JP3433093B2 - Temperature control method and temperature control device for injection machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection machine temperature control method and a temperature control apparatus for controlling the temperature of heating means provided on the outer periphery of a heating cylinder by feedback control. The present invention relates to a temperature control method and a temperature control device for an injection machine, which feedback-controls the temperature of a heating means provided on the outer peripheral portion of the heating device at different set temperatures during molding and during molding stop.

[0002]

2. Description of the Related Art As is well known, a heating cylinder of an injection molding machine is apparently divided into a plurality of temperature control zones in the axial direction, and the outer peripheral portion of the heating cylinder is heated corresponding to the divided temperature control zones. A heater is provided. Further, a temperature sensor is provided at a predetermined depth position of the heating cylinder for each temperature control zone, and each heating heater is feedback-controlled by PID operation or the like so that the temperature measured by these temperature sensors reaches a set temperature. Is controlled by. Therefore, when the temperature of the heating cylinder, that is, the heating temperature of the heating heater is set, the screw provided in the heating cylinder is driven to rotate, and the resin material is supplied to the heating cylinder, the resin material is heated in the process of being sent forward. The heat applied from the heater and the shearing action of the screw rotation,
It is plasticized and weighed by the heat generated by frictional action.

[0003]

As described above, since the conventional heater is also controlled by the feedback control so as to reach the set temperature, there is no particular problem in the stable molding state. However, the resin material discolors due to heat at the start of molding, during the cancellation of molding, etc., and the temperature change of the resin material is large from the initial molding stage to the molding stable region, so the viscosity change is large and the quality of the molded product may be deteriorated. is there. More specifically, when molding is started,
The heat of the heating cylinder is taken from the inner wall surface by the resin material being kneaded and melted. By the way, in a general feedback control system such as PID control, since the deviation between the set temperature and the detected temperature is generated, that is, the temperature of the heating cylinder is lowered, the heating is performed by the heater, so that the compensation operation is performed. A delay occurs and the temperature of the heating cylinder drops significantly. The state in which the heating by the heater is delayed and the temperature of the heating cylinder and the temperature of the resin material are lowered is shown in (a) to (c) of FIG.

On the contrary, when the molding is completed, the resin material does not take heat from the inner wall surface of the heating cylinder, so that the heating amount of the heating heater for maintaining the set temperature can be small. By the way, the conventional temperature control system reduces the heat generation amount after the deviation occurs. That is, the amount of heat generation is reduced after overshooting. As a result, the temperature starts to drop after the temperature overshoots. Such a state is shown in (d) and (e) of FIG. Considering the phenomenon during the molding stop, the resin material staying in the heating cylinder during the molding stop is heated from the heating cylinder and rises with the passage of time, and gradually approaches the temperature of the heating cylinder. When the molding is started from this state, it is molded by the retained high temperature resin material, that is, the low viscosity resin material. On the other hand, as the molding progresses, a new resin material having a relatively low temperature is supplied from the hopper, the resin temperature becomes lower than that at the initial stage of molding, and the resin material is molded with high viscosity. The degree of lowering becomes larger as the molding volume is larger, the molding cycle time is shorter, and the residence time in the heating cylinder is shorter. As described above, according to the conventional control method, the viscosity greatly changes according to the temperature of the resin material from the initial stage of molding to the molding stable region, which induces temporal fluctuation of the quality of the molded product.

Furthermore, if the resin material is heated to a high temperature while molding is stopped, discoloration occurs, which is a direct cause of defective molding such as burns. In addition, a resin material that is sensitive to heat decomposes during molding to cause black spots. An object of the present invention is to provide a temperature control method and a temperature control device for an injection machine, which eliminates the above-mentioned conventional drawbacks. Specifically, the temperature change of the resin material is small, which results in high quality and quality. It is an object of the present invention to provide a temperature control method and a temperature control device for an injection machine, which can obtain a molded product having a constant temperature.

[0006]

Means for Solving the Problems The present invention, in order to achieve the above object, the temperature of the heating means provided on the outer periphery of the heating cylinder, and the set temperature in the molding set, formed
It is configured to perform feedback control according to different set temperatures of the set temperature during the molding stop in which the resin temperature in the shape is stored . That is, in order to achieve the above object, the invention according to claim 1 sets the temperature of the heating means provided on the outer peripheral portion of the heating cylinder to the set temperature during molding and the resin temperature during molding. Is a temperature control method for an injection machine in which feedback control is performed based on different set temperatures of the set temperature during molding cancellation, in which the temperature of the heating means is set during molding from the flushing before molding or from the start of molding. When the molding is stopped or finished, the temperature of the heating means is controlled by switching from the set temperature during molding to the set temperature during molding cancellation. The invention according to claim 2, the temperature of the heating means provided on the outer periphery of the heating cylinder, and the set temperature in the molding set, set in the molding discontinue the resin temperature during molding are stored A method for controlling the temperature of an injection machine in which the temperature is feedback controlled by different set temperatures, and the molding cycle time is measured by controlling the temperature of the heating means from the flushing before molding or from the start of molding by the set temperature during molding. However, when the preset upper and lower limits of the molding cycle time are exceeded, the preset temperature during the molding is switched to the preset temperature during the suspension of molding to control the temperature of the heating means. According to a third aspect of the present invention, the temperature of the heating means provided on the outer peripheral portion of the heating cylinder is set based on the relationship between the set temperature during molding, the residence time of the resin in the heating cylinder, and the resin temperature. A method for controlling the temperature of an injection machine that performs feedback control based on different set temperatures of the set temperature during the expected molding stop, wherein the temperature of the heating means is controlled by the set temperature during molding from the flushing before molding or the start of molding. Then, when the molding is stopped or ended, the temperature of the heating means is controlled by switching from the set temperature during the molding to the set temperature during the molding stop, and the invention according to claim 4 is the heating cylinder. the temperature of the heating means provided on the outer periphery of a setting temperature of forming <br/> in form of being set, shaped stop that is predicted from the relationship between the residence time of the resin in the heating cylinder and the resin temperature A method for controlling the temperature of an injection machine in which feedback control is performed according to different set temperatures of the set temperature of the molding machine, wherein the temperature of the heating means is controlled by the set temperature during molding from the flushing before molding or the start of molding, and the measured molding is performed. When the cycle time exceeds a preset upper and lower limit value of the molding cycle time, the temperature of the heating means (H2) is controlled by switching from the preset temperature during molding to the preset temperature during suspension of molding. It In the invention according to claim 5, the temperature of the heating means provided on the outer peripheral portion of the heating cylinder is set.
And the set temperature in the molding that the resin temperature during the molding is stored
And the set temperature in the molding stop are different set temperatures a temperature controller of the injection machine for feedback control, the temperature control device, switching means for switching between setting temperature during discontinued molding set temperature during the molding And the addition point at which the temperature detected by the heating cylinder and the set temperature during molding or the set temperature during molding stopped by the switching means are input, and the deviation amount obtained at the addition point is adjusted to the heating means. According to the invention of claim 6, the temperature of the heating means provided on the outer peripheral portion of the heating cylinder is set to a set temperature during molding which is set. set temperature during molding discontinue the resin temperature during the molding is stored, a temperature control apparatus for an injection machine that performs feedback control by different set temperature, the temperature control device is set in the molding Switching means for switching between the temperature and the set temperature during the molding stop, the addition point at which the detected temperature of the heating cylinder and the set temperature during the molding or the set temperature during the molding stop input by the switching means are inputted, and the addition point It consists of adjusting / operating means for adjusting the deviation amount obtained at the confluence and outputting the operation amount to the heating means, and judging means for judging whether or not molding is in progress. When the judging means judges no, the switching means It is configured to output the set temperature during the suspension of molding to the joining point.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a schematic diagram showing a part of the injection machine in cross section along with a control block diagram. As shown in the drawing, the injection machine includes a heating cylinder 1. A screw 2 is provided inside the heating cylinder 1 as is well known in the art, and a hopper 3 in which a resin material is temporarily stored at a rear end of the heating cylinder 1 and a screw are arranged in a rotational direction and an axial direction. A drive device 4 including an electric motor 5 and the like for driving the vehicle is provided. The heating cylinder 1
It is apparently divided into a plurality of temperature control zones K1 to K3, and heaters H1 to H3 are provided on the outer peripheral portions of the temperature control zones K1 to K3, respectively.

The heaters H1 to H3 are controlled as a whole or individually as described below, but in the present embodiment, only one heater H2 is controlled by the temperature controller C. It is shown. Temperature controller C
Includes an addition point 10 and an adjustment / operation unit 11 that adjusts the deviation signal obtained at the addition point 10 and outputs the operation amount of the heater H2. Furthermore, the switch circuit 1
2, a comparator 13, a temperature setter, and the like are also provided, and these are configured as described below.

One input terminal of the joining point 10 and the first temperature sensor S1 embedded in the heating cylinder 1 corresponding to the temperature control zone K2 are connected by a signal line a. The other input terminal of the adding point 10 and the output terminal of the switch circuit 12 are connected by a signal line b.
The output terminal of the joining point 10 is connected to the adjustment / operation unit 11 by the signal line c, and the output terminal of the adjustment / operation unit 11 is
The heater H2 is connected by the line d.

The output terminals of the temperature setting device 20 and the storage device 21 are connected to the input terminals of the switch circuit 12 by signal lines e and f, respectively. And the storage device 21,
The second temperature sensor S2 provided so as to face the measuring chamber of the heating cylinder 1 is connected by a signal line g. The temperature setter 20 manually sets the heating temperature of the temperature control zone K2 during molding, and the memory 21 stores the resin detected by the second temperature sensor S2 during molding in the present embodiment. The temperature is stored as the set temperature of the temperature control zone K2 during the suspension of molding. Therefore, the set temperature of the heating heater H2 during molding and the set temperature of the heating heater H2 during the molding stop stored in the storage unit 21 are input to the switch circuit 12 as described later in detail, and Any set temperature will be output to the joining point 10.

The one input terminal of the comparator 13 and the molding cycle time setting device 22 are connected by a signal line h, and the other input terminal and the molding cycle time measuring device ST are connected by a signal line i, respectively. The molding cycle time setter 22 sets an upper limit value and a lower limit value of the molding cycle time. On the other hand, the molding cycle time measuring device ST measures the molding cycle time, and is provided in association with, for example, the electric motor 5 that drives the screw 2 in the present embodiment. And the comparator 1
3 compares the molding cycle time set by the molding cycle time measuring device S with the set upper limit value and lower limit value, and outputs "H", for example, when the value is out of the set range, When it is inside, it outputs a low "L". Then, these signals are input to the AND gate 25 through the signal line j. Also,
The other terminal of the AND gate 25 is connected to the start switch 23 by the signal line k through which the timer 24 is interposed. This timer 24 uses the start switch 2
When 3 is pressed, for example, high “H” is output for the set time,
When the set time has elapsed, a low "L" is output. The output terminal of the AND gate 25 is connected to the switch circuit 12 by the signal line n. When a signal is applied to the switch circuit 12, the set temperature during molding set by the temperature setter 20 is input to the joining point 10. When the signal is not applied, the setting temperature is changed so that the preset temperature stored in the storage unit 21 during the suspension of molding is input.

Next, the operation of the above embodiment will be described. The temperature setter 20 sets the heating temperature of the heating cylinder 1, that is, the set temperature Ts of the heater H2. Further, the molding cycle time setter 22 sets the upper limit value and the lower limit value of the molding cycle time. Then, the start switch 23 is pressed. Then, the timer 24 outputs high "H" to the AND gate 25 for a predetermined time. Since it is not molded at this time, the molding cycle time detected by the molding cycle time measuring device ST is outside the set range. Therefore, the comparator 13 outputs a high “H” to the AND gate 25. The AND gate 25 is turned “on”, a signal is applied to the switch circuit 12, and the switch circuit 12 is switched and the set temperature Ts during molding set by the temperature setter 20 is input to one input terminal of the joining point 10. The detected temperature detected by the first temperature sensor S1 is input to the other input terminal of the joining point 10. The deviation signal obtained at the joining point 10 is operated by the adjustment / operation unit 11 in a known manner, and a predetermined operation amount is output to the heater H2. As a result, the heater H
2 is feedback-controlled so as to reach the set temperature Ts during molding. When a predetermined time has elapsed, the timer 24 outputs a low "L" to the AND gate 25. However, since the molding cycle time is within the set range, the comparator 13 outputs a low "L" to the AND gate 25. Is output to. Therefore, the AND gate 25 continues to be in the "ON" state, and the heater H2 is controlled at the set temperature Ts during molding set by the temperature setter 20.

As described above, the heater H2 is controlled so that the temperature of the heating cylinder 1 reaches the set temperature Ts, the resin material is supplied from the hopper 3, and the screw 2 is rotationally driven by the drive unit 4 to measure. Then, when the measured molten resin is driven in the axial direction and injected into the mold, a molded product can be obtained in a conventionally known manner. At this time, the molding cycle time is measured by the molding cycle time measuring device S.
It is detected at T and input to the comparator 13. If the detected molding cycle time is between the upper limit value and the lower limit value of the set molding cycle time, although not shown in FIG. 1, the timer is reset to move to the next shot. Thereafter, the same measurement is performed and injection is performed to obtain a molded product. The resin temperature Tj during molding in this way is measured by the second temperature sensor S2, and is stored in the storage unit 21 as the set temperature Ts' during molding suspension.

If the molding is stopped, stopped, or ended during the molding as described above, the temperature is controlled by the set temperature Ts' during the molding stop stored in the memory 21, but this embodiment is performed. In the above form, the determination as to whether or not molding is in progress is made based on the molding cycle time. For example, if the resin material is insufficient, it takes time to plasticize, and the molding cycle time becomes long. On the other hand, when the molding operation is stopped in the initial stage such as during injection / pressure holding, for example, the measurement is completed immediately, and the molding cycle time is shortened.

Therefore, when the molding cycle time detected by the molding cycle time measuring device ST exceeds the range between the upper limit value and the lower limit value of the set molding cycle time, it is judged that the molding is stopped or stopped, and the comparator 13 determines. A high "H" is output to the AND gate 25 this time. Since the low "L" is output from the timer 24 to one input terminal of the AND gate 25, the AND gate 25 is turned "OFF", the switch circuit 12 is switched, and this time it is stored in the memory 21. The resin temperature Tj, that is, the set temperature Ts ′ during the suspension of molding is input to one input terminal of the joining point 10. The detected temperature detected by the first temperature sensor S1 is input to the other input terminal of the joining point 10. The deviation signal obtained at the joining point 10 is operated by the adjustment / operation unit 11 as described above, and a predetermined operation amount is output to the heater H2. As a result, the heater H2 is feedback-controlled so as to reach the set temperature Ts' during the suspension of molding. When restarting the molding, the start switch 23 is pushed. Then, as described above, the timer 24 outputs a high "H" and the AND gate 25 is "on".
The heater H2 is feedback-controlled so as to reach the set temperature Ts during molding.

According to the above embodiment, various effects can be obtained. For example, the set temperature Ts ′ during the molding stop is maintained at the resin temperature Tj during the molding and is controlled so as to reach the set temperature Ts during the molding at the same time when the molding is started. Therefore, the set temperature Ts during the molding is stopped. When the temperature is higher than the medium set temperature Ts', the heater H2 is immediately heated. As a result, the decrease in the resin temperature is compensated for by the increase in the set temperature, and the heating is performed at the same time when the molding is started, so that the fluctuation in the resin temperature is reduced. A state in which such an effect is obtained is shown in (a) to (c) of FIG. Further, since the temperature is controlled by the low set temperature Ts' during the suspension of molding at the same time as the termination or suspension of the molding, the heating value of the heater H2 is also reduced at the same time. Therefore, as shown in (d) and (e) of FIG. 3, the overshoot amount of the heating cylinder 1 is suppressed. In addition, the set temperature T is low during the suspension of molding.
Since it is controlled by s', the temperature rise of the resin material accumulated in the heating cylinder 1 is suppressed. This prevents the resin material from discoloring, burning, and the like.

For a resin material whose temperature becomes higher during molding due to heat generated by friction and shearing due to rotation of the screw 2 during plasticization, a set temperature Ts' during molding is stopped.
Is higher than the set temperature Ts during molding, but is controlled by the high set temperature during the suspension of molding, so that the temperature difference between the resin material during molding and during the suspension of molding can be suppressed to a small value. In any case, the fluctuation of the resin temperature is small and the fluctuation of the quality of the molded product is also small.

The present invention is not limited to the above embodiment and can be implemented in various forms. For example, similarly to pressing the start switch 23, it is obvious that the control can be performed at the preset temperature Ts during the molding from the flushing time before the start of the molding. Further, in the above embodiment, the switch circuit 12
Changes depending on whether or not the measured molding cycle time is within the set upper and lower limit values.However, other means, such as when molding is stopped, can be set manually during molding stop. It is also clear that it is possible to switch to the temperature Ts'.

Further, according to the above embodiment, the set temperature Ts' during the suspension of molding is the temperature Tj of the resin material measured during the molding. Therefore, the temperature of the heating cylinder 1 during the suspension of molding is accurately determined by the resin temperature. However, since the second temperature sensor S2 for measuring the temperature of the resin material must be provided in the measuring chamber or the like in the heating cylinder 1,
There may be problems such as the mounting and processing cost of the temperature sensor S2, and the adhesion and retention of the resin material on the mounted second temperature sensor S2. In particular, when molding an optical component, if a resin material that has been discolored due to adhesion or retention falls off and mixes into the molding material, a molding failure will occur directly. Therefore, the set temperature Ts ′ during the suspension of the molding can be set to a temperature close to the resin temperature during the molding based on experience without the actual measurement by the second temperature sensor S2. Even with such an empirical setting, it is apparent that the temperature change of the resin material is smaller during the molding stop as compared with the conventional case where the temperature is controlled at the same set temperature as during the molding. It is also possible to predict the set temperature Ts' during the suspension of molding. FIG. 2 is a graph showing the residence time of the resin material on the horizontal axis and the temperature of the resin material on the vertical axis. A heating cylinder equipped with a temperature sensor such as the second temperature sensor S2 is used. Thus, the set temperature Ty during the suspension of molding can be set based on the relationship between the residence time of the resin material and the temperature of the resin material. It is clear that the same effect can be obtained by such prediction.

[0020]

As described above, according to the present invention, the temperature of the heating means provided on the outer peripheral portion of the heating cylinder is set during flushing before molding or during molding. When the molding is stopped or finished , the resin temperature during molding is recorded from the set temperature during molding.
Since it is controlled by switching to the set temperature that is remembered during molding cancellation, it can be applied from the initial molding to stable molding, and the temperature change of the resin material during molding cancellation can be suppressed small.
Therefore, the effect peculiar to the present invention is obtained in which a molded product having high quality and constant quality can be obtained without forming defects such as deterioration of the resin material and burning. Further, according to another aspect of the present invention, the molding cycle time to be measured is, if the result exceeds the preset upper and lower limit values of the molding cycle time was, the resin temperature during the molding from the set temperature during molding is set
Since the temperature of the heating means is controlled by switching to the preset temperature during which molding is stopped, the temperature is automatically switched to the preset temperature during molding cancellation, at the end of molding, etc.
Similar effects are obtained. Further, according to the invention, the set temperature during the molding stop is the set temperature predicted from the relationship between the residence time of the resin in the heating cylinder and the resin temperature. The problem of defective molding due to adhesion and retention of resin material by the sensor is also eliminated.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a heating cylinder portion and a control block line according to an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between residence time and resin temperature according to the embodiment of the present invention.

FIG. 3 is a graph showing an operation according to the embodiment of the present invention, in which (A) to (E) are graphs showing different operations.

FIG. 4 is a graph showing the operation of the conventional heating control method in correspondence with the operation according to the embodiment of the present invention, in which (A) to (E) are graphs showing different operations.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heating cylinder 10 Addition point 11 Adjusting / operating section 12 Switch circuit 13 Comparator 25 AND gate C Controllers K1 to K3 Temperature control zones H1 to H3 Heating heater

Continuation of the front page (56) Reference JP-A-8-132501 (JP, A) JP-A-4-164622 (JP, A) JP-A-62-121120 (JP, A) JP-A-9-76321 (JP , A) Actually developed 61-40221 (JP, U) Actually developed 2-126813 (JP, U) Actually developed 3-36427 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB) (Name) B29C 45/00-45/84

Claims (6)

(57) [Claims] 1. A heating means provided on the outer periphery of the heating cylinder (1) the temperature of (H2), and the set temperature in the molding is set (Ts), the resin temperature during molding are stored
That the set temperature during the molding suspension of (Ts'), different settings a temperature control method of an injection machine for feedback controlling the temperature during the molding the temperature of the heating means from the time of flushing or molding start before molding (H2) When the molding is stopped or terminated, the temperature of the heating means (H2) is controlled by switching from the set temperature during molding (Ts) to the set temperature during molding cancellation (Ts'). A temperature control method for an injection machine, which is characterized by controlling. 2. A heating means provided on the outer periphery of the heating cylinder (1) the temperature of (H2), and the set temperature in the molding is set (Ts), the resin temperature during molding are stored
That the set temperature during the molding suspension of (Ts'), different settings a temperature control method of an injection machine for feedback controlling the temperature during the molding the temperature of the heating means from the time of flushing or molding start before molding (H2) When the actually measured molding cycle time exceeds the upper and lower limit values of the molding cycle time, which is controlled by the set temperature (Ts) of
A temperature control method for an injection machine, wherein the temperature of the heating means (H2) is controlled by switching from a set temperature (Ts) during molding to a set temperature (Ts') during molding stop. The temperature of wherein heating means are provided on the outer periphery of the heating cylinder (1) (H2), and the set temperature in the molding is set (Ts), the residence of the resin in the heating cylinder (1) A temperature control method for an injection machine, wherein feedback control is performed according to different preset temperatures (Ts') during molding suspension predicted from the relationship between time and resin temperature. The temperature of the heating means (H2) is controlled by the set temperature (Ts) during molding, and when the molding is stopped or finished, the set temperature during molding (Ts) is switched to the set temperature during molding stopped (Ts'). The temperature control method of the injection machine is characterized by controlling the temperature of the heating means (H2). The temperature of 4. A heating means provided on the outer periphery of the heating cylinder (1) (H2), and the set temperature in the molding is set (Ts), the residence of the resin in the heating cylinder (1) A temperature control method for an injection machine, wherein feedback control is performed according to different preset temperatures (Ts') during molding suspension predicted from the relationship between time and resin temperature. When the temperature of the heating means (H2) is controlled by the set temperature (Ts) during molding and the actually measured molding cycle time exceeds the preset upper and lower limits of the molding cycle time,
A temperature control method for an injection machine, wherein the temperature of the heating means (H2) is controlled by switching from a set temperature (Ts) during molding to a set temperature (Ts') during molding stop. 5. A heating means provided on the outer periphery of the heating cylinder (1) the temperature of (H2), and the set temperature in the molding is set (Ts), the resin temperature during molding are stored
That the set temperature during the molding suspension of (Ts'), a temperature control apparatus for an injection machine that performs feedback control by different set temperature (C), the temperature control device (C) is a set temperature in the molding (Ts) And a set temperature (Ts') during molding stop, and a set temperature (Ts) during molding which is switched by the temperature detected by the heating cylinder (1) and the switching means (12), or a molding stop Adjustment point for inputting the set temperature (Ts') therein and adjustment for outputting the operation amount to the heating means by adjusting the deviation amount obtained at the addition point (10).
A temperature control device for an injection machine, comprising: an operating means (11). 6. A heating means provided on the outer periphery of the heating cylinder (1) the temperature of (H2), and the set temperature in the molding is set (Ts), the resin temperature during molding are stored
That the set temperature during the molding suspension of (Ts'), a temperature control apparatus for an injection machine that performs feedback control by different set temperature (C), the temperature control device (C) is a set temperature in the molding (Ts) And a set temperature (Ts') during molding stop, and a set temperature (Ts) during molding which is switched by the temperature detected by the heating cylinder (1) and the switching means (12), or a molding stop Adjusting / operating means for adjusting the deviation point obtained at the addition point (10) and the addition point (10) to which the set temperature (Ts ′) therein is inputted and outputting the operation amount to the heating means (H2). (11) and a judging means (13) for judging whether or not molding is in progress. When the judging means (13) judges no, the switching means (12) sets the preset temperature (Ts') during molding stop. Is output to the addition point (10). Temperature control device for that injector.