JPH052575U - Actuator - Google Patents

Abstract

(57) [Abstract] [Purpose] The object of the present invention is to provide a burnout protection element capable of reliably detecting an abnormal heat generation state of the motor, which enables downsizing of the motor and easy assembly of the burnout protection element. Therefore, it is to provide an actuator suitable for automation. [Structure] The actuator S according to the present invention is a thermistor element 1 having a positive change in resistance value with respect to temperature change.
0 and the motor M are connected in series, and the output device 20 connected to the output of the motor M is provided in the housing 30. A substrate 11 is attached to the end frame 4 of the motor M, a through hole 14 is formed in the substrate 11, and the substrate 11 is provided with contact plates 12a and 12c connected to the electrodes 5a and 5b of the motor M. I have it. Then, the thermistor element 10 is placed in the through hole 14 of the substrate 11 and brought into contact with the end frame 4 of the motor M. It is also connected to the motor M via the contact plates 12a and 12c.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention relates to an actuator, for example, opening and closing an air conditioner damper for an automobile. Actuator.

[0002]

[Prior art]

  In the case of an actuator equipped with a motor, the motor When the rotation axis is constrained or is in a state close to it, the motor current increases due to a sudden increase in load current. May generate heat abnormally, resulting in burnout. In order to prevent such accidents, Burnout protection of so-called positive temperature coefficient thermistors whose resistance changes with temperature changes An actuator used for a motor as a protective element is known.   That is, in an actuator using a positive temperature coefficient thermistor as a burnout protection element, , The positive temperature coefficient thermistor is connected in series with the motor and the power supply voltage for driving the motor is printed. It is common to be added. And, in general, The star is soldered to a printed circuit board near the motor or a dedicated holder. Etc. And if the motor gets stuck for some reason Since the motor heats up due to the increase in load current, the positive temperature coefficient thermistor In response, the resistance value rises. At the same time, the positive temperature coefficient thermistor reduces the load current of the motor. Since it is still flowing, it generates heat due to Joule heat.

[0003]

[Problems to be solved by the device]

  The above-mentioned positive temperature coefficient thermistor has some resistance even at room temperature. Therefore, a voltage drop occurs even when the motor is operating normally. Therefore, the actu As a motor used for data, it compensates for the power loss in this PTC thermistor. It is necessary to select a motor with sufficient output characteristics so that the Need to be increased, which hinders miniaturization of the actuator and I was invited to stop.   In addition, a printed circuit board and a dedicated holder for mounting the PTC thermistor are provided. It was necessary to increase the number of parts of the entire device. In addition, print Assembly of the board and dedicated holder with the actuator is not suitable for automation It was a composition.   On the other hand, in order to reduce the voltage drop in the positive temperature coefficient thermistor during normal operation, If you use a low resistance value, the voltage drop in the thermistor is naturally lowered. However, if this is done, the positive temperature Since the amount of heat generated in the motor is reduced, the current flowing to the motor cannot be sufficiently limited, The overcurrent energization time will be prolonged.   Therefore, the motor will be exposed to the heat generation state for a longer period of time. Risk of motor damage and actuator damage before the drive is stopped was there.

[0004]   The purpose of the present invention is to provide a burnout protection element that can reliably detect the abnormal heat generation state of the motor. The motor can be downsized and the burnout protection element can be easily assembled. It is to provide an actuator suitable for automation.

[0005]

[Means for Solving the Problems]

  The actuator according to the present invention has a positive characteristic that the resistance value changes with temperature. A motor in which burnout protection elements are connected in series, and an output connected to the output of the motor An actuator including a device in a housing, the actuator comprising: The motor includes a board attached to the end frame of the motor and a through hole formed on the board. A through hole and a contact plate provided on the substrate and connected to the electrodes of the motor, An end frame of the motor, wherein the burnout protection element is arranged in a through hole of a substrate. And contact with the motor through the contact plate. Of.

[0006]   According to a second aspect of the invention, the motor is disposed in the housing at the position where the board is provided. A contact plate that extends to the By assembling the motor with the contact plate connected to the electrode of the motor It is preferable to configure the connection.

[0007]

[Action]

  In the actuator according to the present invention, the burnout protection element is attached to the motor end frame. Since they come into direct contact, when an overcurrent is about to flow in the motor, the burnout protection element The burnout protection element directly receives the heat generated by the motor and the heat generated by the motor itself. Because of this Since the range of temperature change that acts on the loss protection element can be made large, the burnout protection element The resistance change of can be increased. That is, the resistance value during normal operation of the motor can be reduced. On the other hand, when overheating is caused by overcurrent, the resistance becomes high and the current flowing to the motor is limited. To prevent motor burnout. Therefore, as in the past, the printed circuit board mounting space In addition to eliminating the need for a base and a dedicated holder, it also directly contacts the end frame of the motor. Since it is touching, the thermal conductivity is improved and abnormal heat generation of the motor can be caught quickly and reliably. It will be possible.

[0008]   Also, at the motor installation position in the housing, the contact Plate is placed and this contact plate is connected to the electrodes of the motor. If the tact plate and motor are connected to each other by connecting, This eliminates the need for soldering or other connection to the electrode of the battery, making it more suitable for automating the assembly process. It

[0009]

【Example】

  An embodiment of the present invention will be described below with reference to the drawings. The parts described below The material, the layout, etc. are not limited to the present invention, and may be variously modified within the scope of the present invention. It is something that can be done.   1 to 3 show an embodiment of an actuator according to the present invention, The configuration will be described below with reference to these drawings.

[0010]   The actuator S of this example has a motor M and a change in resistance value with respect to a temperature change that is positive. Thermistor element 10 which is a characteristic burnout protection element, and this thermistor element 10 A substrate 11 that holds the output, an output device 20 connected to the output of the motor M, and a housing It is composed of a group 30 and.   As the actuator S, for example, an air conditioner damper for an automobile is opened and closed. Is an electric actuator S using a motor M for The motor M and the output device 20 are disposed in the ring 30.   In this example, the housing 30 includes an upper housing 31 and a lower housing 32. The lower housing 32 is provided with a motor M as shown in FIG. The portion 33 is formed, and one end side (left side in FIG. 4) of the motor arrangement portion 33 is In the motor M side, that is, in the direction of the upper housing 31 (that is, the front side of the paper surface), the contact The rates 34 and 35 are extended and arranged. This contact plate 34,3 5 is a spring, which slightly extends inward of the lower housing 32 (right side in FIG. 4). It is arranged. Reference numeral 36 in FIG. 4 denotes an arrangement portion for arranging the speed reducing portion 21 described below. is there.

[0011]   The output device 20 of the present example is composed of a speed reducer 21 and an output part 22, and is used to rotate the motor M. A worm 2 is formed on the output shaft 1a which is one end side of the rolling shaft 1. And a plurality of intermediate gears 21a that form the reduction gear portion 21 mesh with each other, and , And the output gear 22a forming the output unit 22 meshes. This output gear 22a has The output shaft 23 of the actuator S is integrally formed, and the output of the motor M is the output shaft 23. Is configured to be transmitted to.

[0012]   On the side opposite to the output shaft 1 of the motor M of this example, as shown in FIG. A frame 4 is formed, and the end frame 4 is opposite to the output shaft 1a of the rotary shaft 1. The motor shaft 1b, which is one end on the opposite side, extends and faces the motor shaft 1b with the motor shaft 1b interposed therebetween. Then, the electrodes (terminals) 5 a and 5 b project from the end frame 4.   The substrate 11 of this example is composed of a resin plate, and includes an end frame 4 and A contact play is made on the flat surface portion 11a that abuts and on the surface opposite to the flat surface portion 11a. A mounting surface 11b on which the components 12a, 12b, 12c, the thermistor element 10 and the like are mounted. It consists of That is, the substrate 11 of this example has a center for housing the motor shaft 1b. A hole 13, a through hole 14 for disposing the thermistor element 10, and a contact plate. Recesses 14a, 14b, 14c for accommodating the doors 12a, 12b, 12c are formed. The recess 14a has protrusions 15a and 15b and a hole 16a penetrating the electrode 5a. Accordingly, the protrusion 17a is formed in the recess 14b. Further, the projection 18 is provided in the recess 14c. A, 18b and a hole 16b penetrating the electrode 5b are formed.

[0013]   The contact plate 12a has holes 41a for engaging with the projections 15a and 15b. , 41b are formed, and the holes 1 of the substrate 11 are formed in the contact plate 12a. A hole 42a is formed so as to be aligned with 6a. Also contact plate 12 A hole 43a that engages with the protrusion 17a is formed in b. In addition, The tact plate 12c has holes 44a and 44b that engage with the protrusions 18a and 18b. And the holes 42b are formed so as to be aligned with the holes 16b of the substrate 11. It The two contact plates 12a, 12b are at least the lower side Aligned with the positions of the contact plates 34 and 35 formed on the housing 32. It is arranged to do. Reference numeral 45 indicates the contact plate 12a Reference numeral 46 indicates a contact plate that separates the contact plate 12b from the contact plate. It is a partition part that partitions the rate 12b and the contact plate 12c.

[0014]   In this example, the thermistor element 10 is used as the burnout protection element. A well-known one having a positive resistance change with respect to temperature change is used. In this example The thermistor element 10 basically has the above-mentioned known characteristics. However, the resistance value at room temperature is lower than that of the thermistor element used in this type of protection device. I am using an old one. The reason for this will be described in the explanation of operation below. It   The thermistor element 10 of this example is formed in a disk shape and has the above-mentioned contact plate. The contact plates 12a and 12b. Contact with the contact plates 34, 35 on the side housing 32 on the electrode side Will be continued.   That is, the contact plate 34 on the electrode side is connected to the contact plate 12a. The contact plate 35 on the other electrode side is the same as above. , Contact plate 12b.

[0015]   Next, a procedure for assembling the embodiment having the above configuration will be described below.   First, the substrate is attached to the end frame 4 side of the motor M. At this time, the center hole 13 The motor shaft 1b, the electrodes 5a and 5b, and the holes 16a and 16b are fitted together. Next, each The contact plates 12a, 12b, 12c are mounted, but at this time, the contacts The holes 41a, 41b, 43a, 44 of the plates 12a, 12b, 12c, respectively. a and 44b are fitted together. It should be noted that the contact with the hole 42a of the contact plate 12a The holes 42b of the plate 12c are also fitted with the electrodes 5a and 5b. And The projections protruding from the holes of each plate are welded and caulked to be integrated.   The thermistor element 10 is arranged in the through hole 14 of the substrate 11 and has the leads 10a, 1 0b connects to the contact plates 12a, 12b.   It should be noted that the thermistor element 10 and the two contact plates 12a and 12b are joined together. , Further, joining of the electrodes 5a, 5b and the contact plates 12a, 12c described above. Are made by using well-known joining means such as soldering or spot welding.

[0016]   Next, the one in which the motor M and the substrate 11 are integrated is used as a motor of the lower housing 32. Attached to the mounting portion 33. By this assembly, the contact plates 12a, 12 c is connected to the contact plates 34 and 35 on the electrode side. And output device 2 0 is assembled and the lower housing 32 and the upper housing 31 are assembled with screws or the like. It is attached.

[0017]   FIG. 6 shows a drive circuit using the thermistor element 10 for the motor M of the actuator. An example is shown. This motor M opens and closes an air conditioner damper for an automobile, for example. Used as the actuator S for the thermistor element for the motor M. Are connected in series. Further, the power source 6 is connected in series so that the energizing circuit of the motor M is Composed.

[0018]   When the motor M is operating normally, heat generation during normal operation of the motor M The heat is transferred from the end frame 4 directly to the thermistor element. As a result, The thermistor element will exhibit a resistance value according to the transferred heat. However In the present invention, the thermistor element 10 is a thermistor element which is conventionally used in this type of device. In order to use a device that has a relatively lower resistance value than the The voltage drop in the thermistor element is also It is relatively small compared to.

[0019]   However, the output shaft 1 of the motor M is restricted or substantially restricted due to an external load or the like. When the state is close, the load current of the motor M increases. This load current is Since it also flows to the thermistor element 10, Joule heat by the thermistor element 10 itself However, as mentioned above, the thermistor element 10 has a resistance during normal operation (at low temperature). Since the one with a small value is used, the thermistor element 10 itself generates less heat. However, the thermistor element 10 is disposed in direct contact with the end frame 4 of the motor M. Therefore, the heat generation temperature of the motor M itself can be directly received. Sanawa The temperature of the object to be protected can be directly detected. Therefore, the motor M If it is heated, it can receive a large amount of heat, It becomes the resistance value. This limits the overcurrent flowing through the motor M.

[0020]   In addition, the resistance value of the thermistor element 10 of the present example is, as described above, conventionally The value used is relatively lower than that used in the device. The reason The reason is that the thermistor element 10 is first contacted with the end frame 4 of the motor M. By mounting the motor M, the heat generation state of the motor M itself is immediately detected. However, since it can be directly received, control according to the state of the motor M is possible. Therefore, the thermal conductivity from the motor M to the thermistor element 10 is the same as that of the conventional one. Good thing to compare. And if the thermistor element has the same resistance value as the conventional one However, since the heat transfer from the motor M is good, the motor M does not generate much heat. In the non-heated state, that is, it is not necessary to limit the energization of the motor M The power supply to the motor M will be restricted, and the operation of the motor M will be adversely affected. This is because it will happen.

[0021]

[Effect of device]

  In the present invention, the burnout protection element is directly contacted with the end frame of the motor as described above. Therefore, it is possible to directly receive the heat generation state of the motor itself and protect the motor quickly. It can be done quickly and reliably. In addition, the burnout protection element was mounted as in the past. The printed circuit board and holder for the The cost can be reduced because the size is reduced and the simple assembling work is required.   Also, connect the motor electrode to the contact plate, and Since it is connected just by assembling the contact plate on the power supply side, the The power supply method can be simplified and the assembling ability is greatly improved, making it suitable for automation.   Furthermore, by improving the thermal conductivity between the motor and the burnout protection element, Since the temperature range for receiving heat can be widened, the resistance value of the motor when operating at room temperature is low. It is possible to use a burnout protection element, and as a result, a motor with a smaller capacity than before Can be used, and a remarkable effect such as miniaturization of the device can be obtained.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an example of a mounted state of an end frame of a motor which constitutes an actuator according to the present invention.

FIG. 2 is a side view of a motor that constitutes an actuator.

FIG. 3 is a view seen from the direction X in FIG.

FIG. 4 is a plan view showing one side of a housing.

FIG. 5 is a cross-sectional view of an actuator.

FIG. 6 is a schematic explanatory diagram of a motor protection circuit using a burnout protection element.

[Explanation of symbols]

4 end frame 5a, 5b Electrode (terminal) 10 Burnout protection element (thermistor element) 11 board 12a, 12b, 12c Contact plate 14 through holes 20 Output device 30 housing 34, 35 contact plate (power supply side) M motor S actuator

Claims (2)

[Scope of utility model registration request] 1. An actuator comprising, in a housing, a motor in which a burnout protection element having a positive change in resistance value with respect to a temperature change is connected in series, and an output device connected to the output of the motor. The motor of the actuator includes a substrate attached to the end frame of the motor,
A through-hole formed in the substrate and a contact plate provided on the substrate and connected to an electrode of the motor are provided, and the burnout protection element is arranged in the through-hole of the substrate and brought into contact with the end frame of the motor. At the same time, an actuator characterized in that it is connected to a motor via the contact plate. 2. A contact plate extending to the substrate side is arranged at a motor mounting position in the housing, and the contact plate is assembled with the contact plate connected to the electrode of the motor. The actuator according to claim 1, wherein the actuators are connected by.