JP5928949B2 - Insert molding apparatus and method - Google Patents

Description

  The present invention relates to an insert molding apparatus and method for integrally molding a resin material on a metal member.

  There is a strong demand to use a metal member formed by integrally molding a resin material in various products such as automobiles and electric / electronic parts. In such a case, insert molding is often performed in which a molten resin is injected into a cavity around the metal member after the metal member is placed in the mold.

  For example, in Patent Document 1, both ends of a metal insert part are exposed to the outside of a molded product, and a metal mold is provided with an insulator between the metal insert part and both ends of the metal insert part are energized. A method is described in which a resin material is integrally formed on a metal member by injecting a molten resin into a cavity after heating the metal insert part in the mold. The heating temperature of the metal insert part is adjusted by the energization time of the metal insert part (see paragraph 0023 of Patent Document 1).

  Further, in Patent Document 2, a metal member is preheated with a high-frequency magnetic induction coil at a temperature higher than the melting temperature of the resin in a mold cavity, and then the molten resin is injected and injected into the cavity. Describes a method of integrally molding a resin material. The metal member is heated by supplying a high frequency current to the high frequency magnetic induction coil for a predetermined time (see paragraph 0026 of Patent Document 2).

Japanese Patent No. 3873030 JP 2011-168036 A

  However, in the methods described in Patent Literatures 1 and 2, the heating temperature of the metal insert part or the metal member is adjusted by the energization time or the high-frequency current supply time, and therefore decreases after the energization or high-frequency current supply ends.

  Then, in order to prevent the resin from partially curing until the completion of the molten resin injection, it is necessary to maintain the temperature of the metal insert part or the metal member at a temperature exceeding the melting temperature of the resin. For this reason, at the end of energization or supply of high-frequency current, the temperature of the metal insert part or metal member needs to be much higher than the melting temperature of the resin, and there is a problem that the resin material may be deteriorated.

  In view of the above, an object of the present invention is to provide an insert molding apparatus and method capable of integrally molding a resin material on a metal member without causing partial curing and deterioration of the resin material.

  The insert molding apparatus of the present invention is an insert molding apparatus that integrally molds a resin material on a metal member, and a mold in which a cavity in which the metal member is disposed is formed, and molten resin is injected into the cavity. A molten resin supply unit; a plurality of electrodes that are electrically conductive with the metal member; an insulator that insulates the mold from the electrode; a power source that supplies current to the electrode; and a temperature of the metal member. A temperature sensor for detecting the temperature, and when the temperature detected by the temperature sensor is equal to or lower than the preset temperature, the power source is activated, and when the temperature detected by the temperature sensor exceeds the preset temperature, the power source And a control unit for controlling the power supply so as to stop the operation.

  According to the insert molding apparatus of the present invention, the metal member detected by the temperature sensor is maintained at the preset temperature, and the selection of the operation / stop of the power source that supplies current to the electrode is directly performed according to the temperature detected by the temperature sensor. This is done by the control unit. Thereby, the temperature of a metal member is settled in the temperature range of a slight width | variety from the preset preset temperature. Therefore, the resin material can be integrally formed on the metal member without causing partial curing and deterioration of the resin.

  The temperature sensor may directly detect the temperature of the metal member. However, the temperature sensor detects the temperature of a member that is in contact with the metal member and has the same temperature as the metal member, for example, a resistor described later. The temperature of the member may be detected in an articulated manner.

  By the way, in the method described in Patent Document 1, since an insulator is interposed between the mold and the metal insert part, heat is transferred from the metal insert part to the mold via the insulator. In the method described in Patent Document 2, the entire mold is heated together with the metal member by the high frequency magnetic induction coil.

  Therefore, the methods described in Patent Documents 1 and 2 have a problem that the mold cannot be quickly cooled after the molten resin is injected, and the cycle time becomes long. Moreover, since a metal mold | die is heated to high temperature, there exists a subject that the lifetime of a metal mold | die becomes short.

  Therefore, in the insert molding device of the present invention, it is preferable to include a heat absorbing member disposed between the metal member and the mold.

  In this case, most of the heat from the electrode is absorbed by the heat absorbing member, and the metal member is heated quickly, but the temperature of the mold does not rise so much. Therefore, the mold can be quickly cooled after the molten resin is injected, and the cycle time is shortened. Further, since the mold does not reach a high temperature, the life of the mold is extended.

Furthermore, the insert molding device of the present invention, the metal member is sandwiched by the resistor, the metal member through the resistor Ru is electrically connected with said electrode.

Thereby , the temperature of the energized resistor rises rapidly, and the metal member is heated quickly. Therefore, the time required for energization heating is short, the thermal efficiency is excellent, and the cycle time is also shortened. And since the metal member is clamped with the resistor, the whole metal member can be heated uniformly.

  In the insert molding device of the present invention, it is preferable that the electrode is disposed outside the mold.

  In this case, the connection configuration between the electrode and the power source can be simplified as compared with the case where the electrode is disposed inside the mold.

The insert molding method of the present invention is an insert molding method in which a resin material is integrally molded with a metal member , and the plurality of electrodes in which the metal member sandwiched by the resistor is insulated from the mold through the resistor. And electrically supplying the electrode with a current from a power source, and when the temperature detected by a temperature sensor that detects the temperature of the metal member is equal to or lower than the preset temperature, the power source is activated. When the temperature detected by the temperature sensor exceeds the preset temperature, the step of controlling the power supply to stop the power supply, and after the temperature detected by the temperature sensor exceeds the preset temperature And a step of injecting a molten resin into a cavity formed in the mold in which the metal member is disposed.

  According to the insert molding method of the present invention, the metal member detected by the temperature sensor is maintained at a preset temperature, and the selection of activation / deactivation of the power supply for supplying current to the electrode is directly performed according to the temperature detected by the temperature sensor. To do. Thereby, the temperature of a metal member is settled in the temperature range of a slight width | variety from the preset preset temperature. Therefore, the resin material can be integrally formed on the metal member without causing partial curing and deterioration of the resin.

The schematic top view of the insert molding device concerning a 1st embodiment of the present invention. The schematic side view of an insert molding apparatus. The expanded sectional view of a metal mold | die and an electrode unit. The block diagram of an insert molding apparatus. The flowchart which shows the insert molding method which concerns on 1st Embodiment of this invention. The schematic front view of the insert molding apparatus which concerns on 2nd Embodiment of this invention. The schematic side view of an insert molding apparatus. The expanded sectional view of a metal mold | die and an electrode unit. The block diagram of an insert molding apparatus. The flowchart which shows the insert molding method which concerns on 2nd Embodiment of this invention. The graph which shows the conventional temperature change. The graph which shows the temperature change at the time of insert molding of this invention.

(First embodiment)
Hereinafter, the insert molding apparatus 1 which is 1st Embodiment of this invention is demonstrated.

  1 to 4, an insert molding apparatus 1 is an apparatus for obtaining a product M obtained by integrally molding a resin molded portion M2 on a metal member M1.

  The insert molding apparatus 1 includes a mold 10, an electrode unit 20, an energization unit 30, an injection unit 40, a temperature sensor 50, and a control unit 60. Then, two sets of molds 10 each having the electrode unit 20 disposed thereon are installed on a turntable 72 configured to be rotatable with respect to the base 71.

  The metal member M1 is made of a metal that can be energized. The metal used as the material of the metal member M1 is not particularly limited. For example, steel materials such as stainless steel, simple non-ferrous metals such as copper, aluminum, and zinc, various alloys including aluminum, nickel, chromium, titanium, copper, etc. Is mentioned.

  The material of the resin molding part M2 is not particularly limited as long as it is a resin. For example, various synthetic resins and natural resins including polybutylene terephthalate (PBT), polyamide (PA), and polyphenylene sulfide (PPS) are used. Is mentioned.

  Here, the metal member M1 has a cylindrical shape having two annular protrusions. And the resin molding part M2 is a cylindrical shape which has two annular recessed parts inside and has a level | step difference outside here.

  The annular recessed portion of the resin molded portion M2 has a shape corresponding to the annular protrusion of the metal member M1, thereby further strengthening the bonding between the metal member M1 and the resin molded portion M2. In addition, although the contact surface with the resin molding part M2 of the metal member M1 is preferable if it is a rough surface since joining strength will improve further, a mirror surface may be sufficient.

  Each mold 10 includes a fixed mold 11 and a movable mold 12. The fixed mold 11 is installed with respect to the rotary table 72, and the movable mold 12 is configured to be openable and closable with respect to the fixed mold 11. Recesses are formed on the surfaces of the fixed mold 11 and the movable mold 12 that are in contact with each other, and these recesses are combined to form a cavity C that defines the outer shape of the resin molded part M2. The remaining space excluding the space where the metal member M1 of the cavity C is disposed becomes a molding space for molding the resin molding part M2. Although not shown, the movable mold 12 has a runner communicating with the cavity C from the upper surface.

  Here, the electrode unit 20 is configured to be bilaterally symmetric, and is an electrode 21 that is an energizing contact that contacts the metal member M1, a pressing mechanism 22 that presses the electrode 21 against the metal member M1, and an electrical connection between the electrode 21 and the electrode 21. And a power receiving terminal 23 disposed on the outer surface of the mold 10.

  The electrode 21 includes a resistor 24 in contact with the metal member M1 and an electrode base 25 to which the resistor 24 is fixed. The resistor 24 is made of a material that has a higher thermal conductivity than copper and generates heat when energized, such as carbon, a carbon composite material, silicon carbide, and stainless steel. The resistor 24 comes into contact with an exposed portion exposed to the outside of the resin molded portion M2 of the metal member M1.

  The resistor 24 is configured to reliably contact the metal member M1 and not to contact the resin molded portion M2. Here, the resistor 24 has a conical tip, and is formed so as to be in uniform contact with the inner peripheral end surface of the metal member M1. The electrode base 25 is made of a conductor such as copper, molybdenum, or tungsten.

  An insulator 13 made of bakelite, ceramic, or the like is installed between the mold 10 and the electrode 21, that is, the resistor 24 and the electrode base 25 so that the mold 10 is not energized and heated through the electrode 21. Has been. Further, a heat absorbing member 14 having a very high thermal conductivity is disposed on the surface of the mold 10 that is in contact with the resistor 24. Here, the heat absorbing member 14 is a thin film layer made of carbon nanotubes coated on the surface of the mold 10.

  A heater 15 (see FIG. 4) for heating the mold 10 is built in the mold 10. Although the details of the heater 15 are not shown, for example, the oil flowing through the oil passage formed in the mold 10 is heated by a heating source different from the power source 31 and the temperature is adjusted by a temperature controller, so that the mold 10 can be maintained at the set temperature.

  Here, the pressing mechanism 22 is disposed between the cooling plate 26 configured to be movable in the left-right direction with respect to the electrode 21, and between the outer surface of the mold 10 and the cooling plate 26, and applies a biasing force in the extending direction. And a spring 27 arranged to do so. The cooling plate 26 is made of a conductor such as copper, molybdenum, or tungsten. As a result, the two left and right electrodes 21 are pressed inwardly by the pressing mechanism 22 from the outer side in the left and right direction, so that the state in which the metal member M1 is held between the electrodes 21 is stably maintained.

  The cooling plate 26 is configured to be cooled by circulating a cooling fluid such as pure water or tap water by a cooling mechanism (not shown). Further, the power receiving terminal 23 may be provided with a cooling mechanism. Since most of the cooling plate 26 and the power receiving terminal 23 are located outside the mold 10, it is easy to provide a cooling mechanism, and it is easy to cool.

  Here, the power receiving terminal 23 is fixed to the back surface of the mold 10 via an insulator 28 made of bakelite, ceramic or the like. The power receiving terminal 23 is connected to the cooling plate 26 via a connection conductor 29 disposed outside the mold 10. Both the power receiving terminal 23 and the connection conductor 29 are made of a conductor such as copper, molybdenum, or tungsten. In this way, the electrode 21 and the power receiving terminal 23 are always electrically connected.

  The energization unit 30 includes two power supply terminals 32 of a positive electrode and a negative electrode connected to a power source 31 via a cable (not shown). The energization unit 30 is configured to be slidable with respect to a rail 73 fixed to the base 71 and can switch between a state in which the power supply terminal 32 and the power reception terminal 23 are in contact with each other and a non-contact state. Here, the energization unit 30 is configured to be movable in the left-right direction on the rail 73 using an air cylinder.

  Here, the power source 31 is an inverter control pulse power source. The power supply 31 includes an inverter having a rectifier circuit, a diode, and a thyristor, and is configured such that a pulse characteristic adjusting element such as a pulse waveform, a pulse width, a pulse interval, a current, and a voltage to be generated can be changed by the control unit 60. ing.

  The injection unit 40 is a molten resin supply unit that discharges molten resin from the nozzle 41 and injects the molten resin into the cavity C. The nozzle 41 is connected to the upper side of the runner of the mold 10, and the molten resin discharged from the nozzle 41 is injected into the cavity C through the runner.

  The temperature sensor 50 detects the temperature of each resistor 24 through a hole formed in the mold 10. Here, the temperature sensor 50 is a non-contact type sensor such as an infrared radiation thermometer, and is fixed to the support shaft 74 of the rotary table 72. The temperature sensor 50 may be replaced with a contact sensor such as a thermocouple that measures the temperature by contacting the surface of the resistor 24, or a non-contact sensor and a contact sensor may be used in combination.

  Since the resistor 24 is in contact with the metal member M1 and has high thermal conductivity, the temperature thereof is the same as the temperature of the metal member M1. Therefore, by detecting the temperature of the resistor 24 with the temperature sensor 50, the temperature of the metal member M1 can be detected in an articulating manner.

  The control unit 60 includes a CPU, a ROM, a RAM, an I / O, and the like, and an operation unit 61 and a display unit 62 are electrically connected. Here, the operation unit 61 includes various operation switches such as a start switch and a start switch, an input panel including a touch panel, and the like. Information input from the operation unit 61 is transmitted to the control unit 60.

  Further, a detection signal is input from the temperature sensor 50 to the control unit 60. The control unit 60 is based on the detection signal from the temperature sensor 50, information input from the operation unit 61, and control information such as injection pressure, mold holding pressure, set temperature Ts, and set holding time Hs stored in the storage unit. Control signals are output to the movable mold 12, the heater 15, the power source 31, the injection unit 40, the rotary table 72, and the like. The control unit 60 corresponds to the control unit of the present invention.

  Here, the set temperature Ts is a temperature that is set when the electrode 21 is energized, is detected by the temperature sensor 50, and is monitored by the control unit 60. The set temperature Ts is a temperature higher by a predetermined temperature within the melting temperature of the resin forming the resin molding part M2 or about several tens of degrees C. The set temperature Ts is appropriately set in advance through a trial experiment or the like.

  The set holding time Hs is a time for holding the metal member M1 at the set temperature Ts, and is also a time required for filling the cavity C with the molten resin. The set holding time Hs is also appropriately set in advance through a trial experiment or the like.

  The temperature sensor 50 directly outputs an off signal for turning off the power supply 31 to the power supply 31 when the detected temperature exceeds the set temperature Ts. Further, the temperature sensor 50 directly outputs an ON signal for turning on the power supply 31 to the power supply 31 when the detected temperature becomes equal to or lower than the set temperature Ts. Thus, since the signal is directly output from the temperature sensor 50 to the power supply 31 without going through the control unit 60, the temperature T of the metal member M1 can be quickly returned to the set temperature Ts. Therefore, the temperature T of the metal member M1 is always maintained at the set temperature Ts.

  In addition, a display unit 62 is electrically connected to the control unit 60. Here, the display unit 62 includes a digital display panel, a lamp, and the like. The display unit 62 receives information from the control unit 60 based on an input to the control unit 60 or a calculation result in the control unit 60, and displays the information.

  Next, the process at the time of implementing the insert molding method which concerns on 1st Embodiment of this invention using the insert molding apparatus 1 mentioned above is demonstrated with reference to FIG. The following processes S2 to S13 are executed by the control unit 60. During the processes of S2 to S13, the heater 15 is operated to maintain the temperature of the mold 10 at a predetermined set temperature, and the cooling fluid is circulated through the cooling plate 26 by a cooling mechanism (not shown), whereby the electrode 21 Has been cooled.

  First, the worker installs the metal member M1 in the state where the metal member M1 is sandwiched between the electrodes 21 on the stationary mold 11 located on the near side, that is, on the left side in FIGS. 1 and 2 (S1).

  When the start switch of the operation unit 61 is turned on by the operator (S2: YES), the rotary table 72 is rotated (S3), and the fixed mold 11 on which the metal member M1 is installed is located on the back side, that is, FIGS. Move to the right side of 2. Thereafter, the movable mold 12 is lowered and the mold 10 is closed (S4).

  Then, the power source 31 is started, and the power supply terminal 32 is brought into contact with the power receiving terminal 23 to energize the electrode 21 (S5). Thereby, the resistor 24 is heated and the temperature rises, and the temperature of the metal member M1 rises accordingly.

  Thereafter, after the temperature T of the resistor 24 detected by the temperature sensor 50 exceeds the set temperature Ts and the temperature of the mold 10 reaches the set temperature (S6: YES), the set temperature Ts of the resistor 24 is maintained. While maintaining the state, the molten resin is injected from the injection unit 40 into the cavity C (S7). The set temperature Ts is maintained when the temperature sensor 50 directly outputs an off signal or an on signal to the power supply 31.

  And the state which maintained the predetermined preset temperature Ts set beforehand is maintained, and injection | pouring of molten resin is continued only for the preset predetermined setting holding time Hs (S8). Whether or not the set holding time Hs has continued is determined with reference to a timer (not shown) of the control unit 60.

  After the set holding time Hs elapses, the power source 31 is stopped, the power supply terminal 32 is separated from the power receiving terminal 23, and the energization of the electrode 21 is finished (S9).

  When the temperature T of the resistor 24 detected by the temperature sensor 50 falls below the softening temperature of the resin (S10: YES), the movable mold 12 is raised and separated from the fixed mold 11 to open the mold 10 (S11). ). Thereafter, the rotary table 72 is rotated so that the fixed mold 11 is positioned on the front side (S12), and the product M is released from the fixed mold 11 and taken out (S13).

(Second Embodiment)
Hereinafter, the insert molding apparatus 101 which is 2nd Embodiment of this invention is demonstrated. However, since the insert molding apparatus 101 is similar to the above-described insert molding apparatus 1, only the differences will be mainly described, and the similar configurations are diverted by using reference numerals.

  Referring to FIGS. 6 to 9, insert molding apparatus 101 is a hoop-type apparatus that continuously obtains product M obtained by integrally molding resin molded portion M4 on metal member M3.

  The insert molding apparatus 101 includes a mold 110, an electrode unit 120, a power source 31, an injection unit 140, a temperature sensor 50, a control unit 160, and an operation unit 161. A set of molds 110 on which the electrode units 120 are arranged are installed on the base 171.

  The metal member M3 is made of a metal that can be energized similarly to the metal member M1 described above. The material of the resin molding part M4 is not particularly limited as well as the material of the resin molding part M2 described above.

  Here, the metal member M3 is a long thin plate having a rectangular cross section. And the resin molding part M4 is a rectangular thin plate here. After the resin molding part M4 is integrally formed on the metal member M3, the metal member M3 is cut by another device installed on the downstream side, and the resin molding part M4 is integrally molded on the rectangular plate-shaped metal member. A product M is obtained. However, in the insert molding apparatus 101, the product M may be obtained by integrally molding the resin molding portion M4 on a metal member cut into a rectangular plate shape in advance.

  The mold 110 includes a fixed mold 111 and a movable mold 112. The fixed mold 111 is fixed to the base 171, and the movable mold 112 is configured to be openable and closable with respect to the fixed mold 111. Here, the movable mold 112 is configured to be movable up and down via a pair of rods 172 by an air cylinder, hydraulic cylinder, electric cylinder, etc. (not shown) attached to the base 171 below the fixed mold 111. ing.

  Recesses are formed on the surfaces of the fixed mold 111 and the movable mold 112 that are in contact with each other, and these recesses are combined to form cavities C that respectively define the outer shapes of the two resin molding parts M4. The metal member M3 is transported by the transport device 173 such as a robot so that the portion where the resin molding part M4 of the metal member M3 is integrally molded is located in the cavity C.

  Here, the electrode unit 120 is configured to be vertically symmetrical, and each of the electrodes 121 is a current-carrying contact that contacts the metal member M3, a pressing mechanism 122 that presses the electrode 121 against the metal member M3, and the electrode 121 and the electrical unit. And a power receiving terminal 123 arranged on the outer surface of the mold 110.

  The electrode 121 includes a resistor 124 that is in contact with the metal member M3 and an electrode base 125 on which the resistor 124 is fixed. The resistor 124 is made of a material having higher thermal conductivity than copper and generating heat when energized, for example, carbon, a carbon composite material, silicon carbide, stainless steel, or the like. The resistor 124 is in contact with an exposed portion exposed to the outside of the resin molded portion M4 of the metal member M3.

  The resistor 124 is configured to reliably contact the metal member M3 and not to contact the resin molded portion M4. Here, the resistor 124 is formed in a rectangular parallelepiped shape having a flat contact surface that contacts the metal member M3, and is configured to be in surface contact with the front and back surfaces of the end portion of the metal member M1. . The electrode base 125 is made of a conductor such as copper, molybdenum, or tungsten, and the resistors 124 are fixed to the inner ends thereof.

  An insulator 113 made of bakelite, ceramic, or the like is installed between the mold 110 and the electrode 121, that is, the resistor 124 and the electrode base 125, so that the mold 110 is not energized and heated through the electrode 121. Has been.

  Further, a heat absorbing member 114 having a very high thermal conductivity is disposed on the surface of the mold 110 that is in contact with the resistor 124. Here, the heat-absorbing member 114 is a thin film layer made of carbon nanotubes coated even on the surface of the mold 110. A heater 15 (see FIG. 9) for heating the mold 110 is built in the mold 110.

  Here, the pressing mechanism 122 is disposed between the cooling plate 126 configured to be movable in the vertical direction with respect to the electrode 121, the mold 110, and the cooling plate 126, and applies an urging force in the extending direction. And a spring 127 disposed on the surface. The cooling plate 126 is made of a conductor such as copper, molybdenum, or tungsten. As a result, the upper and lower electrodes 121 are pressed inward by the pressing mechanism 122 from the upper and lower sides, respectively, so that the state in which the metal member M3 is held between the electrodes 121 is stably maintained.

  The cooling plate 126 is configured to be cooled by circulating a cooling fluid such as pure water or tap water by a cooling mechanism (not shown). Further, the electrode base 125 may be provided with a cooling mechanism. Since all of the cooling plates 126 are mostly located on the outside of the mold 110, the electrode base 125 is easily provided with a cooling mechanism and is easy to cool.

  Here, the power reception terminal 123 is disposed on the back side of the mold 110 by being fixed to the cooling plate 126. The power receiving terminal 123 and the cooling plate 126 are made of a conductor such as copper, molybdenum, or tungsten. In this way, the electrode 121 and the power receiving terminal 123 are always electrically connected. And the power receiving terminal 123 and the metal mold | die 110 are insulated via the insulator 113. FIG.

  The power source 31 is fixed to the base 171 and is electrically connected to the power receiving terminal 123 via a cable (not shown).

  The nozzle 141 of the injection unit 140 is connected to the upper surface side of the mold 110, and the molten resin discharged from the nozzle 141 is simultaneously injected directly into the two cavities C from the tip of the nozzle 141.

  The temperature sensor 50 is fixed to the base 171 and detects the temperature of each resistor 124 through a hole formed in the mold 110. Since the resistor 124 is in contact with the metal member M3 and has a high thermal conductivity, the temperature thereof is the same as the temperature of the metal member M3. Therefore, by detecting the temperature of the resistor 124 with the temperature sensor 50, the temperature of the metal member M3 can be detected in an articulating manner.

  The control unit 160 is based on control signals such as a detection signal from the temperature sensor 50, information input from the operation unit 161, and injection pressure, mold holding pressure, set temperature Ts, and set holding time Hs stored in the storage unit. Control signals are output to the movable mold 112, the heater 15, the power source 31, the injection unit 140, the transfer device 173, and the like. The control unit 160 corresponds to the control unit of the present invention.

  Next, processing when the insert molding method according to the second embodiment of the present invention is performed using the above-described insert molding apparatus 101 will be described with reference to FIG. Note that the following processing of S22 to S31 is executed by the control unit 160. During the processing of S22 to S31, the heater 15 is operated to maintain the temperature of the mold 110 at a predetermined set temperature, and the cooling fluid is circulated through the cooling plate 126 by a cooling mechanism (not shown).

  When the start switch of the operation unit 161 is turned on by the operator (S21: YES), the metal member M3 is conveyed by the conveying device 173, and the resin molding part M4 of the metal member M3 is integrally molded on the fixed mold 111. A portion to be processed is installed (S22). Thereafter, the movable mold 112 is lowered and the mold 110 is closed (S23).

  And the power supply 31 is started and it supplies with electricity to the electrode 121 (S24). Thereby, the resistor 124 is heated and the temperature rises, and the temperature of the metal member M3 also rises accordingly.

  Thereafter, after the temperature T of the resistor 124 detected by the temperature sensor 50 exceeds the set temperature Ts (S25: YES), the cavity C is released from the injection unit 40 while maintaining the set temperature Ts of the resistor 124. A molten resin is injected into the inside (S26). The set temperature Ts is maintained when the temperature sensor 50 directly outputs an off signal or an on signal to the power supply 31.

  And the state which maintained the predetermined preset temperature Ts set beforehand is maintained, and injection | pouring of molten resin is continued only for the preset predetermined setting holding time Hs (S27).

  After the set holding time Hs elapses, the power supply 31 is stopped and the energization of the electrode 121 is terminated (S28). Then, the cooling fluid is circulated through the cooling plate 126 by a cooling mechanism (not shown) to cool the electrode 21 (S29).

  When the temperature T of the resistor 124 detected by the temperature sensor 50 becomes lower than the softening temperature of the resin (S30: YES), the cooling is finished (S31), and then the movable mold 112 is raised to raise the fixed mold 111. The product M is released from (S32).

  And the metal member M3 is conveyed by the conveying apparatus 173, and the part by which the resin molding part M4 of the metal member M3 is integrally molded on the fixed mold 111 is installed (S22). Thereafter, similarly, S22 and subsequent steps are repeated.

(Effect of embodiment)
As described above, in the first and second embodiments, the finished product M is obtained by integrally molding the resin molded portions M2 and M4 on the metal members M1 and M3. When the molten resin is injected into the cavity C, the state in which the set temperature Ts is maintained is maintained, so that the resin in the resin molding parts M2 and M4 is of high quality. This will be specifically described below.

  Conventionally, since the control unit that has received the detection signal input from the temperature sensor has instructed the power supply to turn on or off, as shown in FIG. 11, the actual temperature is larger than the set temperature, for example, from several degrees C. There was a difference of 10 ℃. If the temperature is too high than the set temperature, there is a problem that the resin deteriorates. In addition, if the set temperature is maintained for a long time, the temperature may be lower than the set temperature. In this case, there is a problem that the resin is partially cured and the uniformity is lost.

  In the present embodiment, the set temperature Ts is maintained by the temperature sensor 50 directly outputting an off signal or an on signal to the power source 31. Therefore, as shown in FIG. Fits in. As a result, the resin molding parts M2 and M4 are uniform and of good quality.

  Furthermore, by energizing the electrodes 21 and 121 in a state where both ends of the metal members M1 and M3 are sandwiched between the resistors 24 and 124, the entire metal members M1 and M3 can be heated uniformly.

  Further, the metal members M1 and M3 that are in direct contact with the resistors 24 and 124 are heated in the same manner as the resistors 24 and 124 and are uniformly heated. Compared with the case where the entire electrodes 21 and 121 are made of copper or the like (see FIG. 11), as shown in FIG. 12, the energized resistors 24 and 124 rapidly increase in temperature. The time to do is short, the thermal efficiency is excellent, and the cycle time is also shortened.

  Further, heat absorbing members 14 and 114 are interposed between the resistors 24 and 124 and the molds 10 and 110, and most of the heat from the resistors 24 and 124 is absorbed by the heat absorbing members 14 and 114. Therefore, the temperature of the molds 10 and 110 does not increase so much. Therefore, as shown in FIG. 12, the molds 10, 110 can be quickly cooled after the molten resin is injected, and the cycle time is shortened. Further, since the molds 10 and 110 do not reach a high temperature, the service life of the molds 10 and 110 is extended.

(Example)
Hereinafter, the present invention will be described by way of examples.

  The metal member M3 and the resin molding part M4 were integrally molded using the above-described insert molding device 101. However, the metal member M3 is a rectangular plate having a length of 49 mm, a width of 12 mm, and a thickness of 1.5 mm, and the resin molded portion M4 is a rectangular plate having a length of 49 mm, a width of 12 mm, and a thickness of 3.0 mm. It was. And the joining surface was a square shape with a side of 12 mm.

  The material of the metal member M3 was aluminum (A1050) or stainless steel (SUS304). The material of the resin molded part M4 was polybutylene terephthalate (PBT), polyamide 6 (PA6), polyamide MXD-6 (PAMXD-6), or polyphenylene sulfide (PPS).

  As polybutylene terephthalate (PBT), 1101G-X54 manufactured by Toray Industries, Inc., 1015GC6 manufactured by Ube Industries, Ltd. as polyamide 6 and 1012F manufactured by Mitsubishi Engineering Plastics Co., Ltd. as polyamide MXD-6, polyphenylene sulfide As this, BGX-130 manufactured by Tosoh Corporation was used.

  The melt resin temperature, the mold 110 set temperature, the melt resin injection pressure, the mold 110 hold pressure, the set temperature Ts, the set hold time Hs, and the applied current I to the electrode 121 are set as shown in Table 1. did.

  As a result of performing a tensile shear test on the joined members, the base material of the resin molded portion M4 was broken in all examples. From this, it was found that the bonding strength was strong.

  DESCRIPTION OF SYMBOLS 1,101 ... Insert molding apparatus 10, 110 ... Mold, 11, 111 ... Fixed mold, 12, 112 ... Movable mold, 13, 113 ... Insulator, 14, 114 ... Endothermic member, 20, 120 ... Electrode Unit, 21, 121 ... Electrode, 22, 122 ... Pressing mechanism, 23, 123 ... Power receiving terminal, 24, 124 ... Resistor, 25, 125 ... Electrode base, 26, 126 ... Cooling plate, 27, 127 ... Spring, 28 , 128 ... Insulator, 29 ... Connection conductor, 30 ... Current-carrying unit, 31 ... Power supply, 32 ... Power supply terminal, 40, 140 ... Injection unit (molten resin supply part), 50 ... Temperature sensor, 60, 160 ... Control unit ( Control part), C ... cavity, M ... product, M1, M3 ... metal member, M2, M4 ... resin molding part.

Claims (4)

An insert molding device for integrally molding a resin material on a metal member,
A mold having a cavity in which the metal member is disposed;
A molten resin supply section for injecting molten resin into the cavity;
A plurality of electrodes electrically conductive with the metal member;
An insulator that insulates the mold from the electrode;
A power supply for supplying current to the electrodes;
A temperature sensor for detecting the temperature of the metal member;
The power supply is operated when the temperature detected by the temperature sensor is equal to or lower than the preset temperature, and the power supply is stopped when the temperature detected by the temperature sensor exceeds the preset temperature. and a control unit for controlling,
The insert molding apparatus, wherein the metal member is sandwiched by a resistor, and the metal member is electrically connected to the electrode through the resistor .   The insert molding apparatus according to claim 1, further comprising a heat absorbing member disposed between the metal member and the mold. The insert molding apparatus according to claim 1 , wherein the electrode is disposed outside the mold. An insert molding method for integrally molding a resin material on a metal member,
Electrically connecting the metal member sandwiched by the resistor to a plurality of electrodes insulated from the mold through the resistor, and supplying current from the power source to the electrode;
When the temperature detected by the temperature sensor that detects the temperature of the metal member is equal to or lower than the preset temperature, the power source is activated, and when the temperature detected by the temperature sensor exceeds the preset temperature, the power source Controlling the power supply to stop
And a step of injecting a molten resin into a cavity formed in the mold where the metal member is disposed after the temperature detected by the temperature sensor exceeds the preset temperature. Method.

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