Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Journal of KONES

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Measurement of axial motions of piston rings in a two-stroke engine by using back light of LED

Nakashima K., Mizuno M., Usami H.

Journal of KONES

2018

Vol. 25, No. 3

363--369

In two-stroke engines of the crankcase-compression type, the piston rings slide over not only the cylinder wall but also the cylinder ports. It is important for piston ring designers to understand how piston rings behave over cylinder ports. In order to clarify the axial motion of piston rings in two-stroke engines, we established a measurement method using light-emitting diodes (LEDs). We attached LEDs inside the piston, and leaked the backlight of LEDs through the side clearance between the piston ring side face and the piston ring groove side face. From the position of the leaked backlight in the piston ring groove, we determined the axial ring position in the ring groove. Our experiments set this piston with LEDs in an experimental two-stroke engine with a transparent cylinder, and investigated the effects of intake and exhaust ports on axial ring motion under motoring operations. Results indicated that the rings moved in the axial direction by the ring projection and catching in the intake and exhaust ports.

Development of a simplified method for measuring engine motoring friction and its application to valve train friction measurement

Nakashima K., Kato T., Goto K., Murakami Y.

Journal of KONES

2016

Vol. 23, No. 2

261--267

We developed a simpler and less expensive method for measuring friction. Our equipment floats the double-end shaft motor by supporting both sides of the motor shaft with bearings, allowing the stator within the motor case to swing on the rotor with the shaft. Two arms were installed in the motor case; one is attached to a load meter; the other to a balance weight. The motor shaft is connected to the engine shaft, and when the engine is operated by the motor, torque is exerted on the stator with the motor case in the direction opposite to the motor shaft rotation, with engine friction acting as the reaction force. Torque is calculated by multiplying the arm length by the load as measured by the load meter in the arm. As an application of our new motoring friction test method, we measured valve train friction. The cylinder head of a single cylinder gasoline engine was clamped on a test bed, and its camshaft was connected to our friction measuring equipment. Utilizing various follower configurations of the rocker arms, we investigated the friction loss between the rocker arms and the cam. We thus clarified the effect of the valve-opening period and the valve lift on friction loss under various camshaft rotation speeds, and understood the lubricating conditions between the rocker arms and the cam.