321, 331 also ensures the axial positioning of the intake rocker arm 32 and the exhaust rocker arm 33.

More preferably, the engine valve operating device of the present invention further includes a blocking piece 35 including a fixing portion 351 and a stopping portion 352, wherein the fixing portion 351 is fixed to the seat half body 112, and the stopping portion 352 is self-fixing portion The 351 extends beyond the edge of the camshaft support hole 13 to overlap the aforementioned camshaft support hole 13 (and also covers a portion of the bearing 25). In this example, the flap 35 is an L-shaped flap, and the rocker shaft 31 is recessed with a fixing hole 311 on the outer peripheral surface. The fixing hole 311 of the rocker shaft 31 is locked by a bolt 36 simultaneously passing through the fixing portion 351 of the blocking piece 35 (ie, through the blocking piece opening 353 of the fixing portion 351) and the top opening 16 of the top surface of the cam shaft seat 11. The rocker shaft 31 is stabilized in the seat half 112 to exert an effect of limiting the axial displacement and rotation of the rocker shaft 31. The fixing hole 311 can be an operation hole and directly locked with the bolt 36. Stop section 352 has a purpose to limit the axial displacement of camshaft assembly 20 (e.g., directly restricting bearing 25).

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

90‧‧‧ rocker shaft

91‧‧‧ rocker arm

92‧‧‧Torsion spring

921‧‧‧Spiral section

922‧‧‧Extension

10‧‧‧Cylinder head body

101‧‧‧ joint surface

102‧‧‧Fin structure

11‧‧‧Camshaft seat

111,112‧‧‧ seat half

12,13‧‧‧Camshaft support hole

14,15‧‧‧ rocker shaft support hole

16‧‧‧Top opening

20‧‧‧Camshaft assembly

21‧‧‧Camshaft

22‧‧‧Intake cam

23‧‧‧Exhaust cam

24,25‧‧‧ bearing

30‧‧‧ rocker arm mechanism

31‧‧‧ rocker shaft

311‧‧‧Fixed holes

32‧‧‧Intake rocker

320,330‧‧‧Pivot hole

321‧‧‧First bump

331‧‧‧second bump

322, 332‧‧‧ driven

323, 333‧‧‧ valve actuation end

33‧‧‧Exhaust rocker arm

34‧‧‧ Torsion spring

341‧‧‧Spiral section

342‧‧‧First extension

343‧‧‧Second extension

35‧‧ ‧Flap

351‧‧‧ fixed section

352‧‧‧stop section

353‧‧‧Flap opening

36‧‧‧Bolts

40‧‧‧ valve device

Figure 1 is a partial perspective view of a conventional valve actuator.

2 is a perspective view of a cylinder head of an engine in accordance with a preferred embodiment of the present invention.

3 is an exploded view of an engine cylinder head in accordance with a preferred embodiment of the present invention.

Figure 4 is an enlarged view of the rocker arm mechanism of Figure 3.

Figure 5 is a top plan view of the engine cylinder head of Figure 2.

Figure 6 is a cross-sectional view taken along line VI-VI of Figure 5.

10‧‧‧Cylinder head body

101‧‧‧ joint surface

102‧‧‧Fin structure

111,112‧‧‧ seat half

12,13‧‧‧Camshaft support hole

14,15‧‧‧ rocker shaft support hole

16‧‧‧Top opening

21‧‧‧Camshaft

22‧‧‧Intake cam

23‧‧‧Exhaust cam

24,25‧‧‧ bearing

31‧‧‧ rocker shaft

311‧‧‧Fixed holes

32‧‧‧Intake rocker

320,330‧‧‧Pivot hole

33‧‧‧Exhaust rocker arm

34‧‧‧ Torsion spring

341‧‧‧Spiral section

342‧‧‧First extension

343‧‧‧Second extension

351‧‧‧ fixed section

352‧‧‧stop section

353‧‧‧Flap opening

36‧‧‧Bolts

40‧‧‧ valve device

Claims (6)

An engine valve moving device comprises: a camshaft seat, a pair of camshaft support holes and a pair of rocker shaft support holes above the pair of camshaft support holes; a camshaft assembly comprising a camshaft, a An intake cam and an exhaust cam, the camshaft is rotatably carried on the pair of camshaft support holes, and the intake cam and the exhaust cam are fixed on the camshaft; a blocking piece including a fixed section and a stop section fixed to the camshaft seat, the stop section extending from the fixing section and overlapping one of the pair of camshaft support holes; and a rocker arm mechanism including a rocker arm shaft, An intake rocker arm, an exhaust rocker arm and a torsion spring, the rocker arm shaft is carried on the pair of rocker arm shaft support holes and has a fixing hole recessed in the outer peripheral surface, a bolt passes through the fixed section and the camshaft The top surface of the seat is locked into the fixing hole, and the air intake arm and the exhaust rocker arm are coaxially disposed on the rocker arm shaft. The torsion spring includes a spiral section, a first extension section and a second extension. a segment, the spiral segment is sleeved on the rocker shaft and along the axis of the rocker arm Between the intake rocker arm and the exhaust rocker arm, the first extension and the second extension are extended from opposite ends of the spiral section to respectively abut the intake rocker arm and the exhaust a rocker arm, wherein the air intake rocker and the exhaust rocker arm respectively protrude from the rocker arm shaft with a corresponding one of the first bump and the second bump. The engine valve device of claim 1, wherein the spiral segment is not affected by the intake rocker arm and the exhaust rocker arm when the first bump corresponds to the second bump. Clamped. The engine valve actuator of claim 1, wherein the two bumps are located outside the spiral segment and are not in contact with the spiral segment. The engine valve actuator of claim 1, wherein the flap is an L-shaped flap. The engine valve actuator of claim 1, wherein the camshaft assembly further includes a bearing system embedded in one of the pair of camshaft support holes and carrying the camshaft, the stop segment Corresponding to the axial displacement of the bearing. The engine valve actuator of claim 1, wherein the intake rocker arm and the exhaust rocker arm are roller type rocker arms.