JPH0440819B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a time switch that can be applied to microwave ovens, washing machines, etc. and performs intermittent on/off operations.

(Prior art) In some microwave ovens, the heating operation is turned on and off intermittently in the defrosting mode, and in some washing machines, the motor for generating water flow is intermittently turned forward and backward; A time switch is used to make this happen. In recent years, the on/off time or forward/reverse time within one cycle has been changed so that thawing and washing can be performed appropriately even when the object to be thawed or the amount of laundry changes, or various other conditions vary. A so-called switching timer, which can switch the timer, has come into use.

The invention described in Japanese Patent Application Laid-Open No. 60-211724 is a switching timer, in which a switching contact is arranged between a first contact and a second contact, and the switching contact is oscillated by a crank mechanism driven by a clock mechanism. Let me be the first
The contact and the second contact are brought into contact alternately, and the on time or off time within one cycle is changed by changing the interval between the switching contact and the first contact and the second contact.

Also, JP-A-60-207227 or JP-A-60-
Like the invention described in Publication No. 205934, it has a fixed contact and a movable contact, a cam that connects and separates these contacts intermittently, and an operating cam that switches on and off times within one cycle, There is also a device in which the on/off time within one cycle is switched by changing the spacing between the contacts by selectively bringing contacts into contact with the high-step portion and the low-step portion of the operating cam.

(Problems to be solved by the invention) According to what is described in Japanese Patent Application Laid-Open No. 60-211724,
Since there is a limit to the range in which the switching contact can be moved, the on and off times cannot be changed significantly.

The devices described in JP-A-60-207227 and JP-A-60-205934 also have a range in which the distance between the fixed contact and the movable contact can be changed by selecting the high step portion and the low step portion of the operating cam. is limited to a narrow range, so the on and off times cannot be changed significantly. Further, the contact pressure and the mutual spacing between the contacts change by switching the on/off time.

The present invention has been made to solve these conventional problems, and instead of switching the on/off time by changing the interval between the contacts, the present invention is linked to a clock mechanism and has movable contacts. By forming the working surfaces of the contacting cams separately for one intermittent operation and another for intermittent operation, and using them selectively, it is possible to greatly change the on/off time within one cycle. It is an object of the present invention to provide a time switch in which the contact pressure and the distance between the contacts are kept constant even when the on/off time is switched.

(Means for Solving the Problems) The present invention includes a cam rotatably disposed on a machine frame, and a plurality of contact plates having one end fixed to the machine frame, and the plurality of contact plates At least one other end of the time switch constitutes a movable contact plate that swings in response to rotation of the cam, and this movable contact plate and another contact plate constitute a switch element, The cam has first and second working surfaces having different concave and convex shapes superimposed in the axial direction, and moves a driven part of the movable contact plate relative to the cam in the axial direction, The movable contact plate is characterized in that it is provided with a working surface switching operation mechanism that switches between a state in which the movable contact plate can be driven by the first working surface of the cam and a state in which it can be driven by the second working surface of the cam.

(Function) When the cam rotates, the movable contact plate swings following the action surface of the cam, and the switch element including the movable contact plate approaches and separates, turning on and off intermittently. When the driven part of the movable contact plate is moved relative to the cam in the axial direction, the movable contact plate moves between a state in which it can follow the first working surface of the cam and a state in which it can follow the second working surface of the cam. Can be switched. Since the first working surface and the second working surface have different uneven shapes, the intermittent on/off operation times vary.

(Example) Hereinafter, an illustrated example configured as a time switch for a washing machine will be described.

In FIGS. 1 to 5, reference numerals 10 and 11
are machine frames that form the case of the time switch by fitting into each other. The machine frame 11 is formed with a barrel section 110 that houses the Zenmai 20 as a drive source. The barrel section 110 has a hole formed therein for inserting the Zenmai 20. One side edge of the machine frame 10 extends outward to form a waterproof wall 103,
External connection terminals are arranged across this waterproof wall 103. This is to prevent water from entering from the time setting knob side, that is, from the operation panel side of the washing machine, and protect the external connection terminals from water. .

A tube shaft portion 101 is formed in the machine frame 10, and a main shaft 15 is rotatably fitted into the tube shaft portion 101 with play. A protrusion 150 at the upper end of the main shaft 15 is loosely fitted into a shaft support formed at the center of the inner ceiling of the barrel 110 of the machine frame 11. In the figure, the lower end of the main shaft 15 protrudes outward from the machine frame 10, and a time setting knob (not shown) is attached thereto.

A main gear 16 is fitted at the upper end of the main shaft 15 so as to be relatively rotatable, and a friction plate 1 is disposed below the main gear 16.
9 is fitted. One side of the friction plate 19 is the main shaft 1
5, and the other surface is in pressure contact with the main gear 16. The main gear 16 is formed with an engagement recess 160, and the friction plate 19 is formed with an engagement protrusion 190 that can engage with the engagement recess 160. When the main gear 16 and the friction plate 19 rotate relative to each other, The engagement recess 16
0 and the engagement protrusion 190 engage with each other, and the main gear 16 and the friction plate 19 can rotate together. The main gear 16 has a hook portion 161 for latching the starting end of the Zenmai 20.
are integrally provided. The starting end of the Zenmai 20 is inserted into the barrel 110 through the hole formed in the barrel 110, and the through hole at the starting end of the Zenmai 20 is inserted into the hook portion 1.
It can be hung on 61. When the main shaft 15 is rotated in this state, the entire barrel 20 is rolled into the barrel 110, and the terminal end of the entire barrel 20 is latched to a latching portion of the machine frame 10 near the insertion hole.

A shaft 13 is supported on the side of the main shaft 15 between the machine frames 10 and 11 in parallel to the main shaft 15. axis 1
A large-diameter gear 23 is rotatably supported by 3, and a small-diameter gear 22 is rotatably supported around the boss portion of this large-diameter gear 23. Small diameter gear 2
2 meshes with the main gear 16. Large diameter gear 23
has ratchet teeth 230 on the inside, and a ratchet pawl at the tip of an elastic arm 220 integrally molded with the small diameter gear 22 from resin engages with the ratchet teeth 230. In this way, when the main shaft 15 is rotated in the time setting direction, the rotational force of the gear 22 is not transmitted to the gear 23 between the small diameter gear 22 and the large diameter gear 23, and the entire biasing force is applied to the main shaft 15. When rotating in the opposite direction, the rotational force of gear 22 is transferred to gear 23.
A one-way clutch 21 is configured to transmit power to the vehicle.

Another shaft 14 is supported on the side of the shaft 13 between the machine frames 10 and 11 in parallel to the shaft 13. axis 1
4 rotatably supports a gear 24 in which a small diameter gear portion 241 and a large diameter gear portion 242 are integrally molded. The large diameter gear 23 meshes with a small diameter gear portion 241 of the gear 24. The large diameter gear portion 242 of the gear 24 is connected to the large diameter gear 23 on the shaft 13.
The small diameter gear portion 251 of the gear 25 is rotatably supported on the lower side of the gear. The gear 25 is formed by integrally molding the small diameter gear 251 and the large diameter gear portion 252. A shaft 65 and a shaft 67 are also supported parallel to the shaft 13 between the machine frames 10 and 11. The shaft 65 rotatably supports the flywheel 26, which is formed by integrally molding a small-diameter gear portion 261 and a ratchet ring portion 262 having a larger diameter than the small-diameter gear portion 261. The small diameter gear portion 261 of the flywheel 26 meshes with the large diameter gear portion 252 of the gear 25. The rotational force of the main gear 16 is transmitted to the speed increasing gear train 22.
-23-241-242-252-251-26
1 and is transmitted to the goose wheel 26, causing the goose wheel 26 to rotate at high speed. Ratchet ring part 26 of Gangi car 26
2 includes an ankle 2 of the pendulum 27 which is rotatably supported by the shaft 67 and integrally includes a pendulum plate 270.
72 (see Figure 5) are engaged. pendulum 27
is reciprocally rotated by the rotation of the goose wheel 26 in one direction, thereby controlling the rotational speed of the speed increasing gear train and the main shaft 15 to be constant. The gear 24, the gear 25,
A clock mechanism 28 is constituted by the goose wheel 26 and the pendulum 27.

Here, the operation of the above-mentioned mechanical parts will be explained. When the main shaft 15 is turned in the time setting direction, the engagement protrusion 190 of the friction plate 19 and the engagement recess 1 of the main gear 16
60 engages with the main gear 16, the main gear 16 rotates integrally, and the whole gear 20 connected thereto is wound up, accumulating biasing force. In this case, the ratchet pawl at the tip of the elastic arm 220 of the one-way clutch mechanism 21 slides against the ratchet teeth 230 of the large diameter gear 23, and no rotational force is transmitted to the clock mechanism 28. On the other hand, when the main shaft 15 is manually returned to the direction opposite to the time setting direction, a slip occurs between the friction plate 19 and the main gear 16, and the main gear 16 does not rotate and the main shaft 1
Only 5 returns.

When the Zenmai 20 is stored as described above, the main gear 16 is driven to rotate in the opposite direction to the time setting direction by the stored power, and the rotational force is transmitted to the main shaft 15 by the frictional force of the friction surface. The main shaft 15 is driven to rotate. In this rotation, the one-way clutch 21
The ratchet pawl is locked to the ratchet tooth 230, and the small diameter gear 22 and the large diameter gear 23 rotate together to transmit rotational force to the clock mechanism 28. Therefore, the clock mechanism 28 rotates in the opposite direction to the time setting direction, The rotation of the full movement 20 in the unwinding direction is adjusted to a constant speed. The friction clutch consisting of the main gear 16 and the friction plate 19 transmits the rotational force between them within the limit of the rotational force due to the unwinding of the main shaft 15, and the rotational force exceeding a certain level, such as when the main shaft 15 is returned manually, is Don't communicate.

A buzzer cam 17 is fitted and fixed to the main shaft 15 below the main gear 16, and a main cam 18 is rotatably fitted below the main gear 16. As also shown in FIG. 14, the buzzer cam 17 and the main cam 18 are superimposed on each other with the center axis of the main shaft 15 as a common rotation center axis. The buzzer cam 17 has an active surface consisting of a high step part 172 occupying most of the outer circumference and a low step part 173 formed in a part of the outer circumference, and has a protrusion 175 protruding in the axial direction on the lower surface side. The main cam 18 also has a high step portion 182 that occupies most of the outer circumference and a low step portion 183 formed in a part of the outer circumference, and also has a center hole 180 along the outer circumference of the tube shaft portion 101 of the machine frame 10, and a center hole 180 along the outer circumference of the tube shaft portion 101 of the machine frame 10. It has an engagement recess 181 formed by cutting out a part of 180.

When the buzzer cam 17 and the main cam 18 are overlapped, the protrusion 175 of the buzzer cam 17
The two cams 17, 1 fit into the recesses 181 of 8.
Circumferential play is provided between the protrusion 175 and the recess 181 so that the cams 17 and 18 can rotate relative to each other within a predetermined range in this state. Therefore, when the main shaft 15 is rotated, the cam 17 rotates in advance and the cam 18 does not rotate until the protrusion 175 pushes the end of the engagement recess 181. The protrusion 175 fits into the engagement recess 181
After engaging with the end portions of the cams 17 and 18, the cams 17 and 18 rotate together. Furthermore, in the state in which the cams 17 and 18 are superimposed as described above, the low step portions 173 and 183 of each cam 17 and 18 substantially overlap. Note that the low step portion 173 of the cam 17 is formed over a somewhat wider range than the low step portion 183 of the cam 182. When assembling, main cam 18
is rotatably fitted to the outer circumferential side of the tube shaft portion 101 of the machine frame 10, and the main shaft 15 having an integral buzzer cam 17 is fitted so that the buzzer cam 17 overlaps the main cam 18 and the protrusion 175 and the recess 181 fit together. In this way, the main shaft 15 is attached to the tube shaft portion 101 of the machine frame 10.
into.

In FIG. 14, a plurality of elastic contact plates 31, 32, 3 are connected to the cam 17 and the cam 18.
Switch elements 3, 34, and 35 are arranged facing each other. One end of each of the plurality of contact plates is fixed to an insulating base 69 by integral molding, and this insulating base 69 is fixed to the machine frame 10. The other end of each contact plate constitutes a switch element that is moved into contact and separation by swinging following the cams 17 and 18.

The contact plate 31 is driven by the cam 18 via a driven member 41 integrally molded with the contact plate 31, and constitutes a first switch element that comes into contact with and separates from the contact plate 32. This switch element is turned on when the driven portion 411 at the tip of the driven member 41 faces the high step portion 182 of the cam 18, and turned off when it falls into the low step portion 183.

The contact plate 33 is connected to the cam 1 via the driven lever 42.
7 and constitutes a second switch element that connects and separates from the contact plate 32. The driven lever 42 is rotatable around a shaft 691 formed on the insulating base 69, and is connected to the driven portion 421 of the cam 17 and the contact plate 33.
It has abutment portions 422 on both sides of the tip. The second switch element is the driven part 421 of the lever 42.
When the cam 17 faces the high stage part 172, it is turned on, and when it falls into the low stage part 173, it is turned off.

The contact plate 34 is driven by the cam 18 via the slide lever 43 which is driven by the movement of the driven member 41, and constitutes a third switch element that contacts and separates from the contact plate 35. The slide lever 43 slides along a guide groove 105 formed in the machine frame 10.
The contact plate 34 is pushed toward the contact plate 35 by the protrusion 431 formed in the contact plate 3 . The lever 43 follows the movement of the driven member 41 by loosely fitting the pin portion 412 of the driven member 41 into the hole 432 of the slide lever 43 .

The first switch element and the third switch element each constitute a main switch 90, and the
As shown in the figure, a power supply 77 and a water flow generation motor 79
and are connected in series on both sides of the motor 79, respectively. The first and third switch elements perform the same contact/separation operation and are turned on and off at the same time.

The second switch element constitutes a buzzer switch 91. Buzzer switch 91 is connected in series to power supply 77 and buzzer B (not shown), as shown in FIG. The main switch 90 and the buzzer switch 91 are operated in the time setting direction (first direction) of the main shaft 15.
4), the cam 17 moves forward due to the play between the protrusion 175 and the engagement recess 181, so the contact plate 33 separates from the contact plate 32 first. , the buzzer does not sound. On the other hand, the main shaft 15 is in the 14th position with the accumulated power of Zenmai 20.
When rotating clockwise as shown by the solid arrow in the figure, the cam 17 returns first within the range of play, so
The contact plate 33 contacts the contact plate 32 for a predetermined time before the main switch 90 is turned off, and the buzzer sounds for a short time to notify the end of the washing operation. One end of each contact plate 31, 32, 33, 34, 35 projects outward from the insulating base 69 and serves as an external connection terminal.

The base end of the contact plate 31 is connected to a reversing switch which will be described later. A pendulum stop piece 44 is fixed to the tip of the contact plate 32 by resin molding.
When the contact plate 32 is in its natural state, the same contact plate 32
is spaced apart from the contact plate 31, and the stop pin 2 is formed to protrude from the lower end of the pendulum 27 as shown in FIG.
The pendulum stop piece 44 comes into contact with the pendulum 71, stopping the swinging of the pendulum 27 and stopping the drive system of the time switch. When the driven portion 411 of the driven lever 41 faces the high step portion 182 of the cam 18, the contact plate 31 contacts the contact plate 32 while urging the contact plate 32 outward in the radial direction of the cam 18. are bent in the same direction, but the driven part 411 is bent in the same direction as the lower part 18 of the cam 18
3 and the contact plate 31 separates from the contact plate 32, the contact plate 32 returns to its original position due to its own elasticity, and its pendulum stop piece 44 contacts the stop pin 271 as described above.

In FIGS. 2, 5 to 8, the shaft 1
4 includes a reversing cam 50 whose boss portion engages with the boss portion of the gear 24 to rotate integrally with the gear 24;
is supported below the gear 24. Reversing cam 5
0 is a multilayer cam having four layers of working surfaces with different uneven shapes on the outer periphery in the axial direction, in order from the top: a first working surface 51, a second working surface 52, a third working surface 53, a fourth working surface. It has a working surface 54 and is made by integral molding of resin or the like. As shown in FIG. 6, the first working surface 51 consists of a high step portion 511 that occupies most of it and a low step portion 512 that remains. On the other hand, as shown in FIGS. 6 and 7, the second working surface 52 is a high step portion 5 formed over approximately half the circumference.
21 and a low step portion 522 formed over about the remaining half circumference. Each working surface 51, 52 has a depressed portion 501 extending from a high level part to a low level part at the same position.
is formed. Like the first working surface 51, the third working surface 53 also has a high step portion 531 that occupies the majority and a remaining low step portion 532, and is formed in line symmetry with respect to the first working surface 51. Similarly to the second working surface 52, the fourth working surface 54 has a high step portion 541 and a low step portion 542 extending approximately half the circumference, and is formed in line symmetry with the second working surface 52. Each working surface 53,
54, a depressed portion 503 extending from a high step portion to a low step portion is formed at the same position.

1, 4, and 6, the bases of a plurality of elastic contact plates 36, 37, and 38 are fixed to the machine frame 10 via an insulating base 550.
The contact plate 38 is connected to the contact plate 32,
The tip of the contact plate 38 is bent at right angles in a direction across the other contact plates 36 and 37 in the width direction, and a contact 39 is provided at a position facing each contact plate 36 and 37. , 40 are fixed.
The contact plates 36 and 37 constitute a movable contact plate,
Contacts 361 and 371 that can come into contact with the contacts 39 and 40 are fixed to the tip thereof. As shown in FIG. 18, the contact plates 36 and 37 are connected to the normal rotation terminal and the reverse rotation terminal of a water flow generation capacitor motor 79, respectively. In this embodiment, the contact plate 36 and the contact plate 38 constitute a forward rotation switch 55, and the contact plate 37 and the contact plate 38 constitute a reverse rotation switch 56.

The first working surface 51 or the second working surface of the reversing cam 50
A driven portion 611 at the tip of the driven lever 61 is placed on any selected working surface of the working surfaces 52 of the driven lever 61.
are in sliding contact. Further, the driven portion 621 of the driven lever 62 is in sliding contact with any selected one of the third working surface 53 and the fourth working surface 54 of the reversing cam 50 . Each driven lever 61, 62
The reversing cam 50 with which the driven parts 611 and 621 of
The working surface is selected by the working surface switching operation mechanism described later, and when the driven part 611 faces the working face 51, the driven part 621 always faces the working face 53, and the driven part 611 always faces the working surface 53. When facing the surface 52, the driven portion 621 always faces the working surface 54. Bases 613, 6 of each driven lever 61, 62
23 is formed with a shaft hole, and by loosely fitting this shaft hole into the lever shaft 63, each driven lever 61, 62 is driven by the rotation of the reversing cam 50 and rotates the shaft 6.
It swings individually around 3. A contact plate operating portion 612 is formed protruding from the driven lever 61 on the opposite side of the driven portion 611, and similarly a contact plate operating portion 622 is formed protruding from the driven lever 62. When the driven levers 61 and 62 swing following the reversing cam 50, the respective contact plate operating sections 612 and 622 swing the respective movable contact plates 36 and 37. When the driven part 611 of the driven lever 61 faces the low stage part 512 or the low stage part 522 of the reversing cam 50, the contacts 361 and 39 of the contact plates 36 and 38 come into contact, turning on the forward rotation switch 55, and the high stage is turned on. When confronting parts 511 and 521, normal rotation switch 55 is turned off. Further, when the driven lever 62 faces the low stage portion 532 or 542 of the reversing cam 50, the reverse rotation switch 56 is turned on, and when the driven lever 62 faces the high stage portions 531, 541, the reverse rotation switch 56 is turned off. As shown in FIGS. 10 and 11, each lever 61, 62 has a
Curved portions 613 and 623 are formed along arcs substantially concentric with the arc of the cam 50, and engaging protrusions 614 and 624 are formed protruding from inside these curved portions 613 and 623, that is, on the cam 50 side, respectively. ing.

In Figures 4, 6, 9, and 12,
The bases 613, 623 of the levers 61, 62 are
It is rotatably supported within the holding cover 64 by the shaft 63 passing through the upper end 641 and lower end plate 642 of the cover 64. The shaft 63 is supported by the machine frames 10 and 11 at its upper and lower ends. A portion of the outer peripheral surface of the cover 64 is cut out to form a lever window 645, through which the bases 613, 623 of the levers 61, 62 are inserted and mounted. The window 645 is the lever 61,
It is formed within a range that does not impede the swinging of 62. The shaft 63 is located at the lower side of the lower end plate 642 of the holding cover 64.
5 is maintained. The cam 73 has a cylindrical shaft portion 71 integrally in a portion corresponding to the key point of the fan, and this shaft portion 7
The lower end of the cam 73 is loosely fitted into the shaft support 105 integrally formed on the machine frame 10 and the upper end of the shaft 71 passes through a hole in the machine frame 11, so that the cam 73 is centered around the shaft support 105. It is possible to rotate.
A base portion of a manual operating lever 74 is fitted and fixed to the upper end portion of the shaft portion 71 protruding from the machine frame 11. The shaft portion 71 is located inside the curved portions 613, 623 of the levers 61, 62. Shaft part 7
An engaging jetty 712 is formed on the outer periphery of 1 so as to extend along the axial direction and protrude in the radial direction. When the shaft portion 71 is rotated by operating the operating lever 74, this jetty 712 engages the engaging protrusions 61 and 62 of the levers 61 and 62.
1,624, and the same engaging protrusion 614,
624 is pushed by the jetty 712, and the levers 61 and 62 are rotated and separated from the action surface of the reversing cam 50. At this time, the levers 61 and 62 are
1,621 is each high step part 511, 52 of the cam 50
The lever is moved to the same position as when facing 1,531,541 or further outward. When the shaft portion 71 further rotates, the engagement protrusion 61
4, 624 and the engagement jetty 712 are separated and do not interfere with each other, and the levers 61, 62 return to rotation due to the elasticity of the contact plates 36, 37, and the driven portion 61
1,621 comes into contact with the working surface of the reversing cam 50.

The long hole 75 is formed at the tip edge of the cam 73 along an arc centered on the shaft support 105, and the shaft 63 passes through this long hole 75, thereby restricting the rotation range of the cam 73. be done. Note that a protrusion for regulating the rotation cup of the cam 73 is also formed on the machine frame 10 side. A cam surface 72 is provided around the elongated hole 75.
is formed with a lift in the axial direction. The cam surface 72 has a high step portion 721 and a low step portion 722 at both ends, and has an inclined surface 723 connecting the two at the middle portion.

The lower end plate 642 of the holding cover 64 is in sliding contact with the cam surface 72. Upper end plate 64 of holding cover 64
A coil spring 65 is interposed between 1 and the machine frame 11, and the elasticity of the spring 65 causes the holding cover 64 to
A lower end plate 642 is pressed against the cam surface 72. When the operation lever 74 is rotated, the cam 73 rotates integrally, and the lower end plate 6 of the cover 64 is rotated.
The cam surface 72 with which 42 is in sliding contact is switched to a high step portion 721 or a low step portion 722 via an inclined surface 723,
In cooperation with the coil spring 65, the cover 64 and the levers 61, 62 held within the cover 64 move up and down along the shaft 62.

In this way, the lower end plate 642 of the cover 64 is attached to the cam 7.
When the lever 6 is in contact with the high step 721 of 3.
1 and 62 are located above against the spring 65, and the driven parts 611 and 621 of the levers 61 and 62 are connected to the reversing cam 5.
0, respectively. In addition, the lower end plate 642 of the cover 64
When the levers 61 and 62 are in contact with the low step portion 722 of the cam 73, the levers 61 and 62 are in the lower position due to the biasing force of the spring 65, and the driven portions 611 and 62 of the levers 61 and 62
1 faces the second working surface 52 and the fourth working surface 54 of the reversing cam 50, respectively.

In addition, during the rotation operation of the operation lever 74, the engagement jetty 712 of the shaft portion 71 and each lever 6
The levers 61 and 62 are rotated by contact with the engagement protrusions 614 and 624 of No. 1 and 62, and the respective driven portions 611 and 621 are released outward in the radial direction of the cam 50, and the shaft of the cam 50 is rotated. This prevents the driven parts of the levers 61, 62 from being caught by the step portions of the respective operating surfaces 51, 52, 53, 54 when moving in the direction.

An engaging jetty 646 is formed on the outer periphery of the cover 64 in the axial direction. This engagement jetty 646 fits into the guide groove 108 formed in the machine frame 10, and the cover 64 is supported movably along the guide groove 108 but not rotatable around the shaft 63. .

The above operating lever 74, cam 73, holding cover 6
4 and the like are a lever 61 which is a driven part of the movable contact plates 36 and 37 with respect to the reversing cam 50,
62 is moved relative to the cam 50 in the axial direction, and the movable contact plates 36 and 37 are switched between a state in which they can follow one working surface of the cam 50 and a state in which they can follow another working surface. It constitutes a switching operation mechanism 70.

However, it is not essential to use the cam 73 to switch the operating surface of the reversing cam that the movable contact plate slides on, and the driven part of the movable contact plate may be directly moved without using the cam 73. death,
The reversing cam may be moved relative to the movable contact plate. Further, the holding cover 64 can also be omitted.

Now, when the main shaft 15 is rotated to set a time limit, the speed-increasing gear train is rotationally driven as described above by the biasing force of the Zenmai 20, and the main shaft 15 is rotated at a constant speed by the operation of the clock mechanism 28. It is rotated at the same speed in the opposite direction to the time setting direction. The boss portion of the reversing cam 50 is engaged with the boss portion of the gear 24 in the speed increasing gear train, and the reversing cam 50 is rotated integrally with the gear 24 at a relatively high speed. When the reversing cam 50 rotates, the driven parts 6 of the levers 61 and 62
The working surface of the cam 50 that the cams 11 and 621 face alternately switches between a high stage part and a low stage part, and the driven part 61
When the driven parts 611 and 621 face the high stage part, the switch elements 55 and 56 are turned off, and when the driven parts 611 and 621 face the low stage part, the switch element 56 is turned on.

Here, the driven parts 611, 6 of the levers 61, 62
21 faces the first working surface 51 and the third working surface 53 of the reversing cam 50. Most of the outer periphery of the two working surfaces 51 and 53 is the high step part 51.
1,531, the remaining small portion of the outer periphery is low step portions 512, 532, and these low step portions 51
Since the phases of 2,432 are 180 degrees out of phase, the switch element 55 and the other switch element 56 alternately turn on and off with a phase difference of 180 degrees. FIG. 16 shows the operation of these switch elements, where a indicates the operation of the switch element 55, and b indicates the operation of the switch element 5.
6 and c shows the reversing operation of the motor 79 in FIG. 18 by the switch elements 55 and 56.
As shown in FIGS. 16a and 16b, the switch element 5
5 and 56 are turned on and off alternately at a constant cycle with a phase difference of 180 degrees. Since the low step portions 512, 532 of the working surfaces 51, 53 of the cam 50 are formed in narrow ranges, the ON time width a of the switch elements 55, 56 becomes shorter, and the OFF time width becomes longer. Therefore, if the switch element 55 is used for forward rotation of the motor 79 in FIG. 18, and the switch element 56 is used for reverse rotation, the motor 79 rotates in the normal direction for a relatively short period of time indicated by the width a as shown in FIG. It stops for a relatively long time indicated by width b, then reverses for a relatively short time indicated by width a, and then stops for a relatively long time indicated by width b.

Next, by rotating the operating lever 74, the cam 7
Assume that the lower end plate 642 of the holding lever 64 is brought into contact with the lower step 722 of the cam 73 as shown in FIG. 13, and the levers 61 and 62 are moved downward. As shown in FIG.
The second working surface 52 and the fourth working surface 54 are respectively opposed to each other. In this case as well, the switch elements 55 and 56 are turned on and off at regular intervals as the reversing cam 50 rotates, but the second working surface 52 and the fourth working surface 54 are formed by a raised part slightly longer than half the circumference. 521,
541 and low step portions 522, 54 slightly shorter than half the circumference
2, and since the second working surface 52 and the fourth working surface 54 are formed line-symmetrically, the switch element 55 and the other switch element 56 have a phase difference.
Operates alternately on and off at 180 degrees. FIG. 17 shows the operation of these switch elements, where a indicates the operation of the switch element 55, and b indicates the operation of the switch element 56.
c shows the reversing operation of the motor 79 in FIG. 18 by the switch elements 55 and 56. As shown in FIGS. 17a and 17b, the switch element 55,
56 is turned on and off alternately at a constant cycle with a phase difference of 180 degrees. And the working surface 5 of the cam 50
Since the low step portions 522, 542 of No. 2, 54 are formed in a range of nearly 180 degrees, the switch elements 55, 5
The ON time width b within the fixed cycle of 6 is longer than the time width a during the above-mentioned operation. Therefore, as shown in FIG. 17c, the motor 79 in FIG. 18 rotates normally for a relatively long period of time indicated by width b, then stops for a relatively short period of time indicated by width d, and then rotates normally for a relatively short period of time indicated by width b. After reversing for a long time, it stops for a relatively short time indicated by the width d.

As described above, according to the above embodiment, the working surface of the reversing cam 50 that the movable contact plate comes into contact with is formed in advance to be divided into one for intermittent operation and another for intermittent operation. By using this function, the intermittent on/off operation time of the switch element within a certain period can be changed.
The on and off times within one cycle depend on the shape of the working surface of the cam 50, and by changing the shape of the working surface of the cam 50, the on and off times can be greatly changed. Furthermore, since the on/off time is not changed by changing the distance between the movable contact plate and the fixed contact plate, the contact pressure and the contact spacing are kept constant even when the on/off time is switched.

Incidentally, FIG. 19 shows one conventional example for switching the inversion switch ON and OFF operation times within a certain period, and two switch elements 930 and 940 having different on and off times within a certain period are used. This switch element 93
By selecting either one of 0 and 940 with the external selection operation switch 920, the on/off operation time of the reversing switch is changed over. Reference numeral 77 is a power supply, 79 is a motor, 900 is a time switch, and 910 is a buzzer switch.

According to the conventional example described above, it is necessary to provide two sets of switch elements for reversal, and it is also necessary to provide an external selection operation switch for selecting the two sets of switch elements. In contrast, according to the embodiment of the present invention, a set of reversing switch elements and a reversing cam 50
Since the on/off operation time is switched by relatively moving the switch and the switch, only one switch element is required for inversion, there is no need to provide a switch for external selection operation, and wiring can be simplified.

INDUSTRIAL APPLICATION This invention can be applied not only as a defrosting timer of a microwave oven and a water flow reversal timer of a washing machine, but also to a wide range of devices that perform periodic on/off operations. Depending on the application, it is not necessarily necessary to alternately perform the normal rotation operation and the reverse rotation operation, but it is also possible to alternately perform the ON operation and the OFF operation.

(Effects of the Invention) According to the present invention, the working surface of the reversing cam that the movable contact plate comes into contact with is formed in advance into one for intermittent operation and another for intermittent operation, and these are used selectively. As a result, the on/off operation time of the switch element is changed intermittently within a certain cycle, so the on/off time within one cycle depends on the shape of the working surface of the reversing cam. The on/off time can be greatly changed by changing the shape of the working surface of the switch, and the on/off time cannot be changed by changing the distance between the movable contact plate and the fixed contact plate.
Even if the off time is changed, the contact pressure and contact spacing remain constant. Further, only one switch element for inversion is sufficient, and there is no need to provide a switch for external selection operation, which has the effect of simplifying wiring.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an embodiment of the time switch according to the present invention, Fig. 2 is a cross-sectional view showing a part of the speed increasing transmission wheel train in the above embodiment, and Fig. 3 is the above-mentioned extension including the clock mechanism. FIG. 4 is a partially sectional left side view of the above embodiment, FIG. 5 is an exploded perspective view of the above embodiment, and FIG. 6 is a cross sectional view showing another part of the speed transmission wheel train. 7 is a plan view of the reversing switch mechanism; FIG. 7 is a sectional plan view of the reversing cam in the above embodiment; FIG. 8 is a front view showing the relationship between the reversing cam and the reversing switch operated by the reversing cam; FIG. The figure is a front view of the operating surface switching mechanism in the above embodiment, FIG. 10 is a plan view showing different operating modes of the reversing switch mechanism according to FIG. 6, and FIG. 11 is a front view of the reversing switch mechanism used in the reversing switch mechanism. A plan view showing one of the levers, the first
Fig. 2 is a front view showing different operating modes of the reversing cam and reversing switch according to Fig. 8, Fig. 13 is a front view showing different operating modes of the operating surface switching mechanism section according to Fig. 9, and Fig. 14. is a plan view of the time limit switch mechanism and buzzer switch mechanism portion in the above embodiment, FIG. 15 is a plan view showing different operating modes of the above time limit switch mechanism and buzzer switch mechanism portion, and FIG. 16 is a plan view of the operation of the above reversing switch mechanism. 17 is a timing chart showing different operations of the reversing switch mechanism, FIG. 18 is a circuit diagram showing an example of electrical connection relationships applicable to the present invention, and FIG. 19 is a timing chart showing the different operations of the reversing switch mechanism. FIG. 3 is a circuit diagram showing an example of electrical connection. DESCRIPTION OF SYMBOLS 10... Machine frame, 36, 37, 38... Multiple contact plates, 50... Cam, 51, 52, 53, 54... Working surface of cam, 55, 56... Switch element, 511,
521, 531, 541...first action surface, 51
2,522,532,542...second action surface, 7
0...Action surface switching operation mechanism.

Claims (1)

[Claims] 1. A cam rotatably disposed on the machine frame, and a plurality of contact plates having one end fixed to the machine frame, at least one of the plurality of contact plates being , constitutes a movable contact plate which is disposed opposite to the working surface of the cam and whose other end swings in response to the rotation of the cam, the other contact plate of the plurality of contact plates and the movable contact plate In the time switch constituted by a switch element whose other ends are brought into contact and separated intermittently by
and a second action surface are superimposed in the axial direction, the movable contact plate moves the driven part of the movable contact plate relative to the cam in the axial direction, and the movable contact plate performs the first action of the cam. 1. A time switch comprising an operating surface switching operation mechanism that switches between a state in which the surface can be driven and a state in which the second operating surface can be driven.