JP5818739B2 - Flow control valve - Google Patents

Description

  The present invention relates to a flow rate adjusting valve that adjusts the opening degree of a valve port by moving a valve element back and forth with a motor.

  As a conventional flow control valve of this type, a valve body is known which has a valve body attached to the tip of a long valve shaft and a male screw portion having a male screw formed on the outer peripheral surface at the rear end (for example, Patent Document 1). The male screw portion is formed with a male screw on the outer peripheral surface of a cylindrical portion that is thicker than the valve shaft, and is screwed into a female screw portion in which a female screw is formed on the inner peripheral surface of the bottomed cylindrical shape. When the female screw portion is fixed to the main body side and the male screw portion is rotated by a motor such as a stepping motor, the female screw portion is fixed. Therefore, the male screw portion moves along the axial direction while rotating. If the motor is reversed, it moves in the opposite direction along the same axis.

  The valve body is attached to the tip of the valve shaft as described above. When the male screw portion advances and retracts in this way, the valve body also advances and retracts together with the valve shaft. If the valve port is provided in front of the valve body in the forward direction, the opening degree of the valve port is adjusted by moving the valve body forward and backward, whereby the flow rate of the fluid passing through the valve port can be adjusted.

  The valve body is attached so as to be slightly slidable along the axial direction of the valve shaft, and is biased by a spring in the valve closing direction. Therefore, even if the valve shaft advances further from the state in which the valve shaft is advanced and the valve body is seated on the valve seat at the periphery of the valve port and the valve port is completely closed, the motor is not subjected to excessive torque. Has been. However, if the valve shaft is allowed to advance indefinitely, the valve shaft may collide with the casing. Further, when the motor is a stepping motor, it is necessary to find the origin if necessary. Therefore, a stopper structure is provided so that when the male screw part is advanced, the forward side end face of the male screw part comes into contact with the bottom surface of the female screw part, and the valve shaft does not advance further together with the male screw part.

JP 2010-31986 (FIG. 1)

  In the above-described conventional device, when the male screw portion is advanced, the forward-side end surface of the male screw portion contacts the bottom surface of the female screw portion at the forward end position of the male screw portion, and the advancement of the male screw portion is stopped. At the time of the abutment, the male thread part abuts against the bottom surface of the female thread part while rotating, and stops when the motor torque increases rapidly. Then, the forward-side end surface of the male screw portion is in close contact with the bottom surface of the female screw portion, and when the motor is reversely rotated to retract the male screw portion, a torque larger than the normal driving torque is required. Therefore, since the male screw portion cannot be moved backward with a minimum motor for generating the drive torque, it is necessary to enlarge the motor only for the reverse rotation.

  In addition, when the forward end surface of the male screw part comes into contact with the bottom surface of the female screw part, the male screw part rotates as described above, so that both wear and generate wear powder, and the male screw part and the female screw part A problem arises in that wear powder enters the threaded portion and the drive torque during normal operation increases.

  Therefore, in view of the above-mentioned problems, the present invention does not generate wear powder when the male screw portion stops at the forward end, and does not require excessive torque to retract the male screw portion from that state. It is an object to provide a valve.

In order to solve the above problems, a flow control valve according to the present invention includes a valve body at one end of a long valve shaft and a male threaded portion at the other end, and a female threaded portion that is screwed into the male threaded portion is fixed. In the flow control valve that adjusts the opening degree of the valve port facing the valve body by moving the male screw part in the forward and reverse directions with a motor to move the valve shaft forward and backward together with the male screw part, the male screw part has a cylindrical surface. It has a crest formed in a spiral shape on the outer periphery, and an abutment surface perpendicular to the ridgeline of the crest is formed at the advancing side end of the crest, and this abutment is made at the advancing end position of the male thread. A stopper that is in contact with the surface and prevents rotational movement of the male screw portion in the forward direction is formed in the valley portion of the female screw portion , the valve shaft is not stopped, and the valve body is It is retracted between the valve shaft and the valve shaft without being prevented from rotating. Is biased in the valve closing direction by Irubane, characterized in that the valve stem wound coil spring in the opposite direction to the rotational direction when moving in the closing direction.

  In the conventional device, the movable surface is in contact with the fixed surface as described above while rotating. However, in the above configuration, the movable-side abutting surface is formed perpendicular to the ridge line of the peak portion. Therefore, the abutting surface abuts against the stopper in the rotational direction and the forward movement is prevented, so that no rubbing or the like occurs between the abutting surface and the stopper.

By the way, the valve shaft is not prevented from rotating, and the valve body is biased in the valve closing direction by a coil spring which is contracted between the valve shaft and the valve body in a state where the valve body is not prevented from rotating. If the valve body is seated on the valve opening while the valve body and the coil spring are rotated together with the valve shaft, the valve shaft is closed when a slip occurs between the valve body that has stopped rotating and the coil spring that continues to rotate. by winding a coil spring in the opposite direction with respect to the rotation direction of when moving in the direction of your phrases.

  If comprised in this way, the end surface of a coil will not scrape the contact part of a valve body, and a valve body will not be damaged.

  As is apparent from the above description, the present invention does not generate abrasion powder because the abutment surface does not rub between the abutment surface and the stopper when abutting against the stopper. Reverse torque is not required and excessive torque is not required to separate the abutting surface from the stopper.

The figure which shows the structure of one embodiment of this invention II-II sectional view Diagram showing details of valve assembly Cross section of female thread member The figure which shows the shape of a male screw member Diagram explaining the rotation direction of the valve shaft and the winding direction of the coil spring

  With reference to FIG. 1, 1 is a three-way valve which is a kind of flow control valve. The three-way valve 1 is provided with three openings 11, 12, and 13. For example, when a fluid flows into the inside from the opening 11, the fluid branches out in two directions of the openings 12 and 13 and flows out. The branching ratio is adjusted by the motor 2. Conversely, when fluid flows in from the openings 12 and 13, two systems of fluid (for example, hot water and cold water) are mixed inside and flow out of the opening 11. The mixing ratio is also adjusted by the motor 2.

  Referring to FIG. 2, a worm (not shown) is attached to a rotating shaft of a stepping motor (hereinafter simply referred to as a motor) 2, and a worm wheel 21 that meshes with the worm is disposed in the vicinity of the motor 2. The rotating shaft 22 of the worm wheel 21 is formed hollow, and serrations are formed in the vertical direction on the inner peripheral surface. A serration portion 42 formed on the male screw member 4 meshes with the serration of the rotating shaft 22, and when the motor 2 rotates, the male screw member 4 rotates.

  A male screw is formed on the outer peripheral surface of the male screw member 4 and meshes with the female screw member 5. Since the female screw member 5 is fixed, when the male screw member 4 rotates, the male screw member 4 moves in the vertical direction in the figure while rotating.

  The male screw member 4 is attached to the end of the valve shaft 3, and the valve body set 6 is attached to the other end of the valve shaft 3. As described above, when the male screw member 4 moves in the vertical direction, the valve body assembly 6 moves in the vertical direction together with the valve shaft 3. And since the ratio of the opening degree of the valve openings 13 and 14 changes when the valve body set 6 moves up and down, the branching ratio and the mixing ratio change as described above.

  Referring to FIG. 3, the valve body set 6 includes two valve bodies 61 and 62 on the upper and lower sides, and a coil spring 63 is contracted between the two. For this reason, the valve bodies 61 and 62 are both biased in a direction away from each other, but the valve body 61 is restricted from moving downward and the valve body 62 is restricted from moving upward. The valve bodies 61 and 62 are urged in the vertical direction by the coil spring 63 within the vertical regulation range. In this state, for example, if the valve body 61 is pushed upward, the valve body 61 can slide upward against the urging force of the coil spring 63. Further, if the valve body 62 is pushed downward, the valve body 62 can be slid downward. The valve bodies 61, 62 are fitted with rubber packings 61a, 62a, respectively.

  4 and 5, the female screw member 5 is formed in a bottomed cylindrical shape, and a female screw is formed on the inner peripheral surface 51 of the cylindrical portion. A stopper 53 is formed at substantially the lower end of the valley 52 of the female screw. In the present embodiment, this female screw is a double thread, and therefore, one stopper 53 is formed at a target position in addition to the illustrated position.

  A male screw is formed on the outer peripheral surface of the male screw member 4, and an abutting surface 41 perpendicular to the ridge line of the male screw is formed at the lower end of the crest of the male screw. Since this male screw is also a double thread, two abutment surfaces 41 are formed at mutually target positions.

  When the male screw member 4 is screwed into the female screw member 5 and the male screw member 4 is screwed in, the male screw member 4 moves downward in the figure while rotating, but the lower end surface 40 of the male screw member 4 is the bottom surface 54 of the female screw member 5. Immediately before the contact, the abutment surface 41 is set to contact the stopper 53. Thereby, for example, when the origin of the motor 2 is performed, the male screw member 4 is lowered until the abutting surface 41 contacts the stopper 53, and the origin is reset in the contacted state. If the motor 2 is rotated reversely after reset, the abutting surface 41 moves away from the stopper 53, and the male screw member 4 moves upward in the drawing.

  With the configuration described above, when the motor 2 is rotated in the forward and reverse directions, the valve body set 6 moves in the vertical direction, so that the opening ratio of the valve ports 13 and 14 is adjusted.

  By the way, since the valve shaft 3 is not prevented from rotating, the valve shaft 3 is rotated when the male screw member 4 is rotated, even when the male screw member 4 is fixed to the valve shaft 3 and when it is loosely fitted. Also rotate in the same direction. In a state where the valve body set 6 is not seated on any of the valve ports 13 and 14, if the valve shaft 3 rotates, the valve body set 6 rotates in the same direction as the valve shaft 3.

  For example, when the male screw member 4 is rotated forward and the valve shaft 3 is lowered, the lower valve body 61 of the valve body set 6 comes into contact with the valve port 13, and at that time, the valve body 61 is caused by friction with the valve port 13. It will not rotate. However, the valve shaft 3 and the other valve body 62 and the coil spring 63 continue to rotate.

  Referring to FIG. 6, for example, when the valve shaft 3 moves downward F, if it rotates in the right direction R toward the traveling direction, the coil spring 63 is wound in the left direction which is the reverse direction. Is desirable. As described above, when the valve shaft 3 and the coil spring 63 are rotated in the right direction with the valve body 61 not rotating, the lower end portion 63a of the coil spring 63 is relatively moved in the direction indicated by the arrow a. It is possible to prevent the valve body 61 from being cut.

  When the male screw member 4 is reversed and the valve shaft 3 is pulled up, the valve shaft 3 rotates in a direction opposite to that when the valve shaft 3 is lowered, but the valve shaft 3 also rotates in the right direction R toward the upper direction, which is the traveling direction. It will be. Therefore, even if the valve body 62 is seated on the valve port 14 and does not rotate, the upper end portion 63b of the coil spring 63 moves relatively in the direction indicated by the arrow b, so the upper end portion 63b scrapes the valve body 62 side. There is no.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention. For example, although the case where the present invention is applied to a three-way valve having two valve bodies has been described in the above embodiment, the present invention can be applied to a flow control valve having one valve body.

DESCRIPTION OF SYMBOLS 1 Three-way valve 2 Motor 3 Valve shaft 4 Male thread member 5 Female thread member 6 Valve body assembly 41 Abutting surface 53 Stopper 61 Valve body 62 Valve body 63 Coil spring

Claims (1)

A long threaded shaft is provided with a valve body at one end and a male threaded part at the other end. The male threaded part is rotated in the forward and reverse directions by a motor while the female threaded part that is screwed into the male threaded part is fixed. In the flow rate adjusting valve that adjusts the opening degree of the valve port facing the valve body by moving the valve shaft forward and backward together, the male threaded portion has a crest formed in a spiral shape on the outer periphery of the cylindrical surface. The abutting surface perpendicular to the ridge line of the mountain part is formed at the forward end of the mountain part, and the male screw part is rotated in the forward direction by contacting the abutting surface at the forward end position of the male screw part. A stopper for blocking is formed in the valley portion of the female screw portion , the valve shaft is not prevented from rotating, and the valve body is not rotated against the valve shaft. Is biased in the valve closing direction by a coil spring that is contracted between Flow control valve, characterized in that by winding a coil spring in the opposite direction to the rotational direction when moving in the direction.

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