JPS6199781A - Method of machining valve seat for flow control valve - Google Patents

Abstract

PURPOSE:To obtain a valve seat having a smooth seat surface by forming the seat surface of the valve seat by press-machining. CONSTITUTION:A bottomed cylinder 4 is formed by press molding an aluminum plate 1.2mm to 2mm thick. A projecting portion 4b is formed at the central portion of the bottom plate of the cylinder by stepped press molding, and a through hole 4c is formed on the central part of the projecting portion. The thus constructed bottomed cylinder 4 is placed on a die C of a press machine. Secondly, the inner face of the through hole 4c disposed on the bottomed cylinder is cleaned out by a punch F having a blanking blade D of an outside diameter equal to the diameter of a normal through hole at the lower end and the upper outer periphery pressure applying portion E, and the sheet surface 4a is press molded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention mainly relates to a method of manufacturing a valve seat for a flow control valve used by intervening in a fuel passage of a gas appliance.

(Conventional technique @) The valve seat of this type of am 1I1110 valve is conventionally made by pressing a metal plate into a bottomed cylinder a as shown in Fig. 4, and drilling a through hole C in the center of the bottom plate. and the bottomed cylindrical body a
The seat surface is formed by cutting after chucking from the outer circumference with a chuck or chucking from the inner circumference. However, with this product, the cut portion is in a distorted shape as shown by the chain line in Fig. 4 during chuckking, and since cutting is performed in this state, the cut surface, that is, the seat surface, not only becomes distorted but also slightly distorted. Cutting parts remain. In general, in this type of flow control valve that intervenes in the gas supply gas flow, if the gap between the valve seat and the valve body is 1 ml+ or more, in reality, i m h
+ m is no longer performed, especially when the heat generation m is large, P,
With G gas, the desired flow ma and II cannot be controlled unless the gap is controlled to 0.3a11 or less.

Further, the flow m Il+ m+ valve is designed so that its axis can swing somewhat freely, and the valve body is in close contact with the valve seat when the valve is closed.

Therefore, in reality, the gap between the valve seat and the valve body is controlled so that they are always in contact with each other at one point.

For this reason, as mentioned above, if the seat surface d is not formed accurately, the surrounding resistance will increase and the hysteresis will increase, or even the proportional control valve will get caught in the cut groove, as shown in Figure 5. It exhibits step-like flow characteristics, making it impossible to perform accurate III-III control, and especially in the case of the governor control valve, hysteresis occurs as shown in Figure 6, making it difficult to perform accurate 1-1 control. The leakage opening between the valve seat and the valve increases immediately before the valve closes, causing problems such as poor control characteristics as shown in FIG.

(Problems to be Solved by the Invention) In view of the current situation, an object of the present invention is to provide a processing method that allows a valve seat with an extremely accurate seating surface to be obtained.

(Means for Solving the Problems) The present invention provides a valve seat with a through hole provided in a metal plate, a slope formed at the peripheral edge of the through hole as a seating surface, and a valve seat that moves forward and backward with respect to the seating surface. A flow Q control valve comprising a valve body and in which a flow is caused in a gap formed between the seat surface and the valve body, characterized in that the seat surface of the valve seat is formed by press working. do.

(Example) An example of implementing the present invention will be described in the case of an electromagnetic proportional valve.

In the drawings, (1) shows the valve port, and (2) shows the valve seat that divides the gas passage (3) in the valve port (1) into an inflow side passage A and an outflow side passage B, and the valve seat ( As shown in Fig. 2, a metal plate is press-formed into a bottomed cylindrical body (4), and a protrusion (4b) is formed by step pressing in the center of the bottom plate (4a), and the protrusion (4b) A through hole (4C) is provided in the center of the through hole (4C).
) is formed on the seat surface (4d), and as shown in FIG. With the valve body (D) operated by the diaphragm (6) facing, the actuator (5) moves the valve body (7) to the seat surface (4d).
), and a diaphragm (6) is used to adjust the gap between the seat surface (4d) and the valve body (7) to adjust the outflow side pressure.

In the drawing, (8) is a backing interposed between the valve seat (4) and the valve port (1), and (9) is a spring that springs the valve body 7> toward the valve closing side. .

The configuration up to now is not particularly different from what has been generally known.

The present invention provides a seat surface (4) of the valve seat (4).
4a) is formed by press working.To explain one example of the processing method, an aluminum plate with a thickness of about 1.2a+a+ to 2m is formed into a bottomed cylinder (4) by press forming, and the bottom plate (4) is formed by press forming. A protrusion (4b) is formed by step pressing in the center of 4a), and at the same time or separately, a through hole (4C) is formed in the center of the text (4b). In this case, the diameter of the through hole (4C) is set to be, for example, about 0.2 d smaller than the final hole diameter.

In this state, the bottomed cylinder (4) is placed on a pressing die C as shown in Fig. 1, and then a punching blade with an outer diameter equal to the regular through-hole diameter is provided at the lower end. , the work of sinking the inner surface of the through hole (4C) provided in the bottomed cylinder (4) with the punch F equipped with the upper outer periphery coining part E, and the work of press forming the seat surface (4a). .

When doing so, the axis of the punch F is aligned with the axis of the through hole (4C), and in this state, the coined part E of the punch 8 is applied to the lower peripheral edge of the through hole (4C) on the seat surface ( 4a), and especially when the punch F is made of M3 hard material and the coined surface E is a superfinished surface, the seat surface (4a) can be superfinished by only press working. It can be a face. Incidentally, the coined part E of the punch F shall have a radius of about 0.5 cm or a slope of 0.5 cm, so that the seat plate (4) has an arcuate or flat slope. ) was formed. In addition, with the spring (9) removed, insert the flow control valve obtained in this way into the inflow side passage.
When a leakage test was conducted when a water pressure of 11H20 was applied, the leakage peak was 12a/hr with the conventional cutting method, but was 2.61a/hr with the method of the present invention.
/hr. (However, when the air temperature is 15°C) (Effects of the invention) As described above, according to the present invention, 21um It, I
Since the seat surface of the valve seat of the I tit valve is formed by press working, the valve seat is simply placed on a die and pressed, so there is no distortion easily. It is possible to easily obtain a valve seat with a seat surface, and thereby a flow control valve capable of highly accurate flow control can be obtained.

[Brief explanation of drawings]

The drawings show an example of the implementation of the method of the present invention, and FIG. 1 is a cross-sectional side view of an apparatus for implementing the method, and FIG.
A cutaway side view of an example of a lit valve device, FIG. 3 is an enlarged view of a part of the valve seat, FIG. 4 is an explanatory diagram explaining a conventional processing method, and FIGS. 5 to 7 are , is a flow ffi characteristic diagram thereof. 2 people outside

Claims (1)

[Claims] A through hole is provided in a metal plate, and the valve seat is formed on the periphery of the through hole and has a seat surface, and a valve body that moves forward and backward with respect to the seat surface. 1. A method for processing a valve seat for a flow control valve, which comprises forming a seat surface of the valve seat by press working in a flow control valve that controls the flow rate using a gap formed between the valve seats.