JP2000297616A - Reliability test device for valve system of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety and simplify the structure of a reliability test device for a valve system of an engine by providing a closing member fixed to an open end of a port portion provided on a cylinder head, having a valve and supplying high-pressure compressed air discontinuously via the closing member. SOLUTION: A closing member, to be fixed and sealed to an open end of a port portion 3 of a cylinder head 1, is formed with a cover member 7. An air compressor 8 for supplying high-pressure compressed air is connected to the cover member 7 via an air pipe 9 and communicated to the port potion 3 via an inner hole 7a. Also, a low-pressure air source 10, for supplying low- pressure compressed air, is connected to the air pipe 9 via an air pipe 12. With this configuration, a valve 4 is bounded by supplying high-pressure air discontinuously from the air compressor 8 to the port portion 3, while supplying low- pressure compressed air from the low-pressure air source 10 as base pressure. This enables obtaining a simply-structured test device and safely reproduce conditions under high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for testing reliability of an engine valve train.

[0002]

2. Description of the Related Art As a conventional reliability test apparatus for a valve operating system of an engine, as shown in FIG. As in a valve train wear test apparatus disclosed in Japanese Unexamined Patent Publication No. Hei 6-307988, a wear test of a valve or the like is performed by forcibly driving a crankshaft of an engine with a motor.

[0003]

In the conventional test apparatus shown in FIG. 2, it is desired to perform a test by applying heat to the valve f or the valve seat g. There is a problem that there is a risk of occurrence, and test conditions are restricted.

A camshaft a, a push rod p, a rocker arm d,
It is necessary to drive the entire valve train such as the valve bridge v,
There is a problem that the test equipment becomes large.

Further, when changing the stress on the valve f or the valve seat g, it is necessary to change the cam profile or the valve gap. For this reason, depending on the case, parts other than the evaluation parts, such as the tappet b, the push rod p, etc. May be broken first during the test.
In FIG. 2, c indicates a cylinder block, h indicates a cylinder head, and s indicates a valve spring. The present invention has been made to solve the above-described problems of the conventional device, and has a structure. It is an object of the present invention to provide a simple and improved safety test device for an engine valve train with improved safety.

[0006]

In order to achieve the above object, according to the present invention, a closing member is attached to an opening end of a port portion of a cylinder head on which a valve is set, and high-pressure compressed air is supplied through the closing member. The valve is intermittently supplied to generate bounce in the valve.
(Claim 1) Further, a low-pressure compressed air is supplied as a base pressure. (Claim 2) Further, an air discharge pipe having a variable orifice for communicating the inside of the port portion with the outside air is attached to the closing member. (Claim 3)

[0007]

[Operation] A valve is bounced by intermittently supplying high-pressure air to a port portion using low-pressure compressed air from a low-pressure air source as a base pressure.

When the valve is separated from the valve seat by the supply of the high-pressure air to the port, the compressed air in the port is instantaneously released, and the valve is seated again on the valve seat by the force of the valve spring. By repeating this, a reliability test is performed. In this case, the amount of bounce of the valve is set by adjusting a variable orifice provided in the air discharge pipe.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, reference numeral 1 denotes a cylinder head of an engine 2, which is set at an appropriate location L during a test, and a port (an intake port or an exhaust port) 3 is provided with a valve (an intake valve or an exhaust bull bar) 4 at the time of a test. Is set. The valve 4 is normally held closed by sitting on the valve seat 6 by the elastic force of the valve spring 5.

Reference numeral 7 denotes a cover member forming a closing member hermetically attached to the open end of the port 3 of the cylinder head 1. A seal member (not shown) can be interposed between the cover member 7 and the end face of the cylinder head 1 as necessary.

Reference numeral 8 denotes an air compressor for supplying high-pressure compressed air, which is driven by a motor M via a belt or the like. The air compressor 8 is connected to the cover member 7 by an air pipe 9 and has an inner hole. It communicates with the port 3 via 7a.

Reference numeral 10 denotes a low-pressure air source such as factory air for supplying low-pressure compressed air as a base pressure. Have been. The low-pressure compressed air is used to replenish the compressed air so that the compressed air does not leak from a gap such as between the valve 4 and the valve guide 13 to cause a pressure drop in the port portion 3. Also, the one-way valve 11
This is for preventing the compressed air from flowing out to the low pressure side when the air compressor 8 operates.

Reference numeral 14 denotes an air discharge pipe having one end connected to the cover member 7 and the other end open to the atmosphere. A variable orifice 15 is provided on the way. Air discharge pipe 14
Is communicated with the port portion 3 through the inner hole 7b of the cover member 7. The variable orifice 15 is provided as an impact force control means when the valve 4 is seated on the valve seat 6 at the time of the test. When the orifice 15 is almost closed, the bounce amount increases, The seating impact force increases.

Reference numeral 16 denotes a heater for reproducing the valve 4 and the valve seat 6 under a high temperature. The heater 16 transfers the entire cylinder head 1 to a high-temperature tank (not shown) as required. The installation can be omitted by inserting.

In the test apparatus having the above-described configuration, the high-pressure air from the air compressor 8 is intermittently supplied to the port portion 3 while the low-pressure compressed air from the low-pressure air source 10 is supplied as the base pressure. , The valve 4 can be bounced. When the valve 4 is separated from the valve seat 6, the compressed air in the port 3 is instantaneously released, and the valve 4
Is seated on the valve seat 6 again.

By repeating this operation, a reliability test is performed. The amount of bounce of the valve 4 is determined by the air discharge pipe 1
4 is set by adjusting the variable orifice 15 provided in the fourth orifice 4. Further, the operation state of the valve 4 and the valve seat 6 at a high temperature can be reproduced by installing the heater 16.

In the present invention, a low-pressure compressed air is supplied as a base pressure, and a high-pressure air, which is opened instantaneously by a valve against the elastic force of the valve spring 5, is intermittently supplied thereto. The system is subjected to a reliability test, and the timing of supplying high-pressure air is determined by selecting the range in which the engine rotates.

As described above, in this test apparatus, it is not necessary to drive the entire valve train such as the camshaft, the push rod, and the rocker arm by the motor M and its driving means.
The configuration of the test apparatus is simplified. Further, in this test apparatus, the main part of the valve mechanism is constituted by the valve 4 and the valve spring 5, and only high-pressure air is used as a means for opening the valve 4. Therefore, the movement of the push rod, rocker arm, etc. There is no need to supply lubricating oil to the valve system,
Further, it is possible to reproduce a high temperature state by applying heat to the valve 4 and the valve seat 6 without fear of fire.

Furthermore, when changing the stress on the valve 4 and the valve seat 6, it is not necessary to change the cam profile and the valve gap as in the conventional case, so that parts other than the evaluation parts, such as tappets and push rods, are damaged. This problem is also solved.

[0020]

As described above, in the reliability test apparatus for a valve train according to the present invention, the closing member is attached to the opening end of the port portion of the cylinder head on which the valve is set, and the high-pressure compression is performed through the closing member. It is characterized by intermittently supplying air to generate bounce in the valve, and has the following effects.

A) It is not necessary to drive the entire valve train such as the camshaft, push rod and rocker arm by the motor and its driving means, and the configuration of the test apparatus is simplified.

B) Further, there is no need to supply lubricating oil to the valve operating system, heat is applied to the valves and valve seats, and there is no risk of reproducing this high-temperature state and there is no danger of fire, and safe and limited test conditions. It is possible to provide a test apparatus that is not performed.

C) Further, when changing the stress on the valve or the valve seat, it is not necessary to change the cam profile and the valve gap as in the conventional case, so that the problem that the parts other than the evaluation parts are damaged can be solved. .

D) Since low-pressure compressed air is supplied as the base pressure, a pressure drop from a gap such as between the valve and the valve guide can be prevented, and a reliable test apparatus can be provided. it can.

E) Further, an air discharge pipe having a variable orifice for communicating the inside of the port portion with the outside air is attached to the closing member, so that the amount of bounce of the valve can be appropriately set by adjusting the air discharge pipe. A more accurate test apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is an overall schematic system diagram showing an embodiment of a reliability test apparatus for a valve train of an engine according to the present invention.

FIG. 2 is a partially sectional side view showing an example of a conventional test apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder head 3 Port part 4 Valve 6 Valve seat 7 Cover member 8 Air compressor 10 Low pressure air source 14 Air discharge pipe 15 Variable orifice 16 Heater

Claims (3)

[Claims] 1. A valve, wherein a closing member is attached to an opening end of a port portion of a cylinder head in which a valve is set, and high-pressure compressed air is intermittently supplied through the closing member to generate bounce on the valve. Characteristic reliability test equipment for engine valve train. 2. The reliability test apparatus for a valve train of an engine according to claim 1, wherein low-pressure compressed air is supplied as the base pressure. 3. An engine valve system reliability test apparatus according to claim 1, wherein an air discharge pipe having a variable orifice for communicating the inside of the port portion with the outside air is attached to the closing member. .