Injection molding machine, injection device, and method for controlling injection molding machine

Abstract

When the detected temperature of the injection nozzle is lower than the nozzle reference temperature (YES in step S2), the injection molding machine heats the injection nozzle using the detected temperature of the synchronization section as a target temperature (step S6). Furthermore, when the detected temperature of the injection nozzle is higher than the nozzle reference temperature (no in step S2), the injection molding machine heats the injection nozzle using the nozzle setting temperature as the target temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to an injection molding machine, an injection device, and a control method of an injection molding machine. BACKGROUND

[0002] Japanese Patent Application Publication No. 2006-240203 discloses an injection molding machine. The injection molding machine controls the temperature of a nozzle and the temperature of a cylinder by feedback control. SUMMARY

[0003] In the injection molding machine as described above, the volume of the nozzle is usually smaller than the volume of the cylinder, and the cylinder stores a material for injection therein, so the heat capacity of the cylinder is larger than the heat capacity of the nozzle. Therefore, in a case where the same amount of heat is applied to the nozzle and the cylinder, the temperature of the nozzle increases faster than the temperature of the cylinder.

[0004] Thus, in the injection molding machine, in a case where the nozzle and the cylinder are warmed up, the temperature of the nozzle reaches the set temperature earlier than the temperature of the cylinder reaches the set temperature. In this case, after the temperature of the nozzle reaches the set temperature, the nozzle needs to be continuously heated in order to maintain the temperature of the nozzle until the temperature of the cylinder reaches the set temperature. Therefore, there is a problem that unnecessary electric power is consumed in order to maintain the temperature of the nozzle.

[0005] The present application is to solve such a problem, and an object thereof is to suppress the electric power consumed when the nozzle is warmed up.

[0006] In the injection molding machine of the present application, the temperature of the nozzle is controlled based on the temperature of the cylinder so as not to exceed the temperature of the cylinder.

[0007] The above and other objects, features, aspects and advantages of the present application will become more apparent from the following detailed description of the present application when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a diagram for explaining the configuration of the injection molding machine of the present embodiment. Figure 2 is a diagram for explaining the heating cylinder and the injection nozzle. Figure 3 is a functional block diagram of the control device. Figure 4 is a flowchart for explaining the main processing of the control device. Figure 5 is a diagram showing the simulation results of the present embodiment. DETAILED DESCRIPTION

[0009] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. Figure 1The embodiments of the present application will be described in detail below. Furthermore, the same reference numerals are used throughout the drawings to designate the same or similar parts, and the description thereof will not be repeated.

[0010] [Structure of injection molding machine]

[0011] Figure 1 is a view for explaining the structure of the injection molding machine 100 of the present embodiment. Furthermore, for the sake of convenience of explanation, the same reference numerals are used for the same or similar parts, and the description thereof will not be repeated. Figure 1 In the present embodiment, the ground surface on which the injection molding machine 100 is disposed is set as the XY plane, and the direction perpendicular to the ground surface is set as the Z-axis direction. Sometimes, the positive direction of the Z-axis is referred to as the upper surface side or the upward direction, and the negative direction is referred to as the lower surface side or the downward direction. Furthermore, the injection molding machine 100 is shown as a horizontal type injection molding machine, but is not limited to the horizontal type, and can be a vertical type injection molding machine.

[0012] The structure of the injection molding machine 100 includes a clamping device 110 for clamping a mold, an injection device 120 for melting and injecting an injection material, an operation panel 130, and a control device 140. Figure 2 In the present embodiment, the clamping device 110 is disposed on the negative direction side of the X-axis with respect to the injection device 120.

[0013] The clamping device 110 includes a base 111, a fixed disc 112, a clamping housing 113, a movable disc 114, a tie rod 115, a clamping mechanism 116, molds 117, 118, and a ball screw 119. The base 111 is disposed on the ground surface, and on the upper surface thereof, the fixed disc 112, the clamping housing 113, the movable disc 114, and the like are mounted.

[0014] The fixed disc 112 is fixed to the end portion on the side closer to the injection device 120 (that is, the positive direction of the X-axis) on the base 111. The clamping housing 113 is disposed on the end portion of the negative direction of the X-axis on the base 111. The fixed disc 112 and the clamping housing 113 are linked by the tie rod 115 including a plurality of rods. The clamping housing 113 is movable in the X-axis direction on the base 111.

[0015] The movable disc 114 is disposed between the fixed disc 112 and the clamping housing 113 on the base 111. The movable disc 114 is configured to be movable in the X-axis direction. The clamping housing 113 and the movable disc 114 are linked by the clamping mechanism 116. The clamping mechanism 116 has a toggle mechanism. The ball screw 119 is linked to the toggle mechanism, and by driving a servo motor 151 disposed in the clamping housing 113 to rotate the ball screw 119, the movable disc 114 can be relatively moved in the X-axis direction with respect to the clamping housing 113. Furthermore, as the clamping mechanism 116, a direct-acting hydraulic cylinder driven by hydraulic pressure can also be used.

[0016] Molds 117 and 118 are respectively disposed on the movable disk 114 and the fixed disk 112. Molds 117 and 118 are arranged opposite each other between the movable disk 114 and the fixed disk 112. By using the mold closing mechanism 116 to move mold 117 along the X-axis, mold 117 can be brought into close contact with mold 118, or mold 117 can be separated from mold 118. In the following description, the process of transitioning from the state of separation of molds 117 and 118 to the state of close contact is called "mold closing". In addition, the process of transitioning from the state of close contact of molds 117 and 118 to the state of separation is called "mold opening".

[0017] With molds 117 and 118 in close contact during the mold-closing process, molten material (resin) is filled into the mold and allowed to cool and solidify, thereby forming a product (molded article) of the desired shape. After the product is formed, with mold 117 separated from mold 118 during the mold-opening process, an ejector mechanism (not shown) disposed on movable disk 114 is activated, thereby removing the molded product from mold 117. The ejector mechanism is driven by a servo motor 152 disposed on movable disk 114. Furthermore, the process of removing the product using the ejector mechanism is referred to as the "ejection" process.

[0018] The injection device 120 includes a base 121, a heating cylinder 122, a working device 124, a hopper 125, an injection nozzle 126, a nozzle contact device 127, and a temperature sensor. The heating cylinder 122 and the injection nozzle 126 correspond to the "cylinder" and "nozzle" of this invention, respectively. The temperature sensor will be described later. Figure 2 Temperature sensors T1 to T7.

[0019] The base 121 is disposed on the ground on the positive X-axis side of the base 111, and the working device 124 is mounted on its upper surface. Servo motors 153 and 154 are disposed on the working device 124.

[0020] The working device 124 is equipped with a heating cylinder 122 extending along the X-axis. The heating cylinder 122 includes a heating device for heating its interior (described later). Figure 2 The device includes a heating element 18 and a screw 123. The screw 123 is driven by a servo motor 153 within the working device 124 and is configured to rotate about the X-axis. Alternatively, the screw 123 is driven by a servo motor 154 and is configured to move along the X-axis.

[0021] The injection nozzle 126 is located at the front end of the mold clamping device 110 side of the heating cylinder 122 (that is, the end in the negative direction of the X-axis). The heating cylinder 122 heats and melts the bead-shaped resin material fed from the hopper 125, and mixes it using the screw 123, thereby generating molten material. This process of melting the resin material in this way is called the "plasticizing" process. The plasticizing process also includes the measurement of the molten material used for one injection.

[0022] The nozzle contact device 127, for example, is a mechanism using a hydraulic cylinder or a mechanism using a ball screw, connecting the working device 124 and the fixed platen 112 of the mold clamping device 110. When the nozzle contact device 127 is configured using a ball screw, it is driven by the working device 124, causing the working device 124 and the heating cylinder 122 to move along the X-axis. Through the nozzle contact device 127, the injection nozzle 126 contacts the sprue sleeve of the mold 118 in the mold clamping device 110, injecting molten material from the injection nozzle 126, thereby injecting the molten material into the molds 117 and 118. Furthermore, the cavities of the molds 117 and 118 are filled with molten material. The servo motor 154 applies pressure to the molten material by moving the screw 123 within the heating cylinder 122 in the negative X-axis direction, maintaining a constant pressure on the molten material injected into the molds 117 and 118, as well as the pressure of the injected molten material after injection.

[0023] Furthermore, the configuration of the nozzle contact mechanism is not limited to the configuration described above, where the injection device is moved as a whole via a ball screw positioned between the fixed platen 112 and the working device 124; other configurations are also possible. For example, it could be configured such that a ball screw connects the device frame and the fixed component at the rear of the heating cylinder, causing the heating cylinder itself to move toward the mold. Alternatively, it could be configured such that a ball screw connects the sliding seat carrying the injection device to the device frame, causing the injection device and the sliding seat to move together, thereby bringing the injection nozzle into contact with the mold.

[0024] Furthermore, the process of injecting molten material into molds 117 and 118 is called the "injection" process. In addition, the process of maintaining the molten material filled in molds 117 and 118 at a fixed pressure and cooling it after the injection process is called the "pressure holding" process.

[0025] If the pressure holding process is completed, the mold opening process and the ejection process are performed to remove the molded product.

[0026] The injection molding machine 100 can continuously form products by repeatedly performing the mold closing process, injection process, pressure holding process, plasticizing process, mold opening process and ejection process in a cycle.

[0027] The control device 140 is housed inside the base 121. The control device 140 includes a CPU 141, a memory 142, and a servo amplifier 143 for driving servo motors 151-154. The control device 140 acquires detection values ​​from various sensors configured on the injection molding machine 100 and controls the injection molding machine 100 in a coordinated manner.

[0028] The control panel 130 is a device for users to operate the injection molding machine 100, including a display 132 with a display area for displaying various images, and input devices such as a keyboard. The control panel 130 is connected to the control device 140 and can acquire and display the status of the injection molding machine 100, or output user operation signals from the input devices to the control device 140.

[0029] The display 132 in this embodiment is a touch panel capable of displaying images and receiving input (instructions) from the user. The control device 140 receives input (instructions) from the user. The operation panel 130 can be mounted on the base 111 or the base 121 of the injection molding machine 100, or it can be configured in a position independent of the injection molding machine 100.

[0030] [Heating cylinder and injection nozzle] Figure 1 This is a diagram illustrating the heating cylinder 122 and the injection nozzle 126. The heating cylinder 122 extends along the extension direction ( Figure 2 The X-axis is divided into multiple partitions. Figure 2 In this example, the heating cylinder 122 is divided into five sections: section CZ1, section CZ2, section CZ3, section CZ4, and section CZ5. Additionally, the injection nozzle 126 is also divided into multiple sections along the aforementioned extension direction. Figure 2 In the example, the injection nozzle 126 is divided into two partitions, NZ1 and NZ2.

[0031] Partition CZ1 is the partition to which the injection nozzle 126 is connected, corresponding to the "connection partition" of the present invention. Partition CZ2 is the partition adjacent to partition CZ1, corresponding to the "adjacent partition" of the present invention.

[0032] The heating device 18 can individually heat the heating cylinder 122 and the injection nozzle 126 under the control of the control device 140. The heating device 18 includes a plurality of heaters arranged corresponding to each heating zone. Figure 3 In this example, the heating device 18 includes heaters 181, 182, 183, 184, 185, 186, and 187. Heaters 181 to 185 heat zones CZ1 to CZ5 respectively. Heaters 186 and 187 heat zones NZ1 and NZ2 respectively.

[0033] Furthermore, the injection device 120 includes temperature sensors T1, T2, T3, T4, T5, T6, and T7. Temperature sensors T1 through T7 detect the temperatures of zones CZ1 through CZ5, zone NZ1, and zone NZ2, respectively. The detected temperatures from each temperature sensor are output to the control device 140.

[0034] The control device 140 stores the set temperature of each zone. The set temperature of each zone can be the same, and at least two of the set temperatures of each zone can be different.

[0035] The control device 140 performs PID (Proportional Integral Derivative) control on each heater individually, so that the detected temperature based on each temperature sensor becomes the set temperature of each zone.

[0036] In this embodiment, the control device 140 simultaneously starts heating of heaters 181 to 187. Furthermore, after the detected temperature of each zone reaches the set temperature corresponding to that zone, the injection molding machine 100 begins the injection molding process.

[0037] Typically, the volume of the injection nozzle is smaller than that of the heating cylinder, and the heating cylinder stores the material for injection, thus its heat capacity is greater than that of the injection nozzle. Therefore, when the same amount of heat is applied to both the injection nozzle and the heating cylinder, the injection nozzle will heat up faster than the heating cylinder.

[0038] Therefore, when heating both the injection nozzle and the heating cylinder, the injection nozzle reaches its set temperature earlier than the heating cylinder. In this case, after the injection nozzle reaches its set temperature, it needs to be continuously heated to maintain the nozzle temperature until the heating cylinder reaches its set temperature. This results in unnecessary power consumption to maintain the injection nozzle temperature.

[0039] Therefore, in this embodiment, the control device 140 controls the temperature of the injection nozzle 126 based on the temperature of the heating cylinder 122 detected by the temperature sensor T2 (described later), so that it does not exceed the temperature of the heating cylinder 122. More specifically, when the injection nozzle 126 is heated, under certain conditions, the control device 140 uses the detected temperature of a predetermined portion of the heating cylinder 122, whose heating rate is slower than that of the injection nozzle 126, as the target temperature, and controls the heaters (heater 186 and heater 187) of the injection nozzle 126. Through this control, the control device 140 synchronizes the heating of the injection nozzle 126 with the predetermined portion of the heating cylinder 122, thereby slowing down the heating rate of the injection nozzle 126.

[0040] Therefore, the injection molding machine 100 can delay the timing of the injection nozzle 126 reaching the set temperature. As a result, in the injection molding machine 100 of this embodiment, unnecessary power consumption for maintaining the temperature of the injection nozzle can be suppressed. Hereinafter, the partitioning of the designated portion of the heating cylinder 122 is also referred to as "synchronization partitioning".

[0041] In this embodiment, the synchronization zone is set to correspond to the zone in each zone of the heating cylinder 122 that has a larger heat capacity than the injection nozzle 126 (that is, the zone with a slower heating rate). Therefore, the injection molding machine 100 can delay the timing of the detection temperature of the injection nozzle 126 reaching the set temperature, thereby suppressing power consumption.

[0042] Furthermore, in this embodiment, the synchronization zone is set to zone CZ2, which has the largest heat capacity among all zones of the heating cylinder 122 (that is, the zone with the slowest heating rate). Therefore, the timing for zone CZ2 to reach the set temperature is the slowest. As a result, the injection molding machine 100 can delay the timing for the injection nozzle 126 to reach the set temperature to the aforementioned slowest timing. As a result, compared to the case where the synchronization zone is set to other zones of the heating cylinder 122, the injection molding machine 100 can better suppress unnecessary power consumption.

[0043] Furthermore, as described above, the temperature of the synchronization zone is detected by temperature sensor T2. Based on the detected temperature of this synchronization zone, the injection molding machine 100 performs PID control on the heater of the injection nozzle 126. Temperature sensors T6 and T7, which detect the temperature of the injection nozzle 126, respectively correspond to the "nozzle temperature sensor" of this invention. Additionally, temperature sensor T2, which detects the temperature of the synchronization zone (zone CZ2), corresponds to the "cylinder temperature sensor" of this invention.

[0044] [Functional block diagram of the control device] Figure 3This is a functional block diagram of the control device 140. The control device 140 includes a setting unit 191, a subtraction operation unit 192, a PID control unit 193, and a memory 142. Figure 3 This is a diagram illustrating the control of the heater 186 for heating the partition NZ1 of the injection nozzle 126. Furthermore, Figure 4 The following example illustrates the situation using the heating of the injection nozzle 126 in section NZ1.

[0045] The control device 140 uses the detected temperature of the synchronous zone as the target temperature to heat zone NZ1 until the detected temperature of zone NZ1 obtained based on temperature sensor T6 approaches the set temperature of zone NZ1. Furthermore, after the detected temperature of zone NZ1 approaches the set temperature of zone NZ1, the control device 140 switches the target temperature to the set temperature of zone NZ1 to heat zone NZ1.

[0046] In the following explanation, "target temperature" refers to the temperature that becomes the target in the PID control of each zone. "Set temperature" is the temperature that each zone ultimately reaches. Additionally, "reference temperature" indicates the temperature at which the target temperature is switched (the switching point) as described above. In other words, the reference temperature is used to determine whether the detected temperature of zone NZ1 is close to the set temperature of zone NZ1.

[0047] The memory 142 stores the set temperature and reference temperature for each zone. In this embodiment, the reference temperature is calculated by subtracting the proportional band from the set temperature. In this embodiment, the reference temperature includes the nozzle reference temperature for zone NZ1 and the cylinder block reference temperature for the synchronization zone.

[0048] The nozzle reference temperature is calculated by subtracting the proportional band of zone NZ1 from the set temperature of zone NZ1. The proportional band of zone NZ1 is the reciprocal of the proportional gain used in the P control of the PID control of zone NZ1. The nozzle reference temperature is such that, during the heating of zone NZ1, the detected temperature of zone NZ1 approaches the set temperature of zone NZ1.

[0049] The cylinder block reference temperature is calculated by subtracting the proportional band of the synchronization zone from the set temperature of the synchronization zone. The proportional band of the synchronization zone is the reciprocal of the proportional gain used in the P control of the PID control of the synchronization zone. The cylinder block reference temperature is the temperature at which the detected temperature of the synchronization zone approaches its set temperature during the heating process.

[0050] The set temperature of zone NZ1 corresponds to the "nozzle set temperature" of this invention. The set temperature of the synchronous zone corresponds to the "cylinder block set temperature" of this invention. The proportional band of zone NZ1 corresponds to the "nozzle specified temperature" of this invention. The proportional band of the synchronous zone corresponds to the "cylinder block specified temperature" of this invention. The proportional gain of zone NZ1 corresponds to the "nozzle proportional gain" of this invention. The proportional gain of the synchronous zone corresponds to the "cylinder block proportional gain" of this invention.

[0051] Additionally, the detected temperatures from the synchronous zone of temperature sensor T2 and the detected temperatures from zone NZ1 of temperature sensor T6 are input to the setting unit 191. Furthermore, the setting unit 191 acquires the set temperature of NZ1, the nozzle reference temperature, and the cylinder reference temperature stored in the memory 142.

[0052] Setting section 191, through the following description Figure 4 The method described in steps S2 to S8 sets the detection temperature of the synchronization partition or the setting temperature of partition NZ1 as the target temperature.

[0053] The subtraction unit 192 calculates the deviation e by subtracting the detection temperature of zone NZ1 from the set target temperature. The deviation e is input to the PID control unit 193. The PID control unit 193 performs PID-based calculations relative to the deviation e, thereby calculating the operating quantity of the heater 186 and controlling the heater 186.

[0054] [Flowchart of the control device] Figure 3 This is a flowchart illustrating the main processes based on the control device 140. The control device 140 executes the processes illustrated in this flowchart at a predetermined period (e.g., 1 ms).

[0055] First, in step S2, the control device 140 determines whether the detected temperature of the injection nozzle 126 is lower than the nozzle reference temperature. If the detected temperature of the injection nozzle 126 is lower than the nozzle reference temperature (yes in step S2), the process proceeds to step S4.

[0056] In step S4, the control device 140 determines whether the detection temperature of the synchronous zone of the heating cylinder 122 is lower than the cylinder reference temperature. If the detection temperature of the synchronous zone is lower than the cylinder reference temperature (yes in step S4), that is, in the initial state after the injection nozzle 126 and the heating cylinder 122 have started heating, the process proceeds to step S6.

[0057] In step S6, the control device 140 sets the target temperature of the injection nozzle 126 to the detection temperature of the synchronous zone of the heating cylinder 122. Therefore, through the processing in step S6, in the aforementioned initial state, the injection molding machine 100 can synchronize the heating rate of the injection nozzle 126 with the heating rate of the synchronous zone of the heating cylinder 122. Thus, the injection molding machine 100 can slow down the heating rate of the injection nozzle 126 in the aforementioned initial state.

[0058] On the other hand, if the detected temperature of the injection nozzle 126 is higher than the nozzle reference temperature (no in step S2), that is, if the detected temperature of the injection nozzle 126 is close to the set temperature of the injection nozzle 126, the control device 140 advances the process to step S8. Additionally, if the detected temperature of the synchronization zone of the heating cylinder 122 is higher than the cylinder reference temperature (no in step S4), that is, if the synchronization zone of the heating cylinder 122 is close to the set temperature of that zone, the control device 140 also advances the process to step S8.

[0059] In step S8, the control device 140 restores the target temperature of the injection nozzle 126 to the set temperature of the injection nozzle 126. Thus, when the detected temperature of the injection nozzle 126 is close to the set temperature of the injection nozzle 126, the control device 140 can heat the nozzle to the final target temperature by setting the temperature of the injection nozzle 126 to the set temperature.

[0060] After the processing in step S6 or S8 is completed, in step S10, the control device 140 executes PID control using the set target temperature of the injection nozzle 126. Furthermore, PID control is... Figure 4 The subtraction operation unit 192 and the PID control unit 193 process the data.

[0061] As described above, the control device 140 controls the detection temperature of the injection nozzle 126 based on the detection temperature of the heating cylinder 122, ensuring that it does not exceed the temperature of the heating cylinder 122. More specifically, in the initial state where the nozzle temperature is sufficiently lower than the set temperature, the control device 140 switches the target temperature of the injection nozzle 126 to the detection temperature of the synchronous zone for heating control, thereby slowing down the heating rate of the injection nozzle 126 (step S6). Furthermore, as the heating progresses over time and the detection temperature of the injection nozzle 126 approaches the set temperature of the injection nozzle 126, the control device 140 restores the target temperature of the injection nozzle 126 to the set temperature of the injection nozzle 126 for heating control (step S8). Therefore, the control device 140 can delay the timing of the injection nozzle 126 reaching the set temperature to the timing of the synchronous zone reaching the set temperature, while simultaneously heating to the final set temperature. Thus, the injection molding machine 100 of this embodiment can suppress the power consumed when heating the injection nozzle 126.

[0062] In addition, through Figure 3 The step S2 involves comparing the detected temperature of the injection nozzle 126 with the nozzle reference temperature, and the step S4 involves comparing the detected temperature of the synchronous zone with the cylinder reference temperature, to set the target temperature of the injection nozzle. Therefore, the injection molding machine 100 of this embodiment does not require complex calculations, and can suppress the power consumption in the temperature control of the injection nozzle 126 through a relatively simple process.

[0063] In addition, such as Figure 5 As shown, a "proportional band" is used to set the reference temperature. Therefore, the injection molding machine 100 can be set as the switching point for the target temperature, taking control gain into account. This allows for a suitable switching point to be set, enabling smooth control. Furthermore, the unit of the proportional band is temperature, making the switching point easy for the user to understand.

[0064] [Simulation Results] Figure 5 This is a diagram showing simulation results for illustrating the effects of the injection molding machine 100 in this embodiment. Figure 5 (A) is a graph showing the simulation results of the comparative injection molding machine. The comparative injection molding machine controls each heater by using the set temperature corresponding to each zone as the target temperature. Figure 5 (B) is a graph showing the simulation results of the injection molding machine 100 according to this embodiment. Furthermore, Figure 5 (A) Figure 5 The vertical axis of (B) represents the detected temperature obtained based on temperature sensors T1 to T7. Figure 5 (A) Figure 5 The horizontal axis of (B) represents time.

[0065] Figure 5 (A) Figure 5 In (B), the set temperatures of the seven zones (zones CZ1 to CZ5, NZ1, and NZ2) are represented by dashed lines. In this simulation example, the set temperatures of all seven zones are set to the same value.

[0066] As described above, the heating rate of the injection nozzle is faster than that of the heating cylinder. Therefore, in the comparative example, such as Figure 4 As shown in the diagram of temperature sensors T6 and T7 in (A), the timing of the injection nozzle reaching the set temperature is earlier than the timing of the heating cylinder reaching the set temperature. In this case, after the injection nozzle temperature reaches the set temperature, it is necessary to continue heating the injection nozzle to maintain its temperature until the heating cylinder temperature reaches the set temperature, consuming unnecessary power.

[0067] In contrast, the control applied in this embodiment... ​ In (B), the injection molding machine 100 controls the detected temperature of the injection nozzle 126 (based on the detected temperatures of temperature sensors T6 and T7) to ensure that it does not exceed the temperature of the heating cylinder 122 (the detected temperatures of temperature sensors T1 to T5). More precisely, the injection molding machine 100 performs... ​ The temperature is controlled by switching the target temperature, thereby synchronizing the heating rate of the injection nozzle 126 with the heating rate of the synchronous zone. This allows for a timing delay in the arrival of the detected temperature of the injection nozzle 126 at the set temperature, resulting in reduced power consumption for temperature control of the injection nozzle 126.

[0068] <Other Implementation Methods> (1) This example shows the use of a "proportional band" as the "specified temperature" that determines the switching point, but the specified temperature may not necessarily be the same as the proportional band. For example, the specified temperature may also be set to a value within a range of plus or minus 20% relative to the proportional band.

[0069] That is, the upper limit of the nozzle's specified temperature range is the value obtained by multiplying the nozzle proportional band by a real number A (A > 1), and the lower limit of the nozzle's specified temperature range is the value obtained by multiplying the nozzle proportional band by a real number B (0 < B < 1). For example, A = 1.2 and B = 0.8.

[0070] In addition, the upper limit of the specified range of cylinder block temperature is the value obtained by multiplying the cylinder block proportional band by a real number C (C > 1), and the lower limit of the specified range of cylinder block temperature is the value obtained by multiplying the cylinder block proportional band by a real number D (0 < D < 1). For example, it can be set as C = 1.2 and D = 0.8.

[0071] (2) In the above embodiment, it is explained that the synchronous partition is the partition CZ2 with the largest heat capacity in the heating cylinder 122. However, the synchronous partition may also be a partition of the heating cylinder 122 that is different from partition CZ2.

[0072] Embodiments of the present invention have been described, but it should be understood that all points of the embodiments disclosed herein are illustrative and not limiting. The scope of the present invention is defined by the technical solutions, including equivalents and all modifications made within that scope.

Claims

1. An injection molding machine, wherein, include: An injection device that melts and injects the raw material; A mold closing device for closing a mold into which the injection material has been injected; as well as Control device for controlling the injection device Here, the injection device includes: Cylinder block; A screw disposed within the cylinder and heating the injected raw material to generate molten material; A nozzle located at the front end of the cylinder body that injects the heated molten material into the mold; A nozzle temperature sensor for detecting the temperature of the nozzle; A cylinder block temperature sensor for detecting the temperature of the cylinder block; and A heating device controlled by the aforementioned control device and capable of independently heating the nozzle and the cylinder. The control device controls the temperature of the nozzle based on the temperature detected by the cylinder temperature sensor, so that it does not exceed the temperature of the cylinder.

2. The injection molding machine according to claim 1, wherein, The cylinder block temperature sensor detects the temperature of a specified portion of the cylinder block. The nozzle heats up faster than the specified portion. The control device controls the heating device to make the temperature of the nozzle reach the nozzle set temperature. If the temperature obtained by subtracting the specified nozzle temperature from the set nozzle temperature is set as the nozzle reference temperature, then the control device, in order to ensure that the nozzle temperature does not exceed the cylinder body temperature, If the nozzle temperature is lower than the nozzle reference temperature, the nozzle is heated to a target temperature based on the temperature of a predetermined portion obtained from the cylinder block temperature sensor. If the temperature of the nozzle is higher than the nozzle reference temperature, the nozzle is heated using the nozzle set temperature as the target temperature.

3. The injection molding machine according to claim 2, wherein, The cylinder block is divided into multiple sections along its extension direction. The heating device is capable of heating each of the multiple zones individually. The specified portion corresponds to the portion of the plurality of zones whose heat capacity is greater than that of the nozzle.

4. The injection molding machine according to claim 3, wherein, The specified portion is the partition with the largest heat capacity among the multiple partitions.

5. The injection molding machine according to claim 4, wherein, The plurality of partitions includes: The nozzle is connected to the connecting partition; and Adjacent partitions adjacent to the connected partition The specified portion refers to the adjacent partitions.

6. The injection molding machine according to any one of claims 2 to 5, wherein, The control device uses nozzle proportional gain to control the heating device that heats the nozzle. The specified temperature of the nozzle is set within a specified range that includes the reciprocal of the nozzle proportional gain.

7. The injection molding machine according to claim 6, wherein, The specified temperature of the nozzle is the reciprocal of the nozzle proportional gain.

8. The injection molding machine according to any one of claims 2 to 7, wherein, The control device controls the heating device to make the temperature of the specified section reach the set temperature of the cylinder. If the temperature obtained by subtracting the cylinder block specified temperature from the cylinder block set temperature is set as the cylinder block reference temperature, then when the nozzle temperature is lower than the nozzle reference temperature, and when the temperature of the specified portion is lower than the cylinder block reference temperature, the control device will use the temperature of the specified portion as the target temperature to heat the nozzle.

9. The injection molding machine according to claim 8, wherein, When the temperature of the nozzle is lower than the nozzle reference temperature, and when the temperature of the specified portion is higher than the cylinder reference temperature, the control device heats the nozzle by using the nozzle set temperature as the target temperature.

10. The injection molding machine according to claim 8, wherein, The control device uses cylinder proportional gain to control the heating device that heats the specified portion. The specified temperature of the cylinder block is set within a specified range that includes the reciprocal of the cylinder block proportional gain.

11. The injection molding machine according to claim 10, wherein, The specified temperature of the cylinder block is the reciprocal of the proportional gain of the cylinder block.

12. An injection device, wherein, include: Cylinder block; A screw disposed within the cylinder and heating the injected raw material to generate molten material; A nozzle located at the front end of the cylinder body that injects the heated molten material into the mold; A nozzle temperature sensor for detecting the temperature of the nozzle; A cylinder temperature sensor for detecting the temperature of the cylinder block; and A heating device capable of independently heating both the nozzle and the cylinder. Here, the temperature of the nozzle can be controlled based on the temperature detected by the cylinder temperature sensor so that it does not exceed the temperature of the cylinder.

13. A control method for an injection molding machine, wherein, The injection molding machine includes: An injection apparatus that melts and injects the raw material; and A mold closing device for closing a mold into which the injected raw material has been injected. The injection device includes: Cylinder block; A screw disposed within the cylinder and heating the injected raw material to generate molten material; and A nozzle located at the front end of the cylinder body injects the heated molten material into the mold. The control method includes step (a) of controlling the temperature of the nozzle based on the temperature of the cylinder to ensure that it does not exceed the temperature of the cylinder.

14. The control method for an injection molding machine according to claim 13, wherein, The nozzle heats up faster than a specified portion of the cylinder. If the temperature obtained by subtracting the specified nozzle temperature from the nozzle set temperature is set as the nozzle reference temperature, then in order to ensure that the temperature of the nozzle does not exceed the temperature of the cylinder, step (a) includes: Step (b) involves heating the nozzle by using the temperature of a predetermined portion as the target temperature when the nozzle temperature is lower than the nozzle reference temperature; and Step (c) involves heating the nozzle by setting the nozzle temperature as the target temperature when the nozzle temperature is higher than the nozzle reference temperature.

15. The control method for an injection molding machine according to claim 14, wherein, The cylinder block is divided into multiple sections along its extension direction. It can heat the multiple partitions individually. The specified portion corresponds to the portion of the plurality of zones whose heat capacity is greater than that of the nozzle.

16. The control method for an injection molding machine according to claim 15, wherein, The specified portion is the partition with the largest heat capacity among the multiple partitions.

17. The control method for an injection molding machine according to claim 16, wherein, The plurality of partitions includes: The nozzle is connected to the connecting partition; and Adjacent partitions adjacent to the connected partition The specified portion refers to the adjacent partitions.

18. The control method for an injection molding machine according to any one of claims 14 to 17, wherein, In the control method of the injection molding machine, a nozzle proportional gain is used for heating the nozzle. The specified temperature of the nozzle is set within a specified range that includes the reciprocal of the nozzle proportional gain.

19. The control method for an injection molding machine according to claim 18, wherein, The specified temperature of the nozzle is the reciprocal of the nozzle proportional gain.

20. The control method for an injection molding machine according to any one of claims 14 to 19, wherein, If the temperature obtained by subtracting the specified cylinder temperature from the specified cylinder temperature is taken as the cylinder reference temperature, then step (a) includes: Step (e) involves heating the nozzle by taking the temperature of the specified portion as the target temperature when the nozzle temperature is lower than the nozzle reference temperature and the temperature of the specified portion is lower than the cylinder reference temperature.

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