JPH02107875A - Waterproofing structure for electric expansion valve - Google Patents

Abstract

PURPOSE:To prevent the malfunction or failure cause by dew by soldering part of a led wire as a bare wire section, covering it with a covering material, and using an anaerobic seal agent for a lock nut connecting the holder of a valve body and a storage section. CONSTITUTION:Part of the outer cover 9B of the portion of a lead wire 9 facing the side wall 4B of a case 4 is removed to form a bare wire section 9D,and it is soldered to bind a conductor 9A. An insulating band T such s an insulating tape is provided on the side wall 4B so that the bare wire section 9D is not brought into contact with the case 4, and a motor section 2 is covered with a covering material 22. A binding section 9E is also buried in the covering material 22, thus the binding section 9E prevents the advance of moisture even if moisture infiltrates into the outer cover 9B from the other end provided with a connecting terminal connected to a control unit and an interrupting unit or the like. An anaerobic seal agent K is provided between the female screw of a lock nut 21 and the male screw of the storage section 19 of a valve main body 3, thereby the infiltration of moisture and dew can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a waterproof structure for an electric expansion valve used in a refrigeration cycle of a refrigerator-freezer, an air conditioner, or the like.

(b) Conventional technology Japanese Patent Application Laid-Open No. 62-215184 (F1a 41/10
) includes a stepping motor housed in a case, a motor part of an electric expansion valve consisting of a motor part having a leader line extending outside from the stepping motor, and a valve body, and a leader line along the motor part of the electric expansion valve. In covering a part,
A structure has been disclosed in which an insulating material such as rubber or resin that hardens after melting is used as a covering material, and this covering material is welded and integrated with a motor part and a lead wire to make an electric expansion valve waterproof.

(c) Problems to be solved by the invention According to the above-mentioned conventional technology, the following problems occur.

■The part of each leader wire that runs along the case is buried in the covering material, and one end of each leader wire connected to the stepping motor is housed in the case covered with the covering material.
The parts of the leader wires that are covered with the covering material are well-waterproofed, but each leader wire has a large number of long, slender conductors that are housed inside an outer sheath such as a tube made of vinyl chloride. A continuous gap is formed between the jacket and the conductor along its entire length, and at the other end where a connection terminal for connection to a controller or repeater is provided, the jacket is cut and the conductor becomes a bare wire. Due to the relationship between As a result, if the electric expansion valve is used for a long period of time, moisture that has entered the leader line may move into the motor and cause the stepping motor to malfunction. Ta.

■The motor part is covered with a covering material, but since the valve body below the motor is exposed to air in a low-temperature region, it is straddled between the holder that screws and supports the driver and the storage part that stores the valve body. Therefore, the valve body, including the lock nut that is screwed together, is exposed to cold air while the refrigeration cycle is operating, and is exposed to relatively warm air when the refrigeration cycle is not operating.
Therefore, there is a problem in that dew generated on the valve body during the suspension period enters the threaded portion between the lock nut, the holder, and the storage portion, enters the storage portion through the threaded portion, and interferes with the operation of the valve body.

The present invention aims to solve the above-mentioned problems (1) and (2).

(d) Means for Solving the Problem The present invention, as a means for solving the above problem (2), forms a bare wire portion with the outer sheath removed in a portion of each lead wire along the case, and A waterproof structure was adopted in which the bare wires were soldered to form a binding part that bound each conductor, and the area from the lead wire binding part to the lead-out part was covered with a covering material.

In addition, the following two methods were adopted to solve the problem (2) above.

One is a waterproof structure that continuously covers the motor part, part of the lead wire that runs along the motor part, and the lock nut of the valve body.

The other waterproofing method is to cover the motor part and part of the lead wires along the motor part with a coating material, and to apply an anaerobic sealant between the lock nut of the valve body and the holder and storage part. structure.

(f) Effect In the former method described above, a bare wire portion is formed in the attached portion of each lead wire that faces the side wall of the case, where the conductor wire is exposed by removing a portion of the outer sheath. At the same time, a binding part is formed on this bare wire part by soldering, and since it is buried in the covering material, it can be connected from the other end of the lead wire equipped with a connection terminal to be connected to a controller, interrupter, etc. Even if moisture enters the jacket, since the covering material is welded to the bare wire portion and the bundled portion, the bundled portion acts as a barrier to prevent moisture from advancing.

In addition, in one of the latter methods described above, the covering material is continuously formed up to the valve body and also covers the lock nut, so that the covering material is welded to the valve body and the female screw of the lock nut and the housing part are connected. Since it covers the gap with the male thread, it can prevent dew adhering to the valve body from entering the gap.

Furthermore, in another one of the latter methods mentioned above, an anaerobic sealant is provided between the female thread of the lock nut and the male thread of the storage part, so that as the two screws are screwed together, the space between the two screws becomes tighter. The air will be exhausted and the sealant will remain between both screws.

(f) Example The present invention will be described in detail below based on the drawings.

In the figure, (1) is an electric expansion valve used in the refrigeration cycle of refrigerators, air conditioners, and other refrigeration/air conditioning equipment, and the motor part (2)
and a valve body (3) provided at the bottom of the motor section. The motor section (2) is housed in a box-shaped aluminum case (4), a stainless steel cover (5) covering the bottom of the case, and the case (4), and provides pulse signals. a stepping motor (6) that is driven by a gear mechanism (8) connected to a shaft (7) of the stepping motor;
A) extending out of the case (4) through said case (4).
It consists of a plurality of lead wires (9), for example, six lead wires, which can be connected to signal lines from a controller (not shown) along the side wall (4B) of the controller. On the other hand, the valve body (3) has a spindle (11) fixed to the gear mechanism (8) and passing through a stopper (10) attached to the cover (5);
A screw-shaped driver (13) connected to this spindle and in a threaded relationship with the holder (12) and a retractable bellows (14) are suspended and supported by the dryer/<
- The valve body (1
6), and a valve seat (1) on which the needle part (15) is seated.
7) and a bent portion (18) formed in the space above the valve seat.
), and both inlet and outlet pipes (I) (0) connected at one end so as to communicate with this bent part, and are screwed together across the holder (12) and storage part (19). It is connected to the motor part (2) by a removable lock nut (21). In addition, as shown in Fig. 7, the storage section (19)
The lock nut (21) has a male thread (20A) and a female thread (20B>).

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 movement is caused by a gear mechanism (8) and a spindle (1).
1) The valve body (16) can be moved in the insertion/extraction direction by being converted into reciprocating linear motion by the transmission mechanism of the driver (13), and the valve body (16) is fully open when seated on the valve seat (17). The refrigerant flow rate control function from the position of 1 to the fully open position located above and away from the valve seat (17), that is, it has both a pressure reduction function and an opening/closing function.

(22) is an elastic covering material made of a thermal and electrical insulating material such as rubber or epoxy resin that covers the motor part (2), and forms a side part (23) that also covers the lead wire (9). ing. By covering the entire motor part (2) with this coating material (22), the motor part (2) used in a low temperature region (
2) The heat insulation and waterproof effects can be improved.

Each of the lead wires (9) is made of a large number of extremely thin conductive wires (9A) called stranded wires and a resin such as vinyl chloride or silicone, and is extruded together with the conductive wires (9A). It consists of a tube-shaped jacket (9B) that covers the conducting wire. Each lead wire (
9), the attached part (9C) facing the side wall (4B) of the case (4) has a bare conductor 1 (9A) exposed by removing a part of the outer cover (9B). Line part (
9D) is formed. (9E) is a binding part formed by soldering a part of this bare wire part, and each week*(9A) is bound by this binding part. Before the attached part (9C) covers the motor part (2) with the covering material (22), the bare wire part (9D) is covered with the case (as shown in FIG. 3).
4) Avoid touching the side wall (4B) of the case (4) directly.
An insulating band (T) such as an insulating tape is provided on the insulating tape. Since this insulating band (1) has adhesive on both sides,
Insulating the bare wire portion (9D) and temporarily fixing the attached portion (9C) can be performed, and the work of temporarily fixing the lead wire (9) using tape in the covering process to be described later can be eliminated.

(K) shown in Fig. 7 is an anaerobic sealant, which is applied to the inner surface of the lock nut (21) and/or the outer surface of the housing part (19), and is used to screw the male screw (20A) onto the female screw (20B). This allows the air between both screws (20A) and (20B) to be exhausted to the outside.Before covering the motor part (2) with the covering material (22), attach the valve body (3) to the motor part (2). It will be done.

Next, a method of covering the motor section (2) will be explained.

(24) shown in FIGS. 4 to 6 is a bottomed cylindrical casting mold with 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. There is a longitudinally long bulge (27) in a part from the bottom wall (25) to the bottom wall (26).
) to form a side channel (29) that becomes a part of the recess (28). (30) is an appropriate number of step-like protrusions formed across the inner surface of the peripheral wall (25) and the upper surface of the bottom wall (26) and protrudes into the recess (28); When the motor section (2) is housed in the recess (28) as shown in FIG. The motor section (2) is supported in this way. In other words, each protrusion (30) becomes a mold contact part of the motor part (2), and this motor part (2)
) and functions as a spacer to form a space. As shown in FIG. 3, the motor part (2) is coated with a band-shaped anti-rust coating on an annular surface extending from the outer edge of the upper surface of the case (4) facing the projection (30) to the upper edge of the circumferential surface. is applied in advance to form a painted surface (31).

When storing the motor part (2) in the recess (28) of the casting mold (24), first insert the lead wire (9) into the insulating band (1) on the circumference of the case (4) as shown in FIG. ), then insert the motor part (2) in the recess (28) with the top surface facing the bottom surface and the lead wire (9) corresponding to the side channel (29) of the casting mold (24). The painted surface (31) of the motor section (2) is placed on each protrusion (30). With this placement, a space is formed between the peripheral wall (25) and bottom wall (26) of the casting mold (24) and the motor part (2) housed in the recess (28), causing A molten rubber or resin insulating material is poured into the space formed in the recess (28) in this state, and after a cooling period for this insulating material to harden, the casting mold (28) is poured.
24) by pulling out the motor part (2) from the first
As shown in the figure, a covering material (22) is obtained which is integrally welded to the attached part (9C) of the motor part (2) and has a side part (23) that covers the motor part and the lead wire (9). .

Incidentally, the surface of the painted surface (31) that is in contact with each protrusion (30) becomes an exposed surface.

In addition, in another embodiment of the present invention shown in FIG.
2) is continuously formed up to the valve body (3), and the lock nut (2) is formed continuously up to the valve body (3).
1) is also covered. In this example, RockNara 1
- (21) is covered with the covering material (22), so the seventh
The anaerobic sealant (K) shown in the figure does not have to be used.

According to the above structure, the attached portion (9C) of each lead wire (9) faces the side wall (4B) of the case (4).
By removing a part of the jacket (9B), a bare wire part (9D) is formed in which the conductor (9A) is exposed, and this bare wire part (9D) is bound by soldering. Since the part (9E) is formed and embedded in the sheathing material (22), moisture will not enter the sheath (9B) from the other end, which is equipped with a connection terminal that can be connected to a controller, interrupter, etc. However, since the covering material (22) is welded to the bare wire portion (9D) and the bundled portion (9E), the bundled portion (9E) acts as a barrier to prevent the advance of moisture, and as a result, the bundled portion The area from the part (9E) to the stepping motor (6) has a good waterproof effect, and no moisture enters through the lead wire (9), thereby eliminating failure of the stepping motor (6) due to moisture.

Furthermore, by continuously forming the covering material (22) up to the valve body (3) and also covering the lock nut (21), the covering material (22) is welded to the valve body (3) and the lock nut (2) is welded to the valve body (3).
2) female screw (20B) and the male screw (2
0A), it is possible to prevent dew adhering to the valve body (3) from entering the gap, and prevent dew from entering the gap between the valve body (3) and the valve body (3).
) malfunctions and breakdowns can be avoided.

In addition, an anaerobic sealant (
By providing K), both screws (20A) (20B)
As the two screws are screwed together, the air between the two screws is exhausted and the sealant (K) stays between the two screws.
It is possible to prevent moisture and dew from entering the valve body, and to avoid malfunctions and failures of the valve body (3) caused by dew.

(g) Effects of the invention According to the present invention described above, the following effects are produced.

■Even if moisture enters the jacket from the other end of the lead wire, which has a connection terminal that can cause incorrect connection to a controller or interrupter, the insulation will not be fully welded to the bare wires and bundled parts. The binding part acts as a barrier to prevent the advance of moisture, and as a result, the area between the binding part and the stepping motor salt has a good waterproof effect, preventing moisture from entering through the lead wires, and preventing stepping motor failures caused by moisture. disappears.

■ By forming the covering material continuously up to the valve body and also covering the lock nut, the covering material will be welded to the valve body and cover the gap between the female thread of the lock nut and the male thread of the storage part. It is possible to prevent dew adhering to the valve from entering the gap, thereby avoiding malfunctions and failures of the valve body caused by dew.

■ By providing an anaerobic sealant between the female thread of the lock nut and the male thread of the housing, as both screws are screwed together, the air between the two screws is exhausted and the sealant is spread between the two screws. As a result, the sealant can prevent moisture and dew from entering between both screws, and malfunction or failure of the valve body due to dew can be avoided.

[Brief explanation of drawings]

The drawings all show embodiments of the present invention; FIG. 1 is an overall vertical cross-sectional view of an electric expansion valve with a covering material formed thereon, and FIG. 2 is an overall perspective view of the electric expansion valve before the covering material is formed. , 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 A-A in FIG. 4, and FIG. 6 is a rear perspective view of the casting mold.
FIG. 7 is a sectional view of a main part of another embodiment, and FIG. 8 is an overall longitudinal sectional view of another embodiment. (2)...Motor section, (3>...Valve body, (4)
...Case, (9)...Lead wire, (9A)
... Conductor, (9B) ... Sheath, (9D) ... Bare wire part, (9E) ... Binding part, (12) ... Holder (13) ... Driver (16)・・・
Valve body, (19)... Storage part, (20A>... Male thread, (20B)... Female thread, (21)...
Lock nut, (22)... sheathing material, (K)...
...Anaerobic sealant. Figure 4

Claims (3)

[Claims] 1. A stepping motor is housed in a case equipped with a cover that covers an opening on the bottom surface, and one wire is made up of a number of conductive wires and an outer sheath that covers the conductive wires, and the stepping motor is passed through the upper part of the case to the outside of the case. pulled out,
It consists of a motor part including a plurality of lead wires along the side wall of the case, a valve body, and an insulating material such as rubber or resin,
In the electric expansion valve comprising the motor part and a covering material covering the lead wires, a bare wire part is formed in a part of each lead wire along the case with the outer covering removed, and this bare wire part is soldered. A waterproof structure for an electric expansion valve, in which a binding part is formed to bind each conductive wire, and the area from the binding part to the lead wire is covered with a covering material. 2. A stepping motor is housed in a case equipped with a cover that covers an opening on a lower surface, and a motor section includes a plurality of lead wires extending from the stepping motor through an upper part of the case and along a side wall of the case; A driver that converts the rotational motion of the stepping motor into a reciprocating linear motion, a valve body that is moved in the insertion/extraction direction by the driver, a holder that screws and supports the driver and whose upper surface is in contact with the cover, and a holder that accommodates the valve body and that is in contact with the cover. A storage section located below, a valve body having a lock nut that is screwed into both the holder and the storage section to connect them, the motor section, a part of the lead wire that runs along the motor section, and the lock nut. The waterproof structure of the electric expansion valve consists of a covering material that continuously covers the 3. A stepping motor is housed in a case equipped with a cover that covers an opening on a lower surface, and a motor section includes a plurality of lead wires extending from the stepping motor through an upper part of the case and along a side wall of the case; A driver that converts the rotational motion of the stepping motor into a reciprocating linear motion, a valve body that is moved in the insertion/extraction direction by the driver, a holder that screws and supports the driver and whose upper surface is in contact with the cover, and a holder that accommodates the valve body and that is in contact with the cover. A valve body is provided with a storage section located below, a lock nut that is screwed into both the holder and the storage section to connect them, the motor section, and a part of the lead wire that runs along the motor section. A waterproof structure for an electric expansion valve comprising a coating material, and an anaerobic sealant provided between the lock nut and the holder and storage section.