JP2836914B2 - Molding method of resin molded body - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming a resin-made molded product by using a multi-station type slush molding die.

[Related Art] For example, a skin body (molded body) formed by slush molding using a resin-based molding material is used as an interior body in which an instrument panel of an automobile is incorporated.

In this case, in the slush molding, a step of pre-heating the molding die, a step of charging a molding material such as plastisol or powder made of vinyl chloride into the heated molding die, and a step of discharging excess molding material, There is a step of further heating the mold, a step of cooling the heated mold, and a step of taking out the skin from the mold. The skin is formed by sequentially transporting a plurality of molds between each step. Have been.

[Problems to be Solved by the Invention] By the way, in order to efficiently and mass-produce the skin body, for example, by heating each mold for a preset time while keeping the amount of heat from a heating burner constant, There is a method of heating the mold to a desired temperature in a short time. However, especially when using electroforming molds as molding dies, heating conditions fluctuate due to differences in the thickness of each electroforming mold and the like, making it difficult to always heat these electroforming molds to a constant temperature. I have.

The present invention solves this kind of problem and enables efficient and accurate heating of two or more molds circulated and transferred between stations to a desired temperature, and eliminates unnecessary heat. It is an object of the present invention to provide a method for molding a resin molded article capable of efficiently molding a molded article by reducing the waiting time as much as possible.

[Means for Solving the Problems] In order to solve the above problems, the present invention relates to a method for heating a mold by a heating station by circulating and transferring the mold between work stations. A resin-based molding material is supplied and welded therein, and further, the molding die is cooled in a cooling station to form a molded body, which comprises a heating furnace provided in the heating station. Setting the discharge temperature (T1) of the molding die, detecting the temperature (T2) of the molding die before being carried into the heating furnace, and detecting the temperature in the heating furnace before carrying the molding die. Detecting (T3), the set furnace temperature (T1) of the mold, the detected temperature (T2) of the mold before loading, and the temperature (T3) of the heating furnace. Is input to a control device, and the control device Calculating the heating time (A) of the molding die from the furnace temperature (T1), the temperature of the molding die (T2), and the temperature in the heating furnace (T3) based on the arithmetic expression stored in And adjusting a standby time (B) of the molding tool carried into a station before the heating station based on the calculated heating time (A) in the control device. It is characterized by.

[Operation] In the method of molding a resin molded article according to the present invention, the temperature of the molding die before being transferred into the heating furnace, the temperature of the molding die before being introduced into the heating furnace, Since the heating time of the mold is calculated from the temperature in the heating furnace before the mold is carried in, the mold can always be accurately heated to a desired temperature without being affected by changes in external conditions. . In addition, by adjusting the standby time of the molding dies carried into the station before the heating station based on the heating time, the standby time is reduced as much as possible, and the compact is efficiently formed. It becomes possible.

[Examples] Examples of the method for molding a resin molded article according to the present invention will be described in detail below with reference to the accompanying drawings in connection with a molding apparatus for performing the method.

In FIG. 2, reference numeral 10 indicates a molding apparatus for performing the molding method according to the present embodiment. This molding device 10
Comprises a first heating station 14 for heating a mold 12 fixed to a carrier 11 to a desired temperature;
12, a welding station 16 for supplying and welding a resin-based molding material and then discharging an unnecessary molding material, a second heating station 18 for heating the welded molding material, and cooling for cooling the molding die 12. Station 20 and an unloading station for removing the skin from the mold 12 after cooling is completed
22, a first heating station 14, a welding station 16, and a first and second lifting station for forming a two-stage structure of the second heating station 18 and the cooling station 20.
24, 26, and a transport mechanism 28 capable of circulating and transferring the mold 12 between the stations 14 to 26, and a control device 29
Is driven and controlled.

The first heating station 14 has a heating furnace 30 in which a burner 32 serving as a heating means is arranged, and a driving means 34 for rotating (swinging) the forming die 12.
Is provided. The heating furnace 30 is provided with a temperature detection sensor (not shown) for detecting the temperature inside the heating furnace 30, and this temperature detection sensor supplies temperature information inside the heating furnace 30 to the control device 29.

The welding station 16 includes a resin supply mechanism 36 for molding a skin layer in the molding cavity of the mold 12 and a foamable resin supply mechanism 38 for molding a foam layer on the skin layer.
And a driving unit 40 for rotating the molding die 12.

The second heating station 18 has a heating furnace 42 and a driving means 44 for swinging the mold 12 within a predetermined angle range in the heating furnace 42.

Shutters 48a to 48d that engage cylinders 46a to 46d are provided at the entrances and exits of the first heating station 14, the welding station 16 and the second heating station 18, respectively.

The cooling station 20 has a cooling chamber 52 in which a cooling water supply means 50 is accommodated, and the molding die 12
And a driving unit 54 for inverting the driving direction. An air blow means 56 is arranged between the cooling station 20 and the second heating station 18 to gradually cool the skin.

The removal station 22 is provided outside the circulating conveyance path of the molding apparatus 10 and has a driving unit 58 for swinging the molding die 12 to remove the skin from the molding die 12.

The first and second lifting stations 24 and 26 are provided with a motor 60.
The transport belts 64 and 66 which constitute the transport mechanism 28 and are arranged vertically in parallel with each other, and the lift platform 62 form an annular transport path. The transfer mechanism 28 has a transfer path 68 arranged at the unloading station 22, and the transfer path 68 moves the mold 12 between the unloading station 22 and the elevating table 62.

A radiation thermometer (not shown) is provided at the first lifting station 24 to detect the temperature of the mold 12, and supplies the temperature information of the mold 12 to the control device 29.

Next, the operation of the molding apparatus 10 configured as described above,
The relationship with the molding method according to the present embodiment will be described below with reference to FIG.

The discharge temperature T1 of the molding die 12 from the heating furnace 30 provided in the first heating station 14 is set based on characteristic data such as the material and shape of the molding die 12 and supplied to the control device 29.

The temperature T2 of the molding die 12 before being carried into the heating furnace 30 is detected by a radiation thermometer provided in the first elevating station 24 and supplied to the control device 29.

The temperature T3 in the heating furnace 30 before the molding die 12 is carried in,
Control device detected via a temperature detection sensor (not shown)
Supplied to 29.

The set furnace exit temperature T1 of the molding die 12, the detected temperature T2 of the molding die 12 before carrying in and the temperature in the heating furnace 30.
The heating time A of the molding die 12 is calculated by the control device 29 through the temperature information relating to T3. This heating time A is
It is obtained from the following equation.

A = α × T2 + β × T3 + γ × T1 + K Here, α, β, γ, and K take a large number of data sets of T1, T2, T3, and A, and determine the most by a statistical method based on the data. Selected to an appropriate value.

Here, when α = −0.8, β = −0.1, γ = 0.3, and K = 200, the heating time A becomes a value shown in Table 1 below.

In this case, Example 1 shows the heating time A at general temperatures T2 and T3, Example 2 shows the case where the mold 12 is low temperature and the heating time A is long, and Example 3 3 shows a case where the temperature T3 is high and the heating time A is short.

As described above, by adjusting the heating time A, the mold 12 can be always heated to a desired discharge temperature T1 without being affected by fluctuations of various external conditions. Can be formed.

A reference heating time A 'at the first heating station 14;
The reference standby time B 'at the unloading station 22 is set in advance. Here, the reference standby time B ′ is determined in consideration of the transport time of the new molding die 12 so that the new molding die 12 can be disposed near the heating furnace 30 immediately after the end of the heating operation of the molding die 12. A value smaller than the reference heating time A 'is selected.

If the calculated heating time A is smaller than the reference heating time A ′ (A′−A = C ≧ 0), the standby time B at the unloading station 22 is determined by the difference C from the reference standby time B ′. (B = B'-C).

If the heating time A is within the reference range (-25 <C <0),
The standby time B is set to the reference standby time B '. On the other hand, when the heating time A is longer than the reference range (C ≦ −25), the molding apparatus 10 is stopped as an abnormal condition.

Next, the forming operation by the forming apparatus 10 will be described briefly. The forming die 12 transferred into the heating furnace 30 of the first heating station 14 rotates integrally with the transfer table 11 via the driving means 34. While being heated through the burner 32.
At that time, the next molding die 12 has been carried into the unloading station 22, and the counting of the heating time A and the standby time B is started.

Here, since the reference standby time B 'is set to a value smaller than the reference heating time A', the standby time B ends before the heating time A elapses. Therefore, a new mold 12 from which the skin is removed at the removal station 22
After the elapse of the standby time B, the wafer is transported to the vicinity of the heating furnace 30 via the transport path 68 constituting the transport mechanism 28 and the elevating table 62 of the first elevating station 24. And heating time A
After the elapse of the driving means 34 is stopped, the molding die 12 after heating is conveyed to the welding station 16 under the action of the conveyance mechanism 28, and a new molding die 12 is placed in the heating furnace 30. It is carried in.

Thus, in the present embodiment, the first heating station 14
By calculating the heating time A, the mold 12 can always be accurately heated to the desired furnace temperature T1, and the standby time B at the unloading station 22 is adjusted based on the fluctuating heating temperature T1. . This makes it possible to adjust the timing at which each of the molds 12 is conveyed, and to achieve an effect that the molding operation of the skin can be efficiently performed.

Further, during the heating operation in the first heating station 14 which takes the longest time, a new molding die 12 which has completed the operation of removing the skin at the extraction station 22 is transported to the vicinity of the heating furnace 30. Immediately after the completion of the heating operation in the first heating station 14, a new mold 12 can be carried into the heating furnace 30. For this reason, a new molding die 12 is made to stand by at the unloading station 22, and unnecessary waiting time is reduced as compared with a case where the new molding die 12 is transported to the first heating station 14 after the completion of the heating operation. Thus, a more efficient skin forming operation can be achieved.

Next, after the heating is completed, the molding die 12 is conveyed to the welding station 16 via the conveyance mechanism 28, and first, a powdery non-foamable resin is charged into the molding cavity under the action of the resin supply mechanism 36. Thus, a skin layer is formed. Furthermore, after the powdery foamable resin is supplied to the skin layer and welded under the action of the foamable resin supply mechanism 38, the carrier 11 rotates 360 ° under the action of the driving means 40, and the inside of the mold 12 is rotated. Unnecessary foaming resin is discharged outside.

The molding die 12 conveyed to the second heating station 18 swings within a predetermined angle range via the driving means 44, and the foamable resin foams to form the skin.

The transfer table 11 is transferred to the lift 62 of the second lift station 26 and lowered under the action of the motor 60. At this time, the air blow means 56 is driven to supply cooling air to the mold 12, and the mold 12 and the skin are gradually cooled.

The transfer table 11 transferred to the cooling station 20 via the transfer mechanism 28 is inverted under the action of the driving unit 54, and the cooling water is supplied to the outer surface side of the molding die 12 via the cooling water supply unit 50. The mold 12 is rapidly cooled.

The transfer table 11 transferred from the cooling station 20 to the first lifting station 24 is raised to the same height as the transfer path 68 via the lift table 62, and then transferred to the unloading station 22 via the transfer path 68 and driven. The work is taken out of the epidermis by being rocked by the means 58.

Here, three molding dies 12 are circulated and conveyed to the molding apparatus 10, and the skins are sequentially molded by these molding dies 12.

In this embodiment, the worker may be notified of the elapse of the standby time B by an alarm or the like, and the worker may drive the control device 29 to transport a new molding die 12, or the control device 29 can detect the elapse of the standby time B and automatically convey a new mold 12.

[Effects of the Invention] As described above, the method for molding a resin molded article according to the present invention has the following effects and advantages.

The heating time of the mold is calculated from the temperature of the mold at the exit of the mold, the temperature of the mold before being carried into the heating furnace, and the temperature in the heating furnace, and is affected by changes in external conditions and the like. The molding die can always be accurately heated to a desired temperature without the need, and a high quality resin molded product can be obtained. Moreover, by adjusting the standby time of the mold carried into the station before the heating station based on the heating time, the standby time is shortened as much as possible, and the compact is efficiently formed. be able to.

[Brief description of the drawings]

FIG. 1 is a flow chart for explaining a method for molding a resin molded article according to the present invention, and FIG. 2 is a front view of a molding device and a control device for carrying out the molding method. 10 Molding equipment 11 Carrying table 12 Mold 14 Heating station 16 Welding station 18 Heating station 20 Cooling station 22 Unloading station 24, 26 Lifting station 28 Transport mechanism 29 ... Control device

Continuation of the front page (72) Inventor Yasunori Okita 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Inventor Kenji Shinoyama 1-1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) B29C 41/00-41/52 B29L 31:58

Claims (2)

(57) [Claims] 1. A mold is heated by a heating station by circulating and transferring a mold between respective work stations, and then a resin-based molding material is supplied and welded into the mold. A molding method of a resin molded body, wherein the molding is cooled in a cooling station to form a molded body, comprising: setting a discharge temperature (T1) of the molding die from a heating furnace provided in the heating station; A step of detecting a temperature (T2) of the molding die before being carried into the heating furnace; a step of detecting a temperature (T3) of the molding furnace before being carried into the molding die; The unloading furnace temperature (T1), the detected temperature (T2) of the forming die before carrying-in and the detected temperature (T3) in the heating furnace are input to a control device and stored in the control device. Based on the calculation formula, the outlet temperature (T1), Calculating the heating time (A) of the molding die from the temperature (T2) of the molding die and the temperature (T3) of the heating furnace; and calculating the heating time (A) in the control device. Adjusting the standby time (B) of the molding die carried into the station before the heating station based on the heating method. 2. The molding method according to claim 1, wherein the control unit adjusts the standby time so that the standby time ends before the heating time elapses. Molding method.