JPH0694910B2 - Electric control valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric control valve used for controlling a refrigerant flow rate, such as an electric expansion valve of a refrigeration system.

2. Description of the Related Art FIG. 3 shows a conventional example (Japanese Patent Laid-Open No. 60-196477), in which an electric control valve comprises a valve section V and a stepping motor section M, and in the valve section V, a primary port 1a of the valve body 1 and A valve seat 2a is provided on the partition wall 2 between the secondary ports 1b,
A needle valve comes in contact with and separates from the needle 2a, and the needle valve 3 is axially slidably supported in a male screw tube 4 screwed to the valve body 1 on the side of the secondary port 1b. .

A lower lid 5 is provided above the valve body 1 with the male screw tube 4 as a center, and a closed case 6 in the stepping motor section M is fixed on the lower lid 5. Case 6
A stator 8 containing a coil 7 is provided on the outer peripheral portion of the. A rotor 9 is rotatably supported by the male screw tube 4 in the case 6. The rotor 9 is a support cylinder 10
A cylindrical permanent magnet 11 is fitted to the outer peripheral portion of the same, and then the upper edge portion 10a is spread over the permanent magnet 11 to integrate the two, and is fitted inside the support cylinder 10 at the lower side. Fixed female screw tube
The screw 12 is screwed into the male screw tube 4 so as to be rotatable and movable in the axial direction.

A connecting plate 10b is formed in an axially intermediate portion of the support cylinder 10, and a small diameter 3a of the needle valve 3 is inserted into the hole 10c of the connecting plate 10b.
It is fixed by a stopper 13 such as a ring. A compression coil spring 14 is wound around the small diameter portion 3a of the needle valve 3 between the stepped portion 3b and the connecting plate 10b.

In this structure, the rotor 9 is rotatably supported in a cantilever manner by screwing the female screw tube 12 provided on the inner peripheral portion of the rotor 9 into the male screw tube 4 fixed to the valve body 1. In the cantilevered support structure, since the rotor 9 is supported only by the screw portion, there are drawbacks that the screw portion is easily worn and a vibration sound is easily generated.

On the other hand, the double-support structure having bearings at both ends of the rotor requires high precision in the centering manufacturing technique, and it is not easy to increase the precision of the double-support structure in the sealed case.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned points, and in a cantilevered support member that rotatably supports a rotor, by providing a guide portion together with a screw portion, the screw portion is provided. This load is reduced, and the wear and vibration noise are reduced.

Means for Solving the Problems In order to achieve the above object, in the present invention, a rod-shaped support member that rotatably supports a rotor is provided inside a hermetically-sealed case having an electromagnetic coil on the outer periphery, and the support member is provided. A male screw portion and a cylindrical guide portion are continuously provided in the axial direction of the, and a female screw portion that engages with the male screw portion is engaged with an engaging pipe fixed inside the rotor. The sliding tube portion is provided, and the valve body separate from the rotor is brought into contact with and separated from the valve seat by the rotation of the rotor.

Embodiment In FIG. 1, an electric control valve comprises a valve portion V and a stepping motor portion M, and in the valve portion V, a valve seat 21a is provided on a partition wall 21 between a primary port 20a and a secondary port 20b of a valve body 20. The needle valve 22 comes into contact with or separates from the valve seat 21a.

A closed case 23 in the stepping motor section M is fixed on the valve body 20, and a rod-shaped support member 24 is provided so as to hang down from the upper end of the closed case 23 toward the valve body 20. A cylindrical guide portion 24a and a male screw portion 24b are connected to the rod-shaped support member 24 in the axial direction.

Reference numeral 25 denotes a rotor, and the rotor 25 is fitted with a cylindrical permanent magnet 27 on the outer peripheral portion of the support cylinder 26, and then the upper edge 26a is expanded on the permanent magnet 27 to integrally integrate the two. Engagement tube 2 that is crimped and is fitted and fixed to the intermediate connecting portion 26b of the support tube 26.
The female screw portion 28a of 8 is screwed into the male screw portion 24b, and the sliding tube portion 28b thereof is engaged with the guide portion 24a.

A connecting pipe 29 is further fixed to the connecting portion 26c of the support cylinder 26, and a small diameter portion of the needle valve 22 is inserted into a hole 29b of a bottom wall 29a of the connecting pipe 29.
The stopper 22b is configured to penetrate through the bottom wall 29a, and the compression coil spring 30 is provided between the bottom wall 29a and the step portion 22c of the needle valve 22.
30 always biases the needle valve 22 in the valve closing direction.

A stator 32 having a coil 31 built therein is provided on the outer peripheral portion of the hermetically sealed case 23. Reference numeral 33 denotes an engaging rod provided on the rotor 25, and 34 denotes a stopper, which engage with each other when the rotor 25 makes one final rotation when the valve is closed.

In the above structure, when the coil 31 of the stator 32 is energized, the rotor 25 rotates and the female screw portion 28a and the male screw portion 24b rotate.
The sliding pipe portion 28b moves on the cylindrical guide portion 24a by the screwing. When the coils 31 are sequentially energized, the rotor 25 attempts to move non-uniformly in the axial direction and the radial direction, but the movement is dispersed between the screw portion by the engagement of the sliding tube portion 28b and the guide portion 24a. Then, the abrasion of the screw portion is reduced and the rattling sound of the screw portion during operation is reduced.

In the embodiment shown in FIG. 2, a cylindrical rod-shaped support member 24 'is provided upright on the upper portion of the valve body 20, and a cylindrical guide portion 24a' and a male screw portion 24b 'are connected in series to form a rotor. 25 support tubes
Female thread portion 28 of engaging tube 28 'fitted and fixed inside 26'
a'is screwed into the male screw portion 24b 'and the sliding tube portion 28
b'is engaged with the guide portion 24a '.

Then, the needle valve 22 'penetrates through the cylindrical rod-shaped support member 24', and the small diameter portion 22a 'is fixed in the support cylinder 26' at the upper portion of the engagement pipe 28 ', and the upper wall 29a of the connecting pipe 29'. ′ Hole 29
A stopper 22b 'is configured to project above b'to engage with the upper wall 29a', and a compression coil spring 30 is provided between the upper wall 29a 'and the step portion 22c' of the needle valve 22 '. There is.

In FIG. 2, the same reference numerals are attached to the same structural parts as in FIG.

As described above, the present invention provides a rod-shaped support member for rotatably supporting the rotor inside the hermetically-sealed case having the electromagnetic coil on the outer periphery, and the male screw portion is provided in the axial direction of the support member. A cylindrical guide part is continuously provided, and an engagement pipe fixed to the inside of the rotor is provided with a female screw part to be engaged with the male screw part and a sliding pipe part to be engaged with the guide part. Since the valve element connected to the rotor is brought into contact with and separated from the valve seat by the rotation of the rotor, the cantilever support structure for the rotor is adopted in the sealed case of the electric control valve to improve the accuracy while manufacturing. And the uneven movement in the radial direction that occurs when the rotor is rotated and the female screw part and the male screw part are screwed together to move in the vertical direction. Distributed by department This has the effects of reducing the wear of the screw portion and reducing the rattling noise of the screw portion during operation.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view of another embodiment of the above, and FIG. 3 is a sectional view of a conventional example. 20 ... Valve body, 21a ... Valve seat, 22 ... Valve body, 24,24 '...
A rod-shaped support member, 24a: a cylindrical guide portion, 24b: a male screw portion, 25: a rotor, 28: an engaging pipe, 28a: a female screw portion, 28b: a sliding pipe portion.

Claims (1)

[Claims] 1. A rod-shaped support member for rotatably supporting a rotor is provided inside a hermetically-sealed case having an electromagnetic coil on the outer periphery, and a male screw portion and a cylindrical guide portion are provided in the axial direction of the support member. An engaging pipe fixed inside the rotor is provided with a female screw portion that is screwed into the male screw portion and a sliding pipe portion that engages with the guide portion, and the rotor is rotated by the rotation of the rotor. An electric control valve characterized in that a separate valve element is brought into and out of contact with the valve seat.