JPS6334200Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement in a timer mechanism, particularly a two-speed switching type timer mechanism.

BACKGROUND TECHNOLOGY A timer mechanism is used to operate desired electrical appliances and other various devices at preset times. Control takes place.

Normally, the controllable time with a timer mechanism is determined by the motor speed and cam shape, but with conventional general timer mechanisms, the motor speed and cam rotational speed are constant, so long timer settings are not possible. If this is done, there is a problem that the accuracy of the cam operation will be lowered and a large timer error will occur.On the other hand, if the rotational speed of the cam is increased to improve the timer accuracy, there is a problem that the timer can only be set for a short time. It was hot.

Therefore, the conventional timer mechanism is currently only used in limited fields such as simple on/off operation of electric circuits.

However, in recent years, there has been a demand for not only simple on/off control for starting operation, but also various switching controls for the operating state of the device, and a timer mechanism that is compatible with this has been desired. In such a device, a first timer mechanism is used to control a relatively long period of time until the start of operation, and a second cam mechanism is used to control a short period of time from the start of operation with high precision. An example of such a timer mechanism is a timer for a rice cooker.

In other words, recent rice cookers not only automatically control the start of cooking with a timer, but also control various heating controls with a timer after the start of cooking, and thereby accurately adjust the uneven cooking time or double cooking time. , has a function that can always and stably provide good cooked rice, and various timer mechanisms have been put into practical use for this purpose.

For example, Japanese Patent Application Laid-Open No. 57-46434 discloses a timer device that performs uneven cooking and double cooking control up to and after the start of rice cooking as described above, and this allows rice to be cooked well.

However, in normal cases, it takes more than 10 hours to set the timer to start cooking rice, while the actual cooking time is several 10 minutes, and there is a big difference in the time required to start cooking and the subsequent control. For this reason, it is extremely difficult to control this using the same timer device, and even in the conventional device described above, essentially two timer mechanisms are used separately.

Therefore, conventional devices have various drawbacks such as complicated structures, larger devices, and correspondingly higher prices, and it is difficult to attach such an expensive timer to an inexpensive rice cooker. I had a problem that I couldn't do it.

Purpose of the invention The present invention was devised in view of the above-mentioned conventional problems, and its purpose is to provide an improved timer mechanism that can effectively perform the two types of timer control with different time periods described above. .

Structure of the Invention In order to achieve the above object, the present invention includes a set shaft that has a slow gear supported on a timer board and is slidable in the axial direction, and a set shaft that is meshed with the slow gear and moves the set shaft at a low speed. A low-speed gear train that is rotationally driven by a low-speed gear train, a slow-speed cam that is fixed to the set shaft and that can move the set shaft in the axial direction by cooperating with a cam groove provided on the timer board at a predetermined rotational position, a fast-cut cam that is played with the slow-speed cam and controls the first switch on and off in cooperation with the slow-speed cam; a spring that presses and biases the slow-speed cam toward the timer board; and a spring that controls the second switch on and off. A rapid cam that is loosely engaged with the shaft and has a rapid gear that can move freely in the axial direction, a high-speed gear train that rotates the rapid cam at high speed while meshing with the rapid gear, and drives a low-speed gear train and a high-speed gear train. The invention is characterized in that it has a drive motor.

Structure of Embodiment A preferred embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows a schematic configuration of a preferred embodiment in which the timer mechanism according to the present invention is used as a timer for a rice cooker. In the figure, a set shaft 14 is rotatably supported on a timer board consisting of an upper support plate 10 and a mechanism support plate (case) 12, and this set shaft 14 is used to set the rice cooking start time arbitrarily by the user. A knob (not shown) is fixed to the lower end of the set shaft 14 in the figure, and a desired rice cooking start time is set by rotating this knob. In addition, the present invention is characterized in that the set shaft 14 is rotatable and slidable in the axial direction, so that the rotation speed of the set shaft 14 can be changed as will be described later. It is possible to perform both slow rotation for a long time until the start of rice cooking and rapid rotation for a relatively long time for uneven rice cooking and twice-cooking with a single shaft.

The set shaft 14 is provided with a slow speed gear 16, and since the set shaft 14 in this embodiment is made of injection molded zinc die cast, this slow speed gear 16 is also formed integrally with the set shaft 14.

In the present invention, a low-speed gear train is provided in order to mesh with the slow-speed gear 16 and rotate the set shaft 14 at a slow speed. It includes gears 18, 20, 22, 24, and 26 that are pivotally supported between them. The gear 26 includes a slip gear 28 that meshes with the preceding gear 24, and a low-speed gear train slip portion is formed by insert molding the gear body and the slip gear 28. Therefore, even when the user rotates the set shaft 14 to set the time, this rotation can be avoided by the slip gear 28.

A rice cooking start cam 32 is fixed to the set shaft 14 so as to be able to rotate integrally therewith.
forms the slow-speed cam in the present invention, and the cam 30
The outer peripheral surface of the main rice cooking switch 31, which will be described later as a first switch in the present invention, is controlled to turn on and off, and the end surface thereof has protrusions 32a and 32 that cooperate with cam grooves 34a and 34b provided on the timer board.
b is provided, whereby the set shaft 14
The axial movement of can be controlled.

In other words, the outer cam of the rice cooking start cam 32 comes into contact with the operator 31a of the main rice cooking switch 31, and can control the main rice cooking switch 31 on and off. Moreover, as is clear from FIGS. 2 and 3, there are two circles on the end surface of the rice cooking start cam 32 with different radii.
protrusions 32a, 32b are provided, and cam grooves 34a, 34b are provided on the mechanism receiving plate 12 at positions facing the protrusions 32a, 32b, respectively.
are provided, and the projections 32a, 32b and the cam groove 3
Rice cooking starts cam 32 when 4a and 34b match.
In other words, the set shaft 14 is moved downward in FIG.

Furthermore, a quick cut cam 36 is pivotally supported on the rice cooking start cam 32 so as to be freely movable with respect to the rice cooking start cam 32 within a predetermined angle. This quick cutting cam 36
This is to control the main rice cooking switch 31 to be turned off early when the set time has been reached and the rice cooking start cam 32 has fallen downward in FIG. 1 together with the set shaft 14 as described above. That is, immediately before the setting shaft 14 moves in the axial direction shown in FIG.
The operator 31a is already in the V-groove 3 of the rice-cooking start cam 32.
2c, and its switch-off state is supported only by the cam ridge end 36a of the quick-cut cam 36. And fast cutting cam 3
6 has a protruding piece 38 on its side surface as shown in detail in FIG. 3, and this protruding piece 38 has an inclined surface 38a. In the state shown in FIG. 2, the inclined surface 38a is in a position facing the protrusion 40 provided on the mechanism receiving plate 12, and as a result, the engagement between the protrusion 40 and the protrusion piece 38 provides a quick cutting action. It will be done. That is, when the protrusions 32a and 32b of the rice-cooking start cam 32 fall from the state shown in FIGS. 2 and 3 in correspondence with the cam grooves 34a and 34b of the mechanism receiving plate 12, the quick-cut cam 36 also moves in the axial direction. , due to the contact between the projection 40 and the projection piece 38, the quick cutting cam 3
6 rotates counterclockwise in FIG. This state is shown in Figures 4 and 5, and as is clear from the figures,
The cam ridge end 36a of the quick-cut cam 36 is retracted from the operator 31a of the main rice cooking switch 31, and thereby the main rice cooking switch 31 is turned on. At this time, the rice cooking start cam 32 and the quick cut cam 36
FIG. 5 shows a state in which the protrusions 32a and 32b have moved relative to the mechanism receiving plate 12, and the protrusions 32a and 32b are aligned with the cam grooves 34a and 34.
4b, and the protruding piece 38 is understood to have moved to a position where it is in contact with the mechanism receiving plate 12.

As explained above, the set axis 1 according to the present invention
4 is understood to be movable in the axial direction by the rice cooking start cam 32 when a predetermined set time is reached.
Then, in order to perform the axial movement, the set shaft 1
A spring 42 is disposed between the spring receiving portion 14a of No. 4 and the upper receiving plate 10, and this causes the rice cooking start cam 32 to be constantly pressed toward the mechanism receiving plate 12, thereby achieving the above-mentioned settings. The set shaft 14 is axially moved downward in FIG. 1 at the time.

As mentioned above, the set timer operation until the start of rice cooking is controlled by the rice cooking start cam 32.
The timer in the present invention further has a second time control, in the embodiment, a rapid cam for performing the uneven cooking operation and the double cooking operation after the start of rice cooking, and in the embodiment, the uneven cooking and double cooking cam 44, In the embodiment, the uneven and double cooking cam 44 is connected to the set shaft 1.
4 is being played. The uneven and double-cooking cam 44 has an uneven cam portion 44a on the upper side in the axial direction in FIG. 1, and a double-cooker cam portion 44b on the lower side in the axial direction. Each of these cam parts 44a, 44
b cooperates with the unevenness switch 46 and the double boiling switch 48, respectively. The unevenness switch and the double-cooking switch 48 form a second switch in the present invention. In the embodiment, an uneven switch lever 50 is provided between the uneven cam part 44a and the uneven switch 46, and a double-cooker lever 50 is similarly provided between the double-cooker cam part 44b and the double-cooker switch 48. A switch lever 52 is provided, and via these levers 50 and 52, the uneven and double cooking cams can turn on and off the switches 46 and 48.

The uneven and double cooking cam 44 has a rapid gear 54.
By meshing this rapid gear 54 with a high-speed gear train, the uneven and double-cooking cam 44 can be rotated relatively rapidly.

The high-speed gear includes gears 56 and 58 branched from the low-speed gear described above in the embodiment, and the gear 58 meshes with the gear 20 of the low-speed gear train via the gear 56 (in the illustrated cross section, both gears 20 and 56 These gear trains cause the rapid gear 54 to rotate rapidly when it meshes with the gear 58. The rapid gear 5
4 and the gear 58 is controlled by the axial movement of the uneven and double-cooking cam 44, and this axial movement is performed by the axial movement of the set shaft 14 when the aforementioned set time is reached. .

The uneven and double cooking cam 44 is further provided with a stopper protrusion 60, and this stopper protrusion 60 is attached to a stopper portion 62 fixed to the upper receiving plate 10.
By engaging with the uneven and double-cooking cam 44, the rotational position of the uneven and double-cooking cam 44 is regulated, and as is clear from FIG.
is moving upward, the stopper protrusion 6
0 and the stopper portion 62 engage to stop the rotation of the cam 44, and during this timer operation, the cam 4
4 is understood to be slip rotating relative to the set shaft 14. On the other hand, when the cam 44 falls downward in FIG. 1 together with the set shaft 14 when the set time is reached, the engagement between the stopper protrusion 60 and the stopper portion 62 is severed, and at the same time, the rapid gear 54 moves to the gear 58 of the high-speed gear train. By engaging with cam 4,
4 will start rapid rotation.

FIG. 6 specifically shows the cam shapes of the uneven cooking cam 44 and the uneven cooking cam 44.
The shape of the uneven cam part 44a that cooperates with the double-cooker cam part 6 and the double-cooker cam part 44b that cooperates with the double-cooker switch 48 can be understood.

The switches 31, 48, and 46 described above are fastened to the case board by screws 64.

FIG. 7 shows a control circuit for a timer for a rice cooker according to the present invention, in which a drive motor 66 is provided to drive the aforementioned low-speed gear train and high-speed gear train, and this drive motor operates as described below. During rice cooking, the rotation is temporarily stopped and the rotation is restarted when switching from rice cooking to steaming operation.

In order to supply driving power to the drive motor 66, a power source 68 is connected via a rice cooker lid switch 70, a temperature switch 72, and the above-mentioned unevenness switch 46.

In addition, the rice cooker circuit is provided with three heaters for heating rice, a main heater 74 and a body heater 7.
6 and a lid heater 78, both the main heater 74 and lid heater 78 are used during normal rice cooking and double cooking, only the lid heater 78 is used during uneven cooking, and continuous heating by the lid heater 78 and the body heater 76 are used when keeping warm. intermittent heating is used.

The main heater 74 has one end connected to the main rice cooking switch 31.
The other end is connected to the temperature switch 72 via the double boiler switch 48 and to the other end of the body heater 76.

The body heater 76 is connected to the main heater 74 at its intermediate point to the contact 72a of the temperature switch 72 and to the contact 46a of the unevenness switch 46, and one end thereof is connected to the lid switch 70 via the heat retention control switch 80. ing. Further, the lid heater 78 has one end connected to the lid switch 70 and the other end connected to the main rice cooking switch 31.

The lid switch 70 is turned on by tightening the lid of the rice cooker, and the temperature switch 72 can be controlled on and off manually by the user, and the temperature is detected based on the temperature change when rice cooking is completed, that is, the evaporation of water. The heat retention control switch 80 is automatically turned on and off depending on the temperature of the rice cooker. It is understood that the other switches 31, 46 and 48 are switched and controlled by the aforementioned timer mechanism as the motor 66 rotates.

Effects of the Embodiment The embodiment of the present invention has the above configuration, and its effects will be explained in detail below using the timing chart of FIG. 8.

Timer Setting FIG. 7 shows the circuit state before rice cooking is set. The lid switch 70 is turned off due to the lid open state, and no current is supplied to the motor 66 and each heater 74, 76, 78. The timer is in the state before setting, the rice cooking start cam 32 is in the depressed state as shown in FIGS. 4 and 5, and the setting shaft 14 is in the state of being moved downward, unlike in FIG. , at this time, each switch assumes the state shown in FIG.

At time _t1 in FIG. 8, the lid is tightened to set up rice cooking, and the rice cooker is temporarily kept warm.

That is, in the state before rice cooking, the heat retention control switch 80 is in the ON state, and therefore the body heater 76 is connected to the power supply 68 from the lid switch 70, the heat retention control switch 80, the body heater 76, the main heater 74, and the main rice cooking switch 31. A heat-retaining current flows through the current path, which causes the body heater 76 to maintain heat. At this time, current also flows through the main heater 74 through the above-described current path.
4 has a lower resistance value than the body heater 76, so the heat generated by the main heater 74 is almost ignored.
It merely provides a current path. Similarly, the lid heater 78 includes the lid switch 70 and the lid heater 78.
A heat-retaining current is supplied through a current path consisting of the main rice cooking switch 31 and the main rice-cooking switch 31, and a predetermined heat-retaining effect is performed. Next, at time _t2 , the set shaft 14 shown in FIG. 1 is pushed upward to rotate the slow speed gear 16 in mesh with the gear 26 of the low speed gear train as shown in the figure, and the timer is set until the desired rice cooking starts. will be held.

By this timer setting, the main rice cooking switch 31
is in an off-operation state, the current path to the aforementioned body heater 76 and lid heater 78 is cut off, and the rice cooker is in a rice-cooking standby state. And the set axis 1
In the set state of 4, uneven and double cooking cam 4
4 does not rotate but moves the stopper projection 60 and the stopper portion 6 in the axial direction of the set shaft 14.
2 are engaged with each other to maintain the initial position, and at this time, the uneven cam portion 44a is in a state where the actuator of the uneven switch 46 has fallen into the cam as shown at _t1 to _t4 in FIG. There is.

At time _t2 , the drive current is not supplied to the motor 66, so each wheel train is in a stopped state, and the set shaft 14 is also stopped, but at time _t3 , the temperature switch 72 is manually scanned in this state. When the contact is switched to the contact 72a side, a drive current is supplied to the motor 66, whereby the set shaft 14 starts rotating at a slow speed via the low-speed wheel train.

Timer operation At the aforementioned time _t3 , the lid switch 70,
Current is supplied from the temperature switch 72 and the unevenness switch 46 to the motor 66 to start the timer operation, which causes the rice cooking start cam 32 and the quick cut cam 36 to slowly rotate together with the set shaft 14.
This slow rotation continues until a predetermined set time elapses.

Time _t4 indicates when a predetermined set time is reached, and as explained in FIGS. 2 to 5 above, the rice cooking start cam 3 is activated.
2 drops to the lower part of FIG. 1, thereby turning on the main rice cooking switch 31. Therefore, the motor 66
While the rotation of the main rice cooking switch 31 continues, the main rice cooking switch 31
When the main heater 74 and the lid heater 78 are turned on, current is supplied to the main heater 74 and the lid heater 78, and rice cooking starts. That is, the main heater 74 is connected to the lid switch 70, the temperature switch 72, the main heater 74, and the main rice cooking switch 3.
A heating current is supplied to the lid heater 78 through a current path consisting of the lid switch 70, the lid heater 78, and the main rice cooking switch 31.

At this time, since the temperature switch 72 short-circuits both ends of the body heater 76, the body heater 76 does not participate in rice cooking. Due to the above-mentioned switching of each heater and the axial movement of the set shaft 14, the rapid gear 54 of the uneven and double cooking cam 44 also meshes with the high speed gear train, whereby the cam 44 starts rotating. As is clear from FIG. 6, due to the rotation of the cam 44, time t ₅ (in the example, 2 seconds from the start of rice cooking)
(after a minute has elapsed), the irregularity cam section 44a switches the irregularity switch 46 to the contact 46b side, thereby cutting off the current supply to the motor 66 and stopping the motor 66. Stopping the motor 66 is necessary to control the rice cooking time by the temperature switch 72 in accordance with each rice cooking condition, and since the time control by the motor 66 is not appropriate for conditions that differ for each rice cooking, The rice cooking operation of the rice cooker is controlled by the temperature switch 7.
2. When the motor 66 stops, the cam 44 also stops.

The rice cooking operation described above is terminated when the temperature switch 72 is switched to the contact 72b side due to the sudden temperature rise upon completion of rice cooking, and at time _t6 , the power to the main heater 74 is cut off, thereby completing the rice cooking. .

Note that as the rice cooker temperature rises during the rice cooking operation, the heat retention control switch 80 is turned off before rice cooking is completed t ₆ , and therefore no current flows to the body heater 76 even at time t ₆ . .

Uneven operation When the temperature switch 72 is switched at time _t6 , the current supply to the motor 66 is resumed, that is, the lid switch 70, the temperature switch contact 72b, and
Current is supplied from the uneven switch contact 46b to the motor 66, which causes the cam 44 to start rotating again.

In this uneven rice cooking operation, the main rice cooking switch 31 energizes the lid heater 8 to heat the rice, thereby achieving the desired uneven rice cooking.

Double-cooking operation At an appropriate time _t7 during the above-mentioned uneven cooking operation, as shown in FIG. The heater 74 is temporarily supplied with current, and the double-cooking operation is performed for a predetermined short period of time, for example, about one minute, until time _t8 determined by the shape of the double-cooking cam portion 44b.

That is, the main heater 74 is connected to the lid switch 7.
0, temperature switch 72, double boiler switch 48,
A current is supplied through a current path consisting of the main heater 74 and the main rice cooking switch 31, thereby performing a double cooking operation in cooperation with the lid heater 8.
When this double-cooking operation is completed, the uneven cooking operation continues again, and the uneven cooking operation is performed for a time determined by the cam shape of the uneven cooking cam portion 44a from time _t8 to _t9 .

At time _t9 , the uneven cam section 44a shown in FIG. 6 reaches the position where the uneven switch 46 is turned off due to the rapid rotation of the cam 44, and the uneven switch 46 switches to the contact 46a side, thereby causing the unevenness switch 46 to turn off. Then, the power supply to the motor 66 is cut off, and the timer operation is completed. After time _t9 , a predetermined heat retention operation is performed by energizing the body heater 76 in accordance with the on/off of the heat retention control switch 80. That is, the lid heater 78 is continuously energized, and the body heater 76 is energized only when the heat retention control switch 80 is on, so that intermittent heating by the body heater 76 is performed intermittently. The main heater 74 is also included in the current path of the body heater 76 at this time, but as is clear from the above explanation, the heating by the main heater 74 can be almost ignored due to the difference in the resistance values.

In the embodiment, the start of rice cooking is controlled as the first timer operation, and for this purpose a first switch consisting of a main rice cooking switch is used, and a second switch is used.
As a timer operation, heating control is performed until the end of rice cooking, and a second switch consisting of a uniformity switch and a rice cooking switch is used for this purpose. The device can be controlled. In particular, it is extremely suitable for a single timer mechanism that performs long-term timer control until the start of operation of an electric appliance and various controls after the operation ends.

Effects of the Invention As explained above, according to the present invention, a relatively long time timer control and subsequent relatively short time control can be performed with high precision using one timer. Furthermore, according to the present invention, by combining both cam rotation and axial movement, it is possible to form an extremely small and simple timer mechanism with a small number of parts and a simplified circuit wiring process. This makes it possible to achieve various effects such as cost reduction and space reduction for the timer mounting section.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts showing a preferred embodiment of a timer for a rice cooker to which the timer mechanism according to the present invention is applied, FIG. Figure 3 is a sectional view of the main part of Figure 2, Figures 4 and 5 are a plan view and sectional view showing the state of the rice-cooking start cam at the time of starting rice cooking, and Figure 6 explains the operating state of the uneven and double-cooking cam. FIG. 7 is a circuit diagram of a rice cooker suitable for the present invention, and FIG. 8 is a timing chart for explaining the operation of the present invention. 10... Upper receiving plate, 12... Mechanism receiving plate, 14...
Set shaft, 16... Slow gear, 18-28... Gear (related gear train), 31... Main rice cooking switch, 31
a...Rice cooking switch operator, 32...Rice cooking start cam, 32a, 32b...Protrusion, 32c...V
Groove, 34...Cam groove, 36...Quick cutting cam, 38
... Projection piece, 38a ... Inclined surface, 40 ... Projection, 4
2... Spring, 44... Uneven and double cooking cam, 44a... Uneven cam section, 44b... Double cooking cam section, 46... Uneven switch, 48...
Double cooking switch, 54...Rapid gear, 56,5
8... Gear (high speed gear), 60... Stopper protrusion,
62... Stopper part, 66... Drive motor, 70
...Rice cooker lid switch, 72...Temperature switch,
74... Main heater, 76... Body heater, 78...
Lid heater, 80... heat retention control switch.

Claims (1)

[Scope of utility model registration request] A set shaft that is supported by a timer board and has a slow gear and is slidable in the axial direction, a low speed gear train that rotates the set shaft at a low speed while meshing with the slow gear, and a set shaft that is fixed to the set shaft. A slow speed cam that cooperates with a cam groove provided on the timer board at a predetermined rotational position to enable the set shaft to move in the axial direction; It has a fast-cut cam that controls on/off of the switch, a spring that presses and biases the slow-speed cam toward the timer board, and a rapid gear that is loosely connected to the set shaft and moves in the axial direction to control the on/off of the second switch. A timer mechanism that includes a freely adjustable rapid cam, a high-speed wheel train that rotates the rapid cam at high speed while meshing with a rapid gear, and a drive motor that drives the low-speed wheel train and the high-speed wheel train.