Electric valve

Abstract

The present invention provides an electric valve. The foreign matters such as mud and metal powder contained in fluid do not invade into a feeding lead screw part. Sliding performance deterioration of a screw thread part because of nip, wound, etc. is prevented. Furthermore the valve can operate smoothly and reliably. Furthermore, no complicated structure is caused and the cost can be reduced. The electric valve is provided with the following components: a horizontal flow expanding path which has a cross section area that is larger than that of a needle valve so that the fluid that inflows from a valve chamber through a clearance between an insertion hole of a needle valve of a guiding sleeve and the needle valve flows from the center of the needle valve to outside in the horizontal direction; an outer annular flow path which is formed between the guiding sleeve and the inner wall of the valve body so that the fluid which passes through the horizontal flow expanding path annularly flows along the inner wall of the valve body in the horizontal direction; and a longitudinal flow path which is formed between the outer wall of the guiding sleeve and the inner wall of the valve body and is communicated with the valve chamber so that the fluid which flows in the outer annular flow path flows back into the valve chamber.

Description

technical field [0001] The present invention relates to electric valves such as flow control valves used in, for example, refrigerant circulation circuits of air conditioners such as air conditioners. Background technique [0002] Conventionally, in such an electric valve having a rotor magnet made of a permanent magnet, foreign substances such as sludge and metal powder flowing in the refrigerant flow path enter the drive unit together with the refrigerant, thereby hindering the operation of the electric valve. [0003] Therefore, conventionally, for example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2000-320712 ) discloses a structure in which, in order to prevent foreign matters such as sludge and metal powder from intruding into the needle-shaped insertion hole and the needle-shaped gap, the valve main body A communication hole connecting the valve chamber and the rotor chamber is arranged on the top. [0004] In addition, Patent Document 2 (Japanese...

AI Technical Summary

Problems solved by technology

[0009] However, the rotary force of the stepping motor (rotor magnet) is transmitted by the feed screw to move the valve body up and down to control the fluid. In the electric valve with such a structure, if the sludge and metal contained in the fluid If foreign matter such as powder enters the feed screw part, the feed screw part that slides while receiving a high load will become a cause of deterioration of sliding performance due to biting, damage, etc.

[0010] In this way, in the electric valve that uses the rotation of the motor to adjust the flow rate of the valve, in the worst case, it may not be able to operate using the driving torque of the motor.

[0011] However, in the electric valve of Patent Document 1, it is a structure for preventing the intrusion of mud into the gap of the needle insertion hole, and no consideration is given to the intrusion of foreign matter such as mud and metal powder into the threaded part.

[0012] Therefore, in the electric valve disclosed in Patent Document 1, foreign matter such as sludge and metal powder stays in the internal space of the rotor chamber, and these foreign matters enter the feed screw portion, causing the sliding performance to deteriorate due to bite, damage, etc. Furthermore, there is a problem that the operation of the valve body is hindered.

[0013] In addition, in the electric valve of Patent Document 2, a pressure equalizing hole is provided through the guide sleeve at a position away from the fixed threaded portion toward the valve chamber side, but no consideration is given to the intrusion of foreign matter such as sludge and metal powder into the threaded portion.

[0014] Therefore, also in the electric valve of Patent Document 2, foreign substances such as sludge and metal powder remain in the internal space of the rotor chamber, and these foreign substances enter the feed screw part, causing the sliding performance to deteriorate due to bite, damage, etc. , which in turn causes the problem of hindering the work of the valve body

[0015] In addition, in the electric valve of Patent Document 3, it is necessary to install expensive filters such as foamed metal and wire mesh, and the cost becomes high.

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