CN1148676A - Lift valve and production method thereof - Google Patents

Abstract

A valve stem and a valve head are respectively made, and the ends of the valve stem and head are joined by friction welding to form a valve element of a poppet valve. During welding, a burr is transversely formed at the jointed portion to form a receiving plate for preventing oil-down.

Description

Poppet valve and manufacture method thereof

The present invention relates to the method for a kind of poppet valve and manufacturing poppet valve, the lower end that particularly a kind of poppet valve with tray, this tray are positioned at valve rod is used to prevent to drop down oil.

As shown in Figure 5, a poppet valve comprises a valve element 23, and this yuan valve element comprises valve head 21 and valve rod 22.This valve was plugged in the valve guiding element 24 with cylinder cap (not marking) press fit slidably, and this valve is driven by rocking arm 25 or the tappet that promotes in the end.

When engine running, valve rod 22 may produce wearing and tearing or stuck like this in the ground to-and-fro motion of valve guiding element high speed on the surface of contact between valve rod 22 and the guiding element 24.In order to prevent above-mentioned phenomenon, lubricant oil is injected in the gap between valve rod 22 and the valve guiding element 24, and lubricated this slidingsurface.

Yet excessive lubricant oil is injected in the gap of valve rod 22 and valve guiding element 24, can make oil leakage to valve head 21, is called " dropping down oil ".Its shortcoming is to have increased the coefficient of losses of lubricant oil and produce carbonization on the surface of valve head 21 to assemble, and therefore fixes the importing that a lip seal 26 can prevent lubricant oil in the upper end of valve guiding element 24.

Because the long-time running of motor, lip seal 26 effects degenerate, and the initial sealing ability can be damaged gradually, therefore the lubricant oil that injects increases and flows out on the valve head 21, it is carbonized and assembles thereon, valve head 21 is burnt out and leaks gas, thereby reduce the performance of motor.

In order to address these problems, in common poppet valve, one annular tray 27 is by shrink fit or be weldingly fixed on the lower end of the valve rod 22 in the cylinder cap port, flows directly on the high temperature valve head 21 from the lubricant oil that the gap between valve rod 22 and the valve guiding element 24 spills preventing.

If tray 27 is fixed on the valve rod 22 by shrink fit, need improve the through hole precision of tray 27 by machining, and because the difference of thermal coefficient of expansion, tray 27 leaves its fixed position.If tray 27 is fixed on the valve rod 22 by welding, cause distortion to make valve rod 22 bendings by welding heat, and since the vibration tray 27 when moving may peel off from welding portion.Above-mentioned two kinds of means of fixation have increased the fixedly process number of tray, thereby increase manufacture cost.

For overcoming above-mentioned defective, the invention provides the method for a kind of poppet valve and this kind of manufacturing poppet valve, its tray manufacturing is simple and cost is low, thereby need not prevent activity such as the means of fixation of shrink fit or welding and peel off.

According to a scheme of the present invention, the poppet valve that is provided comprises: a valve head, a valve rod and prevent to drop down the outstanding tray of annular of oil between valve head and valve rod with whole formation of poppet valve.

According to another aspect of the present invention, a kind of method of making poppet valve is provided, this method comprises the steps: to make separately respectively valve head and valve rod, the end that connects valve head and valve rod by friction welding forms poppet valve, and the welding overlap of laterally projecting formation constitutes the tray of accepting oil when welding.

In this poppet valve, tray and valve element one constitute and prevent that tray axial motion, its tray from need not pass through means of fixation such as the shrink fit or the welding of usefulness, make simply, and cost is low.

The features and advantages of the present invention are described with reference to the accompanying drawings more lucidly.In the accompanying drawing:

Fig. 1 is poppet valve one an embodiment's of the present invention partial cutaway front view;

Fig. 2 A and 2B illustrate the method for making poppet valve, and wherein Fig. 2 A is that Fig. 2 B is a partial cutaway plan view from above of finishing friction welding by the friction-welding machine valve head of making separately of clamping and the plan view from above of valve rod respectively;

Fig. 3 is the amplification plan view from above of the attachment portion remodeling between valve head and the valve rod;

Fig. 4 is the amplification plan view from above of another remodeling of its attachment portion;

Fig. 5 is the front view of traditional poppet valve.

Fig. 1 illustrates poppet valve of the present invention, wherein valve element 3 comprises by high-quality Ni-Cr the heat resisting alloy for example valve head 1 made of 751 alraies or austenitic heat-resistance steel such as SUH36, and the valve rod 2 made by martensite refractory steel such as SUH3, the upper end of valve head 1 is connected with the lower end of valve rod 2, and valve rod 2 diameters are identical with the valve head diameter.

Fig. 2 A and 2B illustrate the step of making poppet valve, and wherein shown in Fig. 2 A, the surface of the valve head 1 that is shaped by the front forging process is by the rotary chuck clamping of friction-welding machine, and the valve rod of being made by pole 2 is by relative fixed chuck 10 clampings coaxial with chuck 9.Shown in Fig. 2 B, chuck 9 is being with valve head 1 high speed rotating, simultaneously, fixedly chuck 10 moves towards chuck 9, the end face of valve rod 2 contacts with the end face of valve head 1, and its contact surface is reached a high temperature by frictional heat, exerts pressure to valve rod 2 when the end is melted, the end of valve head 1 and valve rod 2 firmly couples together, and forms an annular solder overlap (W) by the attachment portion of melting under pressure.

At last, make the valve element of joint through heat treatment or machining, except welding overlap (W), remaining part is finish-machined to definite size and forms the poppet valve with welding overlap (W), and its welding overlap constitutes tray 8 in the junction, as shown in Figure 1.

As mentioned above, when making poppet valve, prevent dropping down oily tray 8 and forming in being connected simultaneously of 2 of valve head 1 and valve rods, this tray 8 constitutes one with valve head 1 and valve rod 2, and does not need to adopt the affixed mode as the trouble of shrink fit and fixing device.After the connection, tray can landing or disengaging, and valve rod 2 can be crooked owing to thermal strain.

Shown in Fig. 3 and 4, the remodeling of the form of valve head 1 and valve rod 2 attachment portions is described.

Among Fig. 3, form respectively towards valve head 1 and the open circular recess 11 of valve rod 2 each end openings, its annular protruding portion 1a and 2a contact with each other and carry out friction welding, shown in double dot dash line, annular protruding portion 1a and 2a are extruded, increase the welding overlap of a formation tray, accept the lubricant oil that drops down leakage effectively.

Among Fig. 4, the recess similar to the above 11 that on valve rod 2, is shaped, and the chamfered part 1b that on the excircle of valve head 1, is shaped, its angle roughly angle with the conical surface 2b of circumference projection 2a is identical.Conical surface 2b contacts with chamfered part 1b and carries out friction welding, shown in double dot dash line, when the welding beginning, circumference projection 2a is pushed and is extruded by the end of valve head 1, the tray 8 of Xing Chenging (welding overlap) is upwards crooked or crooked towards the right side at Fig. 4 towards valve rod 2 like this, therefore improve the ability of aggregation that drops down lubricant oil down, reduce overflowing to lubricants capacity on the valve head 1.

The present invention also is applied to hollow valve (comprising the metal enclosed valve of sodium) except being applied to above-mentioned suction poppet valve, wherein valve element 3 comprises valve head 1 and the valve rod made from different materials respectively 2.

Above-mentioned relates to the preferred embodiments of the present invention, and those of ordinary skill in the art can carry out variations and modifications under the claim scope situation not breaking away from.

Claims (4)

1, a kind of poppet valve, it comprise a valve head and a valve rod, between valve head and valve rod with the integrally formed outstanding tray of annular of accepting oil of this poppet valve.

2, a kind of method of making poppet valve, this method comprises the steps:

Make a valve head and a valve rod respectively separately;

Connect this valve head and valve rod forms poppet valve by friction welding, the welding overlap of a laterally projecting formation when welding constitutes a tray of accepting oil.

3, method as claimed in claim 2 is wherein made the open circular recess of opening side towards this valve rod and valve head end, is engaged by friction welding.

4, method as claimed in claim 2 is wherein made towards the open circular recess of this valve rod one end opening side, and the chamfered part that forms on the circumference of valve head end face contacts with the internal surface of this valve rod recess.

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