JPH0328286Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Field of Application] The present invention relates to a motor actuator for driving a driven member by the rotational force of a motor, and particularly relates to a proposal in which switching operation using a cam is ensured. [Prior Art] For example, in a refrigerator equipped with a divided freezer compartment and a refrigerator compartment, cold air cooled by a cooler is sent into the freezer compartment or the refrigerator compartment. The supply of cold air is controlled by opening and closing a butthole provided in the passage from the cooler to the freezer compartment or from the cooler to the refrigerator compartment, and a motor actuator is used as the drive source for opening and closing. There is. This motor actuator operates and stops using not only the temperature of the freezer or refrigerator compartment as an input condition but also the open/closed state of the bottle. The open/closed state of this baffle is detected by a cam driven by a motor and a corresponding switch. In other words, the switch detects the change in diameter between the high and low parts of the cam, indirectly measures the amount of rotation of the motor, and stops the motor when it has rotated a predetermined amount of rotation. Generates a signal to Therefore, when the cam stops, the switch always corresponds to the sloped portion of the cam where the diameter changes between the high and low steps. [Problems with the Prior Art] When the switch corresponds to a sloped portion where the diameter of the cam changes, the switching operation is unstable and malfunctions are likely to occur. This unstable state can be solved by making the motor rotate extra for a certain period of time after the switch is switched, using a delay circuit, etc., so that the stable part of the high or low part of the cam corresponds to the switch. It can be solved. If the switching points of the switch are set at two locations on the circumference of the cam, two corresponding delay circuits are required. Therefore, a falling edge detection circuit, a rising edge detection circuit, and two delay circuits of the input signal are required on the control circuit side, which complicates signal processing. [Purpose of the invention] Therefore, the purpose of the invention is to rapidly perform the switching operation on the sloped part of the switching cam, to make the switching state of the switch stable, and to create an electric delay circuit in that part. The goal is to make it possible to omit . [Solution Means of the Invention] Therefore, in the present invention, the cam member for switching is driven in a state where it can rotate in advance in the same direction independently from the drive side, and when the switch is switched, the switching cam member is rotated in advance in the same direction. By pressing the cam against the slope, the cam is rotated independently and in advance from the drive side by the biasing force of the switch member. [Operation of the invention] By doing so, during the switching operation, the switch member rests on a stable portion of the cam member and stops. Further, at this time, since the cam member rotates faster than the rotation of the drive side, the switch operates rapidly, and it is possible to prevent variations in the switching timing and chattering phenomenon caused by slow operation of the switch. [Example] First, FIGS. 1 and 2 show the overall configuration of a motor actuator 1 of the present invention. This motor actuator 1 is assembled inside a split-shaped case 2 and a case cover 3. The motor 4 as a rotational drive source is, for example, an AC motor, and is attached to the side surface of the case cover 3, with the motor gear 6 of the motor shaft 5 facing the inside of the case 2. This motor gear 6
are sequentially meshed with composite reduction gears 7 and 8, and transmit rotational force to a first rotating member 9 made of gears. These gears 7, 8 and first rotating member 9 are fixed to case 2 and rotatably supported by shafts 10, 11, 12 supported by case cover 3. Further, the first rotating member 9 meshes with a second rotating member 13 made of a gear at a gear ratio of 1:1. This second rotating member 13 is rotatably supported between the case 2 and the case cover 3 by a part of the shaft 14, and the first cam member 15 is integrally supported on one side of the second rotating member 13. is formed. The first cam member 15 of this embodiment is configured as an end cam, as shown in FIGS. 1 and 2, as well as shown in FIGS. 3 and 4, and has a rotation angle
Cam surfaces 16 with different inclinations and different circumferential directions with the first position P ₁ of 180 degrees and the second position P ₂ as boundaries
a, 16b, and pin 17 is formed at that part.
is in contact with Note that the pin 17 is supported slidably in the axial direction inside a guide tube 18 formed in the case 2, and when it is pulled into the inside of the case 2,
The baffle 32, which is an example of a driven member, is in a closed state, and conversely, when it is protruding from the inside of the case 2, the buffle 32 is opened. This buttful 32 is rotatably supported by a support shaft 35, and a spring 34 always keeps the opening 3
3 is biased in the direction of closing. Further, the shaft 12 rotatably supports a third rotating member 19. In this embodiment, the third rotating member 19, as shown in FIGS. 5 and 6,
A protruding engagement portion 21 is formed on one side surface, and a low step portion 22a close to the center of the second cam member 20 and a high step portion 22c distant from the center are formed on the outer peripheral surface of the second cam member 20. Slope portions 22b, 2 that connect smoothly
2d is integrally formed. This slope portion 22d
As shown in FIG. 12, the inclination of is set to a large pressure angle β in order to generate enough force to rapidly rotate the third rotating member 19 in response to the pressing force from the switch member 24, which will be described later. It is set. As shown in FIGS. 7 and 8, the engaging portion 21 is formed on the side surface of the first rotating member 9 with a central angle of approximately 140 degrees.
3a and 23b. As a result, the third rotating member 19 is connected to the engaging portion 21 and the engaging portions 23a, 2.
It is designed to be able to rotate freely within a rotation angle of approximately 180 degrees without contacting the holder 3b. When the third rotating member 19 and the second cam member 20 integral therewith rotate 180 degrees, the engaging portion 21
On the other hand, for example, from the engaging part 23a to the other engaging part 23
There is a relationship that is tangential to b. Further, a switch member 24 is rotatably supported inside the case 2 by, for example, a support shaft 25 thereof, and its tip portion is made to correspond to a switch 28 such as a reed switch by a permanent magnet 27.
The contact piece 26 on the back side allows contact with the low step portion 22a, the slope portion 22b, the high step portion 22c, and the slope portion 22d. Note that the switch 28 is attached to the case cover 3. The switch member 24 is a leaf spring 29 incorporated inside the case 2.
As a result, the contact piece 26 is always urged in the direction away from the switch 28, that is, in the direction in which the contact piece 26 comes into contact with the outer periphery of the second cam member 20. Next, FIG. 9 shows a control circuit 30 for the motor 4. As shown in FIG. This control circuit 30 controls the on/off state of the motor 4 using the on/off signal from the switch 28 as well as the signal from the temperature sensor 31 as input conditions. This temperature sensor 31 detects the internal temperature of the refrigerator and sends the temperature information to the control circuit 30. Further, the on/off signal of the switch 28 is input to the control circuit 30 via a fall detection circuit 36 or a rise detection circuit 37 and a delay circuit 38. First, the operation of the control circuit 30 will be explained. When the temperature inside the refrigerator is high and the buttful 32 as a driven member is closed, the control circuit 30
According to the temperature information from the temperature sensor 31, the motor 4 is activated and driven in the direction of opening the blower 32, sending cold air into the refrigerator (operation mode A). Further, when the temperature inside the refrigerator is high and the temperature sensor 32 is in an open state, the control circuit 30 controls the temperature sensor 31.
By continuing that state based on the temperature information from , cold air is sent into the refrigerator (operation mode B). Further, when the temperature inside the refrigerator is lower than the target temperature and the buffer 32 is open, the control circuit 30 closes the buffer 32 (operation mode C). Furthermore, when the internal temperature of the refrigerator is low and the exhaust valve 32 is closed, the control circuit 30 continues this state as not requiring cold air (operation mode D). Such operation modes A, B, C, and D are summarized as shown in the table below.

[Other embodiments of the invention]

In the above embodiment, as an example, the first rotating member 9 is formed with the engaging parts 23a and 23b, and the third rotating member 19 is formed with the engaging part 21. , 23a, 23b may be provided in a relationship opposite to that of the above embodiment. In addition, the engaging portion 2
3a and 23b may be arcuate long holes. [Effects of the invention] In the present invention, the second cam member is rotatably supported in a state where it can rotate ahead of time, and when the switch member comes into contact with the sloped part of the second cam member, the second cam member is rotated independently from the drive side. Since the rotational force in the preceding direction can be applied to the second cam member, the second cam member rapidly rotates in advance when the switch changes to either the rising or falling direction. Therefore, switching of the switch is instantaneous, there is no unstable state when switching of the switch, and the chattering phenomenon can be prevented. Further, the second cam member mechanically rotates in advance,
Since the switch member is in contact with the stable position of the second cam member, when the switch member falls from the high part to the low part, a delay circuit is not required in the signal circuit for the switching, and the electricity is generated accordingly. The circuit can be simplified. Furthermore, in the process of the switch member moving from the lower part to the higher part via the slope part, the detection signal of the detection circuit that detects switching of the switch is delayed by the necessary time by the delay circuit, so the switch member passes over the slope part. Since the motor stops in a state corresponding to the high step, the switch operation will not become unstable here either.

[Brief explanation of the drawing]

Fig. 1 is a bottom view showing the motor actuator of the present invention with the case cover removed, Fig. 2 is a sectional view taken along the meshing line of the gears, Fig. 3 is a plan view of the first cam member, FIG. 4 is a sectional view of the relationship between the cam surface and the pin, FIG. 5 is a plan view of the third rotating member, FIG. 6 is a sectional view thereof, FIG. 7 is a plan view of the first rotating member, and FIG. Figure 9 is a block diagram of the control circuit, Figure 10 is a time chart during normal rotation of the motor, Figures 11 and 1.
FIG. 2 is a plan view showing the relative positional relationship between the rotating member and the cam member. 1...Motor actuator, 4...Motor,
9...first rotating member, 13...second rotating member, 15...first cam member, 16a, 16b...
...Cam surface, 17... Pin, 19... Third rotating member, 20... Second cam member, 21... Engaging portion,
22a...low step part, 22b...slope part, 22c...
...High step part, 22d...Slope part, 23a, 23b...
...Engagement portion, 24...Switch member, 28...Switch, 30...Control circuit, 32...Buffle as an example of driven member, 36...Fall detection circuit, 37...Rise detection circuit, 38 ...Delay circuit.

Claims (1)

[Scope of utility model registration request] a motor that drives a driven member; a first rotating member that rotates in conjunction with the motor;
a third rotating member having a second cam member configured to be driven by the rotating member and having a high step portion, a low step portion, and a slope portion connecting the two; and the second cam member. a switch member that slides by a biasing force; an engaging portion that is provided on the first rotating member and the third rotating member and that can engage with each other in the rotational direction; and the switch member is connected to a second cam member. a detection circuit for detecting switching of a switch by a slope portion moving from a low step portion to a high step portion, and a detection circuit for delaying a detection signal from this detection circuit, when both of the above-mentioned engaging portions are engaged, 3rd above
The rotating member is configured to be pressed by the first rotating member and rotate together with the first rotating member, and further, due to the engagement of the first rotating member and the third rotating member,
In the process of sliding the switch member from the high stage part to the low stage part via the slope part, when the switch member corresponds to the slope part, the slope part of the second cam member A motor actuator characterized in that it is configured to rotate by an urging force from the switch member side regardless of pressure from the rotating member.