JPS60241586A - Electrically-driven control valve in refrigerating apparatus - Google Patents

Abstract

PURPOSE:To obtain high resolving power during steady-state control for a refrigerating apparatus without a special increase in lift of a valve by enlarging a valve angle at the forward end portion of a controlling conical peripheral surfacae portion of a needle valve. CONSTITUTION:A needle valve 2 adapted to advance and separate to and from a valve seart 1 of an expansion valve is driven by a stepping motor. The needle valve has a conical peripheral surface portion B having a large valve angle at the most end thereof, and continuously has a conical peripheral surface portion A having a small valve angle, whereby the boundary portion D is an inflection point to let the needle valve have a flow characteristic having two gradients. A conical peripheral surface portion C having a large valve angle is disposed on the inside of the conical peripheral surface portion A bacaue the conical peripheral surface portion A having such small valve angle is apt to eat into the valve seat 1 at the time of closing the valve. It is necessary that the sectional area of the boundary portion D is about more than 66% of the diameter of the valve seat.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to an electric control valve in a refrigeration system.

The electric control valve of the present invention is used, for example, as an electric expansion valve in a refrigeration system.

JP-A-58-26 as an electric expansion valve in refrigeration equipment
When using a conventional simple needle valve as shown in No. 968, if the valve size is selected according to the steady state of the refrigeration equipment, the flow rate may be insufficient when a large amount of flow is temporarily required, such as during startup. On the other hand, if an attempt is made to match the maximum flow rate during the transition period, the resolution must be reduced or the valve lift must be increased excessively.

The present invention has been made with attention to the above-mentioned points, and it provides a valve closing function when the valve is closed without increasing the valve lift, high resolution during steady control of the refrigeration equipment, and high resolution when the valve is fully opened. The present invention provides an electrically operated control valve that allows a large flow rate to be obtained.

[Structure of the invention]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a needle valve 2 that approaches and separates from a valve seat 1 of an expansion valve
is a configuration driven by a stevening motor (not shown), and has a conical circumferential surface portion B with a large valve angle at the leading edge, and a conical circumferential surface portion A with a small valve angle next,
As shown in FIG. 2, a flow rate characteristic having two "slopes" is obtained with the boundary portion as an inflection point.

If the valve angle of the conical peripheral surface part A is small, there is a risk of it digging into the valve seat 1 when the valve is closed. Therefore, a conical peripheral surface part C with a large valve angle is provided inside the conical peripheral surface part A, The surface portion C makes contact with the valve seat 1 to prevent digging. Since the boundary portion E between the conical circumferential surfaces A and C and the diameter of the valve seat 1 are the same, the conical curved surface portion C has almost no effect on the flow characteristics.

In particular, it is clear from experiments that in order to effectively obtain the effects of the present invention, the cross-sectional area of the boundary portion needs to be approximately 60% or more of the valve seat diameter, as shown in FIG.

FIG. 3 shows a shape obtained by cutting the conical peripheral surface B in FIG.
This means that the same effect as above can be obtained.

〔effect〕

As described above, the present invention is constructed by increasing the valve angle at the tip of the conical circumferential surface for controlling the needle valve, so that the valve angle can be increased during steady control of the refrigeration system without particularly increasing the valve lift. It has the advantage of being able to obtain high resolution and a large flow rate when the valve is fully open.

[Brief explanation of the drawing]

Fig. 1 is a main part configuration diagram of an embodiment of the present invention;
The figure is the same operating characteristic diagram as above, the 3rd TyJ is a main part configuration diagram of another embodiment, the 4th figure is a graph showing each characteristic when the ratio of the cross-sectional area of the boundary part and the valve seat diameter is changed, and the 5th The figure is a longitudinal sectional view of a conventional electric control valve. 2...Needle valve, A...Conical part for control (conical peripheral part) Patent issued by Saginomiya Manufacturing Co., Ltd. No. 50

Claims (1)

[Claims] An electric control valve for a refrigeration system, characterized in that the valve angle is increased at the tip of a conical part for controlling a needle valve, in the electric control valve whose valve body is actuated by a motor.