JP2017193094A - Flexure processing device of thermoplastic resin tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexure processing device of a thermoplastic resin tube capable of simplifying a device and easily conducting flexure processing in short time without possibility of temperature reduction of the flexure processing.SOLUTION: A flexure processing device has a molding tool having heating members 32 and 42 formed with surrounding flexure planned part 2a of a thermoplastic resin tube (tube material 2) as a work and heating the flexure planned part, and having a flexure processing surface for bending the heated flexure planned part and formed with capability to be divided into a first molding tool (inside tool 3) and a second molding tool (outside tool 4), a roller 5 with a pair of grooves arranged symmetrically at both side part of the molding tool so that an outside extending part 2b of the work extending to both outer sides of the flexure planned part when the work is set in the molding tool, and a driving device 6 changing relative positions of the molding tool and the roller with the pair of grooves to a predetermined direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermoplastic resin pipe bending apparatus used when bending a thermoplastic resin pipe used in, for example, a water heater or an air conditioner.

  In a refrigeration equipment represented by a water heater, an air conditioner, and the like, piping parts molded from a thermoplastic resin are mounted. When the route of the piping is long, it is necessary to avoid other parts inside the cooling / heating device, and it becomes a complicated curved shape instead of a straight tube. Therefore, it is necessary to divide and connect the piping. When there are many connected parts, the risk of leakage of the fluid flowing through the pipe increases, so the pipe is preferably a single component. Therefore, it is necessary to perform bending after forming one long pipe. When the tube is simply bent, the preheated tube is fixed to the bending device so that the cross-sectional shape does not flatten, and the fluid is injected into the tube to fill it, thereby increasing the pressure of the fluid generated during processing. There is one that suppresses flattening (see, for example, Patent Document 1).

JP-A-8-309844 (first page, FIG. 1)

  In the above technique, since it is necessary to heat the tube before fixing it to the bending apparatus, a device for heating the tube and a device for bending the tube are required. The tube temperature decreases. In addition, when the tube is long, the amount of liquid injected into the tube increases in order to suppress flattening of the tube, so a processing method for filling the inside of the tube with fluid is taken, but it is necessary for injection and discharge Since time increases, processing time increases. Further, when the processing is finished in a state where the stress generated during the bending process remains in the pipe, there is a problem that the pipe is deformed by the residual stress inside the pipe.

  The present invention has been made in order to solve the above-described problems, and can simplify the apparatus and can be easily bent in a short time without causing a temperature drop in the bending process. The purpose is to obtain a bending apparatus.

  The thermoplastic resin pipe bending apparatus according to the present invention is formed so as to surround the planned bending portion of the thermoplastic resin pipe as a workpiece, and includes a heating member for heating the planned bending portion, A mold having a bending surface for bending the heated portion to be bent and formed so as to be split into a first mold and a second mold, and the workpiece is set in the mold A pair of grooved rollers disposed symmetrically on both sides of the mold so as to be able to engage with the outer extended parts of the workpiece, which sometimes extend to both outer sides of the planned bending part, and the mold And a drive device that changes the relative position of the pair of grooved rollers in a predetermined direction.

  According to the present invention, the planned bending portion is heated by a molding die surrounding the planned bending portion of a thermoplastic resin tube as a workpiece, and a pair of grooves provided symmetrically on both sides of the molding die is provided. By changing the relative position between the roller and the molding die in a predetermined direction, the bent portion is bent along the bending surface, thereby heating and bending the thermoplastic resin tube as a series of flows. Since it can be carried out, the apparatus can be simplified, and the bending process can be easily performed in a short time without being limited by the fear of temperature drop or the timing of bending.

It is a principal part front view which shows notionally the state which set the thermoplastic resin pipe | tube to the bending apparatus which concerns on Embodiment 1 of this invention. It is a principal part front view which shows notionally the state after bending from the state of FIG. It is a schematic perspective view which expands and shows the inner side type | mold shown by FIG. It is a schematic perspective view which expands and shows the outer side type | mold shown by FIG. It is a principal part front view which shows notionally the state which set the thermoplastic resin pipe | tube to the bending apparatus which concerns on Embodiment 2 of this invention. It is a schematic perspective view which expands and shows the inner side type | mold shown by FIG. It is a schematic perspective view which expands and shows the outer side type | mold shown by FIG. It is a principal part front view which shows notionally the state which set the thermoplastic resin pipe | tube in the bending apparatus which concerns on Embodiment 3 of this invention. It is a schematic perspective view which expands and shows the principal part structure of the intermediate | middle type | mold shown by FIG.

Embodiment 1 FIG.
FIG. 1 is a main part front view conceptually showing a state in which a thermoplastic resin pipe is set in a bending apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a conceptual view after bending from the state of FIG. FIG. 3 is an enlarged schematic perspective view showing the inner mold shown in FIG. 1, and FIG. 4 is an enlarged schematic perspective view showing the outer mold shown in FIG. In the drawing, a thermoplastic resin pipe (hereinafter referred to as “tube material”) bending apparatus 1 is arranged so as to be located inside (downward in the drawing) with respect to a planned bending portion 2 a of a pipe material 2. An inner die 3 that is a molding die, an outer die 4 that is a second molding die disposed so as to face the outside thereof, and a pair of grooved rollers 5 that are provided symmetrically on both sides of the outer die 4. And a drive device 6 that moves the inner die 3 up and down, an outer die support base 44, an outer die guide member 45, an elastic member 46 made of a compression spring, a pedestal 10, and the inner die 3 and the outer die 4. A temperature control device 71 is provided that constitutes a heating means 7 that controls heating to a temperature.

  As shown in FIG. 3, the inner die 3 is opposed to the outer die 4 and is in contact with the inner circumference side (lower side in the figure) of the curvature circle when bent in the planned bending portion 2 a of the tube material 2. When the tube material 2 is set between the outer die 4 and the inner die bending surface 31 formed in a mountain shape, the bent portion 2a is predetermined. An inner mold heater 32 as a heating member constituting the heating means 7 and an inner mold temperature sensor 33 for heating to a temperature are provided. The inner side bending surface 31 has a shape that matches the bending angle and bending curvature of the pipe material desired to be realized by bending.

  The inner die 3 is fixed to the upper end portion of the output shaft that is driven in the vertical direction of the drawing provided in the driving device 6 attached to the base 10. The drive device 6 is a device that drives in a linear direction, such as an air or hydraulic cylinder. For example, a commercially available cartridge heater is used as the inner die heater 32 and is attached to the inner die 3 to heat the inner die 3 with electric heat. The temperature of the inner mold 3 is detected by the inner mold temperature sensor 33, and is controlled by adjusting the output of the inner mold heater 32 by the temperature control device 71 in accordance with the detected temperature information. The inner-type temperature sensor 33 is, for example, a thermocouple. However, the type and measurement method of the temperature sensor are not particularly limited as long as they can output a signal corresponding to the temperature. As the temperature control device 71, for example, a device capable of preliminarily programming the heating temperature and time, the heating curve, and the like can be used.

  As shown in FIG. 4, the outer die 4 is opposed to the inner die 3 so as to have an outer die bending surface 41 that comes into contact with the outer peripheral side of the curvature circle when bent in the planned bending portion 2 a of the tube material 2. In addition, when the pipe 2 is set between the inner die 3 and the inner die 3, the outer die heater as a heating member constituting the heating means 7 for heating the planned bending portion 2a to a predetermined temperature. 42 and an outer mold temperature sensor 43 are provided. The outer die bending surface 41 has a shape that matches the shape of the tube material before bending, and here, a semicircular groove is linearly formed. As the outer heater 42, for example, a cartridge heater is used. The temperature of the outer die 4 is controlled by adjusting the output of the outer die heater 42 by the temperature control device 71 based on the signal detected by the outer die temperature sensor 43. The outer mold temperature sensor 43 is the same as the inner mold temperature sensor 33.

The outer die 4 is movable in one axial direction in the vertical direction in the figure through two outer die guide members 45 extending in the downward direction relative to the outer die support base 44 fixed to the pedestal 10. Engaged, and is always urged in the direction of the inner mold 3 by an elastic member 46 formed of a compression spring having one end locked to the outer mold support base 44 and the other end locked to the upper surface of the outer mold 4. . When the outer die 4 moves upward in the figure, a reaction force in the direction opposite to the moving direction is generated by the elastic member 46.
Each of the pair of grooved rollers 5 is provided so as to be rotatable with respect to the pedestal 10, and a groove having a semicircular cross section (not shown) is formed on the outer peripheral surface thereof in the circumferential direction. And the outer peripheral surface of the outer extending portion 2b extending to both outer sides of the planned bending portion 2a of the pipe member 2 sandwiched between the outer mold 4 and the outer die 4 are arranged so that both the left and right can be engaged.

  Note that the position of the outer die 4 on the lower end side in the vertical movable range is such that the straight tube material 2 before bending is engaged with a semicircular groove in cross section (not shown) of the pair of left and right grooved rollers 5. When the outer die bending surface 41 is in close contact with the outer peripheral surface including the planned bending portion 2a of the tube material 2, it is provided so as to be slightly below the position. As a result, when the pipe member 2 is set in the bending apparatus 1, the outer die bending surface 41 of the outer die 4 comes into contact with the outer peripheral surface of the planned bending portion 2 a of the pipe member 2, and the heat generated by the outer die heater 42. Is sufficiently transmitted to the tube material 2 through the outer die bending surface 41. At the stage of starting the bending process, the tube material 2 is sandwiched and fixed between the inner die 3, the outer die 4, and the pair of left and right grooved rollers 5.

  A pipe material 2 to be subjected to bending using the bending apparatus 1 of the present invention is a straight pipe made of thermoplastic resin such as polyethylene, polyphenylene sulfide, polyamide or vinyl chloride resin by injection molding or extrusion molding. It is molded into When the thermoplastic resin is heated to the glass transition temperature, the bending elastic modulus is lowered, so that bending is facilitated. Further, when the glass resin is further heated from the glass transition temperature, the thermoplastic resin melts and its shape largely collapses. Therefore, the bending process is performed at a temperature equal to or higher than the glass transition temperature and with a margin to the melting point. Since the heating target of the inner die heater 32 and the outer die heater 42 is the planned bending portion 2a of the tube material 2, the inner die bending surface 31 of the inner die 3 and the outer die bending surface 41 of the outer die 4 are sufficient. It is installed so that it can be heated without uneven heating. In order to prevent uneven heating, for example, the upper edge of the semicircular arc-shaped inner die bending surface 31 in the inner die 3 is covered so as to cover the exposed portion of the lower half of the planned bending portion 2a shown in FIG. You may make it form the side wall part extended in the upward direction.

  Next, the operation of the first embodiment will be described. It is assumed that the inner die 3 is at a position lowered below the position of FIG. 1 by the driving device 6, and there is a gap between the upper end of the inner die 3 and the lower end of the outer die 4. First, the tube material 2 is brought into contact with the outer die 4 so that the planned bending portion 2a and the center portion of the outer die 4 coincide. When the driving device 6 is driven and the inner die 3 is raised in the direction of the outer die 4, the upper end of the inner die 3 comes into contact with the lower end of the outer die 4. At this time, the tube material 2 is sandwiched between the inner die 3 and the outer die 4. Thereafter, when the inner die 3 is further raised, a pair of outer extending portions 2b of the tube material 2 extending in the horizontal direction on both outer sides of the planned bending portion 2a are symmetrically disposed with respect to the outer die 4. The inner die 3 and the outer die 4 are not moved by being respectively engaged with a semicircular groove (not shown) of the grooved roller 5 and the outer peripheral surface of the planned bending portion 2a of the tube material 2 is bent into the inner die. It will be in the state closely_contact | adhered to the center part of the surface 31, and the whole surface of the outer side bending surface 41. FIG.

  Next, the temperature control device 71 operates the inner die heater 32 built in the inner die 3 and the outer die heater 42 built in the outer die 4 to control the heating of the inner die 3 and the outer die 4. The temperatures of the inner mold 3 and the outer mold 4 are preset by controlling the outputs of the inner mold heater 32 and the outer mold heater 42 from the signals detected by the inner mold temperature sensor 33 and the outer mold temperature sensor 43, respectively. It is controlled so that the temperature is equal to or higher than the glass transition temperature of the pipe material 2 and less than the melting point. The inner mold 3 and the outer mold 4 may be heated after the tube material 2 is fixed to the bending apparatus, or may be heated in advance before the tube material 2 is fixed.

  The tube 2 is heated so that the temperature of the planned bending portion 2a of the tube 2 is equal to the temperature of the inner die 3 and the outer die 4 while being sandwiched between the inner die 3 and the outer die 4 as described above. The temperature of the pipe 2 is detected directly by inserting a contact-type temperature sensor (not shown) into the inner wall of the pipe 2 or using a non-contact-type temperature sensor (not shown). The temperature control device 71 may control the temperature of the planned bending portion according to the detection result. Further, the temperature of the pipe material 2 detected by the inner mold temperature sensor 33 and the outer mold temperature sensor 43 when the pipe material of the same shape and the same material as that of the pipe material 2 is sandwiched between the inner mold 3 and the outer mold 4 and held in advance. It is also possible to clarify the relationship between and the holding time, and estimate the required heating completion time based on the holding time derived based on the relationship.

  After confirming that the temperature of the tube material 2 has become a temperature suitable for bending as described above, the driving device 6 is operated to resist the urging force of the elastic member 46 together with the outer die 4 in the inner die 3. Then push it upward as shown by the arrow in FIG. Outer extending portions 2b at both ends of the bent portion of the tube material 2 are respectively locked by a pair of left and right grooved rollers 5, and the inner mold 3 attaches the tube material 2 to a portion where the tube material 2 and the grooved roller 5 are in contact with each other. A force in the direction opposite to the pressing force is generated, and the planned bending portion 2 a of the tube material 2 is bent in an arc shape along the inner die bending surface 31 of the inner die 3. After the inner mold 3 is pushed upward until the tube material 2 has a desired shape, the operation of the driving device 6 is stopped.

  Next, in the state of FIG. 2 in which the tube material 2 is sandwiched between the inner die 3 and the outer die 4, the outputs of the inner die heater 32 and the outer die heater 42 are reduced, and the temperatures of the inner die 3 and the outer die 4 are reduced. After cooling to 5 ° C. to 10 ° C. lower than the glass transition temperature, the temperature is held for about 5 to 10 minutes. As a result, the pipe material 2 is cooled slowly, the stress generated in the pipe material 2 during bending can be relieved, the residual stress of the pipe material 2 after bending is reduced, and the post-deformation during use of the pipe material 2 is reduced. Can be suppressed.

  In the step of suppressing the residual stress by the slow cooling described above, the temperature of the tube material 2 may be directly measured using a contact type or non-contact type temperature sensor as in the case of heating. In addition, when the slow cooling process is performed and when it is completed, the portion to be bent is bent in advance using a tube of the same shape and material as that of the tube 2, the heater is turned off, and then the inner mold 3 and the outer mold 4 are held. Clarified the relationship between the holding time and the temperature change of the tube material 2 when it was continued, and based on that, the completion of the slow cooling process of the tube material 2 from the holding time and the temperature when removing the tube material 2 It may be estimated. After performing the slow cooling process as described above, the driving device 6 is operated to move the inner die 3 in the direction opposite to that during bending, that is, in the direction away from the outer die 4 (downward in the figure). When the inner mold 3 and the outer mold 4 are separated from each other, the fixing to the tube material 2 is released, and the tube material 2 subjected to the bending process can be taken out. When the inner die 3 moves away from the outer die 4, the outer die 4 can be automatically returned to the state before bending by the urging force of the elastic member 46.

  As described above, in the first embodiment, since the pipe material 2 is bent by the inner mold 3 and the outer mold 4 that can be controlled to be heated to a predetermined temperature, the pipe material 2 is set in the bending apparatus 1 and then the pipe material. The two heating and bending processes can be carried out as a series of flows. In addition, since the temperature of the tube material 2 can be controlled during bending, the tube material 2 can be prevented from being cooled and solidified during the bending process, and is always controlled to a temperature above the glass transition temperature and below the melting point. Thus, bending can be performed with the tube material 2 always softened, and flattening of the tube material 2 can be prevented without injecting fluid into the tube material. In addition, after bending, the pipe material 2 is bent by the inner die 3 and the outer die 4 so as to be held at a temperature lower by 5 ° C. to 10 ° C. than the glass transition temperature. Stress can be relaxed and post-shrinkage after bending can be suppressed. Moreover, since the apparatus can be simplified and the tube material 2 can be heated and bent as a series of flows, there is no risk of temperature drop and the bending timing is not limited, and bending can be easily performed in a short time. .

Embodiment 2. FIG.
FIG. 5 is a front view of a principal part conceptually showing a state in which a thermoplastic resin pipe is set in the bending apparatus according to Embodiment 2 of the present invention, and FIG. 6 is an enlarged view of the inner mold shown in FIG. FIG. 7 is a schematic perspective view, and FIG. 7 is an enlarged schematic perspective view showing the outer mold shown in FIG. In the second embodiment, a fluid such as water or oil is used as a heat source medium for the heating means 7A. In the figure, the heating means 7A of the bending apparatus 1A includes an inner mold temperature adjusting water channel 32A that is a heating member provided in the inner mold 3A and an outer mold temperature adjusting that is a heating member provided in the outer mold 4A. A water flow path 42A, a heating fluid temperature controller 71A and a cooling fluid temperature controller 71B as temperature controllers, and a fluid switching valve 72 are used. Similarly to the first embodiment, the inner die 3A is fixed to the driving device 6, and the outer die 4A is fixed to the outer die support base 44 via the outer die guide member 45. The other constituent members are the same as those in the first embodiment, and thus the description thereof is omitted.

  The heating fluid temperature controller 71A and the cooling fluid temperature controller 71B are, for example, a means for heating a fluid such as water to a preset temperature, and heated water or cold water via the fluid switching valve 72. A pump (both not shown) that feeds and circulates the inner mold temperature control water flow path 32A and the outer mold temperature control water flow path 42A is detected by the inner mold temperature sensor 33 and the outer mold temperature sensor 43. The inner mold 3A and the outer mold 4A are controlled to a preset temperature based on the temperature information. The water flow path (32A, 42A) may be a pipe in which a fluid is passed, embedded in a mold (3A, 4A), or a hole in which a fluid is passed through the mold (3A, 4A). good.

  The fluid switching valve 72 switches the fluid to be circulated through the inner mold temperature adjusting water flow path 32A inside the inner mold 3A and the outer mold temperature adjusting water flow path 42A inside the outer mold 4A to heating water or cold water. In the case of water, the operation is switched to the heating fluid temperature controller 71A, and in the case of cold water, the operation is switched to the cooling fluid temperature controller 71B. The fluid that has passed through the inner mold temperature adjusting water flow path 32A and the outer mold temperature adjusting water flow path 42A is returned to the heating fluid temperature controller 71A or the cooling fluid temperature controller 71B via one fluid switching valve 72, After being heated again to the set temperature, it is circulated again through the other fluid switching valve 72 to the inner-type temperature adjusting water channel 32A and the outer-type temperature adjusting water channel 42A. In addition, although water was mentioned as an example of a fluid, if the temperature of the inner side mold | type 3A and the outer side mold | type 4A can be controlled more than the glass transition temperature of the pipe material 2, in addition to water, fluids, such as oil and gas, for example Good.

  As shown in FIG. 6, the inner die 3 </ b> A includes an inner die bending surface 31, an inner die temperature adjusting water channel 32 </ b> A, and an inner die temperature sensor 33. The shape of the inner side bending surface 31 is a shape that matches the shape of the tube desired to be realized by bending, as in FIG. Inside the inner mold 3A, an inner mold temperature adjusting water channel 32A for adjusting the temperature of the inner mold 3A is provided. The inner mold temperature sensor 33 attached to the inner mold 3A is used to check whether the temperature of the inner mold 3A is set to a preset temperature before bending, and the temperature-adjusted fluid is used for adjusting the inner mold temperature. If the temperature of the inner mold 3A is grasped by the time passing through the inside of the water flow path 32A, it may be omitted.

  As shown in FIG. 7, the outer die 4 </ b> A includes an outer die bending surface 41, an outer die temperature adjusting water channel 42 </ b> A, and an outer die temperature sensor 43. The shape of the outer die bending surface 41 is a shape that matches the shape of the tube before bending as in FIG. Inside the outer mold 4A, an outer mold temperature adjusting water channel 42A for adjusting the temperature of the outer mold 4A is provided. The outer mold temperature sensor 43 attached to the outer mold 4A is for confirming whether the temperature of the outer mold 4A is a set temperature before bending, and the temperature-controlled fluid is used for adjusting the temperature of the outer mold. If the temperature of the outer mold 4A is grasped by the time passing through the inside of the water flow path 42A, it may be omitted.

  Next, the operation of the second embodiment will be described. First, the pipe material 2 is fixed to the bending apparatus 1A as in the first embodiment. Next, the fluid is supplied from the heating fluid temperature controller 71A to the inner mold temperature adjusting water flow path 32A inside the inner mold 3A and the outer mold temperature adjusting water flow path 42A inside the outer mold 4A. The fluid switching valve 72 is switched, and the inner mold 3A and the outer mold 4A are heated so that the temperature is not lower than the glass transition temperature and lower than the melting point. The temperatures of the inner mold 3A and the outer mold 4A are detected by the inner mold temperature sensor 33 and the outer mold temperature sensor 43, respectively. The heating of the inner mold 3A and the outer mold 4A may be performed after the tube material 2 is fixed to the bending apparatus 1A, or may be heated in advance before the tube material 2 is fixed.

Then, in a state where the tube material 2 is sandwiched between the inner die 3A and the outer die 4A, the inner die 3A is pushed up into the tube member 2 by the driving device 6 as in the first embodiment, and bending is performed.
Next, in a state where the bent pipe material 2 is sandwiched between the inner mold 3A and the outer mold 4A, the fluid switching valve 72 is switched, and the inner mold temperature control water flow path 32A inside the inner mold 3A and the inner mold 3A For example, water having a low temperature maintained at about room temperature is supplied from the cooling fluid temperature controller 71B to the outer-type temperature adjusting water flow path 42A. After cooling until the temperature of the inner mold 3A and the outer mold 4A is 5 ° C. to 10 ° C. lower than the glass transition temperature of the tube material 2, the temperature is maintained for about 5 to 10 minutes in the same temperature range as in the first embodiment. Thereafter, the tube 2 is further cooled and taken out from the bending apparatus 1A.

  As described above, according to the second embodiment, the same effect as that of the first embodiment can be obtained by using a fluid such as water or oil as the medium of the heat source used for the heating means 7A. Since the temperatures of the mold 3A and the outer mold 4A can be forcibly cooled by the cooling fluid temperature controller 71B, the time required for the bending process can be shortened as compared with the first embodiment. Is obtained. For example, an electric heater such as the inner die heater 32 and the outer die heater 42 similar to that of the first embodiment is used for heating the pipe material 2, and cold water by the cooling fluid temperature controller 71 B is used for cooling the pipe material 2. You may change suitably, such as using it.

Embodiment 3 FIG.
FIG. 8 is a principal front view conceptually showing a state in which the thermoplastic resin pipe is set in the bending apparatus according to Embodiment 3 of the present invention, and FIG. 9 is a diagram showing the principal part configuration of the intermediate mold shown in FIG. It is a schematic perspective view which expands and shows. In the third embodiment, a plurality of pipes (two in this example) can be bent in a single bending step. In the drawing, the bending apparatus 1B has an intermediate mold 8 interposed between an inner mold 3 and an outer mold 4, and the intermediate mold 8 is connected to the outer mold 4 by two links 9 having elongated holes 9a. The upper hole 9a is connected to be movable in the vertical direction, and is configured to move in a direction opposite to the outer mold 4 (in the vertical direction in the figure) in conjunction with the outer mold 4. As shown in FIG. 9, an inner peripheral bending surface 81 is formed on the surface of the intermediate die 8 facing the outer die 4, and an outer peripheral bending surface 82 is formed on the surface facing the inner die 3. Furthermore, an intermediate type heater 83 and an intermediate type temperature sensor 84 that constitute the same heating member as in the first embodiment are provided.

  The elongated hole 9a is provided so that a sufficient three-dimensional space is formed when the bent upper tube material 2 is removed from the mold after bending. The two pins 85 erected on the intermediate die 8 are respectively engaged with the elongated holes 9a of the corresponding links 9, and the intermediate die 8 is free only in the vertical direction in the figure with respect to the outer die 4. It is engaged so that it can move up and down by the length of the long hole 9a. Here, it is assumed that the intermediate mold 8 is always urged toward the upper end side of the elongated hole 9a by an elastic member (not shown) and is always in contact with the outer mold 4. . On the contrary, a gap is formed between the outer die 4 and the outer die 4 in a free state in which the elastic member is always biased toward the lower end portion of the long hole 9a and is not pushed from the lower side of the figure through the inner die 3. You may be made to do. In any case, the biasing force of the elastic member is such that the intermediate mold 8 can be easily moved up and down with respect to the outer mold 4 by hand, for example, when the pipe 2 or the pipe 2A is set between the corresponding molds. Strength is preferred. Further, the elastic member described above may be omitted.

  The shapes of the inner peripheral bending surface 81 and the outer peripheral bending surface 82 are the same as those of the inner die bending surface 31 and the outer die bending surface 41 in the first embodiment, and the intermediate heater 83 is used. The intermediate temperature sensor 84 is also configured in the same manner as in the first embodiment. A pair of second grooved rollers 5 </ b> A similar to the grooved roller 5 is disposed on both sides of the intermediate mold 8 symmetrically in the drawing. The vertical interval between the lower second grooved roller 5A and the upper grooved roller 5 is such that the upper tube 2 interferes with the lower second grooved roller 5A when bending is performed. In addition, the tube material after bending is set so that it can be easily removed. Further, the temperature control device 71 is configured to control the heating of the intermediate mold 8 at a predetermined temperature and time set in advance as in the case of the inner mold 3 and the outer mold 4. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

Next, the operation will be described. The inner die 3 is lowered to the lower end, and a sufficient gap is formed between the lower surface of the intermediate die 8 and the upper surface of the inner die 3 so that the lower pipe 2A can be inserted in the left-right direction. Although the lower surface of the intermediate mold 8 and the upper surface of the intermediate mold 8 are in contact with each other by an urging force of an elastic member (not shown), the intermediate mold 8 is manually moved downward when inserting the upper pipe member 2 in the lateral direction. It can be easily inserted.
In order to set the pipes 2 and 2A, one pipe 2 is sandwiched between the inner mold 3 and the intermediate mold 8, and the other pipe 2A is sandwiched between the intermediate mold 8 and the outer mold 4 and fixed. For temperature adjustment, the output of the heaters for the inner mold 3 and the outer mold 4 and the output of the intermediate heater 83 may be similarly controlled by the temperature control device 71. The temperature of the intermediate mold 8 is detected by the intermediate mold temperature sensor 84.

  Thereafter, similarly to the first embodiment, after the temperature control device 71 heats the planned bending portion of the pipe materials 2 and 2A to a temperature higher than a preset glass transition temperature, the drive device 6 raises the inner die 3 to obtain an intermediate The mold 8 and the outer mold 4 are both pushed upward in the figure against the urging force of the elastic member 46, and the pipe materials 2 and 2A are bent. Then, after performing the slow cooling process similar to Embodiment 1 which hold | maintains at the temperature 5 to 10 degreeC lower than a glass transition temperature in the state which pinched | interposed the pipe materials 2 and 2A, inner side is carried out by the drive device 6 When the die 3 is lowered, the intermediate die 8 and the outer die 4 are also lowered, and the workpiece after bending can be taken out from the die.

  As described above, the bending apparatus 1B according to the third embodiment can bend the two pipe materials 2 by a single bending process by attaching the intermediate mold 8 between the inner mold 3 and the outer mold 4. It has the characteristics. In addition, in this Embodiment 3, although the case where there was one intermediate mold | type 8 was demonstrated, a bending process can be simultaneously performed to three or more pipe materials 2 by attaching two or more intermediate mold | types 8. FIG. It should be noted that the configuration method of the link 9 and the method of removing the bent pipe material may be appropriately changed.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted. For example, when bending the tube material 2 or the tube material 2A, the intermediate die 8 is pushed up by the driving device 6, but the intermediate die 8 is fixed and the pair of left and right grooved rollers 5 are pushed down. It can be similarly bent by changing the relative position of the pair of grooved rollers in the vertical direction in the figure. Moreover, although the shaping | molding die was comprised in the shape divided | segmented up and down by the inner side die (1st shaping | molding die) and the outer side die (2nd shaping | molding die), it is not limited to this, For example, the surface which follows the centerline of a bending process surface It can also be configured to be divided into two in the front-rear direction.

1, 1A, 1B Bending device, 2, 2A Pipe material (work), 2a Bending part,
2b Outer extending part, 3, 3A Inner mold (first mold), 31 Inner mold bending surface,
32 Heater for inner mold, 32A Water flow path for inner mold temperature adjustment, 33 Temperature sensor for inner mold,
4, 4A outer mold (second mold), 41 outer mold bending surface, 42 outer mold heater,
42A Water flow path for outer mold temperature control, 43 Temperature sensor for outer mold, 44 Outer mold support,
45 outer type guide member, 46 elastic member, 5 grooved roller, 5A second grooved roller,
6 driving device, 7, 7A heating means, 71 temperature control device,
71A Heating fluid temperature controller, 71B Cooling fluid temperature controller, 72 Fluid switching valve,
8 intermediate mold, 81 inner circumferential side bending surface, 82 outer circumferential side bending surface,
83 Heater for intermediate mold, 84 Temperature sensor for intermediate mold, 85 pins, 9 links,
9a Long hole, 10 pedestal.

Claims (7)

  Bending surface for bending the heated portion to be bent, which is formed so as to surround the portion to be bent of the thermoplastic resin tube as a workpiece, and has a heating member for heating the portion to be bent. And a mold that is separable into a first mold and a second mold, and the workpiece that extends to both outer sides of the planned bending portion when the workpiece is set in the mold. The relative positions of the pair of grooved rollers disposed symmetrically on both sides of the mold so as to be able to engage with the respective outer extending portions, and the mold and the pair of grooved rollers are in a predetermined direction. A bending device for a thermoplastic resin pipe, comprising:   The molding die is arranged so as to be opposed to sandwich the planned bending portion from the outer peripheral side and the inner peripheral side of the curvature circle when bent, and the outer die bending surface provided with a variable distance in the opposing direction. The thermoplastic resin pipe bending apparatus according to claim 1, comprising an outer mold as the first mold having the inner mold and an inner mold as the second mold having an inner mold bending surface.   The outer mold is supported so as to be movable in the facing direction with respect to the pedestal, and one end of the outer mold is always urged in the direction of the inner mold by an elastic member fixed to the pedestal. The grooved roller is rotatably attached to both sides of the outer die, the inner die is installed so as to be able to advance and retreat in the facing direction with respect to the outer die, and the driving device moves the inner die to the outer die. 3. The thermoplastic resin pipe bending apparatus according to claim 2, wherein the bending apparatus is installed so as to be pushed against a biasing force of the elastic member in a mold direction.   The outer die bending surface of the outer die is formed by forming a semicircular groove in a straight line, and the inner die bending surface of the inner die has a semicircular cross section corresponding to the planned bending portion. 4. The apparatus for bending a thermoplastic resin pipe according to claim 2, wherein the groove is formed by bending.   An inner side bending surface similar to the inner die bending surface of the inner die is formed between the outer die and the inner die, and is opposed to the inner die. An outer peripheral bending surface similar to the outer die bending surface of the outer die is formed on the surface, and an intermediate die provided with a heating member for heating the planned bending portion is provided, and both side portions of the intermediate die are provided. 5. A pair of second grooved rollers is provided on the two, and the bent portions of the two thermoplastic resin pipes can be bent at the same time. The thermoplastic resin pipe bending apparatus as described.   The thermoplastic resin pipe bending apparatus according to any one of claims 1 to 5, wherein the heating member uses a fluid as a medium of a heat source.   A temperature control device, and the heating member is bent and heated by the temperature control device at a temperature higher than the glass transition temperature of the planned bending portion, and then the bent portion is placed in the mold. The thermoplastic resin pipe bending process according to any one of claims 1 to 6, wherein the thermoplastic resin pipe is controlled to be held at a temperature 5 to 10 ° C lower than a glass transition temperature for a predetermined time. apparatus.

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