JPH0660706U - Valve forced opening / closing device for internal combustion engine - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] In the valve forced opening / closing device of an internal combustion engine in which the intake valve and exhaust valve of the internal combustion engine are forcibly opened and closed by respective cams, Make it easy to adjust the clearance between the rocker arm and the retainer. [Constitution] A rocker arm for opening and closing the rocker that abuts on a cam for opening and a valve for closing the valve provided on a cam shaft, respectively, and the rocker arm for opening the valve is provided with an adjusting screw through a valve stem. In a valve forced opening / closing device of an internal combustion engine in which a locker arm 13 for closing the valve is engaged with a retainer 22 fitted and fixed to a valve stem 29 through a shim 23, the shim 23 is connected to the valve stem 29 with respect to the valve stem 29. A U-shaped groove 25 was formed so that it could be inserted from the side, and a flange 26 for holding the shim 23 was formed on the outer periphery of the retainer 22.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a valve forced opening / closing device for an internal combustion engine in which the intake valve and the exhaust valve of the internal combustion engine are forcibly opened and closed by respective cams.

[0002]

[Prior art]

 A forced valve opening / closing device configured to forcibly open and close intake valves and exhaust valves of an internal combustion engine by respective cams is disclosed in, for example, Japanese Patent Laid-Open No. 60-128910. Has been known for a long time.

Further, a rocker arm for opening and a rocker for closing the valve that abuts and swings on a cam for opening and a valve for closing, which are provided on the camshaft, respectively, are provided, and the rocker arm for opening the valve is provided via an adjusting screw. There is also known a valve forced opening / closing device in which a valve stem end is engaged with a retainer in which a valve closing rocker arm is fitted and fixed to the valve system, and such a valve forced opening / closing device is shown in FIG. As shown in (), between the retainer 32 fixed to the valve system 30 by the cotter 31 and the valve closing rocker arm 33, a shim 34 and a spacer for setting the clearance therebetween to 0 in consideration of thermal expansion. A ring 35 is interposed, and the shim 34 has a ring shape as shown in FIG. 9B.

[0004]

[Problems to be solved by the device]

 However, in the case where the ring-shaped shim 34 is used as described above, when adjusting the thickness of the shim 34 so that the clearance between the retainer 32 and the valve closing rocker arm 33 becomes 0, the thinnest temporary shim 34 is used. After assembling by sandwiching the shim 34, measuring the clearance in that state, remove the cotter 31, remove the retainer 32 and the shim 34 from the valve stem 30, replace the shim 34 with a regular one, and then assemble it again. There was a problem that it was necessary.

In view of the above conventional problems, it is an object of the present invention to provide a valve forced opening / closing device for an internal combustion engine that can easily adjust the clearance between the valve closing rocker arm and the retainer. .

[0006]

[Means for Solving the Problems]

 The present invention is provided with a rocker arm for opening and closing the rocker that abuts on a cam for opening and a cam for closing the valve provided on a cam shaft, respectively, and the rocker arm for opening the valve is connected via an adjusting screw. In a valve forced opening / closing device for an internal combustion engine that engages with the end of the valve stem and engages with a retainer in which the valve closing rocker arm is fitted and fixed to the valve stem via a shim, The feature is that a U-shaped groove is formed so that it can be inserted, and a flange for holding the shim is formed on the outer periphery of the retainer.

[0007]

[Action]

 According to the present invention, when adjusting the clearance between the valve closing rocker arm and the retainer, after the temporary shim and the retainer are assembled, the clearance is measured, and then the closing cam is rotated to the opening position. This allows the valve closing rocker arm to be lowered, and the temporary shim can be pulled out and a regular shim inserted without disassembling the retainer for easy adjustment, and the inserted shim must be secured by the retainer flange. It is retained by and will not fall off.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 2, 1 is a cylinder head, 2 is an intake valve, 3 is an exhaust valve, 4 is an intake port, and 5 is an exhaust port. A camshaft 6 is provided with a valve opening cam 7 and a valve closing cam 8 for the intake valve 2 and the exhaust valve 3, respectively. Reference numeral 9 is a rocker shaft on the intake valve 2 side, and 10 is a rocker shaft on the exhaust valve 3 side. As shown in FIG. 3, rocker arms 11 and 12 for opening the valve and rocker arms 13 and 14 for closing the valve rock respectively. It is supported freely.

As shown in FIG. 4, the valve-opening rocker arms 11 and 12 are provided with a cam slipper 15 that contacts the valve-opening cam 7 of the camshaft 6 on one end side, and the intake valve 2 or the exhaust valve on the other end side. A screw hole 16 is formed corresponding to the upper end of the valve stem of the valve 3. As shown in FIG. 2, an adjusting screw 17 is screwed into the screw hole 16 and fixed by a lock nut 18 so that the position can be adjusted, and the tip of the adjusting screw 17 can be engaged with an end cap 19 attached to the upper end of the valve stem. It is said that.

As shown in FIG. 5, each of the valve closing rocker arms 13 and 14 is provided with a cam slip 20 that comes into contact with the valve closing cam 8 of the camshaft 6 on one end side, and the intake valve 2 or the exhaust valve on the other end side. A fork portion 21 is formed corresponding to the upper portion of the valve stem of the hull 3. As shown in FIG. 2, the fork portion 21 is engaged with a lower surface of a retainer 22 fitted and fixed on an upper portion of the valve stem via a shim 23.

With the above configuration, when the valve opening cam 7 and the valve closing cam 8 rotate with the rotation of the cam shaft 6 interlocked with the crankshaft (not shown), the rotation of the valve opening cam 7 causes the rotation of the valve opening cam 7. As shown in FIG. 6, the rocker arms 11 and 12 for opening the valve are rockably driven from the state shown by the solid line to the state shown by the phantom line, and the intake valve 2 and the exhaust valve 3 are opened at a predetermined timing. Further, as shown in FIG. 7, the rotation of the valve closing cam 8 swings the valve closing rocker arms 13 and 14 from the state shown by the phantom line to the state shown by the solid line, and at a predetermined timing, the intake valve 2 and the exhaust valve 2 are exhausted. 3 is closed. Furthermore, the compulsory closing operation of the intake valve 2 and the exhaust valve 3 by the closing cam 8 is performed up to the position before the completely closed state, and the closing rocker arms 13 and 14 are energized at the final stage of closing. It is configured to be performed by a spring. Therefore, as shown in FIGS. 2 and 8, a torsion spring 24 for urging the valve closing rocker arms 13 and 14 toward the closed positions of the intake valve 2 and the exhaust valve 3 is provided, and one end 24a of the torsion spring 24 is provided. 2 and the other end 24b is engaged with the boss portions of the valve closing rocker arms 13 and 14.

The details of the engaging portion between the fork portion 21 of the valve closing rocker arms 13 and 14 and the retainer 22 in such an overall configuration will be described with reference to FIG. A shim 23 and a spacer for setting the clearance between the retainer 22 fixed to the valve stem 29 by the cotter 28 and the fork portion 21 of the valve closing rocker arms 13 and 14 to 0 in consideration of thermal expansion. The ring 27 is interposed. As shown in FIG. 1B, the shim 23 is formed with a U-shaped groove 25 so that it can be inserted into the valve stem 29 from the side, and the shim 23 is held on the outer periphery of the lower surface of the retainer 22. A flange 26 is formed.

With such a configuration, when adjusting the clearance between the fork portion 21 of the valve closing rocker arms 13 and 14 and the retainer 22, first, the spacer ring 27, the thinnest temporary shim 23, and the retainer 22. 22 is inserted from the upper end of the valve stem 29, the retainer 22 is fixedly assembled by the cotter 28, the clearance is measured in that state, and then the valve closing cam 8 is rotated to the valve opening position to rotate the fork portion. It is possible to easily adjust the valve closing cam 8 by returning the valve closing cam 8 to its original position by lowering the valve 21, disassembling the retainer 22, extracting the temporary shim 23, inserting the regular shim 23. Further, since the inserted shim 23 is securely held by the flange 26 of the retainer 22, it does not fall off unexpectedly.

[0015]

[Effect of device]

 According to the valve forced opening / closing device of an internal combustion engine of the present invention, a U-shaped groove is formed in the shim so that the shim can be laterally inserted into the shim, and a flange for holding the shim is formed on the outer periphery of the retainer. Due to the formation, the temporary shim can be extracted and the regular shim can be inserted without disassembling the retainer after the clearance measurement, and the inserted shim can be securely retained by the flange of the retainer, so it can be accidentally dropped. It is possible to easily adjust the clearance between the valve closing rocker arm and the retainer.

[Brief description of drawings]

FIG. 1 shows an engaging portion between a retainer fixed to a valve stem and a valve closing rocker arm in an embodiment of a valve forced opening / closing device of an internal combustion engine of the present invention, (a) is a sectional view, and (b) is a sectional view.
FIG. 4 is a perspective view of a shim.

FIG. 2 is an overall vertical front view of the embodiment.

FIG. 3 is a plan view of a main part of the embodiment.

FIG. 4 is a perspective view of a valve opening rocker arm in the embodiment.

FIG. 5 is a perspective view of a valve closing rocker arm in the embodiment.

FIG. 6 is an operation explanatory view of the valve opening rocker arm in the embodiment.

FIG. 7 is an operation explanatory view of the valve closing rocker arm in the embodiment.

FIG. 8 is a perspective view showing a mounted state of a biasing spring of the valve closing rocker arm in the embodiment.

9A and 9B show an engaging portion of a retainer fixed to a valve stem and a valve closing rocker arm in a conventional example, FIG. 9A is a sectional view, and FIG. 9B is a perspective view of a shim.

[Explanation of symbols]

 2 intake valve 3 exhaust valve 6 cam shaft 7 valve opening cam 8 valve closing cam 11 valve opening rocker arm 12 valve opening rocker arm 13 valve closing rocker arm 14 valve closing rocker arm 17 adjusting screw 22 retainer 23 shim 25 U-shaped Groove 26 Flange 29 Valve stem

Claims (1)

[Scope of utility model registration request] 1. A rocker arm for opening and closing a rocker that abuts against a cam for opening and a valve for closing, which are provided on a cam shaft, respectively. The rocker arm for opening the valve is provided with an adjust screw. In a valve forced opening / closing device for an internal combustion engine that engages with the end of the valve stem and engages with a retainer fitted and fixed to the valve stem via a shim, inserts the shim into the shim from the side of the valve stem. A valve forced opening / closing device for an internal combustion engine, wherein a U-shaped groove is formed so as to be possible, and a flange for holding a shim is formed on the outer periphery of the retainer.