JP4093585B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator provided with a door opening device that opens a storage compartment door.

  In recent years, refrigerators have a tendency to increase the amount of storage along with the diversification of eating habits, especially in household refrigerators, the class in which the storage volume exceeds 400 liters has become mainstream, and the height and width dimensions of the refrigerator body tend to increase It is in.

  Along with this, the doors of refrigerator compartments, freezer compartments, and vegetable compartments have also increased in size, and in particular, the storage pockets inside the doors of refrigerator compartments with large storage volumes have increased in depth and depth as the height and width are increased. However, the door itself is large, requiring a large amount of force to open the door, and there is a problem that the burden is increased in the case of a weak woman or elderly person.

  In recent years, refrigerators equipped with electromagnetic solenoid type door opening mechanisms that open doors by knocking pins protruding from the main body side by the user's handle switch operation as a configuration to solve the above problems have been offered to the market. It is evaluated as a product that does not require a burden to open the door.

  Here, the energization control of the conventional door opening mechanism will be described with reference to the circuit diagram of FIG. The electromagnetic solenoid 103 using the full-wave rectifier circuit 101 as a power source serves as a drive source for the door opening device 102, and opens the refrigeration room door by applying a force in the opening direction to the refrigerator compartment door when energized.

  The control circuit unit 120 is connected to the switching power source 122 via the AC power source 109 and the full-wave rectifier circuit 121 so that the DC voltage processed by the full-wave rectifier circuit 121 and the switching power source 122 is supplied to the microcomputer 123. It has become.

  In addition, the control circuit unit 120 is configured in the relay switch 108 when a high level signal is input in response to an operation of the handle switch 105 in a door closed state (a state in which a high level signal is input from the door switch 104). The transistor is turned on for a predetermined time set in the timer to energize the relay coil. As a result, the relay switch 108 is turned on, and the electromagnetic solenoid 103 is energized for the predetermined time.

JP 2001-59675 A (FIG. 1)

However, when an Nch MOSFET, for example, is used as a switching element as a circuit configuration, it takes more time to pull out the charge at the OFF time than to apply the charge at the ON time.
The present invention has been made in consideration of the above problems, and an object of the present invention is to shorten the time required for switching the ON / OFF of the switching element of the door opening device.

The invention of claim 1 includes a double doors type door comprising a left door and right door openably provided in the front opening of the main body, and the door opening device by electric drive source to the door opening of the left and right doors, respectively A handle switch for detecting a user operation, a door switch for detecting the opening and closing of the left and right doors, and a detection signal from the handle switch and the door switch. When a user's operation is detected by a handle switch of the other door while the door is detected, the drive source corresponding to the other door is set with a duty value lower than that when one door is closed. and control means for duty-controlling the driving source is duty controlled by the switching element, wherein the switching element, and a circuit connected to the first resistor and the diode, Serial and second resistance value larger first resistance than the resistance value, characterized in that the connected in parallel.

  According to the above-described invention, it is possible to reduce the time required for switching the switching element between ON and OFF.

  Hereinafter, an embodiment of the present invention will be described. FIG. 2 is a front view of the refrigerator, and as shown in FIG. 3 which is a front view of the right door in an open state, the refrigerator main body 1 is provided with a left-right double-folded refrigerator compartment 2 at the top. In the lower corner of the refrigerating room 2, an ice making room 4 that is thermally insulated adjacent to the low temperature chilled room 3, a vegetable room 5 and a freezing room 6 are arranged below the refrigerating room 2 by a drawer door system. .

  The refrigerating room 2 has a configuration in which cold air generated by a cooler (not shown) provided on the back side is introduced into the room by a fan and cooled, and the room formed by the inner box 7 is divided into a plurality of storage parts by the mounting shelf 8. In addition to forming a storage space for refrigerated food, the front opening is divided in the width direction, and left and right doors 9 and 10 of a double door system that can be opened and closed by hinges provided on both sides of the main body are installed. ing.

  The right door has a magnet gasket 10b attached to the peripheral edge of the back side of the left door 9 and the right door 10, and the right side of the left door 9 slides with a pin (not shown) provided in the upper part of the cabinet. However, a rotating partition plate 9a that rotates in accordance with the opening / closing operation of the door is provided.

  The rotary partition plate 9a rotates 90 degrees when the left door 9 is closed. Each magnet gasket is in close contact with the rotary partition plate 9a, and the heat insulation of the ice making chamber 4 is provided below the rotary partition plate notch 9a. By adsorbing the right edge portion of the partition wall 4a and the magnet gasket 10b, the intermediate partition portion of the refrigerator compartment 2 is kept closed.

  A door switch 14 for detecting the open / closed state of the right door 10 by contact with the bead portion 10a of the right door 10 is attached to the peripheral edge of the front opening of the refrigerator compartment 2 so as to output a high level signal when the door is closed. It has become.

  A handle portion 11 is attached to the front surface of the right door 10 facing the left door 9, and a handle switch 12 and an operation panel 13 are attached to the front surface of the handle portion 11.

  In this case, although not specifically illustrated, the operation panel 13 is provided with an indicator for displaying the room temperature, the switching mode, and the like of the refrigerator compartment 2, the vegetable compartment 5, the freezer compartment 6, and the like. 5. An operation switch group for individually switching the set temperature of the freezer compartment 6 and the like is provided.

  The handle switch 12 has a built-in mechanical switch such as a normally open microswitch that is turned on when the touch panel 12a is pressed. The handle switch 12 can also be configured by an optical switch using a photo interrupter or a magnetic switch.

  Each of the refrigerator compartment 2 and the freezer compartment 6 is provided with a temperature sensor 15 for detecting the temperature in the refrigerator, and outputs it to a control circuit unit 35 described later.

  A door opening device 20 for applying a force in the opening direction to the right door 10 is attached to the ceiling portion of the refrigerator body 1. As shown in FIG. 4 which shows a cross-sectional structure of the upper part of the refrigerator, the door opening device 20 is installed in a semi-embedded state in a recessed portion 1a formed in the ceiling portion of the refrigerator body 1, and has a direct current inside. An electromagnetic solenoid 21 to be driven (corresponding to a driving source of the present invention) is included. The electromagnetic solenoid 21 serving as a drive source is not limited to this, and may be a door opening device using a cam mechanism using a motor as a drive source.

  The electromagnetic solenoid 21 includes a coil unit 21a in which a coil formed in a cylindrical shape is resin-molded, a plunger 21b provided in a state of passing through the coil unit 21a, and is fixed coaxially to the plunger 21b. The pressing member 21c is a main component, and the plunger 21b and the pressing member 21c are in the right door 10 direction (the direction of arrow A in FIG. 6) in the energized state (the state in which the coil of the coil unit 21a is energized). ).

  In this case, one end of the plunger 21b (the end opposite to the arrow A) is provided with a flange 21d made of, for example, a C-ring for preventing the plunger 21b from coming off in the direction of the arrow A. A return spring 21e made of a compression coil spring is provided around the flange portion 21d and the coil unit 21a so as to apply an extension force.

  The upper edge of the right door 10 is integrally provided with a receiving tool 10c with which the tip of the pressing member 21c abuts. The electromagnetic solenoid 21 is energized so that the plunger 21b and the pressing member 21c are in the direction of arrow A. When the urging force is applied, the receiving member 10c is pressed by the pressing member 21c, and the right door 10 is opened against the attracting force of the magnet gasket 10b.

  Further, in the door opening device 20, an auxiliary spring 21f made of a torsion coil spring is provided so that the end surface on the flange 21d side of the plunger 21b is urged in the arrow A direction against the return spring 21e. In the steady state where the right door 10 is closed, the tip of the pressing member 21c is configured to abut against the receiving member 10c by the urging force of the auxiliary spring 21f. The urging force of the auxiliary spring 21f is naturally set to a level smaller than the attracting force of the magnet gasket 10b.

  FIG. 1 shows a circuit configuration related to the door opening device 20 among the electrical configuration of the refrigerator according to the present embodiment, which will be described below.

  The electromagnetic solenoid 21 in the door opening device 20 has a DC drive configuration that is output from the AC power supply 33 via the full-wave rectifier circuit 30. Between the pair of output terminals of the full-wave rectifier circuit 30, smoothing is performed. A capacitor 31 is connected in parallel. The full wave rectifier circuit 30 may be a voltage doubler rectifier circuit.

  A switching element 32 is connected in series between one AC output terminal and the electromagnetic solenoid 21. The switching element 32 is composed of a transistor GTIB, a MOSFET, and the like, and changes output ON power (pulse width) by changing a switch ON time (pulse width) with a constant period T in accordance with an input signal from a microcomputer 37 to be described later. The time ratio control (duty control) is performed.

  The control circuit unit 35 includes a switching power source 36 and a microcomputer 37 (hereinafter referred to as a microcomputer). The switching power source 36 chops a DC power source via the full-wave rectifier circuit 30 and the smoothing capacitor 31 to the microcomputer 37. 5 V DC power is supplied, and the microcomputer 37 selects a preset duty value according to inputs from the handle switch 12, the door switch 14, the temperature sensor 15, etc., and controls the duty of the electromagnetic solenoid 21 by the switching element 32. It is configured as follows.

  As a specific circuit configuration, the microcomputer 37 is connected to the switching element 32 through a transistor 42 that amplifies a pulse signal to the switching element 32.

  A resistor 43a (for example, 1 kΩ) and a resistor 43b (for example, 51Ω) are connected to the base (gate) side of the switching element 32, and the anode side of the diode 43c is connected to the resistor 43b. Resistors 43a and 41b and a transistor 42 are connected to the cathode side of the diode 43c.

  The above configuration is a circuit configuration using an Nch MOSFET for the switching element 32. This Nch-MOSFET is configured to apply a charge to the gate when it is turned on and extract the charge when it is turned off, but generally it takes more time to extract the charge. For this reason, the resistor 43a having a large resistance value is used for current limiting when turned on, and is turned off by setting the Lo level via the resistor 43b and diode 43c having a small resistance value in order to quickly extract charges when turned off. It is possible to reduce the time required for the operation. It should be noted that at the time of OFF, it is sufficient that only the amount of electric charge applied to the gate can be extracted, and therefore various changes can be made to the current limiting resistor 43a.

  41a and 42b constitute pull-up resistors (for example, 10 kΩ).

  A resistor 44 (for example, 20 kΩ) that stabilizes the source voltage and a capacitor 45 (for example, 0.01 μF) that processes the stray capacitance of the switching element 32 are connected in parallel between the gate and the source of the switching element 32. .

  The electromagnetic solenoid 21 is connected to a resistor 48a (for example, 1Ω), and the voltage value applied to the resistor 48 is constantly input to the microcomputer to measure abnormal conditions such as disconnection and the current value in the normal state. Is to be detected. 48 b is a resistor (for example, 10 kΩ) that limits the current input to the microcomputer 37. Since the detection method using the resistor 48 is an incidental feature of the present invention, it goes without saying that the effects of the present invention can be obtained without such a detection method.

  By attaching an element that can store data, such as an EEPROM, to the microcomputer 37, a duty value suitable for each model of the refrigerator is stored in advance by an experimental value, and by appropriately changing the setting to a duty value corresponding to each model, The same microcomputer and solenoid can be used for each model.

For example, a model with a large door or a model with strong adhesion of the magnet gasket 10b requires a large door opening force. Therefore, the output power is set to 100%, and conversely with a model with a small door or adhesion of the magnet gasket 10b. In a model with weak force , if the door is pushed out with the same opening force as the above model, the door will open too much. For example, the duty value is set low so that the output power becomes 70%.

  On the other hand, the normally open handle switch 12 has one end connected to the power supply terminal + Vcc and the other end connected to the ground terminal via a pull-down resistor. Thus, the handle switch 12 outputs a low level signal (ground potential level signal) in a non-operating state at all times, and a high level signal (power supply terminal + Vcc potential) when turned on by the user. Level signal).

  The door switch 14 has a well-known configuration that turns off when the right door 10 is closed and turns on when the right door 10 is opened. One end of the door switch 14 is connected to the power supply terminal + Vcc via a pull-up resistor. And the other end is connected to the ground terminal. As a result, the door switch 14 outputs a high level signal when the right door 10 is in a closed state (when it is off) and outputs a low level signal when the right door 10 is opened (when it is on). Will do.

  Next, the operation of the door opening device will be described based on the flowchart of FIG.

  In step 1, it is detected whether the user presses the handle switch 12 and an operation signal is input to the microcomputer 37 (S 1). If there is no operation signal, the right door 10 is utilized using the door opening device 20. It is determined that there is no intention to open the window, and step 1 is repeated. If the operation signal is input, it is determined that there is an intention to open the right door 10 using the door opening device 20, and the process proceeds to Step 2.

  In step 2, it is detected by the detection of the door switch 12 whether or not an opening signal is input (S2). If there is an opening signal, the right door 10 has already been opened and is opened by the door opening device 20. It is determined that it is not necessary to perform the operation, and the process returns to step 1. If there is no opening signal, it is determined that the right door 10 is in a closed state and the door opening device 20 needs to be operated to open the door, and the process proceeds to step 3.

  In step 3, the microcomputer 37 transmits an input signal to the switching element 32 at a predetermined timing according to a preset duty value, and energizes the electromagnetic solenoid 21 (S3). That is, duty control is performed on the electromagnetic solenoid 21 to adjust the output power, and the process proceeds to Step 4.

  When a predetermined power is supplied to the electromagnetic solenoid 21, the plunger 21b and the pressing member 21c are urged toward the right door 10 (the direction of arrow A in FIG. 4).

  In step 4, it is detected whether or not a predetermined time, for example, 1.5 to 2 seconds has passed (S4). If the predetermined time has passed, the receiving member 10c provided on the right door 10 is pressed by the pressing member 21c. Accordingly, it is determined that the right door 10 is opened against the attractive force of the magnet gasket 10b, and the process proceeds to step 5.

  In step 5, the energization of the electromagnetic solenoid 21 is terminated (S5), the process returns to step 1 and waits for the next opening operation. At this time, since the electromagnetic solenoid 21 is heated when the energizing operation is continuously performed, the opening operation may be prohibited for a certain period using a delay timer when the opening operation is performed a predetermined number of times continuously. Good.

  According to the above configuration, in the relay switch that was controlled only by the energization time, the output power could not be adjusted, but by using the switching element, the output power can be adjusted, Since there is no contact between the mechanical contacts, it is possible to eliminate the occurrence of burnout or disconnection of the drive source or electromagnetic solenoid due to contact welding.

  Conventionally, a full-wave rectifier circuit for operating the electromagnetic solenoid has been separately required. However, if a switching element is used, the AC voltage or current is duty-controlled, so a dedicated full-wave rectifier for operating the electromagnetic solenoid is used. A control circuit can be simplified without requiring a circuit.

Furthermore, even in refrigerators with different internal volumes, that is, models with different opening force required to open the door , the same control circuit, drive source with the same output, or electromagnetic solenoid can be used in common only by microcomputer processing. Therefore, cost reduction can be achieved.

  Next, an example of duty control according to the closing time will be described.

  The microcomputer 37 is provided with a door closing time timer 38 that operates a timer in response to a door closing signal from the door switch 14. Specifically, when the door switch 14 inputs a door closing signal to the microcomputer 37, the microcomputer 37 operates the door closing time timer 38 to count the door closing time. When the door opening device 20 is operated, the microcomputer 37 selects a duty value corresponding to the door closing time and controls the output power to the electromagnetic solenoid 21.

In this case, if the predetermined time T, for example, 10 minutes has not elapsed, the pressure difference between the inside and outside of the refrigerator is not large, so it is determined that the door opening force of the door opening device 20 may be weak, and a low duty value is set. When the selection is made, for example, the output power is set to 70%, the electromagnetic solenoid 21 is duty controlled, and if 10 minutes have elapsed, the pressure difference between the inside and outside of the refrigerator is large, and thus the door opening force of the door opening device 20 is strong. The electromagnetic solenoid 21 is duty-controlled by selecting a high duty value, for example, setting the output power to be 100%. Note that it is more effective to divide the time reference into a plurality of stages, and the time reference may be set for each model.

  This is because the opening / closing interval of the right door 10 becomes longer, the pressure difference between the inside and outside of the refrigerator increases as the inside of the refrigerator is cooled, the adsorption state of the magnet gasket 10b is stabilized, and the force required for opening due to this is increased. It has the property of becoming larger.

For this reason, when the door opening force of the door opening device 20 is controlled to be constant, it is difficult to open the right door 10 against the attracting force of the magnet gasket 10b, and vice versa. There is a risk that the door opening force of the door opening device 20 becomes unnecessarily strong.

On the other hand, in this embodiment, the duty control for changing the door opening force of the door opening device 20 in a plurality of steps based on the time detection signal from the opening / closing time timer 38 for detecting the opening / closing interval of the right door 10, that is, As the closing time of the right door 10 becomes longer, the control structure that increases and decreases the opening force of the door opening device 20 can prevent the above-mentioned problems.

  Next, an example of duty control according to the internal temperature will be described.

  The microcomputer 37 is provided with a temperature determination device 39 that determines whether a predetermined temperature has been reached based on a temperature signal from the temperature sensor 15. Specifically, when the temperature detected by the temperature sensor 15 is input to the microcomputer 37, the constant temperature determination device 39 determines whether or not the temperature has reached a predetermined temperature, and operates the door opening device 20. The microcomputer 37 selects the duty value according to the above determination and controls the output power to the electromagnetic solenoid 21.

  In this case, if the room temperature of the refrigerator compartment 2 detected by the temperature sensor 15 is a predetermined temperature, for example, 2 ° C. or more, it is determined that the pressure difference inside and outside the refrigerator is not large, and a low duty value is set. Select, for example, the output power is set to be 70%, and the electromagnetic solenoid 21 is duty controlled. If the temperature is less than 2 ° C., it is determined that the pressure difference between the inside and outside of the refrigerator is large, and a high duty value is selected. Is set to be 100%, and the electromagnetic solenoid 21 is duty-controlled. Note that it is more effective to divide the temperature reference into a plurality of stages, and the temperature reference may be set for each model.

  This is due to the fact that the pressure inside the refrigerator decreases as the inside temperature decreases due to the relationship between temperature and pressure, and the pressure difference between the inside and outside of the refrigerator increases, resulting in a large force required for opening. There is.

  For this reason, when the door opening force of the door opening device 20 is controlled to be constant, it is difficult to open the right door 10 against the attracting force of the magnet gasket 10b, and vice versa. There is a risk that the opening force for the door opening device 20 becomes unnecessarily strong.

On the other hand, in the present embodiment, the duty control for changing the door opening force of the door opening device 20 in a plurality of stages based on the temperature detection signal of the temperature sensor 15 that detects the room temperature of the refrigerator compartment 2, that is, the refrigerator compartment. Since the control structure increases the door opening force of the door opening device 20 as the internal temperature decreases, the above-described problems can be prevented in advance.

  Next, an example of duty control according to the food detection means will be described.

  The microcomputer 37 is provided with a food weight judgment device 40 for detecting whether the quantity of food or the weight of the food is greater than or equal to a predetermined value based on the food signal of the food detection device 16 corresponding to the food detection means of the present invention.

  The food detection device 16 detects the quantity or weight of food stored in a door pocket 10d attached to the right door 10. For example, in the former case, the door pocket 10d is stored when a plastic bottle or the like is stored. It is configured to detect the number of food containers such as plastic bottles by pressing a plurality of switches provided on the back surface of the door. In the latter case, the weight provided on the bottom surface of the door pocket 10d The sensor is configured to detect the weight related to the right door 10.

  In addition, it may be configured according to the type, weight, and quantity of food that is managed by input from the operation panel 13 or the like.

  Further, the food weight determination device 40 estimates the load applied to the right door 10 based on the food signal of the food detection device 16 and detects whether or not a predetermined load or more is always applied. .

  When the food signal of the food detection device 16 is input to the microcomputer 37, the operation of the above configuration is based on the detected weight of the food weight determination device 40. When the door opening device 20 is operated, the microcomputer 37 operates at the door closing time. A corresponding duty value is selected to control the output power to the electromagnetic solenoid 21.

In this case, if the detected weight is less than a predetermined weight, for example, 3 kg, it is determined that the load applied to the right door 10 is not large, and a low duty value is selected, for example, the output power is set to 70%. If the electromagnetic solenoid 21 is duty controlled and the load on the right door 10 is greater than 3 km, it is determined that the door opening force of the door opening device 20 should be increased, and a high duty value is selected. The electromagnetic solenoid 21 is duty controlled by setting the output power to be 100%. Note that it is more effective to divide the weight standard into a plurality of stages, and the weight standard may be set for each model.

This has the property that the force required for opening increases as the load applied to the right door 10 increases, so when the door opening force of the door opening device 20 is controlled to be constant, Although the load applied to the right door 10 is large, the door opening force is weak and cannot be opened, and conversely, the door opening force of the door opening device 20 becomes unnecessarily strong. There is a risk of inviting.

On the other hand, in the present embodiment, duty control for changing the door opening force of the door opening device 20 by a plurality of steps based on the load applied to the right door 10, that is, the load applied to the right door 10 is increased. Accordingly, the control structure that increases the door opening force of the door opening device 20 can prevent the above-described problems.

  Next, an example of duty control of the electromagnetic solenoid when the other door is open in the refrigerator having the double doors will be described.

  A left door switch 17 for detecting the open / closed state of the left door 9 is provided at the front opening edge of the refrigerator compartment 2, and the structure and operation of the left door switch 17 are the same as those of the door switch 14.

  When the left door 9 is opened when the operation signal is input to the right door 10 in the closed state when the left door 9 is opened and the opening signal of the left door switch 17 is input to the microcomputer 37 The output power to the electromagnetic solenoid 21 is controlled by setting the duty value lower than that, for example, 70%. The duty value is preferably set for each model.

  This is because when the left door 9 is in the closed state, the refrigerator compartment 2 is completely closed, so that there is a pressure difference between the inside and outside of the refrigerator, and the magnet gasket 10b of the right door 10 is attached to the rotary partition plate 9a. Although the suction force is strong because it is adsorbed, when the left door 9 is in the open state, the pressure inside and outside the refrigerator is substantially the same because one side is open, and the left door 9 is arranged on the side facing the left door 9a. Since the magnet gasket 10b is adsorbed only on the heat insulating partition wall 4a, the adsorbing force is reduced.

For this reason, when the door opening force of the door opening device 20 is controlled to be constant, the door 9 is opened even though the left door 9 is opened and the force for opening the door is not so much required. There is a risk that the opening force of the opening device 20 becomes unnecessarily strong.

In contrast, in this embodiment, the door opening force of the door opening device 20 is controlled based on the open / closed state of the left door 9, that is, if the left door 9 is opened, the door opening device 20 is opened. Since the control is performed to weaken the door force , it is possible to prevent a situation that causes the above problems.

  Next, another embodiment to which duty control is applied will be described.

  When the electromagnetic solenoid 21 is energized and the right door 10 is opened, the plunger 21d is biased in the direction of arrow A. At this time, the flange 21d is connected to the coil unit 21a via the return spring 21e. A collision sound is generated because the collision stops.

  On the other hand, when the right door 10 is opened, the most force is required when the magnet gasket 10b is peeled off or when the automatic door closing mechanism provided at the hinge is released, and thereafter the door is opened by inertia. However, in order to open a predetermined amount, the door must be kept pressed.

  Therefore, for example, when the time until the flange 8d collides with the coil unit 21a is 0.5 seconds and the time requiring the most force is 0.3 seconds, the electromagnetic solenoid 21 is energized. If the configuration is such that duty control is performed such that 100% power is supplied for 0.3 seconds and 50% power is supplied for 0.3 seconds or the duty value is lowered as time passes, coil unit 21a And the collision sound of the flange 8d can be reduced. Further, if the plunger itself has a magnetic force, the collision noise can be further reduced by reverse energization.

  On the other hand, after the energization is completed, the pressing member 21c is urged in the interior direction by the action of the return spring 21e, but the collar portion 21d collides with the auxiliary spring 21f and is stopped. In such a case, a collision sound is generated.

  Therefore, when the time from the end of energization to the electromagnetic solenoid 21 to the time when the collar portion 21d collides with the auxiliary spring 21f is t, after the right door 10 is opened, the output power to the electromagnetic solenoid 21 is 20%, Alternatively, if duty control is performed to gradually increase the duty value until time t is reached and completely stop energization after time t has elapsed, the return speed of the pressing member 21c is reduced, and the flange portion 21d and the auxiliary spring 21f The collision noise can be reduced.

  As described above, the embodiments of the present invention have been described. However, not only the duty control but also the replacement with the PAM control for controlling the output voltage has no change in the operational effect, and the duty value setting, time, temperature, weight The setting of the reference can be appropriately changed according to the specification form of the refrigerator.

  In addition, various combinations are possible for the embodiment described above. For example, when the closing time is a predetermined time or more and the internal temperature is lower than the predetermined temperature, the output power to the electromagnetic solenoid is 60%. Duty control may be performed so as to decrease.

  Furthermore, the double door type refrigerator door has been described, but there is no problem even if it is a single door refrigerator, and a mode in which a door opening device is provided only on the right door has been described. Needless to say, a door opening device can be provided.

  In general, the human audible range is 20 Hz to 20 kHz, but especially around 4 kHz is sensitive, so that the frequency when the electromagnetic solenoid 21 is energized is prevented from becoming noise due to the vibration sound of the door. Therefore, it is preferable to use a high frequency, for example, a frequency of 8 kHz or more.

It is a circuit diagram which shows the control circuit of this invention. It is a front view which shows the refrigerator of this invention. It is a front view which shows the state which opened the right side door of FIG. It is a longitudinal cross-sectional view which shows the detail of the electromagnetic solenoid of this invention. It is a flowchart which shows the control action of this invention. It is a circuit diagram which shows the conventional control circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Refrigerator body 2 ... Refrigeration room 4 ... Ice making room 4a ... Thermal insulation partition wall 5 ... Vegetable room 6 ... Freezer room 9 ... Left door 9a ... Rotary partition plate 10 ... Right door 10b ... Magnet gasket 10c ... Receiving part 11 ... Handle part DESCRIPTION OF SYMBOLS 12 ... Handle switch 13 ... Operation panel 14 ... Door switch 15 ... Temperature sensor 16 ... Food detection means 17 ... Left door switch 20 ... Door opening device 21 ... Electromagnetic solenoid 21a ... Coil unit 21b ... Plunger 21c ... Pressing member 30 ... Full wave Rectifier circuit 32 ... switching element 35 ... control circuit unit 37 ... microcomputer 38 ... door closing time timer 39 ... temperature judgment device 40 ... food weight judgment device

Claims (1)

Detection and door casement type consisting openably provided left door and right door to the front opening, a door opening device by electric drive source to the door opening of the left and right doors, respectively, the operation of the user of the body A handle switch, a door switch for detecting the opening and closing of the left and right doors, and a detection signal from the handle switch and the door switch, wherein one door switch detects the opening When the operation of the user is detected by the handle switch of the other door, the control means for duty-controlling the drive source corresponding to the other door by setting the duty value lower than that when the one door is closed. With
The drive source is duty-controlled by a switching element, and a circuit in which a first resistor and a diode are connected to the switching element and a second resistance value having a resistance value larger than the first resistance are connected in parallel. Features a refrigerator.

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