JP2019212821A - Torque adjusting device and tap switching device - Google Patents

Abstract

To provide a torque adjusting device and a tap switching device capable of adjusting torque around a drive shaft.SOLUTION: The torque adjusting device includes: a drive shaft 4 for rotating about an axis; an adjustment cam 51 for adjusting torque by being fitted to an outside of the drive shaft 4; a cam follower 55 for contacting the circumferential surface of the adjustment cam 51; an energizing member for energizing the cam follower 55 toward the adjustment cam 51; and a connecting member, for connecting the energizing member and the cam follower 55, capable of rotating around an axis intersecting the drive shaft 4.SELECTED DRAWING: Figure 5

Description

  The present technology relates to a torque adjusting device and a tap switching device that adjust the magnitude of torque around a drive shaft.

  Conventionally, a tap switching device that switches connection between a neutral point of a transformer and an odd-numbered tap or an even-numbered tap has been proposed. A switch is provided between the neutral point and the odd or even tap, and switching is performed by operating the switch. A vacuum valve is provided between the neutral point and the switch, and between the neutral point and the odd-numbered tap.

  The tap switching device includes a drive shaft, a drive cam fitted to the drive shaft on the outside, a cam follower in contact with a peripheral surface of the drive cam, a power storage spring, and a power storage mechanism that stores the power storage spring. With. After the accumulation of the energy storage spring is completed, torque (hereinafter referred to as first torque) due to the energy of the energy storage spring acts on the drive shaft, the drive shaft rotates, and the cam follower moves. The displacement of the cam follower is transmitted to the vacuum valve and the switch, and the opening and closing of the vacuum valve and the switching of the switch are executed at a predetermined timing (see, for example, Patent Document 1).

JP 2004-319975 A

  The first torque changes with time. Torque (hereinafter referred to as second torque) is also generated from the cam follower to the drive cam. When the first torque is too large, or when the first torque and the second torque are torques in the same direction, the switching speed becomes too fast, and the timing of opening and closing the vacuum valve and the switching of the switch deviates greatly from the predetermined timing. There is a fear. When the first torque and the second torque are reverse torques, the torque for rotating the drive shaft becomes too small, and there is a possibility that the opening and closing of the vacuum valve and the switching of the switch cannot be performed.

  The present disclosure has been made in view of such circumstances, and an object thereof is to provide a torque adjusting device and a tap switching device capable of adjusting torque around a drive shaft.

  A torque adjustment device according to the present disclosure includes a drive shaft that rotates about an axis, an adjustment cam that fits outside the drive shaft and adjusts torque, and a cam follower that contacts a peripheral surface of the adjustment cam; An urging member that urges the cam follower toward the adjustment cam, and a connecting member that connects the urging member and the cam follower and is rotatable about an axis that intersects the drive shaft.

  In the present disclosure, the cam follower is in contact with the adjustment cam by the biasing force of the biasing member. The cam follower moves along the cam surface formed on the peripheral surface of the adjustment cam, and the biasing member absorbs or releases energy and adjusts the torque around the drive shaft.

  A tap switching device according to the present disclosure includes a drive shaft that rotates about an axis, a drive cam that is fitted to the outside of the drive shaft and performs tap switching, and is fitted to the outside of the drive shaft to generate torque. An adjustment cam for adjusting the cam, a cam follower that contacts the circumferential surface of the adjustment cam, a biasing member that biases the cam follower toward the adjustment cam, the biasing member and the cam follower are connected, and the drive And a connecting member that is rotatable about an axis that intersects the axis.

  In the present disclosure, the cam follower is in contact with the adjustment cam by the biasing force of the biasing member. The cam follower moves along the cam surface formed on the peripheral surface of the adjustment cam, and the biasing member absorbs or releases energy, adjusts the torque around the drive shaft, and adjusts the torque by the drive cam.

  In the tap switching device according to the present disclosure, a first recess is formed on the peripheral surface of the drive cam, a second recess is formed on the peripheral surface of the adjustment cam, and the position of the first recess is around the drive shaft. It is different from the position of the second recess.

  In the present disclosure, the positions of the first recess of the drive cam and the second recess of the adjustment cam are different around the drive shaft. It is possible to prevent the cam follower from simultaneously moving in each of the first recess and the second recess, thereby preventing an extreme increase or decrease in torque.

  In the tap switching device according to the present disclosure, a first convex portion is formed on the peripheral surface of the drive cam, a second convex portion is formed on the peripheral surface of the adjustment cam, and the first convex portion is provided around the drive shaft. The position of at least a part of the second convex part is the same as the position of the second concave part, and the position of the second convex part is the same as the position of the first concave part around the drive shaft.

  In the present disclosure, in the circumferential direction of the drive shaft, at least a part of the first convex part overlaps the second concave part, and at least a part of the second convex part overlaps the first concave part. For this reason, the torque generated by the drive cam is easily canceled by the adjustment cam, and the power supplied to the drive shaft can be reduced. As a result, it is possible to promote downsizing of the structure for supplying power, promote downsizing of the tap switching device, and reduce the manufacturing cost of the tap switching device.

  In the torque adjustment device and the tap switching device according to the present disclosure, the cam follower is in contact with the adjustment cam by the urging force of the urging member. The cam follower moves along the cam surface formed on the peripheral surface of the adjustment cam, and the biasing member absorbs or releases energy and adjusts the torque around the drive shaft.

It is a figure which shows the electrical structure of a tap selector and a tap switching apparatus. It is a schematic longitudinal cross-sectional view of a tap switching device. It is a schematic plan view of a drive cam. It is a schematic plan view of a drive cam. It is a schematic plan view of an adjustment cam and a drive cam. It is a schematic plan view of an adjustment cam and a drive cam. It is the elements on larger scale which show the part enclosed with the VII line shown in FIG. It is the elements on larger scale which show the part enclosed with the VIII line shown in FIG. It is a graph which shows an example of the torque which acts on a drive shaft.

  Hereinafter, the present invention will be described based on the drawings showing a tap switching device 100 according to an embodiment. FIG. 1 is a diagram showing an electrical configuration of a tap selector and tap switching device 100. The tap selector selects the tap winding Wt connected in series with the main winding Wm of the transformer, the odd taps t1, t3, t5,... Provided on the tap winding Wt, and the odd taps. .., An even tap t2, t4, t6,... Provided in the tap winding Wt, and an even tap selector T2 for selecting the even tap. The odd tap selector T1 is electrically connected to the selected odd tap, and the even tap selector T2 is electrically connected to the selected even tap.

  The tap switching device 100 includes a first vacuum valve Ma that opens and closes a load current that flows through the odd tap selector T1 and the even tap selector T2 during tap switching. One end of the first vacuum valve Ma is connected to the neutral point N of the transformer, and the other end is selectively connected to the odd tap selector T1 and the even tap selector T2 via the changeover switch SW.

  The tap switching device 100 further includes a current limiting resistor r that limits a short-circuit current between taps that flows when the tap is switched, and a second vacuum valve Mb that turns on and off the current limiting resistor r. One end of the second vacuum valve Mb is connected to the neutral point N, and the other end is connected to the odd tap selector T1 through the current limiting resistor r.

  The load current is switched from one of the two taps selected by the tap selectors T1 and T2 to the other by the first vacuum valve Ma and the second vacuum valve Mb and the changeover switch SW.

  When the odd tap is selected, the changeover switch SW is switched to the odd tap selector T1, and the first vacuum valve Ma and the second vacuum valve Mb are closed as illustrated. When the even tap is selected, the changeover switch SW is switched to the even tap selector T2 side, the first vacuum valve Ma is closed, and the second vacuum valve Mb is opened.

  For example, as shown in the figure, it is assumed that the changeover switch SW is connected to the tap selector T1, the first vacuum valve Ma and the second vacuum valve Mb are closed, and the tap t1 is selected. When the tap is switched from the odd-numbered tap to the even-numbered tap, for example, when the tap is switched from t1 to t2, first, the first vacuum valve Ma is opened, and the load current is passed through the current limiting resistor r. Then, after the changeover switch SW is switched to the tap selector T2 side without arcing, the first vacuum valve Ma is closed, the vacuum valve Mb is opened, and the tap change is completed. When the changeover switch SW is switched to the tap selector T2 side and the first vacuum valve Ma is closed, a short-circuit current flows between the taps through the taps t1 and t2. This short circuit current is limited by the current limiting resistor r.

  It is assumed that the tap t2 is selected by closing the first vacuum valve Ma and the second vacuum valve Mb in the state where the changeover switch SW is switched to the tap selector T2 side. When switching from the even tap to the odd tap, for example, when switching the tap from t2 to t3, first the tap t3 is selected by the tap selector T1. Then, the vacuum valve Mb is closed, the current limiting resistor r is connected to the tap t3 through the tap selector T1, and the first vacuum valve Ma is opened to allow the load current to flow through the current limiting resistor r. Then, the changeover switch SW is switched to the tap selector T1 side without arcing, the first vacuum valve Ma is closed, and the tap switching is finished.

  In the tap switching device 100, the switches (the first vacuum valve Ma, the second vacuum valve Mb, and the switching switch SW in the above example) that configure the switching switch in association with the operation of the tap selector at the time of tap switching. A drive mechanism that operates in a predetermined sequence is provided.

  FIG. 2 is a schematic longitudinal sectional view of the tap switching device 100. The tap switching device 100 includes an insulating cylinder 1. The insulating cylinder 1 extends in the vertical direction. A plate-like lower fixed frame 2 is provided inside the lower part of the insulating cylinder 1. A plate-like upper fixed frame 3 is provided on the upper side of the lower fixed frame 2. A plate-shaped intermediate frame 50 is provided between the lower fixed frame 2 and the upper fixed frame 3. The lower fixed frame 2, the upper fixed frame 3, and the intermediate frame 50 are substantially parallel to each other and extend in a direction perpendicular to the axial direction of the insulating cylinder 1.

  The intermediate frame 50 has a through hole (not shown) penetrating in the vertical direction. A drive shaft 4 that is rotatable about the axis is inserted into the through hole with the vertical direction as the axial direction. The drive shaft 4 is rotatably supported by the lower fixed frame 2 and the upper fixed frame 3 via bearings (not shown). The lower end portion of the drive shaft 4 passes through the lower fixed frame 2 and protrudes below the lower fixed frame 2.

  A driving device 5 is disposed below the lower fixed frame 2. The drive device 5 is connected to the lower end of the drive shaft 4. Due to the driving force of the driving device 5, the driving shaft 4 reciprocally rotates in a certain angular range between the first position and the second position. The first position is the rotation start position of the drive shaft 4 when the tap is switched from the odd tap to the even tap, and the second position is the rotation start position of the drive shaft 4 when the tap is switched from the even tap to the odd tap. is there.

  The drive device 5 includes an energy storage spring 6, an energy storage mechanism 7 that stores the energy storage spring 6, and a lever 8. The lever 8 extends in a direction substantially parallel to the lower fixed frame 2. One end of the lever 8 is fixed to the lower end of the drive shaft 4. A spring receiving member 9 </ b> A is attached to the lower side of the other end of the lever 8. A support post 10 is fixed to the lower surface of the lower fixed frame 2. The support post 10 protrudes downward from the lower fixed frame 2. The lower end portion of the support post 10 is located below the lever 8. One end of the lever 11 is rotatably connected to the lower end of the support post 10. The lever 11 rotates with the vertical direction as the rotation axis direction.

  The lever 11 extends in a direction substantially parallel to the lower fixed frame 2. A spring receiving member 9 </ b> B is provided at the other end of the lever 11. The spring receiving member 9 </ b> B protrudes upward from the lever 11 and faces the spring receiving member 9 </ b> A of the lever 8. The accumulator spring 6 has a tension spring. One end of the accumulator spring 6 is connected to the spring receiving member 9A, and the other end is connected to the spring receiving member 9B.

  A support fitting 12 protrudes from the inner peripheral surface of the insulating cylinder 1 toward the radial center of the insulating cylinder 1. The support fitting 12 is disposed below the lever 11. A rotating member 13 is rotatably attached to the support fitting 12. The rotating member 13 is supplied with power from a motor (not shown) and rotates with the vertical direction as the rotation axis direction.

  A first lever 14 is connected to the rotating member 13. The first lever 14 extends from the rotating member 13 in a direction substantially parallel to the lever 11. A pivot 14a is provided at the tip of the first lever 14 with the vertical direction as the axial direction. A second lever 15 is attached to the pivot shaft 14a. The second lever 15 extends in a direction substantially parallel to the lever 11 and is disposed between the first lever 14 and the lever 11. The distal end portion of the second lever 15 is connected to the lower side of the lever 11 via a pivot 15a whose axial direction is the vertical direction.

  When the drive shaft 4 is constrained to the first position or the second position (rotation start position) by the stopper mechanism described later and the rotating member 13 is rotated, the lever 11 rotates and the accumulator spring 6 is pulled, Accumulated. When the stopper mechanism releases the drive shaft 4, the energy stored in the storage spring 6 is released all at once, and the drive shaft 4 rotates from the first position to the second position or from the second position to the first position. Move.

  3 and 4 are schematic plan views of the drive cam 16. FIG. 4 shows a state in which the drive shaft 4 and the drive cam 16 are rotated counterclockwise in plan view from the position shown in FIG. A plate-like drive cam 16 is fitted to the outside of the drive shaft 4 between the intermediate frame 50 and the lower fixed frame 2. The drive cam 16 is substantially orthogonal to the drive shaft 4. A hole penetrating vertically is formed in the drive cam 16, and the drive shaft 4 is inserted into the hole. A cam surface 16 a is formed on the peripheral surface of the drive cam 16. The cam surface 16a includes three first convex portions 16u, 16v, and 16w arranged at intervals of 120 °, and a first concave portion 16c that connects the first convex portions 16u, 16v, and 16w to each other.

  Around the drive shaft 4, three first vacuum valves Ma of U phase, V phase and W phase are arranged at intervals of 120 °, and three second vacuum valves Mb of U phase, V phase and W phase are 120. Lined up at intervals. The three second vacuum valves Mb are respectively disposed between the three first vacuum valves Ma.

  Between the intermediate frame 50 and the lower fixed frame 2, three terminal fittings 17a corresponding to the three first vacuum valves Ma and three corresponding to the three second vacuum valves Mb are provided on the inner peripheral surface of the insulating cylinder 1. Two terminal fittings 17b are provided. The terminal fittings 17 a and 17 b are disposed below the drive cam 16. The vacuum valves Ma and Mb are arranged with their respective central axes oriented in the vertical direction. Terminals are led out from the lower ends of the vacuum valves Ma and Mb, and these terminals are fixed to the terminal fittings 17a and 17b.

  The support member 22 protrudes downward from the intermediate frame 50. L-shaped levers 20 a and 20 b for driving a vacuum valve corresponding to the first vacuum valve Ma and the second vacuum valve Mb are provided between the intermediate frame 50 and the lower fixed frame 2. An intermediate corner portion of the L-shaped levers 20 a and 20 b is rotatably supported by the support member 22 via a rotation shaft 21 extending in a direction perpendicular to the axis of the drive shaft 4.

  A cam follower 23 for driving a vacuum valve made of a roller is attached to one end of each of the L-shaped levers 20a and 20b. The cam follower 23 rolls on the cam surface 16a. The movable shaft 24 protrudes upward from the upper ends of the first vacuum valve Ma and the second vacuum valve Mb. The other ends of the L-shaped levers 20a and 20b are connected to the corresponding movable shafts 24 of the first vacuum valve Ma and the second vacuum valve Mb via a pin 25.

  A spring 26 is disposed between the upper end of the movable shaft 24 and the intermediate frame 50. Due to the biasing force of the spring 26, the cam follower 23 is pressed toward the cam surface 16a of the drive cam 16 and abuts against the cam surface 16a.

  When the first convex portions 16u, 16v, 16w of the cam surface 16a of the drive cam 16 are separated from the cam follower 23 corresponding to the U-phase, V-phase, or W-phase first vacuum valve Ma or the second vacuum valve Mb, The first vacuum valve Ma or the second vacuum valve Mb is in a closed state.

  The first convex portions 16u, 16v, 16w of the cam surface 16a of the drive cam 16 abut on the cam follower 23 corresponding to the U-phase, V-phase, W-phase first vacuum valve Ma or second vacuum valve Mb, and the cam follower 23 Is moved, the movable shaft 24 moves upward against the urging force of the spring 26, and the first vacuum valve Ma or the second vacuum valve Mb is opened.

  A stopper mechanism 30 is provided to prevent the rotation of the drive shaft 4 by restraining the drive shaft 4 at the rotation start position (first position or second position) until the accumulation of the energy storage spring 6 is completed. ing.

  The stopper mechanism 30 includes an auxiliary cam 31 fixed to the intermediate frame 50 side of the drive cam 16. The auxiliary cam 31 has an arc shape extending along the circumferential direction of the drive shaft 4, and a cam surface 31 a is formed on the outer peripheral surface thereof. The stopper mechanism 30 is further provided on the intermediate frame 50 side, and is provided with an auxiliary cam follower 32 that contacts the cam surface 31a of the auxiliary cam 31, and an auxiliary cam follower 32 so as to press the auxiliary cam follower 32 toward the cam surface 31a. And a spring 33 for energizing.

  An L-shaped lever 34 for a stopper mechanism having the same shape and the same dimensions as the L-shaped levers 20 a and 20 b is disposed above the auxiliary cam 31. A support member 36 is fixed to the intermediate frame 50 above the L-shaped lever 34. An intermediate corner portion of the L-shaped lever 34 is supported by a support member 36 via a rotation shaft 35 extending in a direction perpendicular to the axis of the drive shaft 4. An auxiliary cam follower 32 is attached to one end of the L-shaped lever 34. The auxiliary cam follower 32 has a roller that rolls on the cam surface 31a. A spring receiving member 38 is attached to the other end of the L-shaped lever 34 via a pin 37. A spring 33 is provided between the spring receiving member 38 and the upper fixed frame 3. The auxiliary cam follower 32 comes into contact with the cam surface 31 a by the biasing force of the spring 33.

  As shown in FIGS. 3 and 4, the cam surface 31a includes a first stopper portion 31a1 and a second stopper portion 31a2. The first stopper portion 31a1 and the second stopper portion 31a2 are spaced apart from each other in the circumferential direction of the arcuate cam surface 31a. The first stopper part 31a1 and the second stopper part 31a2 protrude radially outward from the cam surface 31a. When the drive shaft 4 is in the first position, the auxiliary cam follower 32 engages with the opposite side of the first stopper portion 31a1 to the second stopper portion 31a2, and prevents the drive shaft 4 from rotating to the second position. When the drive shaft 4 is in the second position, the auxiliary cam follower 32 engages with the second stopper portion 31a2 on the opposite side of the first stopper portion 31a1, and prevents the drive shaft 4 from rotating to the first position. The force applied from the accumulator spring 6 through the drive shaft 4 and the drive cam 16 prevents the drive shaft 4 from rotating until the auxiliary cam follower 32 gets over the stopper portions 31a1 and 31a2.

  When the first stopper portion 31a1 is in contact with the auxiliary cam follower 32 and prevents the auxiliary cam 31 from rotating in the clockwise direction, the drive shaft 4 is disposed at the first position. When the second stopper portion 31a2 is in contact with the auxiliary cam follower 32 and prevents the auxiliary cam 31 from rotating counterclockwise, the drive shaft 4 is disposed at the second position.

  On the lower side of the drive cam 16, a movable contact 41 is attached to the middle surface of the drive shaft 4 via an insulating member 40. A pair of fixed contacts 42, 42 (FIG. 2 shows only one fixed contact 42) is spaced in the rotational direction of the drive shaft 4 so as to face the insulating member 40 and the movable contact 41. It is fixed to the inner peripheral surface of the insulating cylinder 1 in the opened state. The movable contact 41 selectively contacts one of the two fixed contacts 42, 42 as the drive shaft 4 rotates. The movable contact 41 and the fixed contacts 42 and 42 constitute a changeover switch SW. One of the pair of fixed contacts 42, 42 is connected to the odd tap selector, and the other is connected to the even tap selector. The movable contact 41 is connected to a terminal (movable shaft 24) on the movable contact side of the corresponding first vacuum valve Ma via a wiring (not shown).

  A three-phase current limiting resistor r is disposed in a space above the upper fixed frame 3, and the current limiting resistor r is connected between the second vacuum valve Mb of each phase and the odd tap selector. In FIG. 2, the three-phase current limiting resistor r, the odd tap selector, and the even tap selector are omitted.

  When the three-phase selector switch SW is switched to the odd tap selector T1, the vacuum valves Ma and Mb are closed, and the odd tap is selected, the drive shaft 4 is slightly over the first position. It is in. At this time, the first stopper portion 31a1 is located slightly beyond the position in contact with the auxiliary cam follower 32 (the position shown in FIG. 3) in the counterclockwise direction.

  When the tap is switched from this state to the even-numbered tap, the energy storage spring 6 is stored by the power storage mechanism 7. At this time, as shown in FIG. 3, the first stopper portion 31 a 1 abuts the auxiliary cam follower 32, thereby restraining the drive shaft 4 to the first position and preventing the rotation of the drive shaft 4. Make it progress. When the accumulating of the accumulating spring 6 is completed, the force transmitted from the accumulating spring 6 to the auxiliary cam 31 through the drive shaft 4 exceeds the pressing force applied from the spring 33 to the auxiliary cam follower 32, and the stopper portion Since the engagement between 31a1 and the auxiliary cam follower 32 is disengaged, the auxiliary cam 31 starts to rotate together with the drive cam 16 and the drive shaft 4, and the energy accumulated in the accumulator spring 6 is released all at once. As indicated by the arrow 4, it rotates clockwise at once. In the process of rotation of the drive shaft 4, the drive cam 16 opens the first vacuum valve Ma and causes a load current to flow through the current limiting resistor r. Next, after switching the three-phase selector switch SW to the tap selector T2 side without arcing, the first vacuum valve Ma is closed, the vacuum valve Mb is opened, and the tap switching is finished. When the tap switching is finished and the auxiliary cam follower 32 has exceeded the second stopper portion 31a2 of the auxiliary cam 31 (the position where the stopper portion 31a2 is in contact with the auxiliary cam follower 32 is slightly overclockwise), the drive is performed. The axis 4 stops.

  When the tap is switched from this state to an odd-numbered tap, the accumulator spring 6 is again energized by the accumulator mechanism 7. At this time, when the second stopper portion 31a2 contacts the auxiliary cam follower 32, the drive shaft 4 is constrained to the second position to prevent its rotation, and the energy accumulation of the energy accumulation spring 6 is advanced. When the energy storage of the energy storage spring 6 is completed, the force transmitted from the energy storage spring 6 to the auxiliary cam 31 through the drive shaft 4 exceeds the pressing force applied from the spring 33 to the auxiliary cam follower 32. The engagement between the stopper portion 31 a 2 and the auxiliary cam follower 32 is released, and the auxiliary cam 31 starts rotating together with the drive cam 16. In the process of rotation of the drive shaft 4, the drive cam 16 first closes the vacuum valve Mb, then opens the vacuum valve Ma and allows a load current to flow through the current limiting resistor r. Next, after the three-phase selector switch SW is switched to the tap selector T1 side without arcing, the first vacuum valve Ma is closed, and the tap switching is ended. When the tap switching is finished, the auxiliary cam follower 32 exceeds the first stopper portion 31a1 of the auxiliary cam 31 (the state where the stopper portion 31a1 is in contact with the auxiliary cam follower 32 in FIG. 3 slightly overclockwise). At this point, the drive shaft 4 stops.

  5 and 6 are schematic plan views of the adjustment cam 51 and the drive cam 16. FIG. 6 shows a state in which the drive shaft 4, the adjustment cam 51, and the drive cam 16 are rotated counterclockwise in plan view from the position shown in FIG. 5 corresponds to FIG. 3, and FIG. 6 corresponds to FIG. A plate-shaped adjustment cam 51 is fitted to the outside of the drive shaft 4 between the intermediate frame 50 and the upper fixed frame 3. The adjustment cam 51 is substantially orthogonal to the drive shaft 4. A hole penetrating vertically is formed in the adjustment cam 51, and the drive shaft 4 is inserted into the hole. A cam surface 51 a is formed on the peripheral surface of the adjustment cam 51. The cam surface 51a includes three second convex portions 51u, 51v, 51w arranged at intervals of 120 °, and a second concave portion 51c that connects these second convex portions 51u, 51v, 51w.

  The adjustment cam 51 has the same shape as the drive cam 16. As shown in FIG. 5, around the axis of the drive shaft 4, the positions of the tops of the second convex parts 51u, 51v, 51w are shifted by approximately 60 ° from the tops of the first convex parts 16u, 16v, 16w. When viewed from the axial direction of the drive shaft 4, the second convex portions 51u, 51v, 51w are superimposed on the first concave portion 16c, and the top portions of the first convex portions 16u, 16v, 16w are superimposed on the second concave portion 51c. To be arranged. In other words, the positions of the first recess 16c and the second recess 51c are different around the drive shaft 4.

  Three L-shaped levers 52 are arranged around the adjustment cam 51. Three support members 54 protrude downward from the upper fixed frame 3. The three support members 54 correspond to the three L-shaped levers 52, respectively. A corner portion of the L-shaped lever 52 is rotatably supported by the support member 54 via a rotation shaft 53 extending in a direction perpendicular to the axis of the drive shaft 4.

  A cam follower, for example, a roller follower 55 having a roller, is attached to one end of the L-shaped lever 52. A spring 56 is provided between the other end of the L-shaped lever 52 and the upper fixed frame 3. The roller follower 55 is biased toward the cam surface 51 a of the adjustment cam 51 by the biasing force of the spring 56. The roller follower 55 contacts the cam surface 51a and rolls on the cam surface 51a. The torque adjustment device includes an adjustment cam 51, an L-shaped lever 52, a rotation shaft 53, a support member 54, a roller follower 55, and a spring 56.

  7 is a partially enlarged view showing a portion surrounded by the line VII shown in FIG. 6, and FIG. 8 is a partially enlarged view showing a portion surrounded by the line VIII shown in FIG. When the drive shaft 4 rotates in the clockwise direction, as shown in FIG. 7, one cam follower 23 is pushed outward in the radial direction by the first convex portion 16u. On the other hand, as shown in FIG. 8, the one roller follower 55 corresponding to the one cam follower 23 moves in the second recess 51c and moves inward in the radial direction.

  That is, the force caused by the movement of one cam follower 23 acts on the drive shaft 4 as a torque (load torque) opposite to the direction of the torque acting on the drive shaft 4 by the biasing force of the accumulator spring 6. The force caused by the movement of the roller follower 55 acts on the drive shaft 4 as the torque (drive torque) in the same direction as the torque acting on the drive shaft 4 by the biasing force of the accumulator spring 6, and both are attenuated or offset each other. . That is, the spring 56 of the adjustment cam 51 absorbs energy with respect to the driving torque due to the movement of the cam follower 23 and releases the absorbed energy with respect to the load torque due to the movement of the cam follower 23.

  When the one roller follower 55 is pushed outward in the radial direction by the second convex portions 51u to 51w, the one cam follower 23 moves in the first concave portion 16c and moves inward in the radial direction. That is, the force due to the movement of one roller follower 55 acts as a load torque on the drive shaft 4, and the force due to the movement of one cam follower 23 acts as a drive torque on the drive shaft 4, both of which are attenuated or offset. .

  FIG. 9 is a graph showing an example of torque acting on the drive shaft 4. In FIG. 9, T <b> 1 indicates the torque acting on the drive shaft 4 due to the movement of the cam follower 23, T <b> 2 indicates the torque acting on the drive shaft 4 due to the movement of the roller follower 55, and T <b> 3 and T <b> 4 are driven by the accumulating spring 6. Torque acting on 4 is shown. The vertical axis represents each torque. The horizontal axis indicates the rotation angle of the drive shaft 4. In the torques T <b> 1 and T <b> 2, positive torque indicates load torque that acts on the drive shaft 4, and negative torque indicates drive torque that acts on the drive shaft 4. In the torques T3 and T4, a positive torque indicates a drive torque that acts on the drive shaft 4, and a negative torque indicates a load torque that acts on the drive shaft 4.

  As shown in FIG. 9, for example, the roller follower 55 is pushed radially outward by the second convex portions 51 u to w at a substantially angle of 15 to 25 degrees or approximately 55 to 65 degrees, and the cam follower 23 is the first. When the concave portion 16c is moved and moved inward in the radial direction, load torque acts on the drive shaft 4 by movement of the roller follower 55, and drive torque acts on the drive shaft 4 by movement of the cam follower 23. Attenuated or offset. That is, it is possible to prevent an extreme increase in the combined torque acting on the drive shaft 4.

  Further, for example, the cam follower 23 is pushed outward in the radial direction by the first convex portion 16u at a substantially angle of 27 degrees to 37 degrees or approximately 67 degrees to 77 degrees, and the roller follower 55 moves in the second concave portion 51c, When moving inward in the direction, load torque acts on the drive shaft 4 due to movement of the cam follower 23, and drive torque acts on the drive shaft 4 due to movement of the roller follower 55, both of which are attenuated or offset.

  As the rotation of the drive shaft 4 progresses, the energy stored in the energy storage spring 6 decreases. That is, as shown in FIG. 9, the torque T <b> 3 due to the energy storage spring 6 decreases as the rotation of the drive shaft 4 proceeds. Therefore, for example, when the torque T3 decreases and the load torque is applied to the drive shaft 4 due to the movement of the cam follower 23 at approximately an angle of 27 to 37 degrees or approximately 67 to 77 degrees, the combined torque is extremely decreased. Therefore, the drive shaft 4 may stop due to zero or a negative value.

  However, the drive torque acts on the drive shaft 4 by the movement of the roller follower 55. That is, even if the force due to the movement of the cam follower 23 acts as a load torque, the force due to the movement of the roller follower 55 acts as a drive torque, and the load torque is attenuated. Therefore, the combined torque acting on the drive shaft 4 is positive. Easy to keep the value. Therefore, the drive shaft 4 can continue rotating without stopping until it is locked by the stopper portion 31a1 or 31a2. That is, the tap switching device 100 can prevent the combined torque from being extremely reduced, and can continue the rotation of the drive shaft 4.

  Conventionally, the torque generated by the urging force of the accumulator spring 6 is set to such a magnitude that the drive shaft 4 does not stop even when a load torque acting by the movement of the cam follower 23 is applied, for example, the torque T3. In the present embodiment, as described above, the torque T1 generated by the movement of the cam follower 23 is attenuated or offset by the torque T2 generated by the movement of the roller follower 55. Therefore, for example, the torque generated by the urging force of the energy storage spring 6 can be set to a torque T4 that is smaller than the torque T3. Since the torque due to the urging force of the energy storage spring 6 can be reduced, the strength required for the drive device 5 is reduced, and the drive device 5 can be reduced in size. Moreover, the structure of the components which comprise the drive device 5, for example, the energy storage spring 6, can be simplified, and the manufacturing cost of the tap switching apparatus 100 can be reduced.

  In the torque adjusting device and tap switching device 100 according to the embodiment, the torque due to the rotation of the drive shaft 4 can be adjusted. Moreover, the rotational speed of the drive cam 16 can be adjusted, and the opening and closing of the vacuum valves Ma and Mb and the switching of the changeover switch SW can be executed at a predetermined timing.

  The roller follower 55 is in contact with the adjustment cam 51 by the biasing force of the spring 56. The roller follower 55 moves along the cam surface 51a formed on the peripheral surface of the adjustment cam 51, and the spring 56 absorbs or releases energy with respect to the torque generated by the movement of the cam follower 23, thereby driving the drive shaft. The torque around 4 can be adjusted.

  Further, around the drive shaft 4, the positions of the first recess 16 c of the drive cam 16 and the second recess 51 c of the adjustment cam 51 are different. The cam followers 23 and 55 are prevented from moving simultaneously in the first recess 16c and the second recess 51c, respectively, and an extreme increase or decrease in torque can be prevented.

  Further, in the circumferential direction of the drive shaft 4, at least a part of the first protrusions 16u, 16v, 16w overlaps the second recess 51c, and at least a part of the second protrusions 51u, 51v, 51w overlaps the first recess 16c. . Therefore, the torque generated by the drive cam 16 is easily canceled by the adjustment cam 51, and the power supplied to the drive shaft 4 can be reduced. As a result, it is possible to promote downsizing of the structure for supplying power, promote downsizing of the tap switching device 100, and reduce the manufacturing cost of the tap switching device 100.

  The positions of the first convex portions 16u, 16v, 16w, the first concave portion 16c, the second convex portions 51u, 51v, 51w, and the second concave portion 51c shown in the above embodiment are merely examples, and the first convex portions The portions 16u, 16v, 16w, the first concave portion 16c, the second convex portions 51u, 51v, 51w, and the second concave portion 51c can be set at arbitrary positions. The torque adjusting device described above can also be applied to devices other than the tap switching device 100, and the torque in the device can be adjusted. Further, a torque adjusting device may be used not only for reducing or canceling torque but also for increasing torque.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and a scope equivalent to the scope of the claims. Is done.

4 Drive shaft 16 Drive cam 16c 1st recessed part 16u, 16v, 16w 1st convex part 51 Adjustment cam 51a Cam surface 51c 2nd recessed part 51u, 51v, 51w 2nd convex part 52 L-shaped lever (connection member)
55 Roller Follower (Cam Follower)
56 Spring (Biasing member)

Claims (4)

A drive shaft that rotates about an axis;
An adjustment cam that fits outside the drive shaft and adjusts the torque;
A cam follower that contacts the circumferential surface of the adjustment cam;
A biasing member that biases the cam follower toward the adjustment cam;
A torque adjusting device comprising: a connecting member that connects the urging member and the cam follower and is rotatable about an axis that intersects the drive shaft. A drive shaft that rotates about an axis;
A drive cam for engaging the outside of the drive shaft and switching the tap;
An adjustment cam that fits outside the drive shaft and adjusts the torque;
A cam follower that contacts the circumferential surface of the adjustment cam;
A biasing member that biases the cam follower toward the adjustment cam;
A tap switching device comprising: a connecting member that connects the biasing member and the cam follower and is rotatable about an axis that intersects the drive shaft. A first recess is formed on the peripheral surface of the drive cam;
A second recess is formed on the peripheral surface of the adjustment cam;
The tap switching device according to claim 2, wherein the position of the first recess is different from the position of the second recess around the drive shaft. A first convex portion is formed on the peripheral surface of the drive cam,
A second convex portion is formed on the peripheral surface of the adjustment cam,
Around the drive shaft, the position of at least a part of the first convex portion is the same as the position of the second concave portion,
4. The tap switching device according to claim 3, wherein at least a portion of the second convex portion has the same position as the first concave portion around the drive shaft.

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