JP2000274543A - Torque switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque switch to prevent a trouble of malfunction of an electric motor, etc., due to reduction of load torque in accordance with valve stem contraction and to improve reliability of a valve operating mechanism. SOLUTION: It is possible to improve reliability as a switching state is held and a state of a valve operating device is certainly maintained even in the case when load troque is reduced and a crankshaft 12 is revolved by a small angle in the opposite direction due to valve stem contraction of a valveas a switch holding means 19 holds a switch pressing lever 16 until the crankshaft 12 is revolved up to a specified angle even when the crankshaft 12 is revolved in the opposite direction and the switch pressing lever 16 becomes free to move to the switch side after the crankshaft 12 is revolved and comes to be in a state of where the switch pressing lever 16 releases a movable part of the switch by arranging the switch holding means 19 to restrain the switch pressing lever 16 which comes to be in a state of releasing the movable part of the switch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque switch for appropriately switching operation in a valve operating device according to a load torque state.

[0002]

2. Description of the Related Art In a valve disposed in a pipeline for feeding a fluid, a remote control mechanism using an electric motor is generally used in addition to a manual mechanism as an opening and closing operation mechanism. Conventionally, in such a valve operating mechanism using an electric motor, the force on the valve seat surface increases at the valve closed position to completely close the shut-off state when the valve is fully closed, and the driving torque of the operating section exceeds a predetermined value. When this happens, a torque stop (torque seating) method is adopted in which a torque switch is operated to stop the motor and stop the valve closing operation.

FIGS. 8 to 11 show an example of a torque switch used in such a conventional valve operating mechanism. 8 is a cross-sectional view of a conventional valve operating device using a torque switch, FIG. 9 is another cross-sectional view of a conventional valve operating device using a torque switch, FIG. 10 is a front view of a conventional torque switch, and FIG. 1 shows a side view of the torque switch of FIG.

In each of the drawings, a conventional torque switch 1 is shown.
A valve operating device 100 using 10 is a device used in combination with a valve (not shown) disposed in a pipeline.
A device case 101 disposed adjacent to the valve, a substantially cylindrical sleeve 102 rotatably disposed in the device case 101, and a part of the sleeve 102 slidable in the axial direction. A stem bush 103 formed by inserting a valve shaft end (not shown) of the valve into an inner side and formed into a substantially cylindrical body which is inserted and disposed so as to be rotatable integrally with the sleeve 102; A worm wheel 104 rotatably disposed on the outer periphery of the sleeve 102; and a worm wheel 104 disposed on the outer periphery of the sleeve 102 near the worm wheel 104 so as to be slidable in the axial direction and rotatable integrally with the sleeve 102. A clutch 1 that can be moved upward to switch the interlocking between the handwheel 108 and the sleeve 102 or the interlocking between the worm wheel 104 and the sleeve 102
05, and is rotatably disposed in the device case 101,
A worm shaft 106 formed with a worm 106a meshing with the worm wheel 104 at an axially intermediate position;
And a motor 107 disposed outside the device case 101 to drive the worm shaft 106.

The worm shaft 106 is rotatably supported by the device case 101 via a bearing 101a and is movable in a predetermined range in the axial direction. An electric motor 107 is provided at one end of the worm shaft 106a. A gear 106b receiving driving force from the shaft is provided, and a torque detecting unit 106c is formed to protrude in a flange shape from two places on the shaft to engage an end of the torque switch 110 therebetween. Has a configuration in which a torque spring 106d is provided which applies an urging force in the direction opposite to the displacement when the entire shaft is displaced in the axial direction from the neutral position by the load torque from the worm wheel 104.

The conventional torque switch 110 is
A switch base 111 supported and fixed inside the device case 101 of the valve operating device 100, and a rotatably supported by the switch base 111 in a direction orthogonal to the worm shaft 106; A crankshaft 112 that rotates in accordance with the axial movement of the worm shaft 106 by engaging one end of the worm shaft eccentrically with the torque detecting portion 106 c of the worm shaft 106, and the other end of the crankshaft 112. A scale plate 113 formed substantially in a flange shape and having an arc-shaped long hole (see FIG. 4A; long hole 13a) at a predetermined radial position about the crankshaft 112;
A switch switching screw 114 disposed in a long hole of the scale plate 113 so as to be adjustable in position; and a switch rotatably mounted on the crankshaft 112 and urged by a torsion spring 115 in a predetermined rotation direction. The configuration includes a pressing lever 116 and a switch 117 for controlling the electric motor 107 attached to the switch base 111. The switch pressing lever 116 is urged by the torsion spring 115 toward the crankshaft 112 so as to approach the switch 117.
Of the switch 117 is held by pressing the movable portion 117a.

The operation of the above-described conventional torque switch will be described. When the valve is closed from the open state,
When the worm wheel 104 that rotates integrally with the valve shaft cannot rotate, the worm 106 a of the worm shaft 106 that continues to rotate by receiving the driving force from the electric motor 107.
Receives a force in the direction opposite to the worm rotation direction to the worm wheel 104 due to the increase in the load torque, and the worm shaft 106
The whole moves in the axial direction by a distance corresponding to the load torque while receiving the urging force of the torque spring 106d. When the worm shaft 106 moves in the axial direction, the worm shaft 10
6, the crankshaft 112 of the torque switch 110
Then, the scale plate 113 rotates with respect to the switch base 111, and the displacement of the worm shaft 106 is replaced with the rotational displacement.

When the worm shaft 106 moves to an axial position corresponding to a load torque set in advance as an operation limit, the crankshaft 112 also rotates to a predetermined angle corresponding to the load torque, and switches a switch attached to the scale plate 113. The screw 114 contacts the switch pressing lever 116 and presses the switch pressing lever 116. The switch pressing lever 116 releases the movable portion 117a of the switch 117, and the open / close state of the switch 117 is switched. By operating the switch 117 of the torque switch 110 in this manner, the rotation of the electric motor 107 can be appropriately stopped and controlled.

On the other hand, when the motor is started in the opposite direction, such as when the valve is opened from the closed state, the motor 107 is operated to rotate the worm shaft 106 in the valve opening direction opposite to the above. The worm shaft 106 receives the driving force and moves in the opposite axial direction to the crankshaft 112.
Rotates with the movement, and the switch pressing lever 116 receiving the urging force from the torsion spring 115 moves the switch 117 with the movement of the scale plate 113 and the switch switching screw 114.
Side, and the switch pressing lever 116 is
7 is pressed, and the switch 117 is returned to the original state. When the crankshaft 112 rotates as it is, the switch switching screw 114 moves away from the switch pressing lever 116 that has stopped by pressing the switch 117. Thus, in the conventional torque switch 110,
When the motor 107 rotates the worm shaft 106 to open and close the valve, and finally when the valve moves to the closed position or the limit position of opening, the switch 117 is operated to surely stop the motor 107, The adverse effects of overload can be prevented.

In the valve, when the operating mechanism and the valve shaft are integrated, if the valve is closed in a state where the valve is warmed by a pipe for supplying a high-temperature fluid, the temperature on the downstream side of the valve due to the inflow of the high-temperature fluid does not flow. The lowering causes a contraction of the valve shaft, which may lower the adhesion between the valve body and the valve seat and cause trouble. In order to prevent such a phenomenon, a buffer spring that urges the valve shaft to the valve closing side has been built into the operation mechanism, and the valve body is pressed against the valve seat to keep it tight even if the valve shaft contracts due to temperature drop. Is used. In the conventional valve operating device 100, a buffer spring 109 that constantly urges the stem bush 102 integral with the valve shaft in the valve closing direction in the valve closed state is provided in the device case 101, and the temperature decreases in the closed state due to a temperature drop. Even if the valve shaft contracts, a force in the valve closing direction is applied to the valve shaft via the stem bush 102 by the urging of the buffer spring 109, and the valve body can be pressed against the valve seat.

[0011]

The conventional torque switch is constructed as described above. However, the valve shaft contracts after the valve is fully closed, and the valve shaft moves slightly to the valve closing side by the buffer spring 109. Then, the worm wheel 104 also slightly rotates in the valve closing direction to reduce the load torque of the worm shaft 106, and the worm shaft 106 is slightly returned to the neutral side by the urging force of the torque spring 106d.
Ten crankshafts 112 respond to this movement as they are,
The switch 117 is returned to the original state. At this time, in addition to the motor 107 starting to turn in the closing direction again, if the valve operation is controlled by a computer, it is determined that the motor 107 is operating even in the valve closed state, and it is determined that the motor 107 is in an abnormal state. There was a problem that there is.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a valve operating device which prevents troubles such as a malfunction of an electric motor due to a decrease in load torque due to a contraction of a valve shaft, and improves reliability of a valve operating mechanism. It is an object to provide a torque switch.

[0013]

A torque switch according to the present invention includes a switch base fixed to a device case of a valve operating device having a rotating shaft that moves at least a predetermined amount in an axial direction according to a load torque; The switch base is formed of a substantially shaft-like body rotatably supported in a direction orthogonal to the rotation shaft, and has one end eccentric with respect to a support portion to the switch base and a part of the outer periphery of the rotation shaft. And a crankshaft that converts the axial displacement of the rotating shaft into a rotational displacement of the substantially shaft-like body, and is disposed so as to extend from the other end of the crankshaft by a predetermined dimension in the radial direction with respect to the crankshaft. A switch switching part, a switch attached to the vicinity of the crankshaft, and having a movable part for switching an open / closed state by a displacement in a tangential direction with respect to the crankshaft; Contact can be attached to the moving part,
A switch pressing lever which is biased in a direction in which it contacts the movable portion of the switch, is partially located on the track of the switch switching portion that moves with the rotation of the crankshaft, and is capable of contacting the switch switching portion; Wherein the switch pressing lever presses the movable portion of the switch by urging when the crankshaft rotates by a predetermined angle with an axial movement of the rotary shaft of the valve operating device based on a predetermined load torque. Is rotated by being pushed by the switch switching unit that has moved together with the crankshaft, the switch pressing lever moves in a direction away from the switch to release the movable portion of the switch from the pressed state, and the movable portion of the switch moves with the pressing direction. In a torque switch having a mechanism for switching the open / close state of a switch by moving in a reverse direction, a state in which the switch pressing lever releases a movable portion of the switch. A switch holding means for restraining the switch pressing lever against the bias toward the switch until the crankshaft rotates by a predetermined angle in a direction opposite to the rotating direction, and for maintaining a state in which the switch is not pressed. It is.

As described above, according to the present invention, the switch holding means for restraining the switch pressing lever in a state where the movable portion of the switch is released is provided, and the crank is moved from the state where the switch pressing lever presses the movable portion of the switch. After the shaft rotates and the switch pressing lever releases the movable part of the switch, the crankshaft rotates in the opposite direction, the switch switching part also moves in the original direction, and the switch pressing lever is biased. Even if the switch can be moved to the switch side, the switch holding means holds the switch pressing lever so as not to move to the switch side until the crankshaft rotates to a predetermined angle, so that the switch pressing lever is released. Even if the load torque is reduced due to the valve shaft contraction of the valve in a state where the crankshaft is turned, the rotation angle of the crankshaft in the opposite direction is smaller than the predetermined angle. Law, the switch pressing lever is held state of the switch does not return to the switch side, there is no generation of trouble state of the valve operating device is reliably maintained, is to improve the reliability.

Further, the torque switch according to the present invention is supported, if necessary, as the switch holding means so as to be rotatable around an axis parallel to the crankshaft, and to be provided at a predetermined position from a rotation center accompanying the rotation. The trajectory of the movement of the one end separated by a distance is disposed on the switch base in a predetermined arrangement substantially orthogonal to the trajectory of the movement of the switch pressing lever toward the switch, and the switch pressing lever connects the movable portion of the switch. In the disengaged state, a predetermined urging force is applied to rotate, and the one end is brought into contact with a switch pressing lever to restrain the switch pressing lever from moving to the switch side, and the crankshaft is moved. The switch is rotated in the opposite direction to the direction of the urging force in the state where the switch is rotated by the predetermined angle in the opposite direction, and releases the one end from the switch pressing lever to release the constraint of the switch pressing lever. Those with a retaining lever.

As described above, in the present invention, the switch holding lever serving as the switch holding means is rotatably provided on the switch base, and the crankshaft rotates while the movable portion of the switch is pressed by the switch pressing lever. When the switch pressing lever releases the movable portion of the switch, one end of the switch holding lever comes into contact with the switch pressing lever in a predetermined direction to restrain the switch pressing lever, and the movable portion of the switch is pressed by the switch pressing lever. When the crankshaft rotates to the predetermined angle in the opposite direction from the released state, one end of the switch holding lever separates from the switch pressing lever to release the restraint, so that the switch holding lever is engaged with the switch pressing lever. During this operation, the biasing force of the switch pressing lever toward the switch is received by one end of the switch holding lever. The switch pressing lever can be securely held, the switch holding lever is not moved by the force from the switch pressing lever, and the operation of the switch pressing lever can be appropriately controlled by the switch holding lever having a simple structure, thereby improving reliability. .

Further, the torque switch according to the present invention may include a holding lever release member integrally provided with the crankshaft in the vicinity of the switch switching portion, if necessary, and the switch holding lever may be connected to the one end portion. Is in contact with the switch pressing lever, and at least a part of the holding lever releasing body is positioned on the trajectory of movement accompanying the rotation of the crankshaft. When the crankshaft rotates in the reverse direction from the state in which the crankshaft is released, the holding lever release body contacts a part of the switch holding lever, and the crankshaft rotates in the reverse direction by the predetermined angle. In this state, the holding lever release body pushes a part of the switch holding lever to a position where the switch holding lever deviates from the track of the holding lever release body, and the switch holding lever is moved to the one end. There are those that rotates to a position away from the switch press lever. As described above, in the present invention, the holding lever release body is provided integrally with the crankshaft, and a part of the switch holding lever is moved by the switch pressing lever and the switch holding lever in the engagement trajectory. When the crankshaft rotates in the opposite direction to the predetermined angle, the holding lever release body pushes a part of the switch holding lever located on the track out of the track to release the switch holding lever. By rotating the switch and releasing the restraint of the switch pressing lever, the switch holding lever can be moved directly in correspondence with the rotation of the crankshaft via the holding lever release body,
The switch can be returned properly by adjusting the timing of the disengagement of the switch holding lever and the switch pressing lever to the predetermined rotational angle position of the crankshaft, and the switch is held by a simple mechanism consisting of the holding lever release body and the switch holding lever. The engagement between the lever and the switch pressing lever can be released, so that the number of parts can be reduced and the cost can be reduced.

In the torque switch according to the present invention, if necessary, the holding lever release member is provided as a substantially cylindrical pin parallel to the crankshaft, and the switch holding lever is provided with the holding lever. As a portion located on the trajectory of the movement of the lever release body, a substantially cylindrical roller parallel to the crankshaft is rotatably disposed, and the peripheral side surface of the holding lever release body is formed of the switch holding lever. It comes into contact with the peripheral side surface of the roller. Thus, in the present invention, while the holding lever release body is provided as a pin, the switch holding lever is provided with a rotatable roller,
Rolling contact between the roller and the pin makes contact between the roller and the pin a rolling contact, which reduces resistance such as friction, and allows the switch holding lever and crankshaft to move more smoothly, and the operating resistance of the torque switch. Can be reduced, and wear due to sliding is reduced to improve durability. Furthermore, there is no loss due to the contact between the roller and the pin,
The rotation angle of the crankshaft and the rotation angle of the switch holding lever are made to correspond one-to-one, and the timing of disengagement of the switch holding lever and the switch pressing lever can be strictly adjusted to the predetermined rotation angle position of the crankshaft. It is possible to accurately synchronize the return operation of the switch.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A torque switch according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a front view of a torque switch according to the present embodiment,
2 is a partially omitted front view of the torque switch according to the embodiment, FIG. 3 is a side view of the torque switch according to the embodiment, and FIG. 4A is a plan view of the torque switch according to the embodiment. FIG. 4B is a sectional view taken along the line AA of FIG. 1, and FIG.
FIG. 5B is a plan view of a contact state between a switch switching screw and a switch pressing lever in the torque switch according to the embodiment, and FIG. 5B is a plan view illustrating a switch switching screw and a switch pressing lever in the torque switch according to the embodiment. 6 (A) is a plan view of a switching state of the torque switch according to the present embodiment, and FIG. 6 (B) is a switch off state of the torque switch according to the present embodiment. FIG. 7 is a schematic explanatory view of a main part in a switching state.
FIG. 7A is a schematic explanatory view of a main part of the torque switch according to the present embodiment during the disengagement of the switch holding lever and the switch pressing lever, and FIG. 7B is a diagram illustrating the switch holding in the torque switch according to the present embodiment. It is a principal part schematic explanatory drawing at the time of the disengagement of a lever and a switch pressing lever.

As shown in the figures, the torque switch 1 according to the present embodiment has a switch base 11, a crankshaft 12, a scale plate 13 as the switch switching section, Switch switching screw 14, torsion spring 15, switch pressing lever 16
And a switch 17, the difference being that a cylindrical pin as the holding lever release body is formed integrally with the scale plate 13 by projecting from a predetermined position of the scale plate 13 in parallel with the crankshaft 12. A switch holding lever 19 attached to the switch base 11 so as to be rotatable by a predetermined angle about an axis parallel to the crankshaft 12 and to be able to engage with a contact side portion of the switch pressing lever 16 with the switch 17; Is provided. Note that the valve operating device using the torque switch 1 according to the present embodiment is the same as in the conventional case, and a description thereof will be omitted.

The switch holding lever 19 is rotatably supported by the switch base 11 about an axis parallel to the crankshaft 12, and is provided at a portion near the scale plate 13 which is a predetermined distance from the center of rotation. It has a rotatable cylindrical roller 19a protruding in parallel with the shaft 12, and
The switch pressing lever 16 is provided with an engaging portion 19b as the one end which is in contact with and engages with a side surface of the switch pressing lever 16 facing the switch 17 in a state where the switch pressing lever 16 is separated from the switch 15. The trajectory of the movement of the engagement portion 19b separated by a predetermined distance is the switch pressing lever 16
The switch base 11 is disposed at two locations with the crankshaft 12 interposed therebetween so as to be substantially orthogonal to the path of movement toward the switch 17. A spring 19c for urging each switch holding lever 19 in a rotational direction between the two switch holding levers 19 to bring the engaging portion 19b closer to the switch pressing lever 16.
Is arranged. The roller 19a is provided with an engaging portion 19b.
Are arranged on the trajectory of the movement of the pin 18 with the rotation of the crankshaft 12 in a state where the pin 18 is engaged with the switch pressing lever 16.

Next, the operation of the torque switch based on the above configuration will be described. When the valve is closed from the open state, the worm wheel 104 rotates integrally with the valve shaft.
When the motor cannot rotate, the motor
Worm shaft 1 as the rotating shaft receiving a driving force from
06 receives a force in a direction opposite to the worm rotation direction to the worm wheel 104 due to an increase in load torque, and the worm shaft 1
06 moves in the axial direction by a distance corresponding to the load torque. As the worm shaft 106 moves, the torque switch 1
Of the crankshaft 12 and the scale plate 13
, And the displacement of the worm shaft 106 is replaced by the rotational displacement.

When the worm shaft 106 moves to an axial position corresponding to a load torque set in advance as an operation limit, the crankshaft 12 also rotates to a predetermined angle corresponding to the load torque, and switches a switch mounted on the scale plate 13. The screw 14 contacts the switch pressing lever 16 (see FIG. 5) and presses the switch pressing lever 16, and the switch pressing lever 16 releases the movable portion 17a of the switch 17, and the open / close state of the switch 17 is switched (FIG. 5). 6).
The operation of the switch 17 stops the electric motor 107. The switch pressing lever 16 is a movable part 17 of the switch 17.
When the switch pressing lever 16 is released, the engagement between the engaging portion 19b of the switch holding lever 19 and the side surface of the switch pressing lever 16 is released by the movement of the switch pressing lever 16, so that the switch holding lever 19 urged by the spring 19c is turned on. The engaging portion 19b enters between the pressing lever 16 and the switch 17, and engages with the engaging portion 19b in contact with the side surface of the switch pressing lever 16 facing the switch 17 (see FIG. 6). Thus, the switch pressing lever 16 is restrained and held by the switch holding lever 19 with the movable portion 17a of the switch 17 released.

On the other hand, when the motor is started in the opposite direction, such as when the valve is opened from the closed state, the motor 107 is operated to rotate the worm shaft 106 in the valve opening direction opposite to the above. The worm shaft 106 receives the driving force and moves in the opposite axial direction, and the crankshaft 12 rotates with the movement. At this time, switch holding lever 1
9, the switch pressing lever 16 contacts the side surface of the switch pressing lever 16 on the switch 17 side to restrain the switch pressing lever 16, so that the switch pressing lever 16 moves with the movement of the scale plate 13 and the switch switching screw 14. There is no movement and no movement to the switch 17 side.

When the load torque is reduced by driving the worm shaft 106 by the electric motor 107 and the worm shaft 106 approaches the neutral position, the scale plate 13 which rotates together with the crankshaft 12.
Is in contact with the roller 19a of the switch holding lever 19 existing on the trajectory of the pin 18 and moves while pushing the roller 19a in rolling contact. It moves in a direction away from 16 (see FIG. 7A). When the switch holding lever 19 rotates against the bias in a form pressed by the pin 18 and the engaging portion 19b of the switch holding lever 19 separates from the side surface of the switch pressing lever 16 on the switch 17 side (FIG. 7B). Since the movement of the switch pressing lever 16 due to the contact of the switch holding lever 19 is not restricted, the switch pressing lever 16 receiving the urging force from the torsion spring 15 can move toward the switch 17, and the switch pressing lever 16 moves. Then, the movable portion 17a of the switch 17 is pressed to return the switch 17 to the original state (see FIG. 4). After this, the crankshaft 12
When the pin 18 separates from the roller 19a of the switch holding lever 19 with the rotation of the switch, the switch holding lever 19 is turned to the switch pressing lever 16 side by the urging, and the engaging portion 19b of the switch holding lever 19 pushes the switch. The lever 16 comes into contact with the side surface.

Thus, when the switch 17 is actuated when the valve is closed, the motor 107 is stopped and the switch pressing lever 16 is held away from the switch 17 by the switch holding lever 19. When the valve shaft contracts, the valve shaft moves slightly to the valve closing side by the buffer spring 109, and the worm wheel 10
Even if the worm shaft 106 whose load torque has decreased due to the rotation of the shaft 4 moves slightly, the amount of movement of the worm shaft 106 in this case is a small amount that does not reach the neutral position. Although the first crankshaft 12 rotates in response to the worm shaft 106, the switch holding lever 19 reliably holds the switch pressing lever 16 so as not to rotate to the switch 15 return side, and the switch 17 is returned to its original state. Without returning to
It is possible to prevent the electric motor 107 from rotating in the closing direction again.

As described above, in the torque switch according to the present embodiment, the switch holding lever 19 for restraining the switch pressing lever 16 is provided, and the switch 17 operates with the set load torque to stop the electric motor 107. At the same time, the switch holding lever 19 is
Is held with the movable portion 17a of the switch 17 released, and when the torque decreases, the switch holding lever 19 is moved by the pin 18 to release the holding of the switch pressing lever 16, so that the switch 1 of the switch pressing lever 16 is released.
The timing of the release or pressing of the switch 7 can be made different between when the load torque increases and when the load torque decreases, and the return of the switch 17 can be prevented by disabling the switch pressing lever 16 when the torque slightly decreases due to valve shaft contraction or the like. Can,
When the valve operating mechanism is computer-controlled, it is possible to reduce a situation in which the valve operating mechanism is erroneously determined to be abnormal, and to greatly increase the reliability of the control system.

In the torque switch according to the above-described embodiment, the switch holding lever 19 is pushed by the switch pressing lever 16 while the pin 18 serving as the holding lever release member is in rolling contact with the roller 19a of the switch holding lever 19.
However, the present invention is not limited to this, and the contact portion of the switch holding lever 19 with the pin 18 is a fixed contact, and the switch holding lever 19 is moved while sliding with the pin 18. It can also be.

In the torque switch according to the embodiment, two switch switching screws 14, switch pressing levers 16, switches 17, pins 18, and switch holding levers 19 are symmetrically disposed with respect to the crankshaft 12, respectively. The worm shaft 106 of the valve operating device is configured to perform a switching operation for a predetermined load torque for each of the opening direction and the closing direction of the worm shaft 106. In addition, the above components are disposed one by one, A configuration may be used in which the shaft 106 is rotated in either the opening direction or the closing direction.

[0030]

As described above, according to the present invention, the switch holding means for restraining the switch pressing lever in a state where the movable portion of the switch is released is disposed, and the switch pressing lever presses the movable portion of the switch. After the crankshaft turns from this state and the switch pressing lever releases the movable part of the switch, the crankshaft turns in the opposite direction, and the switch switching part also moves in the original direction and the switch is pressed. Even if the lever can be moved to the switch side by the biasing force, the switch holding means holds the switch pressing lever so as not to move to the switch side until the crankshaft rotates to a predetermined angle. Even when the load torque is reduced due to the valve shaft contraction or the like while the valve is released, the rotation angle of the crankshaft in the opposite direction is smaller than the predetermined angle. Unless, the switch pressing lever is held state of the switch does not return to the switch side, there is no generation of trouble state of the valve operating device is reliably maintained, an effect that is to improve the reliability.

Further, according to the present invention, a switch holding lever as a switch holding means is rotatably provided on the switch base, and the crankshaft rotates while the movable portion of the switch is pressed by the switch pressing lever. When the switch pressing lever releases the movable portion of the switch, one end of the switch holding lever comes into contact with the switch pressing lever in a predetermined direction to restrain the switch pressing lever, and the movable portion of the switch is pressed by the switch pressing lever. When the crankshaft rotates to the predetermined angle in the opposite direction from the released state,
When one end of the switch holding lever is separated from the switch pressing lever to release the restraint, while the switch holding lever is engaged with the switch pressing lever, the biasing force of the switch pressing lever toward the switch is applied to one end of the switch holding lever. The switch pressing lever can be held securely by receiving the switch, the switch holding lever is not moved by the force from the switch pressing lever, and the operation of the switch pressing lever can be appropriately controlled by the switch holding lever with a simple structure, which is reliable. This has the effect of enhancing the properties.

Further, according to the present invention, the holding lever release member is provided integrally with the crankshaft, and a part of the switch holding lever is moved in a state where the switch pressing lever and the switch holding lever are engaged with each other. When the crankshaft is rotated in the reverse direction to the predetermined angle, the holding lever release body pushes a part of the switch holding lever positioned on the track out of the track to form a switch. By rotating the holding lever and releasing the restriction of the switch pressing lever, the switch holding lever can be moved directly in response to the rotation of the crankshaft via the holding lever release body, and the switch holding lever and the switch pressing can be moved. The switch can be returned properly by adjusting the timing of disengagement with the lever to the predetermined rotation angle position of the crankshaft, Will be by a simple mechanism including the lifting lever release member and the switch holding lever allows the disengagement of the switch hold lever and the switch pressing lever, has an effect of cost reduction by reducing the number of parts.

Further, according to the present invention, while the holding lever release member is provided as a pin, the switch holding lever is provided with a rotatable roller so that the roller and the peripheral surface of the pin contact each other. As a result, the contact between the roller and the pin becomes a rolling contact, and the resistance such as friction decreases, the switch holding lever and the crankshaft can be moved more smoothly, the operating resistance of the torque switch can be reduced, and wear due to sliding decreases. This has the effect of improving durability. Furthermore, there is no loss due to the contact between the roller and the pin, the rotation angle of the crank shaft and the rotation angle of the switch holding lever are made to correspond one-to-one, and the timing of disengagement of the switch holding lever and the switch pressing lever is adjusted by the crank. It is possible to exactly match the predetermined rotation angle position of the shaft, and it has an effect that the return operation of the switch can be accurately synchronized.

[Brief description of the drawings]

FIG. 1 is a front view of a torque switch according to an embodiment of the present invention.

FIG. 2 is a partially omitted front view of the torque switch according to the embodiment of the present invention.

FIG. 3 is a side view of the torque switch according to the embodiment of the present invention.

FIG. 4 is a plan view of the torque switch according to the embodiment of the present invention and a cross-sectional view taken along line AA of FIG. 1;

FIG. 5 is a plan view and a schematic explanatory view of a main part of a contact state between a switch switching screw and a switch pressing lever in the torque switch according to the embodiment of the present invention.

FIG. 6 is a plan view and a schematic explanatory view of a main part of a torque switch according to one embodiment of the present invention in a switch switching state.

FIG. 7 is a schematic explanatory view of a main part of a torque switch according to another embodiment of the present invention during and after disengagement between a switch holding lever and a switch pressing lever.

FIG. 8 is a sectional view of a conventional valve operating device using a torque switch.

FIG. 9 is another sectional view of a conventional valve operating device using a torque switch.

FIG. 10 is a front view of a conventional torque switch.

FIG. 11 is a side view of a conventional torque switch.

[Explanation of symbols]

 1, 110 Torque switch 11, 111 Switch base 12, 112 Crank shaft 13, 113 Scale plate 13a Elongated hole 14, 114 Switch switching screw 15, 115 Torsion spring 16, 116 Switch pressing lever 17, 117 Switch 17a, 117a Moving part 18 pin 19 switch holding lever 19a roller 19b engaging portion 19c spring 100 valve operating device 101 device case 101a bearing 102 sleeve 103 stem bush 104 worm wheel 105 clutch 106 worm shaft 106a worm 106b gear 106c torque detecting portion 106d torque spring 107 motor 108 Handwheel 109 Buffer spring

Claims (4)

[Claims] 1. A switch base fixed to an apparatus case of a valve operating device having a rotating shaft that moves at least a predetermined amount in an axial direction in accordance with a load torque, and a switch base having a direction perpendicular to the rotating shaft. It is formed of a substantially shaft-like body rotatably supported, one end of which is eccentric with respect to the shaft support portion to the switch base and engages with a part of the outer periphery of the rotating shaft to reduce the axial displacement of the rotating shaft. A crankshaft for converting the rotational displacement of the substantially shaft-like body, a switch switching portion extending from the other end of the crankshaft in a radial direction with respect to the crankshaft by a predetermined dimension, and mounted near the crankshaft. A switch having a movable part for switching between open and closed states by displacement in a tangential direction with respect to the crankshaft; and a switch attached to the crankshaft so as to be rotatable by a predetermined angle and to be able to contact the movable part of the switch. Urged in the direction of contact with the moving part,
A switch pressing lever partly located on a track of the switch switching unit that moves with the rotation of the crankshaft and capable of contacting the switch switching unit; and a predetermined load on a rotation shaft of the valve operating device. When the crankshaft rotates by a predetermined angle along with the axial movement based on the torque, the switch pressing lever pressing the movable portion of the switch by urging is pushed by the switch switching portion moved together with the crankshaft. Pivotally move the switch pressing lever away from the switch to release the movable part of the switch from the pressed state,
In a torque switch having a mechanism in which a movable portion of a switch moves in a direction opposite to the pressing direction to switch an open / close state of the switch, in a state where the switch pressing lever releases the movable portion of the switch, the crankshaft is A torque switch, comprising: switch holding means for restraining the switch pressing lever against the bias toward the switch until the switch pressing lever is turned by a predetermined angle in the direction opposite to the turning direction, so as to keep the switch from being pressed. . 2. The torque switch according to claim 1, wherein the switch holding means is rotatably supported around an axis parallel to the crankshaft and has a predetermined dimension from a rotation center accompanying the rotation. A trajectory of movement of the separated one end portion is disposed on the switch base in a predetermined arrangement substantially orthogonal to a trajectory of movement of the switch pressing lever toward the switch;
In a state where the switch pressing lever releases the movable portion of the switch, the switch pressing lever is rotated by applying a predetermined urging force, and the one end is brought into contact with and engaged with the switch pressing lever, so that the switch pressing lever moves toward the switch side. While restraining the movement, the crankshaft is rotated in the opposite direction by the predetermined angle, and is rotated in the direction opposite to the direction of the urging force, and one end is separated from the switch pressing lever to restrain the switch pressing lever. A torque switch comprising a switch holding lever for releasing. 3. The torque switch according to claim 2, further comprising: a holding lever release body disposed integrally with the crankshaft in the vicinity of the switch switching unit, wherein the switch holding lever is connected to the one end. In a state where the holding lever release body is in contact with and engaged with the switch pressing lever, at least a part of the holding lever release body is located on a trajectory of movement accompanying rotation of the crankshaft, and the switch pressing lever moves the movable portion of the switch. When the crankshaft rotates in the reverse direction from the released state, the holding lever release body contacts a part of the switch holding lever, and the crankshaft rotates in the reverse direction by the predetermined angle. The holding lever release body pushes a part of the switch holding lever out of the track of the holding lever release body until the switch holding lever is released from the end of the switch holding lever. The torque switch is rotated to a position away from the switch pressing lever. 4. The torque switch according to claim 3, wherein the holding lever release body is disposed as a substantially cylindrical pin parallel to a crankshaft, and wherein the switch holding lever is provided with the holding lever. A roller having a substantially cylindrical body parallel to the crankshaft is rotatably disposed as a portion located on a path of movement of the release body, and a peripheral side surface of the holding lever release body is a roller of the switch holding lever. A torque switch that comes into contact with the peripheral side surface of the motor.