JP2007225006A - Valve unit control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve unit control method capable of separating a valve member from a valve seat with smaller driving torque when opening a valve while avoiding the valve member from being excessively compressed against the valve seat when closing the valve seat provided therein. <P>SOLUTION: When the valve member closes the valve seat, more frequent pulses than required for the valve member to close the valve seat are given to a stepping motor to be rotated, whereby a feed screw is displaced at least to a position P<SB>1</SB>for the valve member to abut on the valve seat and the feed screw is further displaced to a position P<SB>2</SB>for the valve member to be compressed between the valve seat and itself. Then, pulses are given to the stepping motor to be rotated in the opposite direction to the previous rotating direction, whereby the feed screw has linear motion to a position X in the opposite direction. Thus, the valve member stays at a position of relaxing the compression of the valve member and holding the condition of closing the valve seat. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control method of a valve unit that is interposed in a piping path and opens and closes the piping path by driving a stepping motor.

  For example, in various devices that handle water, such as washing machines and dishwashers, a stepping motor drive for opening and closing the drain line in response to a signal from the device is provided in the drain line for draining the water after use. The valve unit by is incorporated.

  As a conventional valve unit of this type, a drive piece is engaged with a feed screw that is rotationally driven by the stepping motor so as to be linearly movable along the feed screw, and this drive piece is connected to the drain line. Widely used is a valve member that closes a valve seat provided in a communicating valve chamber so that the valve member can move forward and backward with respect to the valve seat.

  According to the conventional valve unit, the motor is driven by the signal from the device, the feed screw is rotated, and the drive piece and the valve member integrated therewith are linearly advanced and retracted with respect to the valve seat. Thus, the drainage line can be opened and closed.

  By the way, in the said valve unit, generally the position of the valve member inside a housing cannot be detected. For this reason, in order to securely close the valve seat by the valve member, first, the number of pulses of the stepping motor necessary for moving the valve member until it abuts on the valve seat is determined according to the designed length dimension or the like. In addition, a mechanical stopper such as a stopper pin is separately provided at a position where the valve member is pressed against the valve seat by applying an extra pulse number to the stepping motor, and the blocking position by the valve member is determined. The way to decide is taken.

  According to the positioning method of the valve member in such a conventional valve unit, when closing the drainage line, if the above-described extra pulse number is given to the stepping motor, the stopper pin is pressed with the valve member pressed against the valve seat. Therefore, the stepping motor does not rotate even if it is given more pulses, so that it is in a so-called step-out state, so that the valve member can be reliably kept closed by the valve member. There is an advantage.

  However, in the conventional valve unit, since the valve member is generally formed of an elastic member such as silicon or rubber, the valve seat is pressed and compressed in the closed state of the valve seat. . For this reason, when opening the drainage line by releasing the blockage by the valve member, the frictional force between the valve member and the valve seat increases, and thus a driving force by the stepping motor exceeding the frictional force is required. Therefore, the driving torque and mechanical strength required for the stepping motor, the feed screw, and the like become unnecessarily large, which is inferior in economic efficiency.

  In addition, the valve unit normally used for this type of application is in a state where the drainage line is closed except when it is used, so that if the valve unit is not used for a long period of time, the valve body will remain strongly pressed against the valve seat. As a result, the valve body adheres to the valve seat due to minerals and impurities contained in the water.

  For this reason, when opening the drainage line at the time of use, since it is necessary to drive the valve body with a force exceeding the resistance force obtained by adding the fixing force to the friction force to the stepping motor, a larger torque is required. If the stepping motor is less than the driving torque, there is a problem that the stepping motor causes the step-out phenomenon and the drainage line cannot be opened.

  The present invention has been made in view of such circumstances, and when closing a valve seat provided inside, the valve member is not excessively pressed against the valve seat, and therefore, a smaller driving torque when opening the valve. It is an object of the present invention to provide a method for controlling a valve unit that can separate the valve member from the valve seat as a result, and as a result, it is possible to easily realize further downsizing and weight reduction of components such as a stepping motor. To do.

  In order to solve the above-mentioned problem, an invention according to claim 1 is provided in a pipe line, and includes a stepping motor, a conversion mechanism that converts the rotational motion of the stepping motor into a linear motion, and the linear of the conversion mechanism. A valve member made of an elastic body provided on the moving side and capable of closing a valve seat formed in a valve chamber communicating with the piping, and moving the valve member forward and backward with respect to the valve seat A control method for a valve unit that opens and closes a pipe line, and when the valve member is closed by the valve member, the stepping motor is given a pulse more than the number of pulses necessary for the valve member to close the valve seat. The stepping motor is rotated, the valve member is moved toward the valve seat by the linear motion converted by the conversion mechanism, and the valve member is brought into contact with the valve seat. After the member is compressed between the valve seat and the stepping motor, a pulse for rotating in the direction opposite to the rotation direction is applied to the stepping motor, and the linear movement converted by the conversion mechanism is performed in a direction opposite to the linear movement. The valve member is held in a position to relieve the compression of the valve member and maintain a closed state with respect to the valve seat.

  According to a second aspect of the present invention, in the first aspect of the present invention, the conversion mechanism has a male screw that engages with the output shaft of the stepping motor formed on the outer periphery, and a female screw formed at the center. In addition, an output gear provided so as to be rotatable and immovable in the axial direction and a male screw engaging with the female screw of the output gear are formed on the outer periphery of the base end portion so as to be rotatable and movable in the axial direction. And a feed screw member to which the valve member is attached at the tip, and the valve member is made of silicon or rubber.

  In the valve unit control method according to claim 1 or 2, when the valve seat is closed by the valve member and the pipe line is closed, the stepping motor has a number of pulses to the valve seat closing position by the original valve member. After applying an extra pulse and pressing the valve member against the valve seat and compressing the valve member, a pulse for rotating the stepping motor in a direction opposite to the rotation direction is continuously applied to the stepping motor. The friction force generated between the valve member and the valve seat can be reduced by relaxing the compression and keeping the valve seat closed.

  For this reason, when opening a drainage line, the said valve member can be moved by the driving torque smaller than before. In addition, since the valve member is not pressed against the valve seat with a strong force, the valve member and the valve seat can be prevented from sticking even when the closed state is maintained for a long time.

As a result, components such as the stepping motor and the conversion mechanism can be easily reduced in size and weight.
In particular, as in the invention described in claim 2, when the above-described valve member is made of silicon or rubber having a large elastic deformation amount, a remarkable effect can be obtained.

  1 and 2 show a valve unit used in an embodiment of a control method of a valve unit according to the present invention. This valve unit has a large-diameter cylindrical housing with a motor 1 fixed to one end thereof. 2 and a small-diameter cylindrical valve body 3 integrated with the other end of the housing 2 by a mounting screw. A connection port 4 to the inflow side of the pipe line is formed at the tip of the valve body 3, and a connection port 5 to the outflow side is formed to the intermediate side wall, and a communication port 5 a is formed between them. By being provided, the valve chamber 3a is formed inside. In addition, the code | symbol 6 in a figure is a discharge port for escaping the liquid which flowed in from the connection port 4 of an inflow side temporarily, and storing in a tank etc. separately, when the communication port 5a is closed.

  On the other hand, the motor 1 includes a stepping motor 20 including a coil 20a, a rotor 20b, and the like, and a reduction gear train 21 that meshes with a rotary shaft 20c fixed to the rotor 20b. The output shaft 7 integrated with the last stage gear 21a protrudes into the housing 2, and a pinion gear 8 is attached to the outer periphery thereof. Here, a shaft for supporting a reduction gear such as the output shaft 7 is rotatably supported by an intermediate plate 9 interposed between the motor 1 and the housing 2.

  A substantially cylindrical output gear 11 having a male thread 10 that engages with the pinion gear 8 of the output shaft 7 is formed on the outer periphery of the housing 2 at the center thereof. It is provided in a state in which movement is prevented in the axial direction by the formed locking step 2a. The output gear 11 has a female screw 12 formed at the center thereof, and a male screw 13 a formed on the outer periphery of the base end of a feed screw (feed screw member) 13 is engaged with the female screw 12.

  On the other hand, a mounting piece 14 is integrally provided at the tip of the feed screw 13. The mounting piece 14 is provided with a valve member 17 so as to surround it. The valve member 17 is formed by integrally forming a valve body 15 and an expandable / contractible bellows 16 with an elastic material such as silicon or rubber, and a base end portion of the bellows 16 is connected to a holding portion 2b in the housing 2. It is fixed. Further, the valve body 15 is formed in a cylindrical shape in which the mounting piece 14 is fitted and the front end portion is closed. The valve body 15 protrudes in an annular shape from the peripheral surface of the communication port 5a (valve). A seal projection 15a is formed by contacting the seat 18 and closing the communication port 5a together with the distal end surface of the valve body 15.

  Furthermore, when the maximum number of pulses is sent to the stepping motor and the valve member 17 is pressed against the peripheral wall 18, the intermediate portion of the feed screw 13 comes into contact with the locking wall portion 2 c in the housing 2, A stopper pin 19 for mechanically preventing the linear movement of the feed screw 13 is provided.

Next, an embodiment of the control method of the present invention using the valve unit having the above configuration will be described with reference to FIGS. 1 and 2.
In FIG. 2, the vertical axis indicates the magnitude of the force, the symbol a is the thrust of the feed screw 13 driven by the motor 1, b is the maximum water pressure in the pipeline, and c is the water pressure acting on the valve body 15. is there. The horizontal axis, shows the varying position of the feed screw 13, P ₀ is located at the valve fully opened, P ₁ position of the valve is fully closed when the maximum water pressure, P ₂ is a stopper pin 19 the housing 2 The position when it hits the inner locking wall 2c is shown.

Then, this control method, when closing the communication port 5a by the valve member 17, first, the stepping motor 20 of the motor 1, from the number of pulses required to move the valve member 17 to the fully closed position P ₁ to the maximum pressure Also, an extra pulse signal is given to move the stopper pin 19 to a position P _{2 where} it comes into contact with the locking wall portion 2 c in the housing 2. As a result, the valve member 17 is compressed by the seal projection 15 a being in contact with the peripheral wall 18 and being further pressed by the peripheral wall 18.

Then, next, a pulse for rotating the stepping motor 20 in the direction opposite to the rotation direction is given, and the output gear 11 is rotated in the reverse direction, whereby the feed screw 13 is linearly moved in the reverse direction to the position X, and the valve member. 17 is returned in a direction slightly retracting from the peripheral wall 18. At this time, the number of pulses applied to the stepping motor is set so that the return position X of the feed screw 13 is within a range L between the position P ₂ and the position P ₁ . This setting can be performed based on the rotation angle of the stepping motor per pulse, the rotation speed of the output gear 11 via the reduction gear train 21, the displacement amount of the feed screw 13, the elastic deformation amount of the valve member 17, and the like. Approximately several tens of pulses of 100 pulses or less.

According to the control method of the valve unit having the above configuration, when the piping is closed by bringing the valve body 15 of the valve member 17 into pressure contact with the peripheral wall 18 and closing the communication port 5a, After giving an extra pulse than the number of pulses to the valve seat closing position P ₁ by the member, the valve member 17 is pressed against the peripheral wall 18 and compressed, and then continuously to the stepping motor 20 in the rotational direction. The frictional force generated between the valve member 17 and the peripheral wall 18 is reduced by applying a pulse that rotates in the opposite direction and retaining the valve member 17 at the position X that relaxes the compression while keeping the valve member 17 in contact with the peripheral wall 18. Can be made.

That is, in the conventional control method, the stepping motor 20, giving an extra pulse signals, the feed screw 13 by the stopper pin 19 moves to a position P ₂ impinging on the engaging wall portion 2c of the housing 2 a valve body Since the communication port 5a is closed by 17, when the communication port 5a is opened, the thrust of the feed screw 13 is used to resist the frictional force and the adhering force between the valve body 17 and the peripheral wall 18. F ₀ was required. For this reason, when the thrust F ₀ exceeds the thrust a of the feed screw 13 driven by the motor 1, the valve body 17 cannot be moved.

In contrast, in the control method of the present invention, the valve body 17 and the closed position P _2, in the range L between the position P ₁ of the valve is fully closed when the position P ₂ and the maximum pressure to have returned to the predetermined position X, even when the provisionally slight sticking between the valve body 17 and the peripheral wall 18 has occurred, to reduce the thrust force F ₁ of the feed screw 13 for opening the communication port 5a, The thrust a of the feed screw 13 by the drive of the motor 1 can be reliably reduced.

For this reason, when opening a drainage line, the valve member 17 can be moved in the direction away from the surrounding wall 18 with a drive torque smaller than before. In addition, since the valve member 17 is not pressed against the peripheral wall 18 with a strong force, the valve member 17 can be prevented from adhering to the peripheral wall 18 even when the closed state is maintained for a long time.
As a result, components such as the stepping motor 20, the output gear 11, and the feed screw 13 can be easily reduced in size and weight.

It is a longitudinal cross-sectional view which shows the valve unit used for one Embodiment of this invention. It is a graph which shows the relationship between the displacement amount of a feed screw and the force which acts on a valve main body etc. in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Housing 3 Valve body 3a Valve chamber 4 Connection port with inflow side 5 Connection port with outflow side 5a Communication port 7 Output shaft 8 Pinion gear 10, 13a Male screw 11 Output gear 12 Female screw 13 Lead screw (feed screw member)
15 Valve body 16 Bellows 17 Valve member 18 Circumferential wall (valve seat)
20 Stepping motor

Claims (2)

A stepping motor, a conversion mechanism that converts the rotational motion of the stepping motor into a linear motion, and a conversion chamber that is provided on the linear motion side of the conversion mechanism and is formed in a valve chamber that communicates with the piping. A valve unit made of an elastic body capable of closing the valve seat, and a valve unit control method for opening and closing the pipe line by moving the valve member forward and backward with respect to the valve seat,
When closing the valve seat by the valve member, the stepping motor is rotated by applying a pulse more than the number of pulses necessary for the valve member to close the valve seat, and converted by the conversion mechanism. The valve member is moved toward the valve seat by the linear motion, the valve member is brought into contact with the valve seat, and further, the valve member is compressed between the valve seat,
Applying a pulse to the stepping motor to rotate in the direction opposite to the rotation direction, and reducing the compression of the valve member by the linear motion in the direction opposite to the linear motion converted by the conversion mechanism. And a valve unit control method characterized in that the valve unit is held at a position where the valve seat is closed.   The conversion mechanism includes an output gear provided on the outer periphery with a male screw that meshes with the output shaft of the stepping motor, a female screw formed at the center, and a rotatable and non-movable axial direction. A male screw that meshes with the female screw of the output gear is formed on the outer periphery of the end portion, and is provided so as to be rotatable and movable in the axial direction, and a feed screw member to which the valve member is attached at the tip portion. 2. The valve unit control method according to claim 1, wherein the valve member is made of silicon or rubber.

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