JPH01303379A - Pinch valve - Google Patents

Abstract

PURPOSE:To obtain the title pinch valve which is driven through a small power in noiseless by abutting a fixedly holding part on one side of the outer circumferential of a tube while arranging, on the other side, an arm mounted on a drive shaft by a motor. CONSTITUTION:On a bracket 2 mounted on a motor 2, there is provided a fixing/holding part 11 energized upward by a spring 15. There is arranged an arm 5 mounted on a drive shaft 3 of the motor upward from the fixing/ holding part 11. Between the fixing/holding part 11 and the arm 5, there is provided a tube 16. As the motor is driven so as to direct the tip 6 of the arm 5 downward so as to push the tube 16, resulting in the closed fluid path. With the tip 6 of the arm 5 directed upward, the holding force of the tube 16 is released so as to open the fluid path.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a valve used to open and close a flow path for a fluid that needs to be isolated from moving parts of the valve, such as a corrosive fluid, The present invention relates to a pinch valve that allows fluid to flow through a flexible tube and closes or opens an upward flow path by pinching the outer periphery of the tube or removing the pinching force.

Conventional technology and problems to be solved by the invention Conventionally, this type of pinch valve has a solenoid disposed on one side of the outer peripheral surface of the tube, and the movable iron core is separated from the fixed iron core by the elasticity of a compression coil spring. The tube is closed by pressing it between a fixed clamping body that is in contact with the other side of the outer circumferential surface of the tube, and the solenoid is energized to move the movable iron core against the spring force. Solenoid-type pinch valves that open the tube by suction to a fixed core are known, but in such solenoid-type pinch valves, the suction noise when the movable core is attracted to the fixed core causes noise. In addition, since the tube is crushed or deformed quickly to return to its original shape, the tube not only sag quickly and have a short service life, but also has a high risk of water hammer due to rapid opening and closing operations. ,
As shown in the characteristic curve The spring force of the coil spring is determined by the characteristic curve y in the same figure.
As shown in the figure, the characteristic is the smallest when the tube is closed, and in order to close the tube, the minimum value of the spring force must be set to a large value that exceeds the maximum value of the necessary clamping force, and the solenoid Furthermore, as shown in the characteristic curve Z, an attractive force is required to overcome the spring force, which has the disadvantage of increasing power consumption.

As a means for solving the above problems, the pinch valve of the present invention has a pinching part fixed to one side of the outer peripheral surface of a tube made of a flexible material through which fluid flows. At the same time,
On the other side of the outer circumferential surface of the tube, a drive shaft that is rotationally driven by a motor is arranged at a position away from the outer circumferential surface of the tube and oriented in a direction substantially perpendicular to the length direction of the tube. A position in which an arm that rotates around the axis of the drive shaft and has a movable clamping part at its tip is attached, and the arm is driven by a motor to sandwich the tube between the movable clamping part and the fixed clamping part and close it. and a position where the movable clamping part separates from the fixed clamping part to open the tube.

Functions and Effects of the Invention The present invention has the above configuration, and when the arm is rotated to a position where the movable clamping part is spaced apart from the fixed clamping part, the tube opens and fluid flows there. When the motor is driven and the arm attached to the drive shaft is rotated, the movable clamping part rotates around the axis of the drive shaft, sliding the tube lengthwise on the outer circumferential surface of the tube. By pushing it toward the fixed clamping part, the tube gradually becomes flattened, and when the movable clamping part comes closest to the fixed clamping part, the motor is stopped and the rotation of the arm is stopped. Both sides of the outer circumferential surface of the tube are pinched between the movable clamping part and the fixed clamping part, and the tube is closed.
This stops the fluid flow, and when the motor is driven again from this state to rotate the arm, the movable clamping part rotates around the axis of the drive shaft and separates from the fixed clamping part. , the tube is opened by fluid pressure to allow fluid to flow through it, and when the motor is stopped, the tube remains open and fluid flow continues.

As described above, according to the present invention, the movable clamping part at the tip of the arm is rotated around the axis of the drive shaft, and gradually approaches the fixed clamping part while sliding on the outer peripheral surface of the tube in the length direction. Or, by separating the tubes, the tubes are gradually crushed or restored, and the tubes are slowly deformed, which prevents them from prematurely sagging and extends their service life. At the same time, since the opening/closing operation is performed slowly, water hammer is prevented from occurring, and unlike the solenoid type, there is no risk of generating noise due to the suction sound of the movable iron core. As the material is deformed into a flat shape, a larger clamping force is required.
When the torque of the drive shaft is constant, the pressing force exerted by the movable clamping part against the outer peripheral surface of the tube as the arm rotates gradually increases as it approaches the fixed clamping part.
This is almost the same as the characteristics of the clamping force described above, that is, the pressing force by the movable clamping part obtained from the torque of the drive shaft acts efficiently in accordance with the characteristics of the clamping force required to close the tube. , it is possible to suppress the torque of the drive shaft to a small level, and therefore, a small-sized motor can be used, which has the effect of saving power consumption.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 5.

In FIGS. 1 and 2, l is a motor, and a bracket 2 having a U-shaped cross section is attached to the front of the motor 1, and the output shaft 3 of the motor l is located above the both side plates of the bracket 2. The base end of a plate-shaped arm 5 having a constant wide width in the axial direction of the output shaft 3 is fixed to the output shaft 3, and the base end of the arm 5 is fixed to the output shaft 3. The tip of the arm 5 is a movable clamping part 6, and a plate-shaped fixed clamping part 11 having the same width as the arm 5 is installed at a lower position of the arm 5 on the upper surface of the board IO, just below the output shaft 3. A clamping body 9 protruding so as to correspond to the substrate 10
is placed in the storage box 7 formed at the bottom of the bracket 2,
A through hole 1 in which a fixed clamping part 11 is formed in the upper plate 13 of the storage box 7
The clamping body 9 is pushed upward by the elastic expansion force of the compression coil spring 15 that protrudes upward from the board IO and the bottom surface of the bracket 2.
The board IO is fixedly attached by pushing up and pressing the board IO against the edge of the through hole 14, and between the tip of the fixed clamping part 11 and the base end of the arm 5, As shown by the chain line in FIG. 1, a tube 16 made of an elastic material is inserted through the output shaft 3 in a direction perpendicular to it. The tip of the fixed clamping part 11 is rounded with a small diameter, while the movable clamping part 6 is formed to have a circular cross section with a relatively large diameter so that the part that presses the tube 16 is not sharp. ing.

Further, a detection lever 17 is attached to the end of the output shaft 3 of the motor 1 protruding from the right side plate 2a of the bracket 2 so as to face the same direction as the arm 5 and can rotate together with the arm 5. A normally closed limit switch for detecting an open state that is operated by the detection lever 17 to detect the open state and closed state of the tube 16 is located above and below the position of the output shaft 3 on the outer surface of the plate 2a. 18 and a limit switch 19 for detecting a closed state are respectively attached.

Next, the operation of this embodiment will be explained with reference to the circuit diagram shown in FIG.

The solid line in FIGS. 1 and 2 shows the state in which the duplex 16 is closed, and the arm 5 faces downward to dupe between the movable clamping force IK6 and the fixed clamping part I■! At the same time, the detection lever 17 also faces downward and pushes the actuator of the lower closed state detection limit switch 19 to open the limit switch 19, while the open state detection limit switch 18 closes. Motor l is stopped.

In this state, when the main switch 20 shown in FIG. 3 is switched to the open contact side as shown by the broken line, the motor 1 is energized because the open state detection limit switch 18 is closed as described above. As a result, the output shaft 3 of the motor 1 rotates, the arm 5 rotates counterclockwise in FIG. Weakening, tube 16
When the arm 5 opens while restoring to its original shape and fluid flows through it, and the arm 5 rotates 180 degrees to an upward position as shown by the chain line in Figure 1, the detection lever opens as shown by the chain line in Figure 1.2. 17 faces upward and presses the actuator of the open state detection limit switch 18 on the upper side, the limit switch 18 is opened as shown by the broken line in Fig. 3, and the power to the motor l is cut off and the motor l is stopped. However, the rotation of the arm 5 is stopped, the tube 16 is maintained in an open state, and fluid circulation continues.

Next, when the main switch 20 is switched to the closed contact side as shown by the solid line in FIG. 3, the closed state detection limit switch 19 is closed as shown by the broken line during the opening operation of the tube 16. So, the motor again! is energized, the arm 5 rotates counterclockwise, and when the arm 5 has rotated approximately 90 degrees, the movable clamping part 6 closes the tube! Hitting the outer peripheral surface of 6,
The continued rotation pushes down the tube I6, and since the fixed clamping part 11 is in contact with the lower surface of the tube 16, the tube 16 is gradually deformed into a flattened state. In comparison, the movable clamping part 6 is a tube because the contact surface is formed with a relatively flat circular cross section! The tube 16 is smoothly deformed by sliding in the length direction on the outer circumferential surface of the arm 6 without biting into the outer circumferential surface of the arm 6, and when the tube 16 is rotated a little before the arm 5 faces straight down, the tube 16 is moved downward. When the tube 16 deforms into a flat shape and faces straight down, the flesh of the tube 16 is crushed and the tube 16 is completely closed, thereby stopping the flow of fluid.At this time, the detection lever 17 also faces downward and closes. Since the state detection limit switch 19 opens as shown by the solid line in FIG. 3, the power supply to the motor l is stopped, the rotation of the arm 5 is stopped, and the tube I6 is held in the closed state, and from then on, By repeating the above operations, the tube 16 is opened and closed.

Note that, as shown in FIG.
If the torque is Tr, the length of the arm 5 is L1, and the rotation angle is O, then P=Tr/Lcosθ, where if the torque Tr is constant, the movable clamping part 6 approaches the fixed clamping part 11. In other words, as the rotation angle θ approaches 90 degrees from the open state to the closed state, the pressing force F of the movable clamping part 6 gradually increases, and its characteristics are as follows.
As shown by the curve W in the figure, the characteristics are similar to the characteristic curve X of the clamping force required to close the tube 16, and the output shaft 3
The tube 16 can be efficiently clamped by minimizing the torque.

Further, the spring force of the compression coil spring 15 attached to the lower surface of the clamping body 9 forming the fixed clamping part 11 is set to be slightly larger than the pressing force required to completely close the tube 16. When the rotation angle θ of the arm 5 approaches 90 degrees and an excessive pressing force is applied from the movable clamping part 6, the compression coil spring 15 is elastically contracted and the clamping body 9 is released. There is.

Furthermore, in this embodiment, when the tube 16 is in the open or closed state, the power supply to the motor l is stopped and the motor l is maintained in the open or closed state, so there is no risk of being affected by a power outage. There is no.

Note that if the movable clamping part provided at the tip of the arm 3 is formed by a roller, when the roller presses the outer peripheral surface of the tube 16, the roller presses while rolling without getting caught on the outer peripheral surface, so that the tube 16 can be deformed more smoothly. can be done.

In addition, by using a synchronous motor or the like to rotate the arm 3 from the closed state by an arbitrary angle and then stop it, the tube 16 can be opened by an arbitrary opening area, and it can also be used as a simple proportional valve. It becomes possible.

Furthermore, as shown in FIG. 6, the arm 5 is rotated 180 degrees to alternately open and close the two OUT tubes 16b, 16b, which are branched and connected to the IN tube 16a. It can also be used as a three-way valve.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a sectional view taken along the line AA in Fig. 1, Fig. 3 is a circuit diagram showing a switch system, and Fig. 4 is a diagram showing the pressing force of the movable clamping part. An explanatory diagram of the characteristics, FIG. 5 is a characteristic diagram of various forces, and FIG. 6 is an explanatory diagram when used as a three-way valve. l: Motor 3: Output shaft 5: Arm 6: Movable clamping part ll: Fixed clamping part 16.16b: Tube, applicant CKD Co., Ltd. agent Patent attorney Hirotomi Noguchi 4 Plan 5 Park Qi

Claims (1)

[Claims] A fixed clamping part is brought into contact with one side of the outer peripheral surface of a tube made of a flexible material through which fluid flows, and a drive shaft rotationally driven by a motor is mounted on the other side of the outer peripheral surface of the tube.
A movable pinching part is provided at the tip of the drive shaft, the movable clamping part being arranged in a direction substantially perpendicular to the length direction of the tube at a position away from the outer peripheral surface of the tube, and rotating around the axis of the drive shaft. An arm provided with the tube is attached, and by driving the motor, the arm is moved to a position where the tube is sandwiched between the movable clamping part and the fixed clamping part, and the arm is closed, and the movable clamping part is placed in the fixed clamping position. A pinch valve characterized in that the pinch valve is configured to be rotated between a position away from the tube and a position where the tube is opened.