JPH04250330A - Abrasion testing device for valve system component of engine - Google Patents

Abstract

PURPOSE:To obtain an abrasion testing device for the valve system components of an engine, which is capable of minimizing the difference with the abrasion evaluation of valve system performed by actual engine operating method. CONSTITUTION:A jig equivalent to a cylinder is set in a position corresponding to the top dead center of a piston, and a pressurization chamber, into which the head of an engine valve constituting one part of the components of a valve system advances is formed in the jig equivalent to a piston and is operated in association with a supercharging pipe and pressure equivalent to combustion gas pressure obtained when the engine valve opens is preset by a pressure gauge.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear testing device for engine valve train parts, which evaluates the wear of engine valve train parts without using an actual engine.

0002

[Prior Art] Traditionally, in order to test the wear of engine valve train parts, fuel is supplied to the actual engine, the suction and
The so-called actual engine operation method involves applying a load based on the combustion gas pressure to the engine's valve system parts by executing each stroke consisting of compression, explosion, and exhaust to evaluate their wear. In order to add it to the valve train parts, the spring constant of the valve spring that makes up part of the valve train parts is set to correspond to the combustion pressure, and the crankshaft is rotated by a motor to compensate for the vertical movement of the piston. A so-called motoring bench test operation method is known in which valve train components are driven at appropriate timings and wear of the valve train components is evaluated.

0003

[Problem to be solved by the invention] By the way, in the actual engine operation method, combustion gas pressure is applied directly to the engine valve as a valve train component, so it is difficult to obtain a highly reliable evaluation of the wear of valve train components. However, it has the disadvantage of requiring excessive equipment and costs. On the other hand, the motoring bench test operation method has the advantage of requiring relatively little expense and equipment compared to the actual engine operation method, but it has the disadvantage that the wear evaluation based on the actual engine operation method is difficult to match with the evaluation results. There is.

The present invention has been made in view of the above circumstances, and its purpose is to provide an engine valve train system that can minimize the difference in wear evaluation of valve train parts based on actual engine operation methods. The purpose of the present invention is to provide a parts wear testing device.

[0005]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the wear testing device for engine valve train components according to the present invention includes a piston-equivalent jig set at a position equivalent to the top dead center of the cylinder. A pressurized chamber into which the head of the engine valve that forms part of the valve train system enters is formed in a jig corresponding to the piston, and this pressurized chamber is communicated with the supercharging pipe to control the combustion gas pressure when the engine valve opens. It is characterized in that the pressure corresponding to is set in advance by a pressure gauge.

[0006]

[Operation] In the wear test device for engine valve train parts according to the present invention, gas is supplied in advance to the pressurized chamber into which the head of the engine valve, which constitutes a part of the valve train part, enters. A load corresponding to the combustion gas pressure when the engine valve opens is applied to the head. Therefore, when the engine valve is opened or closed, in addition to the load based on the valve spring, a load equivalent to the combustion gas pressure is applied to the engine valve, and each load applied to the valve train components is the actual load that is applied to the engine during actual engine operation. The load is similar to that applied to valve train components when

[0007]

[Example] In Fig. 1, 1 is a cylinder block, 2 is a cylinder block, and 2 is a cylinder block.
3 is a cylinder head, 3 is a camshaft rotated by a crankshaft (not shown), 4 is a cam that is rotated integrally with the camshaft, 5 is a tappet, 6 is a push rod, and 7 is an adjustment screw. These are the rocker arms provided at the top of the cylinder head 2.
system 8, an exhaust valve 11 that opens and closes an exhaust hole 10 communicating with an exhaust passage 9 formed in the cylinder head 2;
Together with a valve spring 12 that biases the valve 1 in the closing direction, the valve operating mechanism is configured. In FIG. 1, reference numeral 13 designates a retainer for receiving the valve spring 12.

A piston equivalent jig 14 is set in the cylinder block 1 at a position corresponding to the top dead center of the piston. A pressurizing chamber 16 is formed in the piston-equivalent jig 14 at a position facing the head 15 of the exhaust valve 11 as an engine valve. This pressurizing chamber 16 is into which the head 15 enters when the exhaust valve 11 is opened, and its depth is set to such an extent that it will not collide with the head 15 when it enters.

[0009] The pressurizing chamber 16 is communicated with a supercharging pipe 17. Air gas is supplied from the supercharging pipe 17. Pressurized chamber 16
The gas pressure is measured by a pressure gauge 18 attached to the cylinder head 2, and the gas pressure corresponding to the combustion gas pressure when the engine valve is opened is set in advance.

When the crankshaft (not shown) is driven by a motor at the same rotation speed as the actual engine, the camshaft 3 is rotated, the push rod 6 is moved up and down based on the rotation of the cam 4, and the rocker arm 8 is rotated. The head of the exhaust valve 11 is hit by the rocker arm 8, and the exhaust valve 11 is opened against the urging force of the valve spring 12 and the gas pressure in the pressurizing chamber 16.

The impact load characteristics applied to the exhaust valve 11 show a distribution as shown by the solid line in FIG. 2 between the opening and closing of the exhaust valve 11. Since the gas pressure corresponding to the combustion gas pressure of is given,
This is similar to the impact load characteristic based on the actual combustion gas pressure shown by the two-dot chain line. In the second figure,
The broken line shows the impact load characteristics of the conventional evaluation method in which the spring constant of the valve spring is set to correspond to the combustion pressure. However, since the influence of gas pressure is not taken into account, the (see reference numeral A), and in the mid-opening period of the exhaust valve 11 (see reference numeral B in the figure), the shock load characteristics deviate considerably from the impact load characteristics based on the actual combustion gas pressure. After the middle of the opening period of the exhaust valve 11 (closing period C), there is almost no difference between the three evaluation methods, but this is probably because most of the combustion gas is exhausted and the influence of the valve spring 12 becomes large. .

[0012] In synchronization with the timing of engine rotation,
The gas pressure corresponding to the combustion gas pressure is supplied from the supercharging pipe 17 to the pressurizing chamber 1.
6, it is possible to perform repeated evaluations.

Although the examples have been described above, the impact load characteristics shown in FIG. 2 were measured using a known method.

[0014]

[Effects of the Invention] Since the wear test device for engine valve train parts according to the present invention is constructed as described above,
The effect is that the load applied to valve train components when the engine valves are opened and closed is similar to the load based on the actual combustion gas pressure, and the difference in wear evaluation of valve train components based on actual engine operation methods can be minimized. play.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the configuration of essential parts of a wear testing device for engine valve train components according to the present invention.

[Fig. 2] Comparison of the load applied to the engine valve by the wear test device for engine valve train parts according to the present invention with the load applied to the engine valve by the engine actual engine operation method and the motoring bench test operation method. It is a diagram.

[Explanation of symbols]

1 Cylinder block 11 Exhaust valve (engine valve) 14 Piston equivalent jig 15 Head 16 Pressurized chamber 17 Supercharging pipe 18 Pressure gauge

Claims (1)

[Claims] Claim 1: A piston-equivalent jig is set at a position corresponding to the top dead center of the cylinder, and the piston-equivalent jig has a pressurized chamber into which the head of an engine valve forming a part of a valve train component enters. A valve train component for an engine, wherein the pressurized chamber is communicated with a supercharging pipe, and a gas pressure corresponding to the combustion gas pressure when the engine valve opens is set in advance by a pressure gauge. wear test equipment.