JP2847547B2 - Switching valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching valve, and more particularly, to a switching valve in which a valve switching operation is performed by a motor.

[Related Art] As this type of switching valve, there is one having the following configuration. That is, a first valve seat and a second valve seat, and a first position in which the first valve seat is pressed to close the first valve seat and a second position in which the second valve seat is pressed against the second valve seat to close the first valve seat. And a replaceable valve element. The valve body is normally pressed against the first valve seat by the urging force of a spring. On the other hand, the energization of the motor causes the valve body to move from the first position to the second position against the urging force of the spring by the rotating power.
There is a switching valve having such a configuration.

[Problem to be Solved by the Invention] With this conventional switching valve, the valve can be switched simply by turning on and off the power supply to the motor by operating a switch, which is convenient. However. The above motor has a problem that a motor having a large torque is required. That is, when the valve body is pressed against the second valve seat when the valve body is moved from the first position to the second position, the motor is provided with the urging force of the spring pressing the valve body against the first valve seat. A large force is added as a load, in which the overcoming force and the reaction force against pressing the valve body against the second valve seat are added. Therefore, the motor needs to have a large torque to overcome such a large load. In addition, when the valve body is kept pressed against the second valve seat, the motor must continuously generate a force that balances the large load as described above, so that a large current flows through the motor. There are also problems that have to be left free and involve a large amount of energy.

In order to solve the above-mentioned problem, a valve body is disposed in a central hollow portion of the valve body so as to be movable left and right, and the valve body is moved left and right by rotation of an eccentric cam, so that the first and the second left and right valves are disposed.
(See Japanese Utility Model Laid-Open Publication No. 1-187777).

The above configuration has a structural effect that two valve seats can be selectively closed by one valve body. Further, as compared with the conventional arrangement in which the valve elements are individually arranged in the respective ports, the configuration for the valve elements is simplified, and there is an advantage that the failure due to the adhesion of "dust" is reduced.

However, the movement width of the valve body is accurately determined by the outer diameter of the eccentric cam. Accordingly, the contact dimension of the valve body with respect to the valve seat is fixed. For example, when the abutment surface of the valve body is worn or its elasticity is reduced due to aging, there is a problem that the liquid leaks.

The present invention has been made in order to solve the above-mentioned problems (technical problems) of the conventional art, and the movement of the valve body from the first position to the second position or vice versa is performed by a light motor, When the valve body is pressed against the valve seat, it can be elastically performed by using the biasing force of the spring, so that only the reaction force of the pressing is applied to the motor as a load, and the above pressing is achieved. In this state, the pressing part of the eccentric body interposed for transmitting force between the motor and the valve body becomes a dead point, and the above-mentioned operation is performed without requiring any energy supply from outside. It is an object of the present invention to provide a switching valve capable of maintaining an elastic pressing state.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a valve body comprising: a hollow portion; a first valve seat connected to the first port and opened to the hollow portion; A second valve seat connected to the port and opening to the hollow portion;
The first valve which is pressed against the first valve seat and closes the first valve seat.
A position and a second position where the valve is pressed against the second valve seat and closes the second position. The position of the valve is variable. The valve body is provided with the valve in the first position and the second position. In a switching valve provided with an operation mechanism adapted to change the position, the operation mechanism is configured to rotate by a motor that is turned by being energized through an operation switch, and to be rotated by the motor. An eccentric body is provided, and on both sides of the eccentric body, there are arranged levers which can be selectively pushed by the pressing portions of the eccentric body by rotating the eccentric body, and a spring is provided between the two levers. Is further interposed between the two levers, and is connected to the valve body in order to change the position of the valve body between the first position and the second position. With a connecting lever that can be pushed selectively And the pressing portion of the eccentric member,
The relative positions of the two levers, the spring, and the connecting lever
In a state where the pressing portion selectively presses one of the two levers, the other lever is retracted by the pulling force of the spring, and the connecting lever moves the valve body to the first position by the urging force of the other lever. Or, it is set so as to be elastically pressed against the corresponding valve seat at the second position, and furthermore, the position where the pressing portions of the eccentric body are in contact with the two levers respectively is determined by the fact that the valve body is the first position. The position is a dead center with respect to the center of rotation of the eccentric body in the position or the second position, and the operating mechanism further includes a state in which the valve body is located in the first position and a second position. In this state, a stop switch mechanism is provided to cut off the current supply to the motors.

[Operation] When the motor is energized through the operation switch and rotates, the eccentric body rotates. The valve body separates from the first valve seat, for example, by the rotation of the eccentric body, and is pressed against the second valve seat by the pressing portion of the eccentric body. When the pressing is achieved, the pressing portion is at a dead point with respect to the center of rotation of the eccentric body. As a result, the eccentric body does not rotate even if the reaction force against the pressing of the valve element against the second valve seat reaches the pressing section. Therefore, the pressing state is maintained without requiring energy for preventing the rotation of the eccentric body.

[Embodiment] Drawings showing an embodiment of the present application will be described below. First
In the figure, the switching valve includes a valve A and an operation mechanism B. First, the valve A will be described with reference to FIGS. This valve A shows a well-known three-way valve, 1 is a valve body, having a hollow portion 2 inside,
Further, a first port 3, a second port 4, and a third port 5 are provided. Reference numeral 6 denotes a first valve seat, and 7 denotes a second valve seat. 8
Is a valve lid, which is attached to the valve body 1 in a watertight manner. 9 is a bearing attached to the valve lid, 10 is a valve shaft rotatably and watertightly attached to the bearing 9, 11 is a valve body, which is attached to a valve body arm 12 attached to the valve shaft 10, A first position where the first valve seat 6 and the second valve seat 7 are pressed against and close the first valve seat 6 so as to be able to interchangeably and tightly close each, and a first position where the first valve seat 6 and the second valve seat 7 are pressed against the second valve seat 7. The position can be freely changed to a second position for closing the position.
The valve body 11 is made of, for example, an elastic rubber material so that the valve seats 6 and 7 can be closed tightly.

Next, the operation mechanism B will be described. The operation mechanism B includes a motor 15, a conversion mechanism 16 that converts the rotational power of the motor into reciprocating motion and transmits the reciprocating motion to the valve shaft 10 of the valve A, and a control mechanism B when the valve body 11 is located at the first position and the second position, respectively. A stop switch mechanism 17 configured to cut off the current supply to the motor 15.

First, the motor 15 will be described. This motor 15
A small geared motor in which the output shaft 18 rotates in one direction when energized is used. 19 is a motor cover.

Next, the conversion mechanism 16 will be described with reference to FIGS. A frame 20 shown in FIG. 1 is fixed to the valve lid 8 and constitutes a base frame of the conversion mechanism 16 together with the valve lid 8. This base frame is a stop switch mechanism 17
And a base frame for mounting the motor 15. twenty one
Is an eccentric body attached to the output shaft 18 of the motor 15 and uses a cam as an integral unit (a crank may be used). 22a,
Reference numerals 22b and 22c denote a pressing portion, a pressing portion, and a releasing portion, respectively, provided on the peripheral surface of the eccentric body 21, and the pressing portion 22a and the releasing portion 22c rotate the eccentric body 21 closer to the pressing portion 22b. The center, that is, the radius from the rotation center of the output shaft 18 is large, and the pressing portion 22b is formed in an arc shape centered on the rotation center. Reference numerals 23 and 24 denote arm levers which are pivotally connected to the valve lid 8 and the frame 20 by using pins 25 and 25. Reference numeral 26 denotes a spring stretched between the free ends of the arm levers 23 and 24 so as to apply an urging force for pulling the arm levers 23 and 24 together. Reference numeral 27 denotes a connecting lever whose base is attached to the valve shaft 10, which is located between the two arm levers 23 and 24.

Next, the stop switch mechanism 17 will be described with reference to FIGS.
This will be described with reference to FIG. 28 indicates the case, two elements
28a and 28b are bonded together. Reference numeral 29 denotes a switch cam attached to the output shaft 18 of the motor 15, and has a switch opening portion 30 in a part of the periphery. Numerals 31 and 32 denote a first stop switch and a second stop switch operably connected to the switch cam 29, respectively, each of which is constituted by a pair of contact plates attached to the case 28 in a known manner. The electric circuit shown in FIG. 6 in connection with these switches 31, 32 will be described.
2 is connected to the motor 15 as shown. Reference numerals 33, 34, and 35 denote connection terminals between the switching valve and an external electric circuit, such as screw terminals or harnesses. In the external circuit, reference numeral 36 denotes a power supply, for example, a well-known 100 volt commercial power supply. An operation switch 37 is a first side 37a as shown in the figure.
And a changeover switch capable of switching to the second side 37b.

Next, the operation of the switching valve having the above configuration will be described with reference to FIG. First, as shown in the column of (a), the operation switch
In a state where 37 is on the first side, the electric circuit, the stop switch mechanism, the conversion mechanism, the valve, and the like are in the states as shown in the drawing. That is, the valve element 11 is pressed against the first valve seat 6 to close it. The first stop switch 31 is in the open state in contact with the open portion 30 of the switch cam 29, and therefore, the motor 15 is not energized and the motor is in the stop state.
In this case, the clockwise rotational force given to the arm lever 23 by the spring 26 exerts a force on the eccentric body 21 at the pressing portion 22b, and the force relationship is balanced by the reaction force of the eccentric body 21 to this force. Since the pressing portion 22b has an arcuate surface, the force applied from the arm lever 23 is directed to the center of rotation of the eccentric body 21. That is, with respect to the force applied from the arm lever 23, the pressing portion 22b becomes a dead center with respect to the center of rotation. Therefore, even when the force from the arm lever 23 is applied to the eccentric body 21, the eccentric body 21 does not rotate. On the other hand, the counterclockwise urging force applied to the arm lever 24 from the spring 26 is
It is the force to rotate 27 clockwise. The connecting lever 27 presses the valve element 11 against the first valve seat 6 via the valve shaft 10 by this rotational force. The force relationship is balanced by the elastic reaction force to the pressing. Valve body for the first valve seat 6
The pressing force of 11 becomes the shutoff force of the valve. The breaking force can be changed by replacing the spring 26 with one having a different urging force. When the valve element 11 is pressed against the first valve seat 6 as described above, the first port 3 is shut off. For example, fluid flowing into the third port 5 passes through the hollow portion 2 of the valve body 1 to the second port 4. leak.

Next, when the operation switch 37 is switched to the second side as shown in the section (b), the motor is passed through the second side 37b of the operation switch 37 and the second stop switch 32 in the closed state, as is apparent from the figure. 15 is energized. This energization causes the motor 15 to operate, and the eccentric body 21 rotates in the direction of the arrow.
When the pushing portion 22a comes into contact with the arm lever 24 by the rotation of the eccentric body 21, the arm lever 24 is rotated clockwise. The arm lever 23 rotates clockwise by coming into contact with the release portion 22c, and rotates the connecting lever 27 counterclockwise. By the above movement of the connecting lever 27, the valve
11 moves away from the first valve seat 6 toward the second valve seat 7.
In this process, the fluid flowing into the third port 5 flows into both the first port 3 and the second port 4.

The above-described movement is continued, and the valve body 11 comes into contact with the second valve seat 7 and starts being pressed against it. And valve body
When the elastic force of 11 and the rotational force applied from the arm lever 23 to the connecting lever 27 reach a balance, the valve element 11 stops moving (second position). When the pressing of the valve body 11 against the second valve seat 7 is performed as described above, except for a small frictional resistance, the pressure applied to the valve body 11 with respect to the pressing of the valve body 11 against the second valve seat 7 is reduced. Only force is linked lever 27, arm lever 23, spring 26
Through the arm lever 24 as a force for pressing the arm lever 24 against the pressing portion 22a of the eccentric body 21. This force becomes a load against the rotation of the eccentric body 21, that is, a load on the motor 15. That is, the motor 15
Is only the reaction force of the pressing.

As described above, as shown in the column of FIG.
When the second stop switch 32 is in a state in which it closes the second valve seat 7 exactly, the second stop switch 32 comes into contact with the open portion 30 of the cam switch 29 and is opened as shown in the figure. As a result, the power supply to the motor 15 is stopped, and the motor 15 is stopped. In this state, an equilibrium state equal to that of the above-described case (a) is achieved (“the arm lever 23” in the description of the above-mentioned case (a)).
With "arm lever 24", "arm lever 24" with "arm lever 23", "clockwise" with "counterclockwise",
"Counterclockwise" should be understood as "clockwise" and "first valve seat 6" should be read as "second valve seat 7", respectively.)
The valve element 11 is pressed against the valve seat 7, and the second port 4 is turned off. In this state, for example, the fluid flowing into the third port 5 passes through the hollow portion 2 of the valve
Outflow to port 3.

Next, as shown in the section (d), when the operation switch 37 is switched to the first side, the valve body 11 separates from the second valve seat 7 by an operation equivalent to the case of the above (b) and the first valve seat 7 is moved. Go to 6. Then, the state as shown in (a) is reached, the rotation of the motor 15 stops, and that state is maintained.

[Effects of the Invention] As described above, in the present invention, the valve body is connected to the hollow portion, the first valve seat connected to the first port and opened to the hollow portion, and connected to the second port. A second valve seat that opens into the hollow portion, and a first position in the hollow portion that is pressed against the first valve seat and closes the first valve seat and a second valve seat that is pressed against the second valve seat. A valve body that can be repositioned at a second position that is in a closed state is provided, and the valve body is provided with an operation mechanism that repositions the valve body between the first position and the second position. Therefore, there is a structural effect that two valve seats can be selectively closed by one valve body. Further, as compared with the conventional configuration in which valve elements are individually arranged in individual ports, the configuration of the valve element is simplified, and there is an advantage that failure due to adhesion of "dust" is reduced.

Further, when it is desired to switch the valve by using the operation mechanism, the operation of the operation switch 37 causes the motor 15 to rotate to separate the valve body 11 from the first valve seat 6 and press the valve body 11 against the second valve seat 7, or vice versa. Since the operation is performed, there is an operational advantage that the switching can be performed very easily.

In addition, as described above, the movement of the valve body 11 is not limited to both the movement from the first valve seat 6 to the second valve seat 7 and the opposite movement.
When the valve body 11 is pressed against the first valve seat 6 or the second valve seat 7 in any of the above-described directions, the spring 26 Simply acts as a linking member, the load on the motor 15 is only the reaction force against pressing the valve body against the valve seat, and the motor 15 may have a small torque enough to overcome the reaction force. There is an effect that becomes possible.

In addition, in the operating mechanism according to the present invention, the pressing portion
In the state where 22b selectively pushes one of the two levers 23 and 24, the other lever is pulled in by the tension of the spring 26, and the urging force of the other lever causes the connection lever to move.
27 moves the valve body 11 to the corresponding valve seat 6, 7 in the first or second position.
, The contact of the valve element 11 with each of the valve seats 6 and 7 is always elastic by the urging force of the spring 26. Therefore, even if the abutment surfaces of the valve seats 6, 7 and the valve body 11 due to aging use are worn, and the elasticity of the valve body 11 is deteriorated, the spring is biased by the biasing force of the spring 26,
It has the effect of preventing liquid leakage.

In a state where the valve body is pressed against the valve seat, the reaction force against the pressing continuously reaches the pressing portion 22b of the eccentric body 21, but since the pressing portion 22b is at the dead point, the above-described reaction force There is a feature that transmission to the motor 15 side can be blocked.
This means that the pressing state can be maintained without generating any force on the motor 15, and there is an advantage that the problem of the related art can be solved and the switching state of the valve can be maintained without energy. .

[Brief description of the drawings]

The drawings show an embodiment of the present invention, and FIG.
FIG. 2 is an exploded perspective view, FIG. 3 is a plan view of a switch mechanism,
FIG. 4 is a plan view of a conversion mechanism, FIG. 5 is a plan view of a valve,
FIG. 6 is an explanatory diagram of the operation. 6 1st valve seat, 7 2nd valve seat, 11 ... valve body, 15 ...
Motor, 21: Eccentric body, 22b: Pressing part, 37: Operation switch.

Claims (1)

(57) [Claims] The valve body includes a hollow portion, a first valve seat connected to the first port and opening to the hollow portion, and a second valve seat connected to the second port and opening to the hollow portion. ,
The position can be freely changed between a first position in the hollow portion where the first valve seat is pressed against the first valve seat and closes the first valve seat and a second position where the second valve seat is pressed against the second valve seat and closes the first valve seat. A valve body, and the valve body is provided with the first valve body in the valve body.
In a switching valve provided with an operation mechanism configured to switch between a position and a second position, the operation mechanism includes a motor configured to rotate by being energized through an operation switch; An eccentric body adapted to be rotated, and on both sides of the eccentric body, a lever is provided which is selectively pressed by a pressing portion of the eccentric body by the rotation of the eccentric body. A spring is interposed between the two levers, and between the two levers,
In order to change the position of the valve body between the first position and the second position, the valve body is provided with a connecting lever which is selectively pushed by the two levers. The relative positions of the pressing portion, the two levers, the spring, and the connecting lever are such that when the pressing portion selectively presses one of the two levers, the other lever is pulled by the spring. The connecting lever is set so as to elastically press the valve body against the corresponding valve seat at the first or second position by the urging force of the other lever. On the other hand, the positions where the pressing portions of the eccentric body are in contact with each other are determined at positions where the valve body is a dead center with respect to the rotation center of the eccentric body when the valve body is located at the first position or the second position. The above operation mechanism,
A switching valve, comprising: a stop switch mechanism configured to cut off the power supply to the motor when the valve body is at the first position and at the second position.