JP3489607B2 - Urethane foam mold - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane foam molding die improved so that a good quality urethane foam molded article can be obtained. [0002] Since urethane foam raw material liquid is well known,
Although the detailed description is omitted, this urethane foam raw material liquid is A
Liquid (mixture of oriol, water, catalyst, detergent, etc.) and B
Liquid (isocyanate). And this A liquid and B
After mixing and injecting the liquid into the cavity surface of the lower mold, the upper mold and the lower mold are brought into close contact to form a closed cavity. Then, in the sealed cavity, the liquid A and the liquid B
The liquid undergoes a chemical reaction, producing urethane with the liquid A,
Urethane is foamed by generating carbon dioxide with the liquid, and the urethane is expanded in the closed cavity (the volume is expanded to 30 to 40 times that of the urethane generated by the liquid A). The urethane spreads over the entire cavity or is formed into a predetermined shape. Due to the simultaneous reaction between the liquid A and the liquid B, the viscosity of the liquid increases with time and the flow of the liquid in the cavity becomes difficult to flow with time, so that the liquid is injected into the cavity surface of the lower mold. At this stage, it is desired to inject the liquid so as to spread as evenly as possible over the cavity surface of the lower mold. Further, the reaction speed of the above-mentioned liquids A and B becomes higher as the temperature of the liquid itself and the temperature of the mold become higher, so that the state of the flow of the liquid is also affected by the temperature. Although the molding is performed by the expansion pressure of the urethane in the cavity, when the portion with a large amount of liquid and the portion with a small amount of liquid are extreme, insufficient portions of the urethane are formed, and molding failure occurs, or Hard and soft parts are formed on the product, which causes defective products. Hereinafter, a seat of a vehicle will be described as an example of a urethane product. FIG. 7 is an exploded view of a vehicle seat, in which a urethane sheet 5 is fitted to a frame 3 provided with a spring 4 for elastically supporting a back portion of a passenger, and a skin 6 is put thereon. A seat back 1 is made. Further, the seat cushion 2 is provided on a frame 8 provided with a spring 8 for elastically supporting a butt portion of the occupant.
It is made by fitting a urethane sheet 9 and covering the skin 10 from above. Also, as shown in FIG. 6, the urethane sheets 5 and 9 have a waist pad 5 which is a partially hard part.
01 and a butt pad 901 are formed. in this way,
In order to partially change the hardness, a mixed liquid in which the prescription of the liquid A and the liquid B is changed is used, and this is hereinafter referred to as different hardness foam molding. A conventional mold for forming and processing the urethane sheet 9 will be described with reference to FIG. In the figure, a lower mold 11 is mounted on a mold carriage 12 via an airbag 13 and a support member 14. On the other hand, the upper mold 15
Is fixed to a frame 16, and the frame 16 can be rotated as shown in the figure by connecting a bracket 18 provided at one end thereof to a bracket 17 provided on the mold carrier 12 with a connecting rod 19. It has become. A locking member 20 is provided at the other end of the frame 16 so as to be rotatable by a pin 21, and the locking member 20 is rotated by a cylinder 22 so that the end of the frame 16 is attached to the die carriage 12. Locking and unlocking can be performed. Then, the frame 16 is rotated to move the frame 1
The upper mold 15 is aligned with the lower mold 11 by locking the end of 6 to the mold carriage 12, and the lower mold 11 is brought into close contact with the upper mold 15 by the internal pressure of the airbag 13. Thereby, a closed cavity 23 is formed. FIG. 12 is an enlarged view of the lower mold 11.
In the figure, the lower mold 11 intentionally tilts the cavity surface 111 so that the mixed liquid of the liquid A and the liquid B flows uniformly on the cavity surface 111 of the lower mold. Then, the mixed liquid L of the liquid A and the liquid B is applied to the peak 112 of the cavity surface 111.
Is injected, this mixed liquid L flows along the inclined surface of the cavity surface 111 as shown by the arrow. As described above, in consideration of allowing the mixed liquid of the liquid A and the liquid B to flow uniformly and naturally onto the cavity surface 111, in designing the lower mold 11, the inclination of the cavity surface 111 is prioritized, and the cavity surface is slightly inclined. Only the undercut portion 113 is formed. If the spring 8 directly contacts the back surface of the urethane sheet 9 in FIG. 7, that portion of the urethane sheet 9 will be damaged, and a spring receiving member is provided at the portion where the spring 8 contacts. . In FIG. 13, a spring receiving member 24 is provided on the cavity surface of the upper mold 15, and the spring receiving member 24 is held so as to pierce a needle 25 implanted on the cavity surface of the upper mold 15. Have been. Then, by urethane foam molding, the spring receiving member 24 is fixed to the back surface of the urethane foam molded article. [0008] In the conventional mold shown in FIGS. 11 and 12, the cavity surface of the lower mold is an inclined surface, and a mixed solution of the liquid A and the liquid B is applied to the inclined surface. So,
The following problems are caused by natural flow. That is, the viscosity of the mixed liquid of the liquid A and the liquid B increases with time at a reaction rate corresponding to the temperature of the mixed liquid itself and the temperature of the lower mold, and does not always flow as expected. In addition, since the release agent is applied to the mold, even when the release agent remains, the flow of the mixed solution is not uniform, and the mixed solution flows as expected. There may not be. As described above, when the mixed liquid does not flow as expected, the mixed liquid is not uniformly injected into the cavity surface of the lower mold, and a defective urethane foam molded article is generated. In addition to the necessity of reworking non-defective products, productivity is reduced, and defective products that cannot be reworked have to be discarded. There are inconvenient problems such as economic loss and pollution problems due to waste disposal. In addition, the flow of the mixed liquid includes the temperature of the mixed liquid,
The temperature of the mold, this temperature changes with the passage of time, and the uncertain factors such as contamination of the mold cavity surface due to the change of the viscosity of the mixed solution and the residual mold release agent are likely. Therefore, it is extremely difficult to satisfy all conditions for teaching by the robot when the injection of the liquid is performed by the robot, and there is a problem that the automatic injection of the mixed liquid by the robot cannot be substantially performed. When the waist portion 501 and buttocks portion 901 are partially hardened as shown in FIG. 6, another mixture is partially applied to the portion by changing the formulation of the solution A and the solution B. Need to be injected. However, in the system in which the mixture is allowed to flow naturally, the mixture must depend on the flow of the mixture, so that even if the mixed solution having a different prescription is injected into a predetermined position, the mixture flows, so that different hardness foaming is performed. There is a problem that molding is difficult. When the urethane foam molding is completed, the upper mold is opened. However, the upper mold may jump up or close due to the expansion pressure of the urethane. There is no problem if the urethane foam molding remains in the lower mold at this time, but when the expanded urethane foam molding protrudes from the lower mold, the upper mold jumps up and the urethane The foam molded product is pressed by the upper mold, and the urethane foam molded product has a trace of the mold (called double copying). Therefore, as shown in FIG. 12, the conventional lower mold has only a small portion of the undercut portion 113, so that there is a possibility that the expanded urethane foam molded product may protrude through the undercut portion. In the case of a large and double copy, it is necessary to rework the urethane foam molded product, and there is a problem that productivity is reduced. Next, as shown in FIG.
When mounting the spring receiving member 4 on the upper mold, the spring receiving member is passed through a needle implanted in the upper mold, and the spring receiving member is held in the upper mold. I couldn't. Then, as shown in FIG. 13, when urethane foam molding is performed with the end 241 of the spring receiving member 24 protruding from the cavity surface of the upper mold, the protrusion hinders the expansion pressure of the urethane. In some cases, urethane does not reach the corner 231 of the cavity 23, and there is a problem that urethane in this portion is insufficient and defective products are generated. According to the present invention, the injection surface of the mixed liquid of the liquid A and the liquid B is made substantially horizontal so that the injected mixed liquid does not flow.
The mixture can be injected by the robot, and the mixture can be injected uniformly, and foaming with different hardness can be performed. Furthermore, double copying can be reduced, and defective products can be prevented by positioning the spring receiving member. The present invention provides a molded urethane foaming mold. Means to be attained from the description of claim 1 according to the present invention for solving the above problems are as follows:
A lower mold is placed on the airbag, and a urethane foaming raw material liquid is injected into the cavity surface of the lower mold, and urethane foaming is performed so that the lower mold is in close contact with the upper mold by the pressure of the airbag. In the molding die, the injection surface for injecting the urethane foaming material liquid in the cavity surface of the lower mold is made substantially horizontal, and the cavity surface portion other than the injection surface is formed.
Forming an undercut portion and mounting a spring receiving member of the upper mold;
Hook the pin insertion hole provided on the spring receiving member
A pin having a constricted portion for holding is implanted . Therefore, in the first aspect, the spring receiving member is mounted on the upper mold spring receiving member mounting surface.
For holding the pin insertion hole provided in the
Since the pin having the constricted portion is implanted , the spring receiving member can be held in the upper mold while being positioned at a predetermined position of the upper mold. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention as understood from the above-mentioned claim 1 will be described. Shown in FIG.
Thus, the urethane foam molding die is
A lower mold 26 is placed on the lower mold 26, and a urethane foaming raw material liquid is injected into the cavity surface of the lower mold 26, and the air bag 1
3 is a urethane foaming mold in which the lower mold 26 is brought into close contact with the upper mold 27 by the pressure of 3.
The injection surface 261 for injecting the urethane foaming raw material liquid on the cavity surface of the lower mold 26 shown in FIG. 2 forming (FIG. 1) is made substantially horizontal. Also, as shown in FIG.
The lower mold 26 is placed on the airbag 13, the urethane foaming material liquid is injected into the cavity surface of the lower mold 26, and the lower mold 2 is pressed by the airbag 13.
6 is a urethane foaming mold in which the upper mold 6 is in close contact with an upper mold 27, and FIG.
The injection surface 261 for injecting the urethane foaming raw material liquid on the cavity surface of the lower mold 26 shown in FIG.
The undercut portion 262 is provided on the cavity surface other than 61.
To form Further, as shown in FIG. 1, urethane foam
In the molding die , the lower die 26 is placed on the airbag 13, and the urethane foaming material liquid is injected into the cavity surface of the lower die 26, and the lower die 2 is pressed by the airbag 13.
6 is a urethane foam molding die in which the upper portion 6 is in close contact with the upper die 27, and the constriction portion 2 is formed on the spring receiving member mounting surface 271 of the upper die 27 as shown in FIG.
5, a pin insertion hole 291 for positioning the spring receiving member 29 mounted on the pin 28 is provided in the spring receiving member 29, as shown in FIG. Hereinafter, embodiments of the present invention will be described in more detail. In FIG. 1, the urethane foam molding die is configured as follows. In the drawing, a lower mold 26 is placed on the mold carriage 12 via an airbag 13 and a support member 14.
Are mounted, while the upper mold 27 is fixed to the frame 16. The frame 16 has a bracket 1 at one end.
8 is connected to a bracket 17 provided on the mold carrier 12 via a connecting rod 19, and a frame 16 is provided.
Can rotate as shown in the figure. Frame 1
A locking member 20 is provided at the other end of the frame 6 so as to be rotatable via a pin 21. By rotating the locking member 20 by a cylinder 22, one end of the frame 16 is It is locked to the carriage 12 and can be released. By rotating the frame 16 and locking one end of the frame 16 to the mold carriage 12 by the locking member 20,
The upper mold 27 can be matched with the lower mold 26, and the lower mold 26 is pushed up by the internal pressure of the airbag 13 and press-bonded to the upper mold 27, so that the closed cavity 2 is formed.
3 are formed. FIG. 2 is a view showing only the lower mold 26 in FIG. 1, and the injection surface 261 of the lower mold 26 is substantially horizontal. In addition, the horizontality of the injection surface 261 is determined by the fact that the mixed liquid of the liquid A and the liquid B injected into the injection surface 261 does not actively flow. Prescription and temperature of mixed solution and lower mold 26
May be inclined vertically α with respect to the horizontal plane of the injection surface 261. An example of the angle α is about 10 degrees. That is, the angle α may be an angle within an allowable flow range that does not affect the quality of the urethane foam molding even if the injection liquid flows (hereinafter, referred to as an allowable angle). The temperature is determined by the shape of the cavity 23. Further, when the lower mold 26 shown in FIG. 2 and the lower mold 11 shown in FIG. 11 for foam-forming the urethane sheet 9 in FIG.
In the case where the injection surface 111 of the lower mold 11 shown in FIG. 12 is inclined, the undercut portion 113 is slightly formed, while the injection surface 26 of the lower mold 26 is formed as shown in FIG.
1 is almost horizontal, the undercut 2
62 can be large. Further, since it is not necessary to consider the flow of the mixed liquid as in the mold shown in FIG. 12, the shape design of the cavity surface forming the cavity 23 (FIG. 1) is facilitated. It becomes easy to form the undercut portion. Next, in FIG. 3 showing the upper mold 27 in FIG. 1, the pin 28
Has been planted. As shown in FIG. 10, the pin 28 has a constricted portion 281 formed therein. Spring receiving member 2
For example, slag urethane, felt, cold sand, etc. are used for 9. Also, as shown in FIG. 4 and FIG.
The distance between the pin insertion holes 291 formed in the spring receiving member 29 is slightly smaller than the distances P1 and P2 in FIG.
'And P2'. P1-P1 '= 2-5 mm and P2-P2' = 2-5 mm as an example of the relationship. Thus, by narrowing P1 'and P2', the spring receiving member 29 can be held by the constricted portion 281 of the pin 28 in a pulled state, and
The spring receiving member 29 can be accurately positioned with respect to the spring member mounting surface 271 of the upper mold 27. The operation of the embodiment constructed as described above will now be described. First, as shown in FIG.
6 was made substantially horizontal, so that this injection surface 2
The mixed liquid of the liquid A and the liquid B injected into the liquid 61 does not flow positively. As described above, since the mixture does not flow positively, the formulation and temperature of the mixture, the temperature of the lower mold, and the shape pattern of the cavity surface of the lower mold 26 forming the cavity 23 are used as teaching conditions for the robot. The liquid A and the liquid B supplied from the hoses A and B are mixed by the robot 30 as shown in FIG.
6 can be automatically injected into a predetermined position of the injection surface 261. For example, in FIG. 2, when the region of W on the injection surface 261 is the buttocks 901 shown in FIG.
The robot 30 automatically moves to the position (b) according to the timing information, and injects the mixture prescribed so that hard urethane can be formed. Then, since the injection surface is substantially horizontal, the injected mixed liquid spreads like a water mark without actively flowing as shown in (e) of FIG. Can be. After the injection of the mixture into the region W, the mixture is switched to a mixture prescribed so that soft urethane is formed, and the robot 30 automatically moves to the position (a) according to the teaching information. Inject a prescribed amount of the liquid mixture formulated to produce soft urethane, then temporarily stop the injection, and then automatically move to the position (c), and transfer the same liquid mixture by the prescribed amount. inject. The robot 30
May be moved to the position (d) to inject the mixture,
According to the shape pattern information on the cavity surface, the injection amount in (a) is set to the amount that urethane is filled up to the point (d) by the expansion pressure of urethane, so urethane foam molding can be performed only by injection of (a) It becomes. As described above, by making the injection surface 261 substantially horizontal, the teaching conditions of the robot 30 can be simplified, and automatic injection by the robot 30 can be performed.
Since the robot 30 can be moved and injected according to the shape pattern of the cavity surface, the design of the cavity surface (the surface forming the cavity 23) can be facilitated, and the undercut portion 262 can be easily formed. Can be. Further, since automatic injection can be performed by the robot 30 in this manner, an automatic urethane foam molding line as shown in FIG. 8 can be formed. To explain this, the mold support cart 12 on which the lower mold 26 and the upper mold 27 are mounted is moved in the direction of the arrow by an endless mold carrier. First, the release agent application robot 31 applies a release agent to the cavity surfaces of the lower mold 26 and the upper mold 27, and then, the A liquid B liquid injection robot 32 applies the release agent to the injection surface 261 of the lower die 26. Inject the mixture. Subsequently, the upper mold 27 is aligned with the lower mold 26 at the mold closing station 33, and the lower mold 26 is pressed against the upper mold 27 by the internal pressure of the airbag 13 to form a closed cavity 23. Then, while the mold carriage 12 moves in the direction of the arrow and reaches the mold opening station 34 (about 7 minutes in an example), the liquid A and the liquid B chemically react to simultaneously generate and solidify urethane and solidify. I do. Then, the upper mold 2 is opened at the mold opening station 34.
7 is opened, the urethane foam molded product is taken out, and moved to the release agent applying robot 31 with the mold opened. As described above, the injection surface 261 is made substantially horizontal, the injection can be performed by the robot 30, and an automatic urethane foam molding line can be formed, so that the productivity can be improved. Next, as shown in FIG. 2, since the undercut portion 262 is formed in the lower mold 26, when the upper mold 27 is opened at the mold opening station 34 in FIG.
Even if 7 jumps up, the urethane foam molded product is held in the lower mold 26 as it is at the undercut portion 262, so that so-called double copying can be prevented. Further, even when the pin 28 is implanted in the upper mold 27 to hold the spring receiving member 29, the undercut portion 2
By providing the sufficient length of the undercut portion 26,
The holding force of No. 2 overcomes the holding force of the constricted portion 281 of the pin 28, so that the urethane foam molded product can be held in the lower mold 26, and so-called double copying can be prevented. Next, the spring receiving member mounting surface 2 of the upper mold 27
A pin 28 is implanted in 71, a pin insertion hole 291 is opened in the spring receiving member 29 as shown in FIG. 5, and the spring receiving member 29 is attached to the spring receiving member mounting surface 271 by being hooked by a constricted portion 281. Since the positioning is performed accurately, for example, the spring receiving member 29 does not protrude at the portion (E) in FIG. 3, and the portion (E) can be smoothly filled with the urethane foam by the expansion pressure. As described in detail above, according to the present invention, which is understood from the detailed description of the present invention, the injection surface for injecting the urethane foaming raw material liquid in the cavity surface of the lower mold is made substantially horizontal, The injected urethane foaming raw material liquid is prevented from flowing, eliminating the uncertain conditions due to the flow of the urethane foaming raw material liquid, enabling the robot to inject the urethane foaming raw material liquid, uniformly injecting the mixed liquid, and urethane foaming. In addition to eliminating defects in molded products, it also enables foam molding with different hardness,
In addition, an automatic line for urethane foam molding is made possible, and productivity can be improved. Also , the injection surface for injecting the urethane foaming raw material liquid on the cavity surface of the lower mold is made substantially horizontal,
Eliminating uncertain conditions due to the flow of the urethane foam raw material liquid, enabling the injection of the urethane foam raw material liquid by a robot to improve productivity, and forming an undercut on the cavity surface other than the injection surface, When the foam molding is completed and the upper mold is opened, the urethane foam molded product can be held in the lower mold, so that so-called double copying can be prevented and the reworking can be eliminated to improve productivity. . Further , the spring receiving member mounting surface of the upper mold is
On the spring receiving member mounting surface of the upper mold, provided on the spring receiving member
Has a constricted part for hooking and holding the pin insertion hole
Since the expanded pins are implanted, the entire area of the cavity can be filled with the urethane foamed by the inflation pressure, and it is possible to improve the productivity by eliminating rework due to the shortage of the foamed urethane.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a urethane foam molding die showing one embodiment of the present invention. FIG. 2 is a longitudinal sectional view of a lower mold in FIG. FIG. 3 is a longitudinal sectional view showing a cavity in FIG. 1 in a partially enlarged manner. FIG. 4 is an arrangement view of pins implanted on a spring receiving member mounting surface of an upper mold in FIG. 3; FIG. 5 is a plan view of a spring receiving member in FIG. 3; FIG. 6 is an explanatory diagram showing a main part of a vehicle seat in a perspective view. FIG. 7 is an explanatory view showing a vehicle seat in an assembled exploded perspective view. FIG. 8 is a plan view of an automatic urethane foam molding line using the urethane foam mold shown in FIG. FIG. 9 is a perspective view schematically showing the urethane foam molding die shown in FIG. FIG. 10 is a side view of the pin in FIG. 3; FIG. 11 is a longitudinal sectional view of a part of a conventional urethane foam molding die. FIG. 12 is a longitudinal sectional view of a lower mold in FIG. 11; FIG. 13 is an explanatory view showing a state in which the cavity in FIG. 11 is partially enlarged and the spring receiving member is shifted. DESCRIPTION OF SYMBOLS 12 Mold carriage 13 Airbag 14 Support member 16 Frame 23 Cavity 25 Needle 26 Lower mold 261 Injection surface 262 Undercut portion 27 Upper mold 271 Spring receiving member mounting surface 28 Pin 281 Narrow portion 29 Spring receiving Member 291 Pin insertion hole 30 Robot 31 Release agent application robot 32 Liquid A liquid B injection robot 33 Mold closing station 34 Mold opening station

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Claims (1)

(57) [Claims] [Claim 1] A lower mold is placed on an air bag, and a urethane foaming raw material liquid is injected into a cavity surface of the lower mold, and the lower mold is lowered by the pressure of the air bag. In a urethane foam molding mold in which a mold is brought into close contact with an upper mold, an injection surface for injecting the urethane foaming raw material liquid in a cavity surface of the lower mold is substantially horizontal, and a cavity other than the injection surface is provided.
Forming an undercut portion on the tee surface,
Pin insertion provided on the spring receiving member through the spring receiving member mounting surface
A pin with a constriction to hook and hold the hole
A urethane foam molding mold characterized by being planted .