JPH0835747A - Electrically-driven flow control valve - Google Patents

Abstract

PURPOSE:To provide an electrically-driven flow control valve which can maintain the joining accuracy of a lower lid after brazing and can increase the strength of the brazed part. CONSTITUTION:The structure of a flow control valve consists of a valve body A and a lower lid 7 joined together by a plurality of crimped parts 23 spaced from one another on the circumference of a projecting opening 13 of the valve body and a gap 20 for passing brazing filler metal therethrough maintained between the inner periphery of a lower lid mounting hole 17 and the outer periphery of the projecting opening 13. A filler flow groove 21 is formed consisting of a ring-like groove 22 arranged circumferentially in the welding position of the lower lid 7 and the valve body A and a plurality of concave groobes 22a provided on the contact surface part of the lower lid 7 and the valve body A extending radially inwardly in communication with the ring-like groove 22 and the mounting hole 17. At the time of brazing the contact surface of the valve body A and the lower lid 7 in an inverted position, the molten filler metal is allowed to flow in around the projecting opening 13 of the lower lid 7 through the filler flow groove 21 and the gap 20 to securely weld the body A and the lower lid 7 together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric flow rate control valve used for controlling the flow rate of a fluid such as a refrigerant used in a refrigeration cycle, and more particularly, it includes a can and a lower lid which form a rotor case of a stepping motor. The present invention relates to an electric flow control valve of a type in which a mounting lower lid is brazed and fixed to an opening of a valve chamber of a valve body.

[0002]

2. Description of the Related Art A conventional electric flow rate control valve known from Japanese Patent Application Laid-Open No. 6-174129 is as shown in FIG. 6, and has a primary port 1a and a secondary port 1b communicating with a valve chamber 1. A valve body A having a valve seat 3a provided at the communication valve port 3 of the secondary-side partition wall 2, and a needle valve 5'having a valve element that comes into contact with and separates from the valve port valve seat 3a of the valve body A; There is a closed case 6 fixed to the outer side of the valve body A opposite to the secondary port 1b, and a stator coil 9 arranged outside the case, and the stator coil 9 is energized and excited inside the case 6. A pulse-controllable stepping motor M provided with a rotor 10 which can be moved in the valve opening / closing direction to be rotated, and a valve operating mechanism B for opening / closing a needle valve 5 ′ by a screw feeding action by the rotor rotation of the stepping motor M. Equipped with,
Joint pipes Pa and Pb for fluid inflow and outflow are fitted to the primary port 1a and the secondary port 1b, and are connected and fixed by brazing and welding.

The closed case 6 is composed of a lower lid 7 welded and fixed to the valve chamber opening of the valve body A, and a cylindrical can 8 attached to the lower lid, and the rotor 10 has a cylindrical shape. It is composed of a sleeve 11 and a cylindrical permanent magnet 12 fitted to the outside of the sleeve 11.

The valve actuating mechanism B has an internally threaded portion 31 inside.
And a cylindrical bush 30 that has a bearing portion 32 and is embedded and fixed in a resin lid 33 of the valve body A so as to hang down into the valve chamber 1, and a male screw portion 36 screwed into the bush female screw portion 31. A valve holder 3 concentrically embedded in and fixed to the central portion of the rotor 10 (sleeve 11 made of synthetic resin) having a rotation bearing portion 37 guided by the bush bearing portion 32.
And 5.

Then, a needle valve 5'having a valve element which is biased in the valve protruding direction by a compression spring 38 inside the valve holder 35, and a fixed ring 39 (the valve which controls the position of the needle valve 5 '). (Having a function of adjusting the position of the needle valve 5'with respect to the valve seat 3a of the main body A at the time of valve assembly), and the valve holder 35 is provided with a shaft portion 35a projecting into the recess at the rear end of the sleeve. 35
A concave shaft bearing body 40 that guides a is fixed to the inner portion of the rear end (upper end in the drawing) of the can 8, and the rotor 10 is rotated and positioned by a double-ended bearing structure including a bush bearing portion 32 and the shaft bearing body 40. Holds movably.

The screwing length of the female screw portion 31 and the male screw portion 36 is set to be the same as or slightly longer than the opening / closing stroke of the needle valve 5 ', and the male screw portion 36 of the valve holder 35 is opened when the needle valve 5a is fully opened. The bush 30 is adapted to be disengaged from the internal thread portion 31 of the bush 30, and a return spring 41 is incorporated between the rotor 10 and the shaft bearing body 40.

This return spring 41 separates from the shaft bearing body 40 when the needle valve 5'is closed, and contacts the shaft bearing body 40 when the needle valve 5'is fully opened, and is compressed as shown in FIG. 10 and valve holder 3
5 acts to urge the holder male screw portion 36 in the direction in which it engages with the bush female screw portion 31. The screw threaded portions of the female threaded portion 31 and the male threaded portion 36 are arranged in the valve chamber 1 of the valve body A, and a fluid (for example, a refrigerant) containing an oil component supplied into the valve chamber 1 is introduced into the screw threaded portion. It is supposed to be lubricated.

Reference numeral 18a designates a valve closing pin integrally formed on the lower end of the sleeve 11 and 19a designates a fully closed stopper integrally formed on the resin lid 33 of the valve body A.
When the needle valve 5'is closed, the pin 18a comes into contact with the outer peripheral surface of the full-close stopper 19a to regulate the valve closing lower limit of the rotor 10. 42 is a motor connector portion having a coil energizing terminal 43.

FIG. 7 shows a device for attaching the lower lid 7 to the valve body A of the electric flow control valve constructed as described above. This conventional electric flow control valve lower lid mounting device is provided with a projection opening 13 having a diameter smaller than the main body outer diameter D2 at the opening of the valve chamber 1 of the valve main body A, and the lower lid 7 is provided outside the main body projection opening 13. After the mounting hole 17 is press-fitted and fixed, the notch 17 on the outer periphery of the mounting hole
The valve body A and the lower lid 7 were fixed by brazing and welding as shown in FIG. 7 by using a (provided at a plurality of locations on the outer periphery of the mounting hole as shown in FIG. 8) as the flow path of the silver brazing R. .

[0010]

In the lower lid attaching device in the conventional electric flow control valve, the main body protrusion 1 of the lower lid 7 is provided.
The press-fitted portion for 3 loosens due to heating during brazing, and in this state the braze R flows into the welded portion and solidifies, so that eccentricity and inclination occur in the lower lid 7, and the fixing accuracy of the lower lid is poor.
Further, since the outer peripheral surface of the lower lid flange 7a and the side surface of the can attachment are machined to obtain accuracy, the cost is increased.

Further, since the flow path of the brazing cannot be secured unless the outer diameter D1 of the cutout portion 17a is larger than the outer diameter D2 of the main body, the flow path gap (the outer peripheral portion of the valve main body A and the outer peripheral portion of the valve main body A cannot be secured after brazing. Since the filling portion of the gap between the lower lid cutout portion 17a and the inner end surface is only the wax R, the strength is insufficient,
There has been a problem that fatigue breakdown occurs when fluid pressure is repeatedly applied when the electric flow control valve is used.

Further, there is a problem that the hermetically sealed case 6 shown in FIG. 6 often has a poor airtightness because pinholes and the like are likely to occur in the wax filling the flow path gap. The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide an electric flow control valve capable of ensuring the fixing accuracy of the lower lid after brazing and increasing the strength of the brazing weld portion. Especially.

[0013]

In order to achieve the above-mentioned object, in the present invention, the valve body A and the lower lid 7 are fixed by a plurality of caulking portions 23 which are divided on the circumference of the body projecting opening 13. Then, a brazing flowable gap 20 is secured between the inner circumference of the lower lid mounting hole 17 and the outer circumference of the projecting port 13, and a circle is formed at the welding position of the lower lid 7 with the valve body A. The annular groove 22 extending in the circumferential direction is a continuous brazing flow in which a plurality of concave grooves 22a extending in the central direction that communicate between the annular groove 22 and the mounting hole 17 are formed on the contact surface portion between the lower lid 7 and the valve body A. When the valve body A and the lower lid 7 are brazed and welded in a state where the lower lid contact surface is inverted (the posture shown in FIG. 4), the melted braze R is formed as the channel groove 21. As shown in FIG. 2, it flows through the gap 20 and around the projecting opening 13 in the lower lid 7, Wherein the main body A and the lower cover 7 is to be welded. The concave groove 22a may be provided on the contact surface portion of the lower lid 7 with the valve body A or on the contact surface portion of the valve body A with the lower lid 7.

[0014]

According to the electric flow control valve of the present invention, since the lower lid 7 is fixed to the valve body A by the caulking portions 23 at a plurality of places, the lower lid fixing portion can be loosened by heating during brazing. No, the fixing accuracy after brazing can be secured.

In addition, the wax flow path has a conventional cutout 17
Instead of a, a circumferential annular groove 22 is provided at a welding position of the lower lid 7 with the valve body A, and a plurality of annular grooves 22 are provided at a contact surface portion between the lower lid 7 and the valve body A. Groove 22a
Since it is formed by the continuous brazing channel groove 21 consisting of the above, when the valve body A and the lower lid 7 are brazed and welded in a state where the lower lid contacting surface is inverted, the molten brazing material is formed in the channel groove 21 and 2 through the gap 20 and around the projecting opening 13 in the lower lid 7.
As shown in (A), the valve body A and the lower lid 7 can be securely welded and fixed. For this reason, the brazing welded portion of the lower lid 7 does not have a brazing portion as in the conventional case, and the strength of the brazing welded area can be increased (about 1.5 times the strength of the conventional type). In addition, the problems of fatigue fracture and poor airtightness as in the past can be solved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
This will be described in detail according to In this first embodiment, the valve chamber 1
A valve body A having a projection opening 13 having a diameter smaller than the body outer diameter D2 at the opening thereof, and a can mounting larger than the body outer diameter D2 having a mounting hole 17 fitted on the outer side of the body projection opening 13 And a mounting hole 17 of the lower lid 7 is formed to have a diameter slightly larger than the outer diameter of the main body projecting opening 13.

Then, the lower lid 7 is fitted to the outside of the main body projecting opening 13 with a gap, and fixed as shown in FIG. 1 by a plurality of (for example, five) caulking portions 23 divided on the circumference of the main body projecting opening 13. Thus, a brazing flowable gap 20 is secured between the inner periphery of the lower lid mounting hole 17 and the outer periphery of the projecting port 13.

At the welding position of the lower lid 7 with the valve body A,
An annular groove 22 extending in the circumferential direction is formed, and the annular groove 22 and the mounting hole 17 are formed in a contact surface portion of the lower lid 7 with the valve body A (a lid portion that abuts on a stepped outer peripheral step surface of the valve body A). A plurality of concave grooves 22a are formed which communicate with each other in the direction of the center, and the annular groove 22 and the concave grooves 22a form a continuous wax flow path groove 21.

When the valve body A and the lower lid 7 are brazed and welded in a state where the lower lid contact surface is installed upside down (the posture shown in FIG. 4), the molten braze R is melted by the flow passage groove 21 and the gap 20.
2A, the valve main body A and the lower lid 7 are separated from each other as shown in FIG.
As shown in the figure, it is fixed by welding.

The symbols Pa and Pb shown in FIGS. 1 and 2 are used.
Is a joint pipe for fluid inflow / outflow that is connected to the primary port and the secondary port communicating with the valve chamber 1 of the valve body A. The lower lid 7 is brazed and welded from the direction of arrow a in the posture shown in FIG. At the time of welding, the valve body A is connected and fixed by brazing in the directions of arrows B and C shown in FIG.

FIG. 5 shows a second embodiment of the present invention. In the second embodiment, an annular groove 22 extending in the circumferential direction is formed at a welding position of the lower lid 7 with the valve main body A, and a contact surface portion with the lower lid 7 of the valve main body A (outside the projection opening of the valve main body A) is formed. The first point shown in FIGS. 1 to 3 is that a plurality of recessed grooves 22a are formed on the surrounding surface) which communicate between the annular groove 22 and the mounting hole 17 toward the center.
The embodiment is different from the above embodiment. The other structure is the same as that of the first embodiment shown in FIGS. 1 to 3, and therefore, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted.

[0022]

As described above, in the electric flow control valve of the present invention, since the lower lid 7 is fixed to the valve body A by the caulking portions 23 of the main body projecting port 13, the lower lid fixing portion is It does not loosen due to heating during brazing, and the fixing accuracy after brazing can be secured.

Further, the flow path of the wax is notched 17 as in the conventional case.
Instead of a, a circumferential annular groove 22 is provided at a welding position of the lower lid 7 with the valve body A, and a plurality of annular grooves 22 are provided at a contact surface portion between the lower lid 7 and the valve body A. Groove 22a
Since it is formed by the continuous brazing channel groove 21 consisting of the above, when the valve body A and the lower lid 7 are brazed and welded in a state where the lower lid contacting surface is inverted, the molten brazing material is formed in the channel groove 21 and The valve body A and the lower lid 7 can be securely welded and fixed to each other through the gap 20 and flow into the vicinity of the projecting opening 13 in the lower lid 7.

Therefore, the brazing weld portion of the lower lid 7 does not have a brazing portion as in the conventional case, and the strength of the brazing weld portion can be increased (the strength can be increased by about 1.5 times that of the conventional case). This has an excellent effect of being able to solve the problems of fatigue fracture and airtightness which have been conventionally encountered.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a main portion (a lower lid mounting portion for a valve body) of an electric flow control valve according to a first embodiment of the present invention in a state where a lower lid is fixed before welding, and FIG. Is a plan view,
The same figure (B) is a central longitudinal cross-sectional view.

2A and 2B are explanatory views showing the lower lid mounting portion of FIG. 1 after welding, in which FIG. 1A is a plan view and FIG. 2B is a central longitudinal sectional view.

3A and 3B are configuration explanatory views of a lower lid applied to the present invention, in which FIG. 3A is a bottom view of the lower lid and FIG.
FIG. 6 is a vertical sectional view taken along line XX of FIG.

FIG. 4 is an operation explanatory view showing a posture and a wire feed welding position during brazing welding.

FIG. 5 is a central longitudinal sectional view showing a main portion (a lower lid mounting portion for a valve body) of an electric flow control valve according to a second embodiment of the present invention in a lower lid fixed state before welding.

FIG. 6 is a central longitudinal cross-sectional view showing a conventional electric flow control valve in a closed state.

7A and 7B are configuration explanatory views showing a lower lid mounting portion of a conventional electric flow control valve, in which FIG. 7A is a plan view and FIG. 7B is a YY line in FIG. 7A. FIG. Central longitudinal sectional view.

8A and 8B are configuration explanatory views of a lower lid applied to a conventional electric flow rate control valve, in which FIG. 8A is a plan view of the lower lid, and FIG. 8B is Z- of FIG. 8A. FIG. 3 is a vertical sectional view taken along the line Z.

[Explanation of symbols]

A ... valve body, 1 ... valve chamber, 7 ... lower lid, 13 ...
17 ... Lower cover mounting hole, 20 ... Wax flowable gap, 21
... wax flow channel groove, 22 ... annular groove, 22a ... concave groove, 23 ... crimped portion, R ... wax.

Claims (2)

[Claims] 1. A valve body having a valve chamber opening portion provided with a projecting opening having a diameter smaller than the outer diameter of the body, and a can mounting lower lid having a mounting hole fitted to the outside of the body projecting opening. Then, in the electric flow control valve for fixing the lower lid to the valve body by brazing and welding, the valve body and the lower lid are fixed by a plurality of caulking portions divided on the circumference of the main body projection port, With a configuration that secures a brazable flow gap between the inner periphery of the lower lid mounting hole and the outer periphery of the protrusion opening, an annular groove that extends in the circumferential direction at the welding position with the valve body of the lower lid, A plurality of concave grooves, which communicate between the annular groove and the mounting hole, are formed in the contact surface portion between the lower lid and the valve main body and extend toward the center as continuous brazing flow passage grooves, and the valve main body and the lower lid are formed. When brazing and welding the lower lid contacting surface in an inverted state, the molten braze is An electric flow rate control valve, characterized in that the valve body and the lower lid are welded and fixed to each other by flowing in around the projecting opening in the lower lid. 2. The electric flow control valve according to claim 1, wherein a plurality of concave grooves directed toward the center are provided in a contact surface portion with the lower lid of the valve body toward the center.