JPH04228983A - Electric expansion valve - Google Patents

Abstract

PURPOSE:To provide an electric expansion valve capable of dispersing and absorbing tensile stress acting on a lead wire, a part of which including curves of the wire comes out of a casing from the upper section of the casing and is buried in the thick side section of the casing along the side wall thereof. CONSTITUTION:A motor section 6 having a lead wire 9 comprising a curved section 9B extended from a stepping motor 6 housed in a casing 4 to the outside thereof via an upper section, and a suspended section 9C along the side wall 4B of the casing 4, is concealed with a covering material 22 to be cured after laid around the casing 4 in molten state. In addition, a side section 23 covering the curved and suspended sections 9B and 9C and having larger thickness than other portions is formed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric expansion valve used in a refrigeration cycle.

0002

[Prior Art] In the solenoid valve disclosed in Japanese Utility Model Publication No. 49-7969, a magnet body M consisting of an electromagnetic coil 3, a cover fitting 5, a stopper 2, and a fixed iron core 1 is made of a specially made electrical resin 9 such as epoxy resin. A structure is disclosed in which components such as the electromagnetic coil 1, the metal cover 5, the stopper 2, the fixed iron core 1, the lead wire 12, and the valve body mounting bracket 8 are integrally coated by casting.

0003

According to the conventional technique, the lead wire 12 extends straight upward from the electromagnetic coil 1, passes through the resin 9, and is drawn out from the upper part of the magnet body M. The tensile stress applied to the leader wire 12 is concentrated at the base of the leader wire 12, and not only is there a risk of breakage during the installation work of the solenoid valve, but also moisture or water attached to the top of the magnet body M or the leader wire 12 may There is a problem that it is easy to enter the electromagnetic coil 1 from between the leader wire 12 and the resin 9, and the moisture-proofing and waterproofing effects are poor.

[0004] The present invention has been made in view of the above, and an object of the present invention is to relieve the tensile stress applied to the lead wire at the curved portion.

[0005]

[Means for Solving the Problems] The present invention provides a stepping motor housed in a case having a cover on the lower surface, a curved part extending from the stepping motor to the outside of the case through the upper part of the case, and a hanging part along the side wall of the case. a motor part equipped with a lead wire, a valve body driven by the stepping motor, and an insulating material such as rubber or resin, which is placed around the case in a molten state and hardened to The present invention provides an electric expansion valve comprising a covering material that covers a case and a lead wire, and has a wall thicker at the side facing the lead wire than at other parts.

[0006]

[Operation] According to the above means, since the curved part of the lead wire is buried in the sheathing material with the curved part extending from the top of the case to the outside of the case, the tensile stress applied to the lead wire is absorbed by the sheathing material near the curved part. will be dispersed and absorbed on the sides of the

[0007]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

Reference numeral 1 in the figure is an electric expansion valve used in the refrigeration cycle of refrigerators, air conditioners, and other refrigeration/air conditioning equipment, and is composed of a motor section 2 and a valve body 3 provided at the bottom of the motor section. There is. The motor section 2 includes a box-shaped aluminum case 4, a stainless steel cover 5 that covers the bottom surface of the case, and a stepping motor 6 housed within the case 4 and driven by receiving pulse signals. , a gear mechanism 8 connected to the shaft 7 of the stepping motor, and a controller (not shown) extending from the stepping motor 6 through the upper wall 4A of the case 4 to the outside of the case 4 and along the side wall 4B of the case 4. It is composed of a plurality of lead wires 9, for example, six lead wires, which are connected to signal wires from. On the other hand, the valve body 3 is fixed to the gear mechanism 8 and connected to a spindle 11 passing through a stopper 10 attached to the cover 5,
A screw-shaped driver 13 that is screwed into the holder 12, and a valve body 16 that is suspended and supported by a telescopic bellows 14, that is in contact with the lower end of the driver 13, and that has a needle portion 15 at the lower end. and the needle part 1
5 is seated, a bent part 18 formed in the space above the valve seat, and both inlet and outlet pipes 19 and 20 connected at one end to communicate with this bent part. It is connected to the motor part 2 by a lock nut 21 which is detachable. In the electric expansion valve 1, a stepping motor 6 rotates forward or backward depending on the number of pulse signals sent from the controller, and this rotational motion is converted into reciprocating linear motion by a transmission mechanism of a gear mechanism 8, a spindle 11, and a driver 13. By being converted, the valve body 16 can be moved in the insertion/removal direction, from a fully closed position where the valve body 16 sits on the valve seat 17 to a fully open position where the valve body 16 is spaced from and above the valve seat 17. It has a refrigerant flow control function, that is, both a pressure reduction function and an opening/closing function.

Reference numeral 22 denotes a covering material made of a thermal and electrical insulating material such as rubber or resin that covers the motor section 2, and includes a base 9A of the lead wire 9 and a curved portion 9B that curves downward from this base. A side portion 23 is formed which also covers the hanging portion 9C along the side wall 4B of the case 4. This side portion 23 is thicker than other portions in order to cover the lead wire 9 as shown in FIG. By covering the motor section 2 with the covering material 22, both the heat insulation and waterproof effects of the motor section 2 used in a low temperature region can be improved. The lead wire 9 is drawn out from the upper wall 4A of the case 4 because the gear mechanism 8 is located at the bottom of the motor section 2.

Next, a method of coating the motor section 2 will be explained.

24 shown in FIGS. 4 to 6 is a cylindrical casting mold with a bottom and an open upper surface, consisting of a peripheral wall 25 and a bottom wall 26 whose inner surfaces are coated with a mold release agent, and from the peripheral wall 25 to the bottom wall 26. A longitudinally elongated bulge 27 is formed in a part of the recess 28 to form a side passage 29 that becomes a part of the recess 28 . Reference numeral 30 denotes an appropriate number of step-like protrusions that are formed across the inner surface of the peripheral wall 25 and the upper surface of the bottom wall 26 at appropriate locations and project into the recess 28;
When the motor section 2 is housed in the recess 28 as shown by the chain line in FIG.
The motor section 2 is supported so as to form a space between the motor section 2 and the inner surface of the motor section 2. That is, each of the protrusions 30 serves as a molding part for the motor section 2 to support the motor section 2 and as a spacer to form a space. As shown in FIG. 3, the motor section 2 is coated with antirust coating in advance in a band-like manner on an annular surface extending from the outer edge of the upper surface of the case 4 facing the protrusion 30 to the upper edge of the circumferential surface. It is formed as a painted surface 31.

When storing the motor section 2 in the recess 28 of the casting mold 24, first, the lead wires 9 are tied together and attached to the circumferential surface of the case 4 with adhesive tape or the like, and then the motor section 2 is
is reversed, that is, the upper surface is the lower surface, and the lead wire 9 is placed in the casting mold 2.
4, and the coated surface 31 of the motor section 2 is placed on each protrusion 30. Along with this placement, the peripheral wall 25 and bottom wall 26 of the casting mold 24,
A space is formed between the motor part 2 housed in the recess 28, and in this state, a molten rubber or resin insulating material is poured into the space formed in the recess 28, and the insulating material is After a cooling period for hardening, the motor part 2 is pulled out from the casting mold 24, and as shown in FIG. A covering material 22 is obtained with side portions 23 covering 9C. In addition, each protrusion 30 of the painted surface 31
The surface in contact with becomes the exposed surface.

According to the above-described structure of the electric expansion valve 1, the covering material 22 is integrated into the motor section 2 as it hardens, and the part including the curved part 9B of the lead wire 9 is made more rigid than the other part. Since it is buried in the thick side part 23, the moisture-proofing and waterproofing effect of the joint part between the case 4 and the cover 5 covering the motor part 2 is good, and the moisture-proofing and waterproofing effect of the base 9A of the lead wire 9 is also improved. As a result, moisture and water can be prevented from entering the motor section 2.

Further, the lead wire 9 is brought out from the upper part of the case 4 to the side wall 4B of the case 4.
3, the tensile stress applied to the lead wire 9 is distributed to the side portion 23 which is thicker and more elastic than the other portions, and as a result, the root 9 of the lead wire 9
The tensile stress on A can be weakened.

[0015]

[Effect of the invention] A part of the lead wire, including the curved part, is brought out of the case from the top of the case and buried inside the thick side wall of the case, along the side wall of the case, so the tension is applied to the lead wire. The stress is dispersed and absorbed at the side portions, and as a result, the tensile stress applied to the base of the lead wire can be weakened, and damage to the base of the lead wire can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an electric expansion valve covered with a covering material.

FIG. 2 is an overall perspective view of the electric expansion valve before being covered with a covering material.

FIG. 3 is an overall perspective view of the motor section.

FIG. 4 is a plan view of the casting mold.

FIG. 5 is a sectional view taken along line AA in FIG.

FIG. 6 is an overall perspective view of the casting mold.

[Explanation of symbols]

2 Motor part 3 Valve body 4 Case 9 Lead wire 9B Song section 22 Covering material 23 Side part

Claims (1)

[Claims] 1. A stepping motor housed in a case having a cover on the bottom surface, a lead wire consisting of a curved part extending from the stepping motor to the outside of the case through the upper part of the case, and a hanging part along the side wall of the case. a valve body driven by the stepping motor, and an insulating material such as rubber or resin, which is disposed around the case in a molten state and hardens to cover the case and lead wires; An electric expansion valve comprising a covering material having a thicker wall on the side facing the lead wire than on other parts.