JPH0360294B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding a block body, and more particularly, the present invention relates to a method for molding a block body, and more particularly, a thermoplastic resin mixed with reinforcing fibers is used to achieve desired strength and weight reduction.
Moreover, the present invention relates to a method for forming a block body that requires less post-processing such as deburring.

2. Description of the Related Art Carburetors, which apply the principle of spraying, are commonly used as fuel supply devices in automobile engines. In this case, the carburetor uses the high-velocity airflow generated during the engine's intake stroke to suck out fuel, atomizes the fuel, and mixes it with air to create an air-fuel mixture. After the mixture is sucked into the cylinder,
It is compressed by the piston and ignited by the spark plug, causing combustion. At this time, the piston is pressed by the expansion force within the cylinder, that is, the explosion pressure of the fuel, and the pressing force is converted into rotational force by a crank connected to the piston.

By the way, conventionally, the carburetor body in which the intake passage is formed and valves etc. are arranged is made of metal,
For example, materials made of zinc or aluminum alloy are widely used. That is, the carburetor main body is cast by a die-casting method, and then holes for attaching parts and holes for flow passages are formed, and surfaces for mating with other members are formed by cutting. Here, in order to reduce the number of post-processing steps for drilling the various holes as described above, when casting, a casting hole that enters the cavity defined by the mold is used. Predetermined holes are formed using pins.

Furthermore, when molten metal is supplied to the cavity, the molten metal is injected through a gate communicating with the cavity, so the gate portion of the cavity tends to be at the highest temperature. As a result, when a cast pin is arranged near the gate,
As the temperature rises, there is a risk that the cast pins may bend or seize, causing problems. Therefore, it is practically impossible to provide a cast pin in the vicinity of the gate, and as a result, the number of holes to be drilled in post-processing must increase. Further, secondary processing such as deburring, precision cleaning, and chemical surface treatment to increase corrosion resistance against fuel is required, and the processing operations required to complete the carburetor body are large and complicated. Moreover, in general, it is desired to reduce the weight of engines in automobiles etc. in order to improve fuel efficiency, but when the carburetor body is constructed of metal as in the past,
Even if the type of metal was changed, there was a limit to how much weight could be reduced.

Therefore, in recent years, attempts have been made to injection mold carburetor bodies made of synthetic resins with excellent heat resistance and rigidity, and in this case, thermosetting resins such as phenolic resins are used as the resin material. In other words, by using a resin material that is relatively lightweight, has high corrosion resistance, and is easy to mold as the constituent material of the carburetor body, the carburetor body that constitutes the engine can be made lightweight, and the carburetor body can be constructed with excellent durability. There is.

However, since the thermosetting resin such as the phenolic resin is extremely hard, repeated molding of the carburetor body causes wear of the joint part of the mold corresponding to the part where the burr occurs, which is called mold warping. However, the drawback is that the mold life is shortened as a result. Furthermore, the mold used in the die-casting method also suffers from heat cracks due to temperature changes, so it cannot be said that the mold has a long lifespan.

The present invention has been made to overcome the above-mentioned disadvantages, and the carburetor body is made of, for example, polyphenylene sulfide (PPS), which is a thermoplastic resin that has excellent strength and does not react with gasoline, alcohol, etc. By mixing glass fibers as reinforcing fibers into the resin, and suitably selecting injection molding conditions such as the temperature of the molten resin, the temperature of the mold, and the injection pressure of the molten metal, it is possible to achieve high dimensional accuracy without the occurrence of burrs, etc. It is an object of the present invention to provide a method for molding a block body, which makes it possible to mold a lightweight carburetor body with excellent corrosion resistance, strength, rigidity, etc.

In order to achieve the above object, the present invention provides a mold that defines a cavity for molding a block body at a temperature of 130°C.
After heating to ~150°C and melting a thermoplastic resin containing 30% to 60% reinforcing fibers at a temperature of 300°C to 340°C, the molten resin is injected at 1000Kg/cm ² to 1300Kg/cm ² The molten resin in the cavity is fed into the cavity under pressure, and then the molten resin in the cavity is 400Kg/cm ² to 700Kg/cm ²
The molten resin is held at a pressure of 100 mL, and after the molten resin is solidified, the molten resin is released from the mold to obtain a block body.

Next, the method for molding a block body according to the present invention will be described in detail below with reference to the accompanying drawings, with reference to preferred embodiments in connection with a molding apparatus for carrying out the method.

First, a mixture body block injection molded by the method of the present invention will be explained with reference to FIGS. 1 and 2. In this case, in FIG. 2, reference number 10 indicates the carburetor body.
The carburetor body 10 is constructed by stacking a throttle body block 12, a mixture body block 14, and an air horn book 16 in order from the bottom, and integrating the blocks 12, 14, and 16. The throttle body block 12 is made of metal such as zinc or aluminum alloy, and the mixture body block 14 and air horn book 16 are made of synthetic resin.

A main intake passage 18 and a secondary intake passage 20 are formed in parallel to each other in the carburetor body 10, and in this case, intermediate portions of the main intake passage 18 and the secondary intake passage 20 are formed in the mixture body block 14. Outer bench lilies 22 and 24 are configured. Furthermore, inner bench lilies 26 and 28 are formed upstream of the outer bench lilies 22 and 24. Furthermore, the main intake passage 1 in the air horn block 16
A choke valve 30 is pivotally supported on the upstream side of the main intake passage 18 in the throttle body block 12.
Throttle valves 32 and 34 are pivotally supported on the downstream side of the secondary intake passage 20. That is, when the carburetor main body 10 is used, the outer bench lily 22,
Fuel is mixed with air in a flow path defined by the inner vent lily 24 and the inner bench lily 26, 28, and is introduced into a cylinder (not shown).

Furthermore, as shown in FIG. 1, the mixture body block 14 includes the outer bench lily 2.
In addition to 2 and 24, for example, a float chamber 36 is formed. An air bleed tube insertion hole 38 extending vertically is formed in the side wall portion defining the float chamber 36, and the air bleed tube insertion hole 38 extends from the bottom side of the float chamber 36 to the deepest point of the air bleed tube insertion hole 38. A fuel jet mounting hole (not shown) communicating with the fuel jet is formed. Further, holes 40 and 42 are formed in the side wall of the mixture body block 14 and communicate with the inside of the float chamber 36 from the outside, and the holes 40 and 42 are later closed by a predetermined member.

Next, a molding apparatus for carrying out the method of the present invention will be explained below.

In FIGS. 3 and 4, reference numeral 50 indicates a molding device. In this case, the molding device 50 includes a fixing part 52 that is fixed at a predetermined position, and a fixing part 52 that is fixed at a predetermined position.
The fixed part 52 includes a fixed mold 56, while the movable part 54
includes a movable mold 58 and sliding molds 60a to 60d. That is, a cavity 6 for molding the mixture body block 14 by the fixed mold 56, movable mold 58, and sliding molds 60a to 60d.
2 is defined.

A fixed plate 64 constituting the fixed part 52 is fixed at a predetermined position, and an adapter 66 is fixed to the center of the fixed plate 64 using a plurality of bolts 67.
8 is installed. In this case, a molten resin supply flow path (not shown) is connected to the nozzle member 68, and the nozzle member 68 is fitted into the fixed mold 56, and the flow path in the gate portion 70 located at the tip thereof is connected to the cavity 62. communicate. Further, the stationary platen 64 is integrally provided with an engagement body 74 for holding the plate body 72 and the stationary mold 56 in a fitted state, and the engagement body 74 is provided with inclined rods 76a to 76d. In this case, the inclined rods 76a to 76d are configured to extend toward the movable portion 54 side. Further, the edge portions of the engaging body 74 are provided with sloped portions 78a, 78b parallel to the sloped rods 76a, 76b.
and the other inclined rod 76c,
There are also inclined rods 76c and 76 near the rod 76d.
A slope portion (not shown) parallel to d is formed.

The fixed part 52 is constructed as described above, and the movable part 54 will be explained next.

A movable platen 80 constituting the movable part 54 is located parallel to the fixed platen 64, and a mold holding member 82 is fixed to the movable platen 80 via bolts 84. A relatively large chamber 86 is formed between the movable platen 80 and the mold holding member 82, and this chamber 86
A hole 88 communicates with the. An extrusion mechanism 90 for extruding and releasing the product molded within the cavity 62 is disposed within the chamber 86.

The extrusion mechanism 90 includes extrusion plates 94a and 94b that are integrated by bolts 92. It is configured so that it can be displaced. That is, essentially, a cylinder rod (not shown) inserted into the hole 88 of the movable platen 80 is fixed to the push-out plate 94a, and the push-out plates 94a, 9 are moved by displacement of the cylinder rod.
4b moves forward and backward relative to the fixed portion 52 side. In this case, the extrusion plate 94b has a cavity 6.
A push-out pin (not shown) is implanted so that it can be accessed inside the mold 2, and the product is released from the mold under the projecting action of the push-out pin. Further, a cylinder mechanism (not shown) is connected to the movable platen 80, thereby making the entire movable part 54 movable forward and backward relative to the fixed part 52.

On the other hand, near the end of the mold holding member 82, there is a recess 9 into which the tips of the inclined rods 76a and 76b fit loosely.
Similarly, recesses (not shown) into which other inclined rods 76c and 76d enter are also formed. Further, a recess 98 is formed in the center of the mold holding member 82, and the movable mold 58 is fixed to the recess 98 using bolts 100.

In this case, the movable mold 58 is provided with a core pin 102 that protrudes into the cavity 62 and forms the air bleed tube insertion hole 38 in the mixture body block 14. The movable mold 58 and the fixed mold 56 are provided with protrusions 58a and 56a for forming the outer bench lily 24 on the mixture body block 14, and protrusions (not shown) for forming other outer bench lilies 22, respectively. Types 56, 58
to form. Furthermore, a protrusion 58b for forming the float chamber 36 is formed on the movable mold 58, and a through hole 103 is bored in this protrusion 58b.

Next, the sliding molds 60a to 60d are fitted into the spaces between the guide blocks (not shown), and the movable mold 5
8. Therefore, the sliding type 60
A to 60d will be explained below.

Mixture body block 1 is installed in the sliding type 60a.
A fuel jet mounting hole (not shown) that communicates with the hole 38 of 4 and a hole 4 that communicates with the float chamber 36.
The core pins 110 and 112 forming the 0 are integrally assembled. Furthermore, sliding type 60
A is provided with an inclined hole 114a through which the inclined rod 76a can slide, and a sloped portion 116a parallel to the sloped portion 78a of the fixing portion 52. On the other hand, the sliding molds 60b to 60d also include an inclined hole portion 114b through which the inclined rods 76b to 76d can slide, and an inclined hole portion (not shown).
A slope portion 116b corresponding to the slope portion 116a and other slope portions (not shown) are formed. Further, each of the sliding molds 60a to 60d is provided with a core pin or the like for forming other holes required for the mixture body block 14.

By the way, support members 118a and 118b are fixed to the upper end portion of the mold holding member 82, and a plate body 120 is installed over the upper end portions of these support members 118a and 118b. A hole 122 is provided in the center of the plate 120.
A bolt 124 is inserted into the hole 122. At this time, a washer 126 and a coil spring 128 are fitted onto the head side of the bolt 124, and the tip of the bolt 124 is screwed onto the sliding die 60b. In this case, a locking nut 130 is screwed onto the tip side of the bolt 124,
As shown in FIG. 4, when the mold opening is completed, the locking nut 130 and the plate 120 are kept in contact with each other by the elastic force of the coil spring 128. In addition, in FIG. 3, a stopper member 134 is fixed to the lower part of the mold holding member 82 via a bolt 132.

The molding apparatus for carrying out the method of the present invention is basically constructed as described above, and its operation and effects will be explained next.

Therefore, the injection molding conditions for carrying out the method of the present invention are set in advance as follows.

That is, as a constituent material of the mixture body block 14, a resin material containing 30% to 60% glass fiber in polyphenylene sulfide, which is a thermoplastic resin, is used. Then, the melting temperature of this resin material is set to 300°C to 340°C, and the mold temperature of each mold 56, 58 and 60a to 60d defining the cavity 62 is heated to 130°C to 150°C. Furthermore, the primary injection pressure for supplying the molten metal to the cavity 62 is
1000Kg/cm ² to 1300Kg/cm ² , and the secondary injection pressure to maintain the pressure of the molten metal in the cavity 62 is 400Kg/cm 2 .
Select between cm ² and 700Kg/cm ² .

Under such injection molding conditions, the molding device 5
The mixture body block 14 is molded using 0. First, the mold is opened from the mold state shown in FIG. 4, and then the mold is clamped. That is, by driving a cylinder mechanism (not shown) connected to the movable platen 80, the movable part 54 is displaced toward the fixed part 52 side. As a result, 4
An inclined rod 76 provided to expand in the direction
a to 76d are inserted into the inclined holes 114a and 114b formed in the sliding molds 60a to 60d and other inclined holes not shown. At that time, the sliding molds 60a to 60d initially had four inclined rods 76a.
Along with the sliding movement with the sliding molds 60a to 76d, the slope parts (116a, 116b) of the sliding molds 60a to 60d are displaced in the mold clamping direction.
etc.) and the slope portions 78a, 78b, etc. of the engaging body 74, and are strongly pressed in the mold clamping direction.
In this case, since the bolt 124 screwed onto the sliding die 60b is displaced downward, the coil spring 128 is compressed between the washer 126 and the plate 120.

Finally, the fixed mold 56 and the movable mold 58
The sliding molds 60a to 60d are brought into pressure contact with each other to define a cavity 62.

Further, when the mold is clamped, the core pin 110, which is displaced integrally with the sliding mold 60a, moves to the protrusion 58 of the movable mold 58.
The core pin 110 is inserted into a through hole 103 formed in b, and the tip of the core pin 110 comes into contact with the tip of the core pin 102 . Furthermore, the core pin 112 is a movable type 5
The protrusion 56 of the fixed mold 56 contacts the protrusion 58b of the fixed mold 56.
a comes into contact with the protrusion 58a of the movable mold 58 (third
(see figure).

While the molds are clamped as described above, each of the molds 56, 58 and 60d is heated to, for example, 130°C. Then, via the nozzle member 68
A resin (polyphenylene sulfide containing 40% glass fiber) melted at 320° C. is supplied into the cavity 62 at an injection pressure of 1200 Kg/cm ² for 2 seconds.

In this case, the molten resin supplied into the nozzle member 68 flows into the cavity 62 via the gate portion 70. Next, after maintaining a pressure of 520 Kg/cm ² on the molten resin in the cavity 62 for 60 seconds,
If a curing time of 60 seconds is provided, the molten resin will solidify as the temperature decreases, and a molded product corresponding to the shape of the cavity 62, that is, the mixture body block 14, will be molded.

Therefore, when opening the mold, the movable part 54 is moved away from the fixed part 52 to the initial mold opening position. That is, in Figure 3,
The movable portion 54 is displaced to the right in the figure. As a result, the movable mold 58 is separated from the fixed mold 56, and the sliding molds 60a to 60d are separated from each other due to the sliding movement between the four inclined rods 76a to 76d and the inclined holes (114a, 114b, etc.). It is displaced in the direction of mold opening. At that time, core pin 110
is removed from the through hole 103 of the movable mold 58, and the sliding mold 60a finally descends to a position where it abuts against the stopper member 134 as shown in FIG. On the other hand, the sliding mold 60b rises due to the sliding movement with the inclined rod 76b and the elastic force of the coil spring 128, and rises to a position where the locking nut 130 abuts against the plate 120.

After the mold is opened in this manner, the mixture body block 14 molded within the cavity 62 and in close contact with the movable mold 58 is moved to the extrusion mechanism 90.
(See Figure 3) to release the mold. That is,
The extrusion plate 94a is inserted through the hole 88 of the movable platen 80.
By sending out a cylinder rod (not shown) fixed to the fixed part 52 side, the extrusion plates 94a, 94
b along the guide rod 96. As a result, an unillustrated extrusion pin, which is fixed to the extrusion plate 94b and whose tip reaches the cavity 62, extrudes the mixture body block 14 toward the fixed portion 52. In the manner described above, a mixture body block 14 made of synthetic resin is obtained.

In this case, according to the method of the present invention, the molding device 50
The mixture body block 14, which is injection molded by
Advantages such as no generation of burrs and good strength can be obtained. In other words, by mixing 30% to 60% glass fiber as reinforcing fiber into polyphenylene sulfide, which is lightweight and has excellent corrosion resistance, it is possible to add sufficient strength and rigidity required for a carburetor. It becomes possible to use the carburetor continuously for a long time. Furthermore, effects produced by setting various molding conditions within the above-mentioned ranges will be explained below.

First, the melting temperature of the resin is selected to be between 300°C and 340°C, but if the temperature of the molten resin is below 300°C, the viscosity of the molten metal will increase. There is a risk that the molten metal will not be filled. On the other hand, if the melting temperature is 340° C. or higher, the curing time of the molten metal becomes longer, resulting in deterioration of properties such as a decrease in strength.

In addition, each of the molds 56, 58 and 60a to 6
If the mold temperature at 0d is below 130°C, the surface of the mixture body block 14 to be molded will become rough and the mold release will be poor, and if the mold temperature is above 150°C, the cooling time of the molten metal will become longer and the molding process will be interrupted. It becomes impossible to do this efficiently in a short period of time.

Furthermore, when the injection pressure when supplying the molten resin into the cavity 62 is 1000 Kg/cm ² or less,
In many cases, the thin portions within the cavity 62 are not sufficiently filled with the molten resin. On the other hand, if the injection pressure is 1300Kg/ ^cm2 or more, each mold 56,
Molten resin flows out from the dividing surfaces 58 and 60a to 60d, and burrs are likely to occur in the mixture body block 14 that is molded.

Next, the molten resin in the cavity 62 was heated to 400%
The pressure is maintained at a pressure of Kg/cm ² to 700Kg/cm ² , but for example, if the pressure is 400Kg/cm ² or less, when the molten resin hardens, there will be dents, especially in the thick part, i.e. , causing sink marks. Further, when the pressure is 700 Kg/cm ² or more, it is pointed out that the mixture body block 14 is susceptible to burrs, warpage, etc., as in the case of the injection pressure described above.

As described above, according to the present invention, glass fibers are mixed into a thermoplastic resin that is lightweight and has excellent corrosion resistance, and molding conditions such as the melting temperature of the resin material, mold temperature, and injection pressure are selected to produce a carburetor body. The mixture body blocks that make up the body are injection molded. Therefore, compared to the conventional mixer body block made of metal, its weight can be reduced at once, and it has excellent heat resistance and corrosion resistance, as well as the strength and strength required for the carburetor body. It becomes possible to obtain a mixture body block having rigidity. Furthermore, it is possible to prevent the mold from collapsing, which was caused by the conventional method of using a thermosetting resin which is quite hard, and it is possible to extend the life of the mold. Moreover, it is possible to avoid burrs, mold release defects, and decreases in surface accuracy and dimensional accuracy that are likely to occur during injection molding, and to efficiently mold extremely good mixture body blocks.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments. Of course, various improvements and changes in design are possible without departing from the gist of the present invention, such as being able to be molded by.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a mixture body block injection molded by the method of molding a block body according to the present invention, FIG. 2 is a longitudinal cross-sectional view of a carburetor body incorporating the mixture body block shown in FIG. The figure is a vertical sectional view showing the molding apparatus in a mold-clamped state for implementing the method of the present invention, and FIG. 4 is a partially omitted vertical sectional view showing the molding apparatus of FIG. 3 in the mold-opened state. 10... Carburetor body, 14... Mixture body block, 22, 24... Outer bench lily,
36... Float chamber, 50... Molding device, 52... Fixed part, 54... Movable part, 56... Fixed mold, 58... Movable mold, 60a to 60d... Sliding mold, 62... Cavity, 68... Nozzle member, 82... Mold Holding member, 90
...Extrusion mechanism, 102, 110, 112... Core pin.

Claims (1)

[Claims] 1. A mold defining a cavity for molding a block body is heated to 130°C to 150°C, and reinforcing fibers are added to 30% to 60°C.
% containing thermoplastic resin at a temperature of 300°C to 340°C, and then melt the molten resin at 1000Kg/cm ² to 1300°C.
The molten resin in the cavity is supplied into the cavity at an injection pressure of Kg/ ^cm2 , and then the molten resin in the cavity is 400Kg/ ^cm2.
A method for molding a block body, characterized in that the molten resin is held at a pressure of ~700 Kg/cm ² and further, after the molten resin is solidified, it is released from the mold to obtain a block body. 2. A method for molding a block body according to claim 1, wherein the reinforcing fibers are glass fibers. 3. A method for molding a block body according to claim 1, wherein the thermoplastic resin contains polyphenylene sulfide. 4. A method for molding a block body according to any one of claims 1 to 3, wherein the block body is a carburetor.